linux-stable/include/linux/iosys-map.h

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dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Pointer abstraction for IO/system memory
*/
#ifndef __IOSYS_MAP_H__
#define __IOSYS_MAP_H__
iosys-map: Add per-word read Instead of always falling back to memcpy_fromio() for any size, prefer using read{b,w,l}(). When reading struct members it's common to read individual integer variables individually. Going through memcpy_fromio() for each of them poses a high penalty. Employ a similar trick as __seqprop() by using _Generic() to generate only the specific call based on a type-compatible variable. For a pariticular i915 workload producing GPU context switches, __get_engine_usage_record() is particularly hot since the engine usage is read from device local memory with dgfx, possibly multiple times since it's racy. Test execution time for this test shows a ~12.5% improvement with DG2: Before: nrepeats = 1000; min = 7.63243e+06; max = 1.01817e+07; median = 9.52548e+06; var = 526149; After: nrepeats = 1000; min = 7.03402e+06; max = 8.8832e+06; median = 8.33955e+06; var = 333113; Other things attempted that didn't prove very useful: 1) Change the _Generic() on x86 to just dereference the memory address 2) Change __get_engine_usage_record() to do just 1 read per loop, comparing with the previous value read 3) Change __get_engine_usage_record() to access the fields directly as it was before the conversion to iosys-map (3) did gave a small improvement (~3%), but doesn't seem to scale well to other similar cases in the driver. Additional test by Chris Wilson using gem_create from igt with some changes to track object creation time. This happens to accidentally stress this code path: Pre iosys_map conversion of engine busyness: lmem0: Creating 262144 4KiB objects took 59274.2ms Unpatched: lmem0: Creating 262144 4KiB objects took 108830.2ms With readl (this patch): lmem0: Creating 262144 4KiB objects took 61348.6ms s/readl/READ_ONCE/ lmem0: Creating 262144 4KiB objects took 61333.2ms So we do take a little bit more time than before the conversion, but that is due to other factors: bringing the READ_ONCE back would be as good as just doing this conversion. v2: - Remove default from _Generic() - callers wanting to read more than u64 should use iosys_map_memcpy_from() - Add READ_ONCE() cases dereferencing the pointer when using system memory v3: - Fix precedence issue when casting inside READ_ONCE(). By not using () around vaddr__ the offset was not part of the cast, but rather added to it, producing a wrong address - Remove compiletime_assert() as READ_ONCE() already contains it Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> # v1 Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220628191016.3899428-1-lucas.demarchi@intel.com
2022-06-28 19:10:15 +00:00
#include <linux/compiler_types.h>
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
#include <linux/io.h>
#include <linux/string.h>
/**
* DOC: overview
*
* When accessing a memory region, depending on its location, users may have to
* access it with I/O operations or memory load/store operations. For example,
* copying to system memory could be done with memcpy(), copying to I/O memory
* would be done with memcpy_toio().
*
* .. code-block:: c
*
* void *vaddr = ...; // pointer to system memory
* memcpy(vaddr, src, len);
*
* void *vaddr_iomem = ...; // pointer to I/O memory
* memcpy_toio(vaddr_iomem, src, len);
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
*
* The user of such pointer may not have information about the mapping of that
* region or may want to have a single code path to handle operations on that
* buffer, regardless if it's located in system or IO memory. The type
* :c:type:`struct iosys_map <iosys_map>` and its helpers abstract that so the
* buffer can be passed around to other drivers or have separate duties inside
* the same driver for allocation, read and write operations.
*
* Open-coding access to :c:type:`struct iosys_map <iosys_map>` is considered
* bad style. Rather then accessing its fields directly, use one of the provided
* helper functions, or implement your own. For example, instances of
* :c:type:`struct iosys_map <iosys_map>` can be initialized statically with
* IOSYS_MAP_INIT_VADDR(), or at runtime with iosys_map_set_vaddr(). These
* helpers will set an address in system memory.
*
* .. code-block:: c
*
* struct iosys_map map = IOSYS_MAP_INIT_VADDR(0xdeadbeaf);
*
* iosys_map_set_vaddr(&map, 0xdeadbeaf);
*
* To set an address in I/O memory, use IOSYS_MAP_INIT_VADDR_IOMEM() or
* iosys_map_set_vaddr_iomem().
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
*
* .. code-block:: c
*
* struct iosys_map map = IOSYS_MAP_INIT_VADDR_IOMEM(0xdeadbeaf);
*
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
* iosys_map_set_vaddr_iomem(&map, 0xdeadbeaf);
*
* Instances of struct iosys_map do not have to be cleaned up, but
* can be cleared to NULL with iosys_map_clear(). Cleared mappings
* always refer to system memory.
*
* .. code-block:: c
*
* iosys_map_clear(&map);
*
* Test if a mapping is valid with either iosys_map_is_set() or
* iosys_map_is_null().
*
* .. code-block:: c
*
* if (iosys_map_is_set(&map) != iosys_map_is_null(&map))
* // always true
*
* Instances of :c:type:`struct iosys_map <iosys_map>` can be compared for
* equality with iosys_map_is_equal(). Mappings that point to different memory
* spaces, system or I/O, are never equal. That's even true if both spaces are
* located in the same address space, both mappings contain the same address
* value, or both mappings refer to NULL.
*
* .. code-block:: c
*
* struct iosys_map sys_map; // refers to system memory
* struct iosys_map io_map; // refers to I/O memory
*
* if (iosys_map_is_equal(&sys_map, &io_map))
* // always false
*
* A set up instance of struct iosys_map can be used to access or manipulate the
* buffer memory. Depending on the location of the memory, the provided helpers
* will pick the correct operations. Data can be copied into the memory with
* iosys_map_memcpy_to(). The address can be manipulated with iosys_map_incr().
*
* .. code-block:: c
*
* const void *src = ...; // source buffer
* size_t len = ...; // length of src
*
* iosys_map_memcpy_to(&map, src, len);
* iosys_map_incr(&map, len); // go to first byte after the memcpy
*/
/**
* struct iosys_map - Pointer to IO/system memory
* @vaddr_iomem: The buffer's address if in I/O memory
* @vaddr: The buffer's address if in system memory
* @is_iomem: True if the buffer is located in I/O memory, or false
* otherwise.
*/
struct iosys_map {
union {
void __iomem *vaddr_iomem;
void *vaddr;
};
bool is_iomem;
};
/**
* IOSYS_MAP_INIT_VADDR - Initializes struct iosys_map to an address in system memory
* @vaddr_: A system-memory address
*/
#define IOSYS_MAP_INIT_VADDR(vaddr_) \
{ \
.vaddr = (vaddr_), \
.is_iomem = false, \
}
/**
* IOSYS_MAP_INIT_VADDR_IOMEM - Initializes struct iosys_map to an address in I/O memory
* @vaddr_iomem_: An I/O-memory address
*/
#define IOSYS_MAP_INIT_VADDR_IOMEM(vaddr_iomem_) \
{ \
.vaddr_iomem = (vaddr_iomem_), \
.is_iomem = true, \
}
iosys-map: Add a few more helpers First the simplest ones: - iosys_map_memset(): when abstracting system and I/O memory, just like the memcpy() use case, memset() also has dedicated functions to be called for using IO memory. - iosys_map_memcpy_from(): we may need to copy data from I/O memory, not only to. In certain situations it's useful to be able to read or write to an offset that is calculated by having the memory layout given by a struct declaration. Usually we are going to read/write a u8, u16, u32 or u64. As a pre-requisite for the implementation, add iosys_map_memcpy_from() to be the equivalent of iosys_map_memcpy_to(), but in the other direction. Then add 2 pairs of macros: - iosys_map_rd() / iosys_map_wr() - iosys_map_rd_field() / iosys_map_wr_field() The first pair takes the C-type and offset to read/write. The second pair uses a struct describing the layout of the mapping in order to calculate the offset and size being read/written. We could use readb, readw, readl, readq and the write* counterparts, however due to alignment issues this may not work on all architectures. If alignment needs to be checked to call the right function, it's not possible to decide at compile-time which function to call: so just leave the decision to the memcpy function that will do exactly that. Finally, in order to use the above macros with a map derived from another, add another initializer: IOSYS_MAP_INIT_OFFSET(). v2: - Rework IOSYS_MAP_INIT_OFFSET() so it doesn't rely on aliasing rules within the union - Add offset to both iosys_map_rd_field() and iosys_map_wr_field() to allow the struct itself to be at an offset from the mapping - Add documentation to iosys_map_rd_field() with example and expected memory layout v3: - Drop kernel.h include as it's not needed anymore Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-3-lucas.demarchi@intel.com
2022-02-16 17:41:33 +00:00
/**
* IOSYS_MAP_INIT_OFFSET - Initializes struct iosys_map from another iosys_map
* @map_: The dma-buf mapping structure to copy from
* @offset_: Offset to add to the other mapping
*
* Initializes a new iosys_map struct based on another passed as argument. It
* does a shallow copy of the struct so it's possible to update the back storage
* without changing where the original map points to. It is the equivalent of
* doing:
*
* .. code-block:: c
*
* iosys_map map = other_map;
* iosys_map_incr(&map, &offset);
*
* Example usage:
*
* .. code-block:: c
*
* void foo(struct device *dev, struct iosys_map *base_map)
* {
* ...
* struct iosys_map map = IOSYS_MAP_INIT_OFFSET(base_map, FIELD_OFFSET);
* ...
* }
*
* The advantage of using the initializer over just increasing the offset with
* iosys_map_incr() like above is that the new map will always point to the
* right place of the buffer during its scope. It reduces the risk of updating
* the wrong part of the buffer and having no compiler warning about that. If
* the assignment to IOSYS_MAP_INIT_OFFSET() is forgotten, the compiler can warn
* about the use of uninitialized variable.
*/
#define IOSYS_MAP_INIT_OFFSET(map_, offset_) ({ \
struct iosys_map copy = *map_; \
iosys_map_incr(&copy, offset_); \
copy; \
})
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
/**
* iosys_map_set_vaddr - Sets a iosys mapping structure to an address in system memory
* @map: The iosys_map structure
* @vaddr: A system-memory address
*
* Sets the address and clears the I/O-memory flag.
*/
static inline void iosys_map_set_vaddr(struct iosys_map *map, void *vaddr)
{
map->vaddr = vaddr;
map->is_iomem = false;
}
/**
* iosys_map_set_vaddr_iomem - Sets a iosys mapping structure to an address in I/O memory
* @map: The iosys_map structure
* @vaddr_iomem: An I/O-memory address
*
* Sets the address and the I/O-memory flag.
*/
static inline void iosys_map_set_vaddr_iomem(struct iosys_map *map,
void __iomem *vaddr_iomem)
{
map->vaddr_iomem = vaddr_iomem;
map->is_iomem = true;
}
/**
* iosys_map_is_equal - Compares two iosys mapping structures for equality
* @lhs: The iosys_map structure
* @rhs: A iosys_map structure to compare with
*
* Two iosys mapping structures are equal if they both refer to the same type of memory
* and to the same address within that memory.
*
* Returns:
* True is both structures are equal, or false otherwise.
*/
static inline bool iosys_map_is_equal(const struct iosys_map *lhs,
const struct iosys_map *rhs)
{
if (lhs->is_iomem != rhs->is_iomem)
return false;
else if (lhs->is_iomem)
return lhs->vaddr_iomem == rhs->vaddr_iomem;
else
return lhs->vaddr == rhs->vaddr;
}
/**
* iosys_map_is_null - Tests for a iosys mapping to be NULL
* @map: The iosys_map structure
*
* Depending on the state of struct iosys_map.is_iomem, tests if the
* mapping is NULL.
*
* Returns:
* True if the mapping is NULL, or false otherwise.
*/
static inline bool iosys_map_is_null(const struct iosys_map *map)
{
if (map->is_iomem)
return !map->vaddr_iomem;
return !map->vaddr;
}
/**
* iosys_map_is_set - Tests if the iosys mapping has been set
* @map: The iosys_map structure
*
* Depending on the state of struct iosys_map.is_iomem, tests if the
* mapping has been set.
*
* Returns:
* True if the mapping is been set, or false otherwise.
*/
static inline bool iosys_map_is_set(const struct iosys_map *map)
{
return !iosys_map_is_null(map);
}
/**
* iosys_map_clear - Clears a iosys mapping structure
* @map: The iosys_map structure
*
* Clears all fields to zero, including struct iosys_map.is_iomem, so
* mapping structures that were set to point to I/O memory are reset for
* system memory. Pointers are cleared to NULL. This is the default.
*/
static inline void iosys_map_clear(struct iosys_map *map)
{
if (map->is_iomem) {
map->vaddr_iomem = NULL;
map->is_iomem = false;
} else {
map->vaddr = NULL;
}
}
/**
* iosys_map_memcpy_to - Memcpy into offset of iosys_map
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
* @dst: The iosys_map structure
* @dst_offset: The offset from which to copy
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
* @src: The source buffer
* @len: The number of byte in src
*
* Copies data into a iosys_map with an offset. The source buffer is in
* system memory. Depending on the buffer's location, the helper picks the
* correct method of accessing the memory.
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
*/
static inline void iosys_map_memcpy_to(struct iosys_map *dst, size_t dst_offset,
const void *src, size_t len)
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
{
if (dst->is_iomem)
memcpy_toio(dst->vaddr_iomem + dst_offset, src, len);
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
else
memcpy(dst->vaddr + dst_offset, src, len);
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
}
iosys-map: Add a few more helpers First the simplest ones: - iosys_map_memset(): when abstracting system and I/O memory, just like the memcpy() use case, memset() also has dedicated functions to be called for using IO memory. - iosys_map_memcpy_from(): we may need to copy data from I/O memory, not only to. In certain situations it's useful to be able to read or write to an offset that is calculated by having the memory layout given by a struct declaration. Usually we are going to read/write a u8, u16, u32 or u64. As a pre-requisite for the implementation, add iosys_map_memcpy_from() to be the equivalent of iosys_map_memcpy_to(), but in the other direction. Then add 2 pairs of macros: - iosys_map_rd() / iosys_map_wr() - iosys_map_rd_field() / iosys_map_wr_field() The first pair takes the C-type and offset to read/write. The second pair uses a struct describing the layout of the mapping in order to calculate the offset and size being read/written. We could use readb, readw, readl, readq and the write* counterparts, however due to alignment issues this may not work on all architectures. If alignment needs to be checked to call the right function, it's not possible to decide at compile-time which function to call: so just leave the decision to the memcpy function that will do exactly that. Finally, in order to use the above macros with a map derived from another, add another initializer: IOSYS_MAP_INIT_OFFSET(). v2: - Rework IOSYS_MAP_INIT_OFFSET() so it doesn't rely on aliasing rules within the union - Add offset to both iosys_map_rd_field() and iosys_map_wr_field() to allow the struct itself to be at an offset from the mapping - Add documentation to iosys_map_rd_field() with example and expected memory layout v3: - Drop kernel.h include as it's not needed anymore Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-3-lucas.demarchi@intel.com
2022-02-16 17:41:33 +00:00
/**
* iosys_map_memcpy_from - Memcpy from iosys_map into system memory
* @dst: Destination in system memory
* @src: The iosys_map structure
* @src_offset: The offset from which to copy
* @len: The number of byte in src
*
* Copies data from a iosys_map with an offset. The dest buffer is in
* system memory. Depending on the mapping location, the helper picks the
* correct method of accessing the memory.
*/
static inline void iosys_map_memcpy_from(void *dst, const struct iosys_map *src,
size_t src_offset, size_t len)
{
if (src->is_iomem)
memcpy_fromio(dst, src->vaddr_iomem + src_offset, len);
else
memcpy(dst, src->vaddr + src_offset, len);
}
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
/**
* iosys_map_incr - Increments the address stored in a iosys mapping
* @map: The iosys_map structure
* @incr: The number of bytes to increment
*
* Increments the address stored in a iosys mapping. Depending on the
* buffer's location, the correct value will be updated.
*/
static inline void iosys_map_incr(struct iosys_map *map, size_t incr)
{
if (map->is_iomem)
map->vaddr_iomem += incr;
else
map->vaddr += incr;
}
iosys-map: Add a few more helpers First the simplest ones: - iosys_map_memset(): when abstracting system and I/O memory, just like the memcpy() use case, memset() also has dedicated functions to be called for using IO memory. - iosys_map_memcpy_from(): we may need to copy data from I/O memory, not only to. In certain situations it's useful to be able to read or write to an offset that is calculated by having the memory layout given by a struct declaration. Usually we are going to read/write a u8, u16, u32 or u64. As a pre-requisite for the implementation, add iosys_map_memcpy_from() to be the equivalent of iosys_map_memcpy_to(), but in the other direction. Then add 2 pairs of macros: - iosys_map_rd() / iosys_map_wr() - iosys_map_rd_field() / iosys_map_wr_field() The first pair takes the C-type and offset to read/write. The second pair uses a struct describing the layout of the mapping in order to calculate the offset and size being read/written. We could use readb, readw, readl, readq and the write* counterparts, however due to alignment issues this may not work on all architectures. If alignment needs to be checked to call the right function, it's not possible to decide at compile-time which function to call: so just leave the decision to the memcpy function that will do exactly that. Finally, in order to use the above macros with a map derived from another, add another initializer: IOSYS_MAP_INIT_OFFSET(). v2: - Rework IOSYS_MAP_INIT_OFFSET() so it doesn't rely on aliasing rules within the union - Add offset to both iosys_map_rd_field() and iosys_map_wr_field() to allow the struct itself to be at an offset from the mapping - Add documentation to iosys_map_rd_field() with example and expected memory layout v3: - Drop kernel.h include as it's not needed anymore Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-3-lucas.demarchi@intel.com
2022-02-16 17:41:33 +00:00
/**
* iosys_map_memset - Memset iosys_map
* @dst: The iosys_map structure
* @offset: Offset from dst where to start setting value
* @value: The value to set
* @len: The number of bytes to set in dst
*
* Set value in iosys_map. Depending on the buffer's location, the helper
* picks the correct method of accessing the memory.
*/
static inline void iosys_map_memset(struct iosys_map *dst, size_t offset,
int value, size_t len)
{
if (dst->is_iomem)
memset_io(dst->vaddr_iomem + offset, value, len);
else
memset(dst->vaddr + offset, value, len);
}
iosys-map: Add per-word read Instead of always falling back to memcpy_fromio() for any size, prefer using read{b,w,l}(). When reading struct members it's common to read individual integer variables individually. Going through memcpy_fromio() for each of them poses a high penalty. Employ a similar trick as __seqprop() by using _Generic() to generate only the specific call based on a type-compatible variable. For a pariticular i915 workload producing GPU context switches, __get_engine_usage_record() is particularly hot since the engine usage is read from device local memory with dgfx, possibly multiple times since it's racy. Test execution time for this test shows a ~12.5% improvement with DG2: Before: nrepeats = 1000; min = 7.63243e+06; max = 1.01817e+07; median = 9.52548e+06; var = 526149; After: nrepeats = 1000; min = 7.03402e+06; max = 8.8832e+06; median = 8.33955e+06; var = 333113; Other things attempted that didn't prove very useful: 1) Change the _Generic() on x86 to just dereference the memory address 2) Change __get_engine_usage_record() to do just 1 read per loop, comparing with the previous value read 3) Change __get_engine_usage_record() to access the fields directly as it was before the conversion to iosys-map (3) did gave a small improvement (~3%), but doesn't seem to scale well to other similar cases in the driver. Additional test by Chris Wilson using gem_create from igt with some changes to track object creation time. This happens to accidentally stress this code path: Pre iosys_map conversion of engine busyness: lmem0: Creating 262144 4KiB objects took 59274.2ms Unpatched: lmem0: Creating 262144 4KiB objects took 108830.2ms With readl (this patch): lmem0: Creating 262144 4KiB objects took 61348.6ms s/readl/READ_ONCE/ lmem0: Creating 262144 4KiB objects took 61333.2ms So we do take a little bit more time than before the conversion, but that is due to other factors: bringing the READ_ONCE back would be as good as just doing this conversion. v2: - Remove default from _Generic() - callers wanting to read more than u64 should use iosys_map_memcpy_from() - Add READ_ONCE() cases dereferencing the pointer when using system memory v3: - Fix precedence issue when casting inside READ_ONCE(). By not using () around vaddr__ the offset was not part of the cast, but rather added to it, producing a wrong address - Remove compiletime_assert() as READ_ONCE() already contains it Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> # v1 Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220628191016.3899428-1-lucas.demarchi@intel.com
2022-06-28 19:10:15 +00:00
#ifdef CONFIG_64BIT
#define __iosys_map_rd_io_u64_case(val_, vaddr_iomem_) \
u64: val_ = readq(vaddr_iomem_)
#define __iosys_map_wr_io_u64_case(val_, vaddr_iomem_) \
u64: writeq(val_, vaddr_iomem_)
iosys-map: Add per-word read Instead of always falling back to memcpy_fromio() for any size, prefer using read{b,w,l}(). When reading struct members it's common to read individual integer variables individually. Going through memcpy_fromio() for each of them poses a high penalty. Employ a similar trick as __seqprop() by using _Generic() to generate only the specific call based on a type-compatible variable. For a pariticular i915 workload producing GPU context switches, __get_engine_usage_record() is particularly hot since the engine usage is read from device local memory with dgfx, possibly multiple times since it's racy. Test execution time for this test shows a ~12.5% improvement with DG2: Before: nrepeats = 1000; min = 7.63243e+06; max = 1.01817e+07; median = 9.52548e+06; var = 526149; After: nrepeats = 1000; min = 7.03402e+06; max = 8.8832e+06; median = 8.33955e+06; var = 333113; Other things attempted that didn't prove very useful: 1) Change the _Generic() on x86 to just dereference the memory address 2) Change __get_engine_usage_record() to do just 1 read per loop, comparing with the previous value read 3) Change __get_engine_usage_record() to access the fields directly as it was before the conversion to iosys-map (3) did gave a small improvement (~3%), but doesn't seem to scale well to other similar cases in the driver. Additional test by Chris Wilson using gem_create from igt with some changes to track object creation time. This happens to accidentally stress this code path: Pre iosys_map conversion of engine busyness: lmem0: Creating 262144 4KiB objects took 59274.2ms Unpatched: lmem0: Creating 262144 4KiB objects took 108830.2ms With readl (this patch): lmem0: Creating 262144 4KiB objects took 61348.6ms s/readl/READ_ONCE/ lmem0: Creating 262144 4KiB objects took 61333.2ms So we do take a little bit more time than before the conversion, but that is due to other factors: bringing the READ_ONCE back would be as good as just doing this conversion. v2: - Remove default from _Generic() - callers wanting to read more than u64 should use iosys_map_memcpy_from() - Add READ_ONCE() cases dereferencing the pointer when using system memory v3: - Fix precedence issue when casting inside READ_ONCE(). By not using () around vaddr__ the offset was not part of the cast, but rather added to it, producing a wrong address - Remove compiletime_assert() as READ_ONCE() already contains it Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> # v1 Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220628191016.3899428-1-lucas.demarchi@intel.com
2022-06-28 19:10:15 +00:00
#else
#define __iosys_map_rd_io_u64_case(val_, vaddr_iomem_) \
u64: memcpy_fromio(&(val_), vaddr_iomem_, sizeof(u64))
#define __iosys_map_wr_io_u64_case(val_, vaddr_iomem_) \
u64: memcpy_toio(vaddr_iomem_, &(val_), sizeof(u64))
iosys-map: Add per-word read Instead of always falling back to memcpy_fromio() for any size, prefer using read{b,w,l}(). When reading struct members it's common to read individual integer variables individually. Going through memcpy_fromio() for each of them poses a high penalty. Employ a similar trick as __seqprop() by using _Generic() to generate only the specific call based on a type-compatible variable. For a pariticular i915 workload producing GPU context switches, __get_engine_usage_record() is particularly hot since the engine usage is read from device local memory with dgfx, possibly multiple times since it's racy. Test execution time for this test shows a ~12.5% improvement with DG2: Before: nrepeats = 1000; min = 7.63243e+06; max = 1.01817e+07; median = 9.52548e+06; var = 526149; After: nrepeats = 1000; min = 7.03402e+06; max = 8.8832e+06; median = 8.33955e+06; var = 333113; Other things attempted that didn't prove very useful: 1) Change the _Generic() on x86 to just dereference the memory address 2) Change __get_engine_usage_record() to do just 1 read per loop, comparing with the previous value read 3) Change __get_engine_usage_record() to access the fields directly as it was before the conversion to iosys-map (3) did gave a small improvement (~3%), but doesn't seem to scale well to other similar cases in the driver. Additional test by Chris Wilson using gem_create from igt with some changes to track object creation time. This happens to accidentally stress this code path: Pre iosys_map conversion of engine busyness: lmem0: Creating 262144 4KiB objects took 59274.2ms Unpatched: lmem0: Creating 262144 4KiB objects took 108830.2ms With readl (this patch): lmem0: Creating 262144 4KiB objects took 61348.6ms s/readl/READ_ONCE/ lmem0: Creating 262144 4KiB objects took 61333.2ms So we do take a little bit more time than before the conversion, but that is due to other factors: bringing the READ_ONCE back would be as good as just doing this conversion. v2: - Remove default from _Generic() - callers wanting to read more than u64 should use iosys_map_memcpy_from() - Add READ_ONCE() cases dereferencing the pointer when using system memory v3: - Fix precedence issue when casting inside READ_ONCE(). By not using () around vaddr__ the offset was not part of the cast, but rather added to it, producing a wrong address - Remove compiletime_assert() as READ_ONCE() already contains it Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> # v1 Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220628191016.3899428-1-lucas.demarchi@intel.com
2022-06-28 19:10:15 +00:00
#endif
#define __iosys_map_rd_io(val__, vaddr_iomem__, type__) _Generic(val__, \
u8: val__ = readb(vaddr_iomem__), \
u16: val__ = readw(vaddr_iomem__), \
u32: val__ = readl(vaddr_iomem__), \
__iosys_map_rd_io_u64_case(val__, vaddr_iomem__))
#define __iosys_map_rd_sys(val__, vaddr__, type__) \
val__ = READ_ONCE(*(type__ *)(vaddr__))
#define __iosys_map_wr_io(val__, vaddr_iomem__, type__) _Generic(val__, \
u8: writeb(val__, vaddr_iomem__), \
u16: writew(val__, vaddr_iomem__), \
u32: writel(val__, vaddr_iomem__), \
__iosys_map_wr_io_u64_case(val__, vaddr_iomem__))
#define __iosys_map_wr_sys(val__, vaddr__, type__) \
WRITE_ONCE(*(type__ *)(vaddr__), val__)
iosys-map: Add a few more helpers First the simplest ones: - iosys_map_memset(): when abstracting system and I/O memory, just like the memcpy() use case, memset() also has dedicated functions to be called for using IO memory. - iosys_map_memcpy_from(): we may need to copy data from I/O memory, not only to. In certain situations it's useful to be able to read or write to an offset that is calculated by having the memory layout given by a struct declaration. Usually we are going to read/write a u8, u16, u32 or u64. As a pre-requisite for the implementation, add iosys_map_memcpy_from() to be the equivalent of iosys_map_memcpy_to(), but in the other direction. Then add 2 pairs of macros: - iosys_map_rd() / iosys_map_wr() - iosys_map_rd_field() / iosys_map_wr_field() The first pair takes the C-type and offset to read/write. The second pair uses a struct describing the layout of the mapping in order to calculate the offset and size being read/written. We could use readb, readw, readl, readq and the write* counterparts, however due to alignment issues this may not work on all architectures. If alignment needs to be checked to call the right function, it's not possible to decide at compile-time which function to call: so just leave the decision to the memcpy function that will do exactly that. Finally, in order to use the above macros with a map derived from another, add another initializer: IOSYS_MAP_INIT_OFFSET(). v2: - Rework IOSYS_MAP_INIT_OFFSET() so it doesn't rely on aliasing rules within the union - Add offset to both iosys_map_rd_field() and iosys_map_wr_field() to allow the struct itself to be at an offset from the mapping - Add documentation to iosys_map_rd_field() with example and expected memory layout v3: - Drop kernel.h include as it's not needed anymore Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-3-lucas.demarchi@intel.com
2022-02-16 17:41:33 +00:00
/**
* iosys_map_rd - Read a C-type value from the iosys_map
*
* @map__: The iosys_map structure
* @offset__: The offset from which to read
* @type__: Type of the value being read
*
iosys-map: Add per-word read Instead of always falling back to memcpy_fromio() for any size, prefer using read{b,w,l}(). When reading struct members it's common to read individual integer variables individually. Going through memcpy_fromio() for each of them poses a high penalty. Employ a similar trick as __seqprop() by using _Generic() to generate only the specific call based on a type-compatible variable. For a pariticular i915 workload producing GPU context switches, __get_engine_usage_record() is particularly hot since the engine usage is read from device local memory with dgfx, possibly multiple times since it's racy. Test execution time for this test shows a ~12.5% improvement with DG2: Before: nrepeats = 1000; min = 7.63243e+06; max = 1.01817e+07; median = 9.52548e+06; var = 526149; After: nrepeats = 1000; min = 7.03402e+06; max = 8.8832e+06; median = 8.33955e+06; var = 333113; Other things attempted that didn't prove very useful: 1) Change the _Generic() on x86 to just dereference the memory address 2) Change __get_engine_usage_record() to do just 1 read per loop, comparing with the previous value read 3) Change __get_engine_usage_record() to access the fields directly as it was before the conversion to iosys-map (3) did gave a small improvement (~3%), but doesn't seem to scale well to other similar cases in the driver. Additional test by Chris Wilson using gem_create from igt with some changes to track object creation time. This happens to accidentally stress this code path: Pre iosys_map conversion of engine busyness: lmem0: Creating 262144 4KiB objects took 59274.2ms Unpatched: lmem0: Creating 262144 4KiB objects took 108830.2ms With readl (this patch): lmem0: Creating 262144 4KiB objects took 61348.6ms s/readl/READ_ONCE/ lmem0: Creating 262144 4KiB objects took 61333.2ms So we do take a little bit more time than before the conversion, but that is due to other factors: bringing the READ_ONCE back would be as good as just doing this conversion. v2: - Remove default from _Generic() - callers wanting to read more than u64 should use iosys_map_memcpy_from() - Add READ_ONCE() cases dereferencing the pointer when using system memory v3: - Fix precedence issue when casting inside READ_ONCE(). By not using () around vaddr__ the offset was not part of the cast, but rather added to it, producing a wrong address - Remove compiletime_assert() as READ_ONCE() already contains it Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> # v1 Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220628191016.3899428-1-lucas.demarchi@intel.com
2022-06-28 19:10:15 +00:00
* Read a C type value (u8, u16, u32 and u64) from iosys_map. For other types or
* if pointer may be unaligned (and problematic for the architecture supported),
* use iosys_map_memcpy_from().
iosys-map: Add a few more helpers First the simplest ones: - iosys_map_memset(): when abstracting system and I/O memory, just like the memcpy() use case, memset() also has dedicated functions to be called for using IO memory. - iosys_map_memcpy_from(): we may need to copy data from I/O memory, not only to. In certain situations it's useful to be able to read or write to an offset that is calculated by having the memory layout given by a struct declaration. Usually we are going to read/write a u8, u16, u32 or u64. As a pre-requisite for the implementation, add iosys_map_memcpy_from() to be the equivalent of iosys_map_memcpy_to(), but in the other direction. Then add 2 pairs of macros: - iosys_map_rd() / iosys_map_wr() - iosys_map_rd_field() / iosys_map_wr_field() The first pair takes the C-type and offset to read/write. The second pair uses a struct describing the layout of the mapping in order to calculate the offset and size being read/written. We could use readb, readw, readl, readq and the write* counterparts, however due to alignment issues this may not work on all architectures. If alignment needs to be checked to call the right function, it's not possible to decide at compile-time which function to call: so just leave the decision to the memcpy function that will do exactly that. Finally, in order to use the above macros with a map derived from another, add another initializer: IOSYS_MAP_INIT_OFFSET(). v2: - Rework IOSYS_MAP_INIT_OFFSET() so it doesn't rely on aliasing rules within the union - Add offset to both iosys_map_rd_field() and iosys_map_wr_field() to allow the struct itself to be at an offset from the mapping - Add documentation to iosys_map_rd_field() with example and expected memory layout v3: - Drop kernel.h include as it's not needed anymore Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-3-lucas.demarchi@intel.com
2022-02-16 17:41:33 +00:00
*
* Returns:
* The value read from the mapping.
*/
iosys-map: Add per-word read Instead of always falling back to memcpy_fromio() for any size, prefer using read{b,w,l}(). When reading struct members it's common to read individual integer variables individually. Going through memcpy_fromio() for each of them poses a high penalty. Employ a similar trick as __seqprop() by using _Generic() to generate only the specific call based on a type-compatible variable. For a pariticular i915 workload producing GPU context switches, __get_engine_usage_record() is particularly hot since the engine usage is read from device local memory with dgfx, possibly multiple times since it's racy. Test execution time for this test shows a ~12.5% improvement with DG2: Before: nrepeats = 1000; min = 7.63243e+06; max = 1.01817e+07; median = 9.52548e+06; var = 526149; After: nrepeats = 1000; min = 7.03402e+06; max = 8.8832e+06; median = 8.33955e+06; var = 333113; Other things attempted that didn't prove very useful: 1) Change the _Generic() on x86 to just dereference the memory address 2) Change __get_engine_usage_record() to do just 1 read per loop, comparing with the previous value read 3) Change __get_engine_usage_record() to access the fields directly as it was before the conversion to iosys-map (3) did gave a small improvement (~3%), but doesn't seem to scale well to other similar cases in the driver. Additional test by Chris Wilson using gem_create from igt with some changes to track object creation time. This happens to accidentally stress this code path: Pre iosys_map conversion of engine busyness: lmem0: Creating 262144 4KiB objects took 59274.2ms Unpatched: lmem0: Creating 262144 4KiB objects took 108830.2ms With readl (this patch): lmem0: Creating 262144 4KiB objects took 61348.6ms s/readl/READ_ONCE/ lmem0: Creating 262144 4KiB objects took 61333.2ms So we do take a little bit more time than before the conversion, but that is due to other factors: bringing the READ_ONCE back would be as good as just doing this conversion. v2: - Remove default from _Generic() - callers wanting to read more than u64 should use iosys_map_memcpy_from() - Add READ_ONCE() cases dereferencing the pointer when using system memory v3: - Fix precedence issue when casting inside READ_ONCE(). By not using () around vaddr__ the offset was not part of the cast, but rather added to it, producing a wrong address - Remove compiletime_assert() as READ_ONCE() already contains it Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> # v1 Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220628191016.3899428-1-lucas.demarchi@intel.com
2022-06-28 19:10:15 +00:00
#define iosys_map_rd(map__, offset__, type__) ({ \
type__ val; \
if ((map__)->is_iomem) { \
__iosys_map_rd_io(val, (map__)->vaddr_iomem + (offset__), type__);\
} else { \
__iosys_map_rd_sys(val, (map__)->vaddr + (offset__), type__); \
} \
val; \
iosys-map: Add a few more helpers First the simplest ones: - iosys_map_memset(): when abstracting system and I/O memory, just like the memcpy() use case, memset() also has dedicated functions to be called for using IO memory. - iosys_map_memcpy_from(): we may need to copy data from I/O memory, not only to. In certain situations it's useful to be able to read or write to an offset that is calculated by having the memory layout given by a struct declaration. Usually we are going to read/write a u8, u16, u32 or u64. As a pre-requisite for the implementation, add iosys_map_memcpy_from() to be the equivalent of iosys_map_memcpy_to(), but in the other direction. Then add 2 pairs of macros: - iosys_map_rd() / iosys_map_wr() - iosys_map_rd_field() / iosys_map_wr_field() The first pair takes the C-type and offset to read/write. The second pair uses a struct describing the layout of the mapping in order to calculate the offset and size being read/written. We could use readb, readw, readl, readq and the write* counterparts, however due to alignment issues this may not work on all architectures. If alignment needs to be checked to call the right function, it's not possible to decide at compile-time which function to call: so just leave the decision to the memcpy function that will do exactly that. Finally, in order to use the above macros with a map derived from another, add another initializer: IOSYS_MAP_INIT_OFFSET(). v2: - Rework IOSYS_MAP_INIT_OFFSET() so it doesn't rely on aliasing rules within the union - Add offset to both iosys_map_rd_field() and iosys_map_wr_field() to allow the struct itself to be at an offset from the mapping - Add documentation to iosys_map_rd_field() with example and expected memory layout v3: - Drop kernel.h include as it's not needed anymore Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-3-lucas.demarchi@intel.com
2022-02-16 17:41:33 +00:00
})
/**
* iosys_map_wr - Write a C-type value to the iosys_map
*
* @map__: The iosys_map structure
* @offset__: The offset from the mapping to write to
* @type__: Type of the value being written
* @val__: Value to write
*
* Write a C type value (u8, u16, u32 and u64) to the iosys_map. For other types
* or if pointer may be unaligned (and problematic for the architecture
* supported), use iosys_map_memcpy_to()
iosys-map: Add a few more helpers First the simplest ones: - iosys_map_memset(): when abstracting system and I/O memory, just like the memcpy() use case, memset() also has dedicated functions to be called for using IO memory. - iosys_map_memcpy_from(): we may need to copy data from I/O memory, not only to. In certain situations it's useful to be able to read or write to an offset that is calculated by having the memory layout given by a struct declaration. Usually we are going to read/write a u8, u16, u32 or u64. As a pre-requisite for the implementation, add iosys_map_memcpy_from() to be the equivalent of iosys_map_memcpy_to(), but in the other direction. Then add 2 pairs of macros: - iosys_map_rd() / iosys_map_wr() - iosys_map_rd_field() / iosys_map_wr_field() The first pair takes the C-type and offset to read/write. The second pair uses a struct describing the layout of the mapping in order to calculate the offset and size being read/written. We could use readb, readw, readl, readq and the write* counterparts, however due to alignment issues this may not work on all architectures. If alignment needs to be checked to call the right function, it's not possible to decide at compile-time which function to call: so just leave the decision to the memcpy function that will do exactly that. Finally, in order to use the above macros with a map derived from another, add another initializer: IOSYS_MAP_INIT_OFFSET(). v2: - Rework IOSYS_MAP_INIT_OFFSET() so it doesn't rely on aliasing rules within the union - Add offset to both iosys_map_rd_field() and iosys_map_wr_field() to allow the struct itself to be at an offset from the mapping - Add documentation to iosys_map_rd_field() with example and expected memory layout v3: - Drop kernel.h include as it's not needed anymore Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-3-lucas.demarchi@intel.com
2022-02-16 17:41:33 +00:00
*/
#define iosys_map_wr(map__, offset__, type__, val__) ({ \
type__ val = (val__); \
if ((map__)->is_iomem) { \
__iosys_map_wr_io(val, (map__)->vaddr_iomem + (offset__), type__);\
} else { \
__iosys_map_wr_sys(val, (map__)->vaddr + (offset__), type__); \
} \
iosys-map: Add a few more helpers First the simplest ones: - iosys_map_memset(): when abstracting system and I/O memory, just like the memcpy() use case, memset() also has dedicated functions to be called for using IO memory. - iosys_map_memcpy_from(): we may need to copy data from I/O memory, not only to. In certain situations it's useful to be able to read or write to an offset that is calculated by having the memory layout given by a struct declaration. Usually we are going to read/write a u8, u16, u32 or u64. As a pre-requisite for the implementation, add iosys_map_memcpy_from() to be the equivalent of iosys_map_memcpy_to(), but in the other direction. Then add 2 pairs of macros: - iosys_map_rd() / iosys_map_wr() - iosys_map_rd_field() / iosys_map_wr_field() The first pair takes the C-type and offset to read/write. The second pair uses a struct describing the layout of the mapping in order to calculate the offset and size being read/written. We could use readb, readw, readl, readq and the write* counterparts, however due to alignment issues this may not work on all architectures. If alignment needs to be checked to call the right function, it's not possible to decide at compile-time which function to call: so just leave the decision to the memcpy function that will do exactly that. Finally, in order to use the above macros with a map derived from another, add another initializer: IOSYS_MAP_INIT_OFFSET(). v2: - Rework IOSYS_MAP_INIT_OFFSET() so it doesn't rely on aliasing rules within the union - Add offset to both iosys_map_rd_field() and iosys_map_wr_field() to allow the struct itself to be at an offset from the mapping - Add documentation to iosys_map_rd_field() with example and expected memory layout v3: - Drop kernel.h include as it's not needed anymore Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-3-lucas.demarchi@intel.com
2022-02-16 17:41:33 +00:00
})
/**
* iosys_map_rd_field - Read a member from a struct in the iosys_map
*
* @map__: The iosys_map structure
* @struct_offset__: Offset from the beggining of the map, where the struct
* is located
* @struct_type__: The struct describing the layout of the mapping
* @field__: Member of the struct to read
*
* Read a value from iosys_map considering its layout is described by a C struct
* starting at @struct_offset__. The field offset and size is calculated and its
iosys-map: Add per-word read Instead of always falling back to memcpy_fromio() for any size, prefer using read{b,w,l}(). When reading struct members it's common to read individual integer variables individually. Going through memcpy_fromio() for each of them poses a high penalty. Employ a similar trick as __seqprop() by using _Generic() to generate only the specific call based on a type-compatible variable. For a pariticular i915 workload producing GPU context switches, __get_engine_usage_record() is particularly hot since the engine usage is read from device local memory with dgfx, possibly multiple times since it's racy. Test execution time for this test shows a ~12.5% improvement with DG2: Before: nrepeats = 1000; min = 7.63243e+06; max = 1.01817e+07; median = 9.52548e+06; var = 526149; After: nrepeats = 1000; min = 7.03402e+06; max = 8.8832e+06; median = 8.33955e+06; var = 333113; Other things attempted that didn't prove very useful: 1) Change the _Generic() on x86 to just dereference the memory address 2) Change __get_engine_usage_record() to do just 1 read per loop, comparing with the previous value read 3) Change __get_engine_usage_record() to access the fields directly as it was before the conversion to iosys-map (3) did gave a small improvement (~3%), but doesn't seem to scale well to other similar cases in the driver. Additional test by Chris Wilson using gem_create from igt with some changes to track object creation time. This happens to accidentally stress this code path: Pre iosys_map conversion of engine busyness: lmem0: Creating 262144 4KiB objects took 59274.2ms Unpatched: lmem0: Creating 262144 4KiB objects took 108830.2ms With readl (this patch): lmem0: Creating 262144 4KiB objects took 61348.6ms s/readl/READ_ONCE/ lmem0: Creating 262144 4KiB objects took 61333.2ms So we do take a little bit more time than before the conversion, but that is due to other factors: bringing the READ_ONCE back would be as good as just doing this conversion. v2: - Remove default from _Generic() - callers wanting to read more than u64 should use iosys_map_memcpy_from() - Add READ_ONCE() cases dereferencing the pointer when using system memory v3: - Fix precedence issue when casting inside READ_ONCE(). By not using () around vaddr__ the offset was not part of the cast, but rather added to it, producing a wrong address - Remove compiletime_assert() as READ_ONCE() already contains it Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> # v1 Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220628191016.3899428-1-lucas.demarchi@intel.com
2022-06-28 19:10:15 +00:00
* value read. If the field access would incur in un-aligned access, then either
* iosys_map_memcpy_from() needs to be used or the architecture must support it.
* For example: suppose there is a @struct foo defined as below and the value
* ``foo.field2.inner2`` needs to be read from the iosys_map:
iosys-map: Add a few more helpers First the simplest ones: - iosys_map_memset(): when abstracting system and I/O memory, just like the memcpy() use case, memset() also has dedicated functions to be called for using IO memory. - iosys_map_memcpy_from(): we may need to copy data from I/O memory, not only to. In certain situations it's useful to be able to read or write to an offset that is calculated by having the memory layout given by a struct declaration. Usually we are going to read/write a u8, u16, u32 or u64. As a pre-requisite for the implementation, add iosys_map_memcpy_from() to be the equivalent of iosys_map_memcpy_to(), but in the other direction. Then add 2 pairs of macros: - iosys_map_rd() / iosys_map_wr() - iosys_map_rd_field() / iosys_map_wr_field() The first pair takes the C-type and offset to read/write. The second pair uses a struct describing the layout of the mapping in order to calculate the offset and size being read/written. We could use readb, readw, readl, readq and the write* counterparts, however due to alignment issues this may not work on all architectures. If alignment needs to be checked to call the right function, it's not possible to decide at compile-time which function to call: so just leave the decision to the memcpy function that will do exactly that. Finally, in order to use the above macros with a map derived from another, add another initializer: IOSYS_MAP_INIT_OFFSET(). v2: - Rework IOSYS_MAP_INIT_OFFSET() so it doesn't rely on aliasing rules within the union - Add offset to both iosys_map_rd_field() and iosys_map_wr_field() to allow the struct itself to be at an offset from the mapping - Add documentation to iosys_map_rd_field() with example and expected memory layout v3: - Drop kernel.h include as it's not needed anymore Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-3-lucas.demarchi@intel.com
2022-02-16 17:41:33 +00:00
*
* .. code-block:: c
*
* struct foo {
* int field1;
* struct {
* int inner1;
* int inner2;
* } field2;
* int field3;
* } __packed;
*
* This is the expected memory layout of a buffer using iosys_map_rd_field():
*
* +------------------------------+--------------------------+
* | Address | Content |
* +==============================+==========================+
* | buffer + 0000 | start of mmapped buffer |
* | | pointed by iosys_map |
* +------------------------------+--------------------------+
* | ... | ... |
* +------------------------------+--------------------------+
* | buffer + ``struct_offset__`` | start of ``struct foo`` |
* +------------------------------+--------------------------+
* | ... | ... |
* +------------------------------+--------------------------+
* | buffer + wwww | ``foo.field2.inner2`` |
* +------------------------------+--------------------------+
* | ... | ... |
* +------------------------------+--------------------------+
* | buffer + yyyy | end of ``struct foo`` |
* +------------------------------+--------------------------+
* | ... | ... |
* +------------------------------+--------------------------+
* | buffer + zzzz | end of mmaped buffer |
* +------------------------------+--------------------------+
*
* Values automatically calculated by this macro or not needed are denoted by
* wwww, yyyy and zzzz. This is the code to read that value:
*
* .. code-block:: c
*
* x = iosys_map_rd_field(&map, offset, struct foo, field2.inner2);
*
* Returns:
* The value read from the mapping.
*/
#define iosys_map_rd_field(map__, struct_offset__, struct_type__, field__) ({ \
struct_type__ *s; \
iosys_map_rd(map__, struct_offset__ + offsetof(struct_type__, field__), \
typeof(s->field__)); \
})
/**
* iosys_map_wr_field - Write to a member of a struct in the iosys_map
*
* @map__: The iosys_map structure
* @struct_offset__: Offset from the beggining of the map, where the struct
* is located
* @struct_type__: The struct describing the layout of the mapping
* @field__: Member of the struct to read
* @val__: Value to write
*
* Write a value to the iosys_map considering its layout is described by a C
* struct starting at @struct_offset__. The field offset and size is calculated
* and the @val__ is written. If the field access would incur in un-aligned
* access, then either iosys_map_memcpy_to() needs to be used or the
* architecture must support it. Refer to iosys_map_rd_field() for expected
* usage and memory layout.
iosys-map: Add a few more helpers First the simplest ones: - iosys_map_memset(): when abstracting system and I/O memory, just like the memcpy() use case, memset() also has dedicated functions to be called for using IO memory. - iosys_map_memcpy_from(): we may need to copy data from I/O memory, not only to. In certain situations it's useful to be able to read or write to an offset that is calculated by having the memory layout given by a struct declaration. Usually we are going to read/write a u8, u16, u32 or u64. As a pre-requisite for the implementation, add iosys_map_memcpy_from() to be the equivalent of iosys_map_memcpy_to(), but in the other direction. Then add 2 pairs of macros: - iosys_map_rd() / iosys_map_wr() - iosys_map_rd_field() / iosys_map_wr_field() The first pair takes the C-type and offset to read/write. The second pair uses a struct describing the layout of the mapping in order to calculate the offset and size being read/written. We could use readb, readw, readl, readq and the write* counterparts, however due to alignment issues this may not work on all architectures. If alignment needs to be checked to call the right function, it's not possible to decide at compile-time which function to call: so just leave the decision to the memcpy function that will do exactly that. Finally, in order to use the above macros with a map derived from another, add another initializer: IOSYS_MAP_INIT_OFFSET(). v2: - Rework IOSYS_MAP_INIT_OFFSET() so it doesn't rely on aliasing rules within the union - Add offset to both iosys_map_rd_field() and iosys_map_wr_field() to allow the struct itself to be at an offset from the mapping - Add documentation to iosys_map_rd_field() with example and expected memory layout v3: - Drop kernel.h include as it's not needed anymore Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-3-lucas.demarchi@intel.com
2022-02-16 17:41:33 +00:00
*/
#define iosys_map_wr_field(map__, struct_offset__, struct_type__, field__, val__) ({ \
struct_type__ *s; \
iosys_map_wr(map__, struct_offset__ + offsetof(struct_type__, field__), \
typeof(s->field__), val__); \
})
dma-buf-map: Rename to iosys-map Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
2022-02-04 17:05:41 +00:00
#endif /* __IOSYS_MAP_H__ */