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dma-pool: fix coherent pool allocations for IOMMU mappings
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[ Upstream commit 9420139 ]

When allocating coherent pool memory for an IOMMU mapping we don't care
about the DMA mask.  Move the guess for the initial GFP mask into the
dma_direct_alloc_pages and pass dma_coherent_ok as a function pointer
argument so that it doesn't get applied to the IOMMU case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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@gregkh
Christoph Hellwig authored and gregkh committed Sep 3, 2020
1 parent b960e50 commit 47184b9
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Showing 5 changed files with 62 additions and 77 deletions.
4 changes: 2 additions & 2 deletions drivers/iommu/dma-iommu.c
View file
Expand Up @@ -1035,8 +1035,8 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,

if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
!gfpflags_allow_blocking(gfp) && !coherent)
cpu_addr = dma_alloc_from_pool(dev, PAGE_ALIGN(size), &page,
gfp);
page = dma_alloc_from_pool(dev, PAGE_ALIGN(size), &cpu_addr,
gfp, NULL);
else
cpu_addr = iommu_dma_alloc_pages(dev, size, &page, gfp, attrs);
if (!cpu_addr)
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3 changes: 0 additions & 3 deletions include/linux/dma-direct.h
View file
Expand Up @@ -67,9 +67,6 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size,
}

u64 dma_direct_get_required_mask(struct device *dev);
gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
u64 *phys_mask);
bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size);
void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
gfp_t gfp, unsigned long attrs);
void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
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5 changes: 3 additions & 2 deletions include/linux/dma-mapping.h
View file
Expand Up @@ -715,8 +715,9 @@ void *dma_common_pages_remap(struct page **pages, size_t size,
pgprot_t prot, const void *caller);
void dma_common_free_remap(void *cpu_addr, size_t size);

void *dma_alloc_from_pool(struct device *dev, size_t size,
struct page **ret_page, gfp_t flags);
struct page *dma_alloc_from_pool(struct device *dev, size_t size,
void **cpu_addr, gfp_t flags,
bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t));
bool dma_free_from_pool(struct device *dev, void *start, size_t size);

int
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13 changes: 9 additions & 4 deletions kernel/dma/direct.c
View file
Expand Up @@ -45,7 +45,7 @@ u64 dma_direct_get_required_mask(struct device *dev)
return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;
}

gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
u64 *phys_limit)
{
u64 dma_limit = min_not_zero(dma_mask, dev->bus_dma_limit);
Expand All @@ -70,7 +70,7 @@ gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
return 0;
}

bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
{
return phys_to_dma_direct(dev, phys) + size - 1 <=
min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);
Expand Down Expand Up @@ -163,8 +163,13 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size,
size = PAGE_ALIGN(size);

if (dma_should_alloc_from_pool(dev, gfp, attrs)) {
ret = dma_alloc_from_pool(dev, size, &page, gfp);
if (!ret)
u64 phys_mask;

gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
&phys_mask);
page = dma_alloc_from_pool(dev, size, &ret, gfp,
dma_coherent_ok);
if (!page)
return NULL;
goto done;
}
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114 changes: 48 additions & 66 deletions kernel/dma/pool.c
View file
Expand Up @@ -196,93 +196,75 @@ static int __init dma_atomic_pool_init(void)
}
postcore_initcall(dma_atomic_pool_init);

static inline struct gen_pool *dma_guess_pool_from_device(struct device *dev)
static inline struct gen_pool *dma_guess_pool(struct gen_pool *prev, gfp_t gfp)
{
u64 phys_mask;
gfp_t gfp;

gfp = dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
&phys_mask);
if (IS_ENABLED(CONFIG_ZONE_DMA) && gfp == GFP_DMA)
if (prev == NULL) {
if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
return atomic_pool_dma32;
if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
return atomic_pool_dma;
return atomic_pool_kernel;
}
if (prev == atomic_pool_kernel)
return atomic_pool_dma32 ? atomic_pool_dma32 : atomic_pool_dma;
if (prev == atomic_pool_dma32)
return atomic_pool_dma;
if (IS_ENABLED(CONFIG_ZONE_DMA32) && gfp == GFP_DMA32)
return atomic_pool_dma32;
return atomic_pool_kernel;
return NULL;
}

static inline struct gen_pool *dma_get_safer_pool(struct gen_pool *bad_pool)
static struct page *__dma_alloc_from_pool(struct device *dev, size_t size,
struct gen_pool *pool, void **cpu_addr,
bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
{
if (bad_pool == atomic_pool_kernel)
return atomic_pool_dma32 ? : atomic_pool_dma;
unsigned long addr;
phys_addr_t phys;

if (bad_pool == atomic_pool_dma32)
return atomic_pool_dma;
addr = gen_pool_alloc(pool, size);
if (!addr)
return NULL;

return NULL;
}
phys = gen_pool_virt_to_phys(pool, addr);
if (phys_addr_ok && !phys_addr_ok(dev, phys, size)) {
gen_pool_free(pool, addr, size);
return NULL;
}

static inline struct gen_pool *dma_guess_pool(struct device *dev,
struct gen_pool *bad_pool)
{
if (bad_pool)
return dma_get_safer_pool(bad_pool);
if (gen_pool_avail(pool) < atomic_pool_size)
schedule_work(&atomic_pool_work);

return dma_guess_pool_from_device(dev);
*cpu_addr = (void *)addr;
memset(*cpu_addr, 0, size);
return pfn_to_page(__phys_to_pfn(phys));
}

void *dma_alloc_from_pool(struct device *dev, size_t size,
struct page **ret_page, gfp_t flags)
struct page *dma_alloc_from_pool(struct device *dev, size_t size,
void **cpu_addr, gfp_t gfp,
bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
{
struct gen_pool *pool = NULL;
unsigned long val = 0;
void *ptr = NULL;
phys_addr_t phys;

while (1) {
pool = dma_guess_pool(dev, pool);
if (!pool) {
WARN(1, "Failed to get suitable pool for %s\n",
dev_name(dev));
break;
}

val = gen_pool_alloc(pool, size);
if (!val)
continue;

phys = gen_pool_virt_to_phys(pool, val);
if (dma_coherent_ok(dev, phys, size))
break;

gen_pool_free(pool, val, size);
val = 0;
}


if (val) {
*ret_page = pfn_to_page(__phys_to_pfn(phys));
ptr = (void *)val;
memset(ptr, 0, size);
struct page *page;

if (gen_pool_avail(pool) < atomic_pool_size)
schedule_work(&atomic_pool_work);
while ((pool = dma_guess_pool(pool, gfp))) {
page = __dma_alloc_from_pool(dev, size, pool, cpu_addr,
phys_addr_ok);
if (page)
return page;
}

return ptr;
WARN(1, "Failed to get suitable pool for %s\n", dev_name(dev));
return NULL;
}

bool dma_free_from_pool(struct device *dev, void *start, size_t size)
{
struct gen_pool *pool = NULL;

while (1) {
pool = dma_guess_pool(dev, pool);
if (!pool)
return false;

if (gen_pool_has_addr(pool, (unsigned long)start, size)) {
gen_pool_free(pool, (unsigned long)start, size);
return true;
}
while ((pool = dma_guess_pool(pool, 0))) {
if (!gen_pool_has_addr(pool, (unsigned long)start, size))
continue;
gen_pool_free(pool, (unsigned long)start, size);
return true;
}

return false;
}

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