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ACPI APEI: Convert atomicio routines

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APEI needs memory access in interrupt context.  The obvious choice is
acpi_read(), but originally it couldn't be used in interrupt context
because it makes temporary mappings with ioremap().  Therefore, we added
drivers/acpi/atomicio.c, which provides:
    acpi_pre_map_gar()     -- ioremap in process context
	acpi_atomic_read()     -- memory access in interrupt context
	acpi_post_unmap_gar()  -- iounmap

Later we added acpi_os_map_generic_address() (2971852) and enhanced
acpi_read() so it works in interrupt context as long as the address has
been previously mapped (620242a).  Now this sequence:
    acpi_os_map_generic_address()    -- ioremap in process context
    acpi_read()/apei_read()          -- now OK in interrupt context
    acpi_os_unmap_generic_address()
is equivalent to what atomicio.c provides.

This patch introduces apei_read() and apei_write(), which currently are
functional equivalents of acpi_read() and acpi_write().  This is mainly
proactive, to prevent APEI breakages if acpi_read() and acpi_write()
are ever augmented to support the 'bit_offset' field of GAS, as APEI's
__apei_exec_write_register() precludes splitting up functionality
related to 'bit_offset' and APEI's 'mask' (see its
APEI_EXEC_PRESERVE_REGISTER block).

With apei_read() and apei_write() in place, usages of atomicio routines
are converted to apei_read()/apei_write() and existing calls within
osl.c and the CA, based on the re-factoring that was done in an earlier
patch series - http://marc.info/?l=linux-acpi&m=128769263327206&w=2:
    acpi_pre_map_gar()     -->  acpi_os_map_generic_address()
    acpi_post_unmap_gar()  -->  acpi_os_unmap_generic_address()
    acpi_atomic_read()     -->  apei_read()
    acpi_atomic_write()    -->  apei_write()

Note that acpi_read() and acpi_write() currently use 'bit_width'
for accessing GARs which seems incorrect.  'bit_width' is the size of
the register, while 'access_width' is the size of the access the
processor must generate on the bus.  The 'access_width' may be larger,
for example, if the hardware only supports 32-bit or 64-bit reads.  I
wanted to minimize any possible impacts with this patch series so I
did *not* change this behavior.

Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Myron Stowe 2011-11-07 16:23:41 -07:00 committed by Len Brown
parent 6f68c91c55
commit 700130b41f
3 changed files with 104 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

102
drivers/acpi/apei/apei-base.c
View file

@ -34,13 +34,13 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/acpi_io.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/kref.h>
#include <linux/rculist.h>
#include <linux/interrupt.h>
#include <linux/debugfs.h>
#include <acpi/atomicio.h>
#include "apei-internal.h"
@ -70,7 +70,7 @@ int __apei_exec_read_register(struct acpi_whea_header *entry, u64 *val)
{
int rc;
rc = acpi_atomic_read(val, &entry->register_region);
rc = apei_read(val, &entry->register_region);
if (rc)
return rc;
*val >>= entry->register_region.bit_offset;
@ -116,13 +116,13 @@ int __apei_exec_write_register(struct acpi_whea_header *entry, u64 val)
val <<= entry->register_region.bit_offset;
if (entry->flags & APEI_EXEC_PRESERVE_REGISTER) {
u64 valr = 0;
rc = acpi_atomic_read(&valr, &entry->register_region);
rc = apei_read(&valr, &entry->register_region);
if (rc)
return rc;
valr &= ~(entry->mask << entry->register_region.bit_offset);
val |= valr;
}
rc = acpi_atomic_write(val, &entry->register_region);
rc = apei_write(val, &entry->register_region);
return rc;
}
@ -243,7 +243,7 @@ static int pre_map_gar_callback(struct apei_exec_context *ctx,
u8 ins = entry->instruction;
if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER)
return acpi_pre_map_gar(&entry->register_region);
return acpi_os_map_generic_address(&entry->register_region);
return 0;
}
@ -276,7 +276,7 @@ static int post_unmap_gar_callback(struct apei_exec_context *ctx,
u8 ins = entry->instruction;
if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER)
acpi_post_unmap_gar(&entry->register_region);
acpi_os_unmap_generic_address(&entry->register_region);
return 0;
}
@ -591,6 +591,96 @@ static int apei_check_gar(struct acpi_generic_address *reg, u64 *paddr)
return 0;
}
/* read GAR in interrupt (including NMI) or process context */
int apei_read(u64 *val, struct acpi_generic_address *reg)
{
int rc;
u64 address;
u32 tmp, width = reg->bit_width;
acpi_status status;
rc = apei_check_gar(reg, &address);
if (rc)
return rc;
if (width == 64)
width = 32; /* Break into two 32-bit transfers */
*val = 0;
switch(reg->space_id) {
case ACPI_ADR_SPACE_SYSTEM_MEMORY:
status = acpi_os_read_memory((acpi_physical_address)
address, &tmp, width);
if (ACPI_FAILURE(status))
return -EIO;
*val = tmp;
if (reg->bit_width == 64) {
/* Read the top 32 bits */
status = acpi_os_read_memory((acpi_physical_address)
(address + 4), &tmp, 32);
if (ACPI_FAILURE(status))
return -EIO;
*val |= ((u64)tmp << 32);
}
break;
case ACPI_ADR_SPACE_SYSTEM_IO:
status = acpi_os_read_port(address, (u32 *)val, reg->bit_width);
if (ACPI_FAILURE(status))
return -EIO;
break;
default:
return -EINVAL;
}
return 0;
}
EXPORT_SYMBOL_GPL(apei_read);
/* write GAR in interrupt (including NMI) or process context */
int apei_write(u64 val, struct acpi_generic_address *reg)
{
int rc;
u64 address;
u32 width = reg->bit_width;
acpi_status status;
rc = apei_check_gar(reg, &address);
if (rc)
return rc;
if (width == 64)
width = 32; /* Break into two 32-bit transfers */
switch (reg->space_id) {
case ACPI_ADR_SPACE_SYSTEM_MEMORY:
status = acpi_os_write_memory((acpi_physical_address)
address, ACPI_LODWORD(val),
width);
if (ACPI_FAILURE(status))
return -EIO;
if (reg->bit_width == 64) {
status = acpi_os_write_memory((acpi_physical_address)
(address + 4),
ACPI_HIDWORD(val), 32);
if (ACPI_FAILURE(status))
return -EIO;
}
break;
case ACPI_ADR_SPACE_SYSTEM_IO:
status = acpi_os_write_port(address, val, reg->bit_width);
if (ACPI_FAILURE(status))
return -EIO;
break;
default:
return -EINVAL;
}
return 0;
}
EXPORT_SYMBOL_GPL(apei_write);
static int collect_res_callback(struct apei_exec_context *ctx,
struct acpi_whea_header *entry,
void *data)

3
drivers/acpi/apei/apei-internal.h
View file

@ -68,6 +68,9 @@ static inline int apei_exec_run_optional(struct apei_exec_context *ctx, u8 actio
/* IP has been set in instruction function */
#define APEI_EXEC_SET_IP 1
int apei_read(u64 *val, struct acpi_generic_address *reg);
int apei_write(u64 val, struct acpi_generic_address *reg);
int __apei_exec_read_register(struct acpi_whea_header *entry, u64 *val);
int __apei_exec_write_register(struct acpi_whea_header *entry, u64 val);
int apei_exec_read_register(struct apei_exec_context *ctx,

10
drivers/acpi/apei/ghes.c
View file

@ -33,6 +33,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/acpi_io.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
@ -48,7 +49,6 @@
#include <linux/pci.h>
#include <linux/aer.h>
#include <acpi/apei.h>
#include <acpi/atomicio.h>
#include <acpi/hed.h>
#include <asm/mce.h>
#include <asm/tlbflush.h>
@ -301,7 +301,7 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic)
if (!ghes)
return ERR_PTR(-ENOMEM);
ghes->generic = generic;
rc = acpi_pre_map_gar(&generic->error_status_address);
rc = acpi_os_map_generic_address(&generic->error_status_address);
if (rc)
goto err_free;
error_block_length = generic->error_block_length;
@ -321,7 +321,7 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic)
return ghes;
err_unmap:
acpi_post_unmap_gar(&generic->error_status_address);
acpi_os_unmap_generic_address(&generic->error_status_address);
err_free:
kfree(ghes);
return ERR_PTR(rc);
@ -330,7 +330,7 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic)
static void ghes_fini(struct ghes *ghes)
{
kfree(ghes->estatus);
acpi_post_unmap_gar(&ghes->generic->error_status_address);
acpi_os_unmap_generic_address(&ghes->generic->error_status_address);
}
enum {
@ -401,7 +401,7 @@ static int ghes_read_estatus(struct ghes *ghes, int silent)
u32 len;
int rc;
rc = acpi_atomic_read(&buf_paddr, &g->error_status_address);
rc = apei_read(&buf_paddr, &g->error_status_address);
if (rc) {
if (!silent && printk_ratelimit())
pr_warning(FW_WARN GHES_PFX