linux-stable/drivers/iommu/tegra-smmu.c
Nicolin Chen 765a9d1d02 iommu/tegra-smmu: Fix mc errors on tegra124-nyan
Commit 25938c73cd ("iommu/tegra-smmu: Rework tegra_smmu_probe_device()")
removed certain hack in the tegra_smmu_probe() by relying on IOMMU core to
of_xlate SMMU's SID per device, so as to get rid of tegra_smmu_find() and
tegra_smmu_configure() that are typically done in the IOMMU core also.

This approach works for both existing devices that have DT nodes and other
devices (like PCI device) that don't exist in DT, on Tegra210 and Tegra3
upon testing. However, Page Fault errors are reported on tegra124-Nyan:

  tegra-mc 70019000.memory-controller: display0a: read @0xfe056b40:
	 EMEM address decode error (SMMU translation error [--S])
  tegra-mc 70019000.memory-controller: display0a: read @0xfe056b40:
	 Page fault (SMMU translation error [--S])

After debugging, I found that the mentioned commit changed some function
callback sequence of tegra-smmu's, resulting in enabling SMMU for display
client before display driver gets initialized. I couldn't reproduce exact
same issue on Tegra210 as Tegra124 (arm-32) differs at arch-level code.

Actually this Page Fault is a known issue, as on most of Tegra platforms,
display gets enabled by the bootloader for the splash screen feature, so
it keeps filling the framebuffer memory. A proper fix to this issue is to
1:1 linear map the framebuffer memory to IOVA space so the SMMU will have
the same address as the physical address in its page table. Yet, Thierry
has been working on the solution above for a year, and it hasn't merged.

Therefore, let's partially revert the mentioned commit to fix the errors.

The reason why we do a partial revert here is that we can still set priv
in ->of_xlate() callback for PCI devices. Meanwhile, devices existing in
DT, like display, will go through tegra_smmu_configure() at the stage of
bus_set_iommu() when SMMU gets probed(), as what it did before we merged
the mentioned commit.

Once we have the linear map solution for framebuffer memory, this change
can be cleaned away.

[Big thank to Guillaume who reported and helped debugging/verification]

Fixes: 25938c73cd ("iommu/tegra-smmu: Rework tegra_smmu_probe_device()")
Reported-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20210218220702.1962-1-nicoleotsuka@gmail.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-03-04 13:20:54 +01:00

1188 lines
28 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011-2014 NVIDIA CORPORATION. All rights reserved.
*/
#include <linux/bitops.h>
#include <linux/debugfs.h>
#include <linux/err.h>
#include <linux/iommu.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/dma-mapping.h>
#include <soc/tegra/ahb.h>
#include <soc/tegra/mc.h>
struct tegra_smmu_group {
struct list_head list;
struct tegra_smmu *smmu;
const struct tegra_smmu_group_soc *soc;
struct iommu_group *group;
unsigned int swgroup;
};
struct tegra_smmu {
void __iomem *regs;
struct device *dev;
struct tegra_mc *mc;
const struct tegra_smmu_soc *soc;
struct list_head groups;
unsigned long pfn_mask;
unsigned long tlb_mask;
unsigned long *asids;
struct mutex lock;
struct list_head list;
struct dentry *debugfs;
struct iommu_device iommu; /* IOMMU Core code handle */
};
struct tegra_smmu_as {
struct iommu_domain domain;
struct tegra_smmu *smmu;
unsigned int use_count;
spinlock_t lock;
u32 *count;
struct page **pts;
struct page *pd;
dma_addr_t pd_dma;
unsigned id;
u32 attr;
};
static struct tegra_smmu_as *to_smmu_as(struct iommu_domain *dom)
{
return container_of(dom, struct tegra_smmu_as, domain);
}
static inline void smmu_writel(struct tegra_smmu *smmu, u32 value,
unsigned long offset)
{
writel(value, smmu->regs + offset);
}
static inline u32 smmu_readl(struct tegra_smmu *smmu, unsigned long offset)
{
return readl(smmu->regs + offset);
}
#define SMMU_CONFIG 0x010
#define SMMU_CONFIG_ENABLE (1 << 0)
#define SMMU_TLB_CONFIG 0x14
#define SMMU_TLB_CONFIG_HIT_UNDER_MISS (1 << 29)
#define SMMU_TLB_CONFIG_ROUND_ROBIN_ARBITRATION (1 << 28)
#define SMMU_TLB_CONFIG_ACTIVE_LINES(smmu) \
((smmu)->soc->num_tlb_lines & (smmu)->tlb_mask)
#define SMMU_PTC_CONFIG 0x18
#define SMMU_PTC_CONFIG_ENABLE (1 << 29)
#define SMMU_PTC_CONFIG_REQ_LIMIT(x) (((x) & 0x0f) << 24)
#define SMMU_PTC_CONFIG_INDEX_MAP(x) ((x) & 0x3f)
#define SMMU_PTB_ASID 0x01c
#define SMMU_PTB_ASID_VALUE(x) ((x) & 0x7f)
#define SMMU_PTB_DATA 0x020
#define SMMU_PTB_DATA_VALUE(dma, attr) ((dma) >> 12 | (attr))
#define SMMU_MK_PDE(dma, attr) ((dma) >> SMMU_PTE_SHIFT | (attr))
#define SMMU_TLB_FLUSH 0x030
#define SMMU_TLB_FLUSH_VA_MATCH_ALL (0 << 0)
#define SMMU_TLB_FLUSH_VA_MATCH_SECTION (2 << 0)
#define SMMU_TLB_FLUSH_VA_MATCH_GROUP (3 << 0)
#define SMMU_TLB_FLUSH_VA_SECTION(addr) ((((addr) & 0xffc00000) >> 12) | \
SMMU_TLB_FLUSH_VA_MATCH_SECTION)
#define SMMU_TLB_FLUSH_VA_GROUP(addr) ((((addr) & 0xffffc000) >> 12) | \
SMMU_TLB_FLUSH_VA_MATCH_GROUP)
#define SMMU_TLB_FLUSH_ASID_MATCH (1 << 31)
#define SMMU_PTC_FLUSH 0x034
#define SMMU_PTC_FLUSH_TYPE_ALL (0 << 0)
#define SMMU_PTC_FLUSH_TYPE_ADR (1 << 0)
#define SMMU_PTC_FLUSH_HI 0x9b8
#define SMMU_PTC_FLUSH_HI_MASK 0x3
/* per-SWGROUP SMMU_*_ASID register */
#define SMMU_ASID_ENABLE (1 << 31)
#define SMMU_ASID_MASK 0x7f
#define SMMU_ASID_VALUE(x) ((x) & SMMU_ASID_MASK)
/* page table definitions */
#define SMMU_NUM_PDE 1024
#define SMMU_NUM_PTE 1024
#define SMMU_SIZE_PD (SMMU_NUM_PDE * 4)
#define SMMU_SIZE_PT (SMMU_NUM_PTE * 4)
#define SMMU_PDE_SHIFT 22
#define SMMU_PTE_SHIFT 12
#define SMMU_PAGE_MASK (~(SMMU_SIZE_PT-1))
#define SMMU_OFFSET_IN_PAGE(x) ((unsigned long)(x) & ~SMMU_PAGE_MASK)
#define SMMU_PFN_PHYS(x) ((phys_addr_t)(x) << SMMU_PTE_SHIFT)
#define SMMU_PHYS_PFN(x) ((unsigned long)((x) >> SMMU_PTE_SHIFT))
#define SMMU_PD_READABLE (1 << 31)
#define SMMU_PD_WRITABLE (1 << 30)
#define SMMU_PD_NONSECURE (1 << 29)
#define SMMU_PDE_READABLE (1 << 31)
#define SMMU_PDE_WRITABLE (1 << 30)
#define SMMU_PDE_NONSECURE (1 << 29)
#define SMMU_PDE_NEXT (1 << 28)
#define SMMU_PTE_READABLE (1 << 31)
#define SMMU_PTE_WRITABLE (1 << 30)
#define SMMU_PTE_NONSECURE (1 << 29)
#define SMMU_PDE_ATTR (SMMU_PDE_READABLE | SMMU_PDE_WRITABLE | \
SMMU_PDE_NONSECURE)
static unsigned int iova_pd_index(unsigned long iova)
{
return (iova >> SMMU_PDE_SHIFT) & (SMMU_NUM_PDE - 1);
}
static unsigned int iova_pt_index(unsigned long iova)
{
return (iova >> SMMU_PTE_SHIFT) & (SMMU_NUM_PTE - 1);
}
static bool smmu_dma_addr_valid(struct tegra_smmu *smmu, dma_addr_t addr)
{
addr >>= 12;
return (addr & smmu->pfn_mask) == addr;
}
static dma_addr_t smmu_pde_to_dma(struct tegra_smmu *smmu, u32 pde)
{
return (dma_addr_t)(pde & smmu->pfn_mask) << 12;
}
static void smmu_flush_ptc_all(struct tegra_smmu *smmu)
{
smmu_writel(smmu, SMMU_PTC_FLUSH_TYPE_ALL, SMMU_PTC_FLUSH);
}
static inline void smmu_flush_ptc(struct tegra_smmu *smmu, dma_addr_t dma,
unsigned long offset)
{
u32 value;
offset &= ~(smmu->mc->soc->atom_size - 1);
if (smmu->mc->soc->num_address_bits > 32) {
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
value = (dma >> 32) & SMMU_PTC_FLUSH_HI_MASK;
#else
value = 0;
#endif
smmu_writel(smmu, value, SMMU_PTC_FLUSH_HI);
}
value = (dma + offset) | SMMU_PTC_FLUSH_TYPE_ADR;
smmu_writel(smmu, value, SMMU_PTC_FLUSH);
}
static inline void smmu_flush_tlb(struct tegra_smmu *smmu)
{
smmu_writel(smmu, SMMU_TLB_FLUSH_VA_MATCH_ALL, SMMU_TLB_FLUSH);
}
static inline void smmu_flush_tlb_asid(struct tegra_smmu *smmu,
unsigned long asid)
{
u32 value;
if (smmu->soc->num_asids == 4)
value = (asid & 0x3) << 29;
else
value = (asid & 0x7f) << 24;
value |= SMMU_TLB_FLUSH_ASID_MATCH | SMMU_TLB_FLUSH_VA_MATCH_ALL;
smmu_writel(smmu, value, SMMU_TLB_FLUSH);
}
static inline void smmu_flush_tlb_section(struct tegra_smmu *smmu,
unsigned long asid,
unsigned long iova)
{
u32 value;
if (smmu->soc->num_asids == 4)
value = (asid & 0x3) << 29;
else
value = (asid & 0x7f) << 24;
value |= SMMU_TLB_FLUSH_ASID_MATCH | SMMU_TLB_FLUSH_VA_SECTION(iova);
smmu_writel(smmu, value, SMMU_TLB_FLUSH);
}
static inline void smmu_flush_tlb_group(struct tegra_smmu *smmu,
unsigned long asid,
unsigned long iova)
{
u32 value;
if (smmu->soc->num_asids == 4)
value = (asid & 0x3) << 29;
else
value = (asid & 0x7f) << 24;
value |= SMMU_TLB_FLUSH_ASID_MATCH | SMMU_TLB_FLUSH_VA_GROUP(iova);
smmu_writel(smmu, value, SMMU_TLB_FLUSH);
}
static inline void smmu_flush(struct tegra_smmu *smmu)
{
smmu_readl(smmu, SMMU_PTB_ASID);
}
static int tegra_smmu_alloc_asid(struct tegra_smmu *smmu, unsigned int *idp)
{
unsigned long id;
id = find_first_zero_bit(smmu->asids, smmu->soc->num_asids);
if (id >= smmu->soc->num_asids)
return -ENOSPC;
set_bit(id, smmu->asids);
*idp = id;
return 0;
}
static void tegra_smmu_free_asid(struct tegra_smmu *smmu, unsigned int id)
{
clear_bit(id, smmu->asids);
}
static bool tegra_smmu_capable(enum iommu_cap cap)
{
return false;
}
static struct iommu_domain *tegra_smmu_domain_alloc(unsigned type)
{
struct tegra_smmu_as *as;
if (type != IOMMU_DOMAIN_UNMANAGED)
return NULL;
as = kzalloc(sizeof(*as), GFP_KERNEL);
if (!as)
return NULL;
as->attr = SMMU_PD_READABLE | SMMU_PD_WRITABLE | SMMU_PD_NONSECURE;
as->pd = alloc_page(GFP_KERNEL | __GFP_DMA | __GFP_ZERO);
if (!as->pd) {
kfree(as);
return NULL;
}
as->count = kcalloc(SMMU_NUM_PDE, sizeof(u32), GFP_KERNEL);
if (!as->count) {
__free_page(as->pd);
kfree(as);
return NULL;
}
as->pts = kcalloc(SMMU_NUM_PDE, sizeof(*as->pts), GFP_KERNEL);
if (!as->pts) {
kfree(as->count);
__free_page(as->pd);
kfree(as);
return NULL;
}
spin_lock_init(&as->lock);
/* setup aperture */
as->domain.geometry.aperture_start = 0;
as->domain.geometry.aperture_end = 0xffffffff;
as->domain.geometry.force_aperture = true;
return &as->domain;
}
static void tegra_smmu_domain_free(struct iommu_domain *domain)
{
struct tegra_smmu_as *as = to_smmu_as(domain);
/* TODO: free page directory and page tables */
WARN_ON_ONCE(as->use_count);
kfree(as->count);
kfree(as->pts);
kfree(as);
}
static const struct tegra_smmu_swgroup *
tegra_smmu_find_swgroup(struct tegra_smmu *smmu, unsigned int swgroup)
{
const struct tegra_smmu_swgroup *group = NULL;
unsigned int i;
for (i = 0; i < smmu->soc->num_swgroups; i++) {
if (smmu->soc->swgroups[i].swgroup == swgroup) {
group = &smmu->soc->swgroups[i];
break;
}
}
return group;
}
static void tegra_smmu_enable(struct tegra_smmu *smmu, unsigned int swgroup,
unsigned int asid)
{
const struct tegra_smmu_swgroup *group;
unsigned int i;
u32 value;
group = tegra_smmu_find_swgroup(smmu, swgroup);
if (group) {
value = smmu_readl(smmu, group->reg);
value &= ~SMMU_ASID_MASK;
value |= SMMU_ASID_VALUE(asid);
value |= SMMU_ASID_ENABLE;
smmu_writel(smmu, value, group->reg);
} else {
pr_warn("%s group from swgroup %u not found\n", __func__,
swgroup);
/* No point moving ahead if group was not found */
return;
}
for (i = 0; i < smmu->soc->num_clients; i++) {
const struct tegra_mc_client *client = &smmu->soc->clients[i];
if (client->swgroup != swgroup)
continue;
value = smmu_readl(smmu, client->smmu.reg);
value |= BIT(client->smmu.bit);
smmu_writel(smmu, value, client->smmu.reg);
}
}
static void tegra_smmu_disable(struct tegra_smmu *smmu, unsigned int swgroup,
unsigned int asid)
{
const struct tegra_smmu_swgroup *group;
unsigned int i;
u32 value;
group = tegra_smmu_find_swgroup(smmu, swgroup);
if (group) {
value = smmu_readl(smmu, group->reg);
value &= ~SMMU_ASID_MASK;
value |= SMMU_ASID_VALUE(asid);
value &= ~SMMU_ASID_ENABLE;
smmu_writel(smmu, value, group->reg);
}
for (i = 0; i < smmu->soc->num_clients; i++) {
const struct tegra_mc_client *client = &smmu->soc->clients[i];
if (client->swgroup != swgroup)
continue;
value = smmu_readl(smmu, client->smmu.reg);
value &= ~BIT(client->smmu.bit);
smmu_writel(smmu, value, client->smmu.reg);
}
}
static int tegra_smmu_as_prepare(struct tegra_smmu *smmu,
struct tegra_smmu_as *as)
{
u32 value;
int err = 0;
mutex_lock(&smmu->lock);
if (as->use_count > 0) {
as->use_count++;
goto unlock;
}
as->pd_dma = dma_map_page(smmu->dev, as->pd, 0, SMMU_SIZE_PD,
DMA_TO_DEVICE);
if (dma_mapping_error(smmu->dev, as->pd_dma)) {
err = -ENOMEM;
goto unlock;
}
/* We can't handle 64-bit DMA addresses */
if (!smmu_dma_addr_valid(smmu, as->pd_dma)) {
err = -ENOMEM;
goto err_unmap;
}
err = tegra_smmu_alloc_asid(smmu, &as->id);
if (err < 0)
goto err_unmap;
smmu_flush_ptc(smmu, as->pd_dma, 0);
smmu_flush_tlb_asid(smmu, as->id);
smmu_writel(smmu, as->id & 0x7f, SMMU_PTB_ASID);
value = SMMU_PTB_DATA_VALUE(as->pd_dma, as->attr);
smmu_writel(smmu, value, SMMU_PTB_DATA);
smmu_flush(smmu);
as->smmu = smmu;
as->use_count++;
mutex_unlock(&smmu->lock);
return 0;
err_unmap:
dma_unmap_page(smmu->dev, as->pd_dma, SMMU_SIZE_PD, DMA_TO_DEVICE);
unlock:
mutex_unlock(&smmu->lock);
return err;
}
static void tegra_smmu_as_unprepare(struct tegra_smmu *smmu,
struct tegra_smmu_as *as)
{
mutex_lock(&smmu->lock);
if (--as->use_count > 0) {
mutex_unlock(&smmu->lock);
return;
}
tegra_smmu_free_asid(smmu, as->id);
dma_unmap_page(smmu->dev, as->pd_dma, SMMU_SIZE_PD, DMA_TO_DEVICE);
as->smmu = NULL;
mutex_unlock(&smmu->lock);
}
static int tegra_smmu_attach_dev(struct iommu_domain *domain,
struct device *dev)
{
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
struct tegra_smmu *smmu = dev_iommu_priv_get(dev);
struct tegra_smmu_as *as = to_smmu_as(domain);
unsigned int index;
int err;
if (!fwspec)
return -ENOENT;
for (index = 0; index < fwspec->num_ids; index++) {
err = tegra_smmu_as_prepare(smmu, as);
if (err)
goto disable;
tegra_smmu_enable(smmu, fwspec->ids[index], as->id);
}
if (index == 0)
return -ENODEV;
return 0;
disable:
while (index--) {
tegra_smmu_disable(smmu, fwspec->ids[index], as->id);
tegra_smmu_as_unprepare(smmu, as);
}
return err;
}
static void tegra_smmu_detach_dev(struct iommu_domain *domain, struct device *dev)
{
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
struct tegra_smmu_as *as = to_smmu_as(domain);
struct tegra_smmu *smmu = as->smmu;
unsigned int index;
if (!fwspec)
return;
for (index = 0; index < fwspec->num_ids; index++) {
tegra_smmu_disable(smmu, fwspec->ids[index], as->id);
tegra_smmu_as_unprepare(smmu, as);
}
}
static void tegra_smmu_set_pde(struct tegra_smmu_as *as, unsigned long iova,
u32 value)
{
unsigned int pd_index = iova_pd_index(iova);
struct tegra_smmu *smmu = as->smmu;
u32 *pd = page_address(as->pd);
unsigned long offset = pd_index * sizeof(*pd);
/* Set the page directory entry first */
pd[pd_index] = value;
/* The flush the page directory entry from caches */
dma_sync_single_range_for_device(smmu->dev, as->pd_dma, offset,
sizeof(*pd), DMA_TO_DEVICE);
/* And flush the iommu */
smmu_flush_ptc(smmu, as->pd_dma, offset);
smmu_flush_tlb_section(smmu, as->id, iova);
smmu_flush(smmu);
}
static u32 *tegra_smmu_pte_offset(struct page *pt_page, unsigned long iova)
{
u32 *pt = page_address(pt_page);
return pt + iova_pt_index(iova);
}
static u32 *tegra_smmu_pte_lookup(struct tegra_smmu_as *as, unsigned long iova,
dma_addr_t *dmap)
{
unsigned int pd_index = iova_pd_index(iova);
struct tegra_smmu *smmu = as->smmu;
struct page *pt_page;
u32 *pd;
pt_page = as->pts[pd_index];
if (!pt_page)
return NULL;
pd = page_address(as->pd);
*dmap = smmu_pde_to_dma(smmu, pd[pd_index]);
return tegra_smmu_pte_offset(pt_page, iova);
}
static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova,
dma_addr_t *dmap, struct page *page)
{
unsigned int pde = iova_pd_index(iova);
struct tegra_smmu *smmu = as->smmu;
if (!as->pts[pde]) {
dma_addr_t dma;
dma = dma_map_page(smmu->dev, page, 0, SMMU_SIZE_PT,
DMA_TO_DEVICE);
if (dma_mapping_error(smmu->dev, dma)) {
__free_page(page);
return NULL;
}
if (!smmu_dma_addr_valid(smmu, dma)) {
dma_unmap_page(smmu->dev, dma, SMMU_SIZE_PT,
DMA_TO_DEVICE);
__free_page(page);
return NULL;
}
as->pts[pde] = page;
tegra_smmu_set_pde(as, iova, SMMU_MK_PDE(dma, SMMU_PDE_ATTR |
SMMU_PDE_NEXT));
*dmap = dma;
} else {
u32 *pd = page_address(as->pd);
*dmap = smmu_pde_to_dma(smmu, pd[pde]);
}
return tegra_smmu_pte_offset(as->pts[pde], iova);
}
static void tegra_smmu_pte_get_use(struct tegra_smmu_as *as, unsigned long iova)
{
unsigned int pd_index = iova_pd_index(iova);
as->count[pd_index]++;
}
static void tegra_smmu_pte_put_use(struct tegra_smmu_as *as, unsigned long iova)
{
unsigned int pde = iova_pd_index(iova);
struct page *page = as->pts[pde];
/*
* When no entries in this page table are used anymore, return the
* memory page to the system.
*/
if (--as->count[pde] == 0) {
struct tegra_smmu *smmu = as->smmu;
u32 *pd = page_address(as->pd);
dma_addr_t pte_dma = smmu_pde_to_dma(smmu, pd[pde]);
tegra_smmu_set_pde(as, iova, 0);
dma_unmap_page(smmu->dev, pte_dma, SMMU_SIZE_PT, DMA_TO_DEVICE);
__free_page(page);
as->pts[pde] = NULL;
}
}
static void tegra_smmu_set_pte(struct tegra_smmu_as *as, unsigned long iova,
u32 *pte, dma_addr_t pte_dma, u32 val)
{
struct tegra_smmu *smmu = as->smmu;
unsigned long offset = SMMU_OFFSET_IN_PAGE(pte);
*pte = val;
dma_sync_single_range_for_device(smmu->dev, pte_dma, offset,
4, DMA_TO_DEVICE);
smmu_flush_ptc(smmu, pte_dma, offset);
smmu_flush_tlb_group(smmu, as->id, iova);
smmu_flush(smmu);
}
static struct page *as_get_pde_page(struct tegra_smmu_as *as,
unsigned long iova, gfp_t gfp,
unsigned long *flags)
{
unsigned int pde = iova_pd_index(iova);
struct page *page = as->pts[pde];
/* at first check whether allocation needs to be done at all */
if (page)
return page;
/*
* In order to prevent exhaustion of the atomic memory pool, we
* allocate page in a sleeping context if GFP flags permit. Hence
* spinlock needs to be unlocked and re-locked after allocation.
*/
if (!(gfp & __GFP_ATOMIC))
spin_unlock_irqrestore(&as->lock, *flags);
page = alloc_page(gfp | __GFP_DMA | __GFP_ZERO);
if (!(gfp & __GFP_ATOMIC))
spin_lock_irqsave(&as->lock, *flags);
/*
* In a case of blocking allocation, a concurrent mapping may win
* the PDE allocation. In this case the allocated page isn't needed
* if allocation succeeded and the allocation failure isn't fatal.
*/
if (as->pts[pde]) {
if (page)
__free_page(page);
page = as->pts[pde];
}
return page;
}
static int
__tegra_smmu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot, gfp_t gfp,
unsigned long *flags)
{
struct tegra_smmu_as *as = to_smmu_as(domain);
dma_addr_t pte_dma;
struct page *page;
u32 pte_attrs;
u32 *pte;
page = as_get_pde_page(as, iova, gfp, flags);
if (!page)
return -ENOMEM;
pte = as_get_pte(as, iova, &pte_dma, page);
if (!pte)
return -ENOMEM;
/* If we aren't overwriting a pre-existing entry, increment use */
if (*pte == 0)
tegra_smmu_pte_get_use(as, iova);
pte_attrs = SMMU_PTE_NONSECURE;
if (prot & IOMMU_READ)
pte_attrs |= SMMU_PTE_READABLE;
if (prot & IOMMU_WRITE)
pte_attrs |= SMMU_PTE_WRITABLE;
tegra_smmu_set_pte(as, iova, pte, pte_dma,
SMMU_PHYS_PFN(paddr) | pte_attrs);
return 0;
}
static size_t
__tegra_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
size_t size, struct iommu_iotlb_gather *gather)
{
struct tegra_smmu_as *as = to_smmu_as(domain);
dma_addr_t pte_dma;
u32 *pte;
pte = tegra_smmu_pte_lookup(as, iova, &pte_dma);
if (!pte || !*pte)
return 0;
tegra_smmu_set_pte(as, iova, pte, pte_dma, 0);
tegra_smmu_pte_put_use(as, iova);
return size;
}
static int tegra_smmu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
{
struct tegra_smmu_as *as = to_smmu_as(domain);
unsigned long flags;
int ret;
spin_lock_irqsave(&as->lock, flags);
ret = __tegra_smmu_map(domain, iova, paddr, size, prot, gfp, &flags);
spin_unlock_irqrestore(&as->lock, flags);
return ret;
}
static size_t tegra_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
size_t size, struct iommu_iotlb_gather *gather)
{
struct tegra_smmu_as *as = to_smmu_as(domain);
unsigned long flags;
spin_lock_irqsave(&as->lock, flags);
size = __tegra_smmu_unmap(domain, iova, size, gather);
spin_unlock_irqrestore(&as->lock, flags);
return size;
}
static phys_addr_t tegra_smmu_iova_to_phys(struct iommu_domain *domain,
dma_addr_t iova)
{
struct tegra_smmu_as *as = to_smmu_as(domain);
unsigned long pfn;
dma_addr_t pte_dma;
u32 *pte;
pte = tegra_smmu_pte_lookup(as, iova, &pte_dma);
if (!pte || !*pte)
return 0;
pfn = *pte & as->smmu->pfn_mask;
return SMMU_PFN_PHYS(pfn) + SMMU_OFFSET_IN_PAGE(iova);
}
static struct tegra_smmu *tegra_smmu_find(struct device_node *np)
{
struct platform_device *pdev;
struct tegra_mc *mc;
pdev = of_find_device_by_node(np);
if (!pdev)
return NULL;
mc = platform_get_drvdata(pdev);
if (!mc)
return NULL;
return mc->smmu;
}
static int tegra_smmu_configure(struct tegra_smmu *smmu, struct device *dev,
struct of_phandle_args *args)
{
const struct iommu_ops *ops = smmu->iommu.ops;
int err;
err = iommu_fwspec_init(dev, &dev->of_node->fwnode, ops);
if (err < 0) {
dev_err(dev, "failed to initialize fwspec: %d\n", err);
return err;
}
err = ops->of_xlate(dev, args);
if (err < 0) {
dev_err(dev, "failed to parse SW group ID: %d\n", err);
iommu_fwspec_free(dev);
return err;
}
return 0;
}
static struct iommu_device *tegra_smmu_probe_device(struct device *dev)
{
struct device_node *np = dev->of_node;
struct tegra_smmu *smmu = NULL;
struct of_phandle_args args;
unsigned int index = 0;
int err;
while (of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
&args) == 0) {
smmu = tegra_smmu_find(args.np);
if (smmu) {
err = tegra_smmu_configure(smmu, dev, &args);
of_node_put(args.np);
if (err < 0)
return ERR_PTR(err);
break;
}
of_node_put(args.np);
index++;
}
smmu = dev_iommu_priv_get(dev);
if (!smmu)
return ERR_PTR(-ENODEV);
return &smmu->iommu;
}
static void tegra_smmu_release_device(struct device *dev) {}
static const struct tegra_smmu_group_soc *
tegra_smmu_find_group(struct tegra_smmu *smmu, unsigned int swgroup)
{
unsigned int i, j;
for (i = 0; i < smmu->soc->num_groups; i++)
for (j = 0; j < smmu->soc->groups[i].num_swgroups; j++)
if (smmu->soc->groups[i].swgroups[j] == swgroup)
return &smmu->soc->groups[i];
return NULL;
}
static void tegra_smmu_group_release(void *iommu_data)
{
struct tegra_smmu_group *group = iommu_data;
struct tegra_smmu *smmu = group->smmu;
mutex_lock(&smmu->lock);
list_del(&group->list);
mutex_unlock(&smmu->lock);
}
static struct iommu_group *tegra_smmu_device_group(struct device *dev)
{
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
struct tegra_smmu *smmu = dev_iommu_priv_get(dev);
const struct tegra_smmu_group_soc *soc;
unsigned int swgroup = fwspec->ids[0];
struct tegra_smmu_group *group;
struct iommu_group *grp;
/* Find group_soc associating with swgroup */
soc = tegra_smmu_find_group(smmu, swgroup);
mutex_lock(&smmu->lock);
/* Find existing iommu_group associating with swgroup or group_soc */
list_for_each_entry(group, &smmu->groups, list)
if ((group->swgroup == swgroup) || (soc && group->soc == soc)) {
grp = iommu_group_ref_get(group->group);
mutex_unlock(&smmu->lock);
return grp;
}
group = devm_kzalloc(smmu->dev, sizeof(*group), GFP_KERNEL);
if (!group) {
mutex_unlock(&smmu->lock);
return NULL;
}
INIT_LIST_HEAD(&group->list);
group->swgroup = swgroup;
group->smmu = smmu;
group->soc = soc;
if (dev_is_pci(dev))
group->group = pci_device_group(dev);
else
group->group = generic_device_group(dev);
if (IS_ERR(group->group)) {
devm_kfree(smmu->dev, group);
mutex_unlock(&smmu->lock);
return NULL;
}
iommu_group_set_iommudata(group->group, group, tegra_smmu_group_release);
if (soc)
iommu_group_set_name(group->group, soc->name);
list_add_tail(&group->list, &smmu->groups);
mutex_unlock(&smmu->lock);
return group->group;
}
static int tegra_smmu_of_xlate(struct device *dev,
struct of_phandle_args *args)
{
struct platform_device *iommu_pdev = of_find_device_by_node(args->np);
struct tegra_mc *mc = platform_get_drvdata(iommu_pdev);
u32 id = args->args[0];
/*
* Note: we are here releasing the reference of &iommu_pdev->dev, which
* is mc->dev. Although some functions in tegra_smmu_ops may keep using
* its private data beyond this point, it's still safe to do so because
* the SMMU parent device is the same as the MC, so the reference count
* isn't strictly necessary.
*/
put_device(&iommu_pdev->dev);
dev_iommu_priv_set(dev, mc->smmu);
return iommu_fwspec_add_ids(dev, &id, 1);
}
static const struct iommu_ops tegra_smmu_ops = {
.capable = tegra_smmu_capable,
.domain_alloc = tegra_smmu_domain_alloc,
.domain_free = tegra_smmu_domain_free,
.attach_dev = tegra_smmu_attach_dev,
.detach_dev = tegra_smmu_detach_dev,
.probe_device = tegra_smmu_probe_device,
.release_device = tegra_smmu_release_device,
.device_group = tegra_smmu_device_group,
.map = tegra_smmu_map,
.unmap = tegra_smmu_unmap,
.iova_to_phys = tegra_smmu_iova_to_phys,
.of_xlate = tegra_smmu_of_xlate,
.pgsize_bitmap = SZ_4K,
};
static void tegra_smmu_ahb_enable(void)
{
static const struct of_device_id ahb_match[] = {
{ .compatible = "nvidia,tegra30-ahb", },
{ }
};
struct device_node *ahb;
ahb = of_find_matching_node(NULL, ahb_match);
if (ahb) {
tegra_ahb_enable_smmu(ahb);
of_node_put(ahb);
}
}
static int tegra_smmu_swgroups_show(struct seq_file *s, void *data)
{
struct tegra_smmu *smmu = s->private;
unsigned int i;
u32 value;
seq_printf(s, "swgroup enabled ASID\n");
seq_printf(s, "------------------------\n");
for (i = 0; i < smmu->soc->num_swgroups; i++) {
const struct tegra_smmu_swgroup *group = &smmu->soc->swgroups[i];
const char *status;
unsigned int asid;
value = smmu_readl(smmu, group->reg);
if (value & SMMU_ASID_ENABLE)
status = "yes";
else
status = "no";
asid = value & SMMU_ASID_MASK;
seq_printf(s, "%-9s %-7s %#04x\n", group->name, status,
asid);
}
return 0;
}
DEFINE_SHOW_ATTRIBUTE(tegra_smmu_swgroups);
static int tegra_smmu_clients_show(struct seq_file *s, void *data)
{
struct tegra_smmu *smmu = s->private;
unsigned int i;
u32 value;
seq_printf(s, "client enabled\n");
seq_printf(s, "--------------------\n");
for (i = 0; i < smmu->soc->num_clients; i++) {
const struct tegra_mc_client *client = &smmu->soc->clients[i];
const char *status;
value = smmu_readl(smmu, client->smmu.reg);
if (value & BIT(client->smmu.bit))
status = "yes";
else
status = "no";
seq_printf(s, "%-12s %s\n", client->name, status);
}
return 0;
}
DEFINE_SHOW_ATTRIBUTE(tegra_smmu_clients);
static void tegra_smmu_debugfs_init(struct tegra_smmu *smmu)
{
smmu->debugfs = debugfs_create_dir("smmu", NULL);
if (!smmu->debugfs)
return;
debugfs_create_file("swgroups", S_IRUGO, smmu->debugfs, smmu,
&tegra_smmu_swgroups_fops);
debugfs_create_file("clients", S_IRUGO, smmu->debugfs, smmu,
&tegra_smmu_clients_fops);
}
static void tegra_smmu_debugfs_exit(struct tegra_smmu *smmu)
{
debugfs_remove_recursive(smmu->debugfs);
}
struct tegra_smmu *tegra_smmu_probe(struct device *dev,
const struct tegra_smmu_soc *soc,
struct tegra_mc *mc)
{
struct tegra_smmu *smmu;
size_t size;
u32 value;
int err;
smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
if (!smmu)
return ERR_PTR(-ENOMEM);
/*
* This is a bit of a hack. Ideally we'd want to simply return this
* value. However the IOMMU registration process will attempt to add
* all devices to the IOMMU when bus_set_iommu() is called. In order
* not to rely on global variables to track the IOMMU instance, we
* set it here so that it can be looked up from the .probe_device()
* callback via the IOMMU device's .drvdata field.
*/
mc->smmu = smmu;
size = BITS_TO_LONGS(soc->num_asids) * sizeof(long);
smmu->asids = devm_kzalloc(dev, size, GFP_KERNEL);
if (!smmu->asids)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&smmu->groups);
mutex_init(&smmu->lock);
smmu->regs = mc->regs;
smmu->soc = soc;
smmu->dev = dev;
smmu->mc = mc;
smmu->pfn_mask =
BIT_MASK(mc->soc->num_address_bits - SMMU_PTE_SHIFT) - 1;
dev_dbg(dev, "address bits: %u, PFN mask: %#lx\n",
mc->soc->num_address_bits, smmu->pfn_mask);
smmu->tlb_mask = (1 << fls(smmu->soc->num_tlb_lines)) - 1;
dev_dbg(dev, "TLB lines: %u, mask: %#lx\n", smmu->soc->num_tlb_lines,
smmu->tlb_mask);
value = SMMU_PTC_CONFIG_ENABLE | SMMU_PTC_CONFIG_INDEX_MAP(0x3f);
if (soc->supports_request_limit)
value |= SMMU_PTC_CONFIG_REQ_LIMIT(8);
smmu_writel(smmu, value, SMMU_PTC_CONFIG);
value = SMMU_TLB_CONFIG_HIT_UNDER_MISS |
SMMU_TLB_CONFIG_ACTIVE_LINES(smmu);
if (soc->supports_round_robin_arbitration)
value |= SMMU_TLB_CONFIG_ROUND_ROBIN_ARBITRATION;
smmu_writel(smmu, value, SMMU_TLB_CONFIG);
smmu_flush_ptc_all(smmu);
smmu_flush_tlb(smmu);
smmu_writel(smmu, SMMU_CONFIG_ENABLE, SMMU_CONFIG);
smmu_flush(smmu);
tegra_smmu_ahb_enable();
err = iommu_device_sysfs_add(&smmu->iommu, dev, NULL, dev_name(dev));
if (err)
return ERR_PTR(err);
iommu_device_set_ops(&smmu->iommu, &tegra_smmu_ops);
iommu_device_set_fwnode(&smmu->iommu, dev->fwnode);
err = iommu_device_register(&smmu->iommu);
if (err)
goto remove_sysfs;
err = bus_set_iommu(&platform_bus_type, &tegra_smmu_ops);
if (err < 0)
goto unregister;
#ifdef CONFIG_PCI
err = bus_set_iommu(&pci_bus_type, &tegra_smmu_ops);
if (err < 0)
goto unset_platform_bus;
#endif
if (IS_ENABLED(CONFIG_DEBUG_FS))
tegra_smmu_debugfs_init(smmu);
return smmu;
unset_platform_bus: __maybe_unused;
bus_set_iommu(&platform_bus_type, NULL);
unregister:
iommu_device_unregister(&smmu->iommu);
remove_sysfs:
iommu_device_sysfs_remove(&smmu->iommu);
return ERR_PTR(err);
}
void tegra_smmu_remove(struct tegra_smmu *smmu)
{
iommu_device_unregister(&smmu->iommu);
iommu_device_sysfs_remove(&smmu->iommu);
if (IS_ENABLED(CONFIG_DEBUG_FS))
tegra_smmu_debugfs_exit(smmu);
}