Teach the atomic DMA pool code to distinguish between encrypted and
decrypted pools, and make pool allocation select the matching pool based
on DMA attributes.
Introduce a dma_gen_pool wrapper that records whether a pool is
decrypted, initialize that state when the atomic pools are created, and
use it when expanding and resizing the pools. Update dma_alloc_from_pool()
to take attrs and skip pools whose encrypted/decrypted state does not
match DMA_ATTR_CC_SHARED. Update dma_free_from_pool() accordingly.
Also pass DMA_ATTR_CC_SHARED from the swiotlb atomic allocation path
so decrypted swiotlb allocations are taken from the correct atomic pool.
Signed-off-by: Aneesh Kumar K.V (Arm) <[email protected]>
---
drivers/iommu/dma-iommu.c | 2 +-
include/linux/dma-map-ops.h | 2 +-
kernel/dma/direct.c | 11 ++-
kernel/dma/pool.c | 163 +++++++++++++++++++++++-------------
kernel/dma/swiotlb.c | 7 +-
5 files changed, 122 insertions(+), 63 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 54d96e847f16..c2595bee3d41 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1673,7 +1673,7 @@ void *iommu_dma_alloc(struct device *dev, size_t size,
dma_addr_t *handle,
if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
!gfpflags_allow_blocking(gfp) && !coherent)
page = dma_alloc_from_pool(dev, PAGE_ALIGN(size), &cpu_addr,
- gfp, NULL);
+ gfp, attrs, NULL);
else
cpu_addr = iommu_dma_alloc_pages(dev, size, &page, gfp, attrs);
if (!cpu_addr)
diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h
index 6a1832a73cad..696b2c3a2305 100644
--- a/include/linux/dma-map-ops.h
+++ b/include/linux/dma-map-ops.h
@@ -212,7 +212,7 @@ void *dma_common_pages_remap(struct page **pages, size_t
size, pgprot_t prot,
void dma_common_free_remap(void *cpu_addr, size_t size);
struct page *dma_alloc_from_pool(struct device *dev, size_t size,
- void **cpu_addr, gfp_t flags,
+ void **cpu_addr, gfp_t flags, unsigned long attrs,
bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t));
bool dma_free_from_pool(struct device *dev, void *start, size_t size);
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 0c2e1f8436ce..dc2907439b3d 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -162,7 +162,7 @@ static bool dma_direct_use_pool(struct device *dev, gfp_t
gfp)
}
static void *dma_direct_alloc_from_pool(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t gfp)
+ dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
struct page *page;
u64 phys_limit;
@@ -172,7 +172,8 @@ static void *dma_direct_alloc_from_pool(struct device *dev,
size_t size,
return NULL;
gfp |= dma_direct_optimal_gfp_mask(dev, &phys_limit);
- page = dma_alloc_from_pool(dev, size, &ret, gfp, dma_coherent_ok);
+ page = dma_alloc_from_pool(dev, size, &ret, gfp, attrs,
+ dma_coherent_ok);
if (!page)
return NULL;
*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
@@ -261,7 +262,8 @@ void *dma_direct_alloc(struct device *dev, size_t size,
*/
if ((remap || (attrs & DMA_ATTR_CC_SHARED)) &&
dma_direct_use_pool(dev, gfp))
- return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
+ return dma_direct_alloc_from_pool(dev, size, dma_handle,
+ gfp, attrs);
if (is_swiotlb_for_alloc(dev)) {
page = dma_direct_alloc_swiotlb(dev, size);
@@ -397,7 +399,8 @@ struct page *dma_direct_alloc_pages(struct device *dev,
size_t size,
attrs |= DMA_ATTR_CC_SHARED;
if ((attrs & DMA_ATTR_CC_SHARED) && dma_direct_use_pool(dev, gfp))
- return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
+ return dma_direct_alloc_from_pool(dev, size, dma_handle,
+ gfp, attrs);
if (is_swiotlb_for_alloc(dev)) {
page = dma_direct_alloc_swiotlb(dev, size);
diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
index 2b2fbb709242..75f0eba48a23 100644
--- a/kernel/dma/pool.c
+++ b/kernel/dma/pool.c
@@ -12,12 +12,18 @@
#include <linux/set_memory.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
+#include <linux/cc_platform.h>
-static struct gen_pool *atomic_pool_dma __ro_after_init;
+struct dma_gen_pool {
+ bool unencrypted;
+ struct gen_pool *pool;
+};
+
+static struct dma_gen_pool atomic_pool_dma __ro_after_init;
static unsigned long pool_size_dma;
-static struct gen_pool *atomic_pool_dma32 __ro_after_init;
+static struct dma_gen_pool atomic_pool_dma32 __ro_after_init;
static unsigned long pool_size_dma32;
-static struct gen_pool *atomic_pool_kernel __ro_after_init;
+static struct dma_gen_pool atomic_pool_kernel __ro_after_init;
static unsigned long pool_size_kernel;
/* Size can be defined by the coherent_pool command line */
@@ -76,7 +82,7 @@ static bool cma_in_zone(gfp_t gfp)
return true;
}
-static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
+static int atomic_pool_expand(struct dma_gen_pool *dma_pool, size_t pool_size,
gfp_t gfp)
{
unsigned int order;
@@ -113,12 +119,15 @@ static int atomic_pool_expand(struct gen_pool *pool,
size_t pool_size,
* Memory in the atomic DMA pools must be unencrypted, the pools do not
* shrink so no re-encryption occurs in dma_direct_free().
*/
- ret = set_memory_decrypted((unsigned long)page_to_virt(page),
+ if (dma_pool->unencrypted) {
+ ret = set_memory_decrypted((unsigned long)page_to_virt(page),
1 << order);
- if (ret)
- goto remove_mapping;
- ret = gen_pool_add_virt(pool, (unsigned long)addr, page_to_phys(page),
- pool_size, NUMA_NO_NODE);
+ if (ret)
+ goto remove_mapping;
+ }
+
+ ret = gen_pool_add_virt(dma_pool->pool, (unsigned long)addr,
+ page_to_phys(page), pool_size, NUMA_NO_NODE);
if (ret)
goto encrypt_mapping;
@@ -126,11 +135,15 @@ static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
return 0;
encrypt_mapping:
- ret = set_memory_encrypted((unsigned long)page_to_virt(page),
- 1 << order);
- if (WARN_ON_ONCE(ret)) {
- /* Decrypt succeeded but encrypt failed, purposely leak */
- goto out;
+ if (dma_pool->unencrypted) {
+ int rc;
+
+ rc = set_memory_encrypted((unsigned long)page_to_virt(page),
+ 1 << order);
+ if (WARN_ON_ONCE(rc)) {
+ /* Decrypt succeeded but encrypt failed, purposely leak
*/
+ goto out;
+ }
}
remove_mapping:
#ifdef CONFIG_DMA_DIRECT_REMAP
@@ -142,46 +155,52 @@ static int atomic_pool_expand(struct gen_pool *pool,
size_t pool_size,
return ret;
}
-static void atomic_pool_resize(struct gen_pool *pool, gfp_t gfp)
+static void atomic_pool_resize(struct dma_gen_pool *dma_pool, gfp_t gfp)
{
- if (pool && gen_pool_avail(pool) < atomic_pool_size)
- atomic_pool_expand(pool, gen_pool_size(pool), gfp);
+ if (dma_pool->pool && gen_pool_avail(dma_pool->pool) < atomic_pool_size)
+ atomic_pool_expand(dma_pool, gen_pool_size(dma_pool->pool),
gfp);
}
static void atomic_pool_work_fn(struct work_struct *work)
{
if (IS_ENABLED(CONFIG_ZONE_DMA))
- atomic_pool_resize(atomic_pool_dma,
+ atomic_pool_resize(&atomic_pool_dma,
GFP_KERNEL | GFP_DMA);
if (IS_ENABLED(CONFIG_ZONE_DMA32))
- atomic_pool_resize(atomic_pool_dma32,
+ atomic_pool_resize(&atomic_pool_dma32,
GFP_KERNEL | GFP_DMA32);
- atomic_pool_resize(atomic_pool_kernel, GFP_KERNEL);
+ atomic_pool_resize(&atomic_pool_kernel, GFP_KERNEL);
}
-static __init struct gen_pool *__dma_atomic_pool_init(size_t pool_size,
- gfp_t gfp)
+static __init struct dma_gen_pool *__dma_atomic_pool_init(struct dma_gen_pool
*dma_pool,
+ size_t pool_size, gfp_t gfp)
{
- struct gen_pool *pool;
int ret;
- pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE);
- if (!pool)
+ dma_pool->pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE);
+ if (!dma_pool->pool)
return NULL;
- gen_pool_set_algo(pool, gen_pool_first_fit_order_align, NULL);
+ gen_pool_set_algo(dma_pool->pool, gen_pool_first_fit_order_align, NULL);
+
+ /* if platform is using memory encryption atomic pools are by default
decrypted. */
+ if (cc_platform_has(CC_ATTR_MEM_ENCRYPT))
+ dma_pool->unencrypted = true;
+ else
+ dma_pool->unencrypted = false;
- ret = atomic_pool_expand(pool, pool_size, gfp);
+ ret = atomic_pool_expand(dma_pool, pool_size, gfp);
if (ret) {
- gen_pool_destroy(pool);
+ gen_pool_destroy(dma_pool->pool);
+ dma_pool->pool = NULL;
pr_err("DMA: failed to allocate %zu KiB %pGg pool for atomic
allocation\n",
pool_size >> 10, &gfp);
return NULL;
}
pr_info("DMA: preallocated %zu KiB %pGg pool for atomic allocations\n",
- gen_pool_size(pool) >> 10, &gfp);
- return pool;
+ gen_pool_size(dma_pool->pool) >> 10, &gfp);
+ return dma_pool;
}
#ifdef CONFIG_ZONE_DMA32
@@ -207,21 +226,22 @@ static int __init dma_atomic_pool_init(void)
/* All memory might be in the DMA zone(s) to begin with */
if (has_managed_zone(ZONE_NORMAL)) {
- atomic_pool_kernel = __dma_atomic_pool_init(atomic_pool_size,
- GFP_KERNEL);
- if (!atomic_pool_kernel)
+ __dma_atomic_pool_init(&atomic_pool_kernel, atomic_pool_size,
GFP_KERNEL);
+ if (!atomic_pool_kernel.pool)
ret = -ENOMEM;
}
+
if (has_managed_dma()) {
- atomic_pool_dma = __dma_atomic_pool_init(atomic_pool_size,
- GFP_KERNEL | GFP_DMA);
- if (!atomic_pool_dma)
+ __dma_atomic_pool_init(&atomic_pool_dma, atomic_pool_size,
+ GFP_KERNEL | GFP_DMA);
+ if (!atomic_pool_dma.pool)
ret = -ENOMEM;
}
+
if (has_managed_dma32) {
- atomic_pool_dma32 = __dma_atomic_pool_init(atomic_pool_size,
- GFP_KERNEL | GFP_DMA32);
- if (!atomic_pool_dma32)
+ __dma_atomic_pool_init(&atomic_pool_dma32, atomic_pool_size,
+ GFP_KERNEL | GFP_DMA32);
+ if (!atomic_pool_dma32.pool)
ret = -ENOMEM;
}
@@ -230,19 +250,44 @@ static int __init dma_atomic_pool_init(void)
}
postcore_initcall(dma_atomic_pool_init);
-static inline struct gen_pool *dma_guess_pool(struct gen_pool *prev, gfp_t gfp)
+static inline struct dma_gen_pool *__dma_guess_pool(struct dma_gen_pool *first,
+ struct dma_gen_pool *second, struct dma_gen_pool *third)
+{
+ if (first->pool)
+ return first;
+ if (second && second->pool)
+ return second;
+ if (third && third->pool)
+ return third;
+ return NULL;
+}
+
+static inline struct dma_gen_pool *dma_guess_pool(struct dma_gen_pool *prev,
+ gfp_t gfp)
{
- if (prev == NULL) {
+ if (!prev) {
if (gfp & GFP_DMA)
- return atomic_pool_dma ?: atomic_pool_dma32 ?:
atomic_pool_kernel;
+ return __dma_guess_pool(&atomic_pool_dma,
+ &atomic_pool_dma32,
+ &atomic_pool_kernel);
+
if (gfp & GFP_DMA32)
- return atomic_pool_dma32 ?: atomic_pool_dma ?:
atomic_pool_kernel;
- return atomic_pool_kernel ?: atomic_pool_dma32 ?:
atomic_pool_dma;
+ return __dma_guess_pool(&atomic_pool_dma32,
+ &atomic_pool_dma,
+ &atomic_pool_kernel);
+
+ return __dma_guess_pool(&atomic_pool_kernel,
+ &atomic_pool_dma32,
+ &atomic_pool_dma);
}
- 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 (prev == &atomic_pool_kernel)
+ return __dma_guess_pool(&atomic_pool_dma32,
+ &atomic_pool_dma, NULL);
+
+ if (prev == &atomic_pool_dma32)
+ return __dma_guess_pool(&atomic_pool_dma, NULL, NULL);
+
return NULL;
}
@@ -272,16 +317,20 @@ static struct page *__dma_alloc_from_pool(struct device *dev, size_t size,
}
struct page *dma_alloc_from_pool(struct device *dev, size_t size,
- void **cpu_addr, gfp_t gfp,
+ void **cpu_addr, gfp_t gfp, unsigned long attrs,
bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
{
- struct gen_pool *pool = NULL;
+ struct dma_gen_pool *dma_pool = NULL;
struct page *page;
bool pool_found = false;
- while ((pool = dma_guess_pool(pool, gfp))) {
+ while ((dma_pool = dma_guess_pool(dma_pool, gfp))) {
+
+ if (dma_pool->unencrypted != !!(attrs & DMA_ATTR_CC_SHARED))
+ continue;
+
pool_found = true;
- page = __dma_alloc_from_pool(dev, size, pool, cpu_addr,
+ page = __dma_alloc_from_pool(dev, size, dma_pool->pool,
cpu_addr,
phys_addr_ok);
if (page)
return page;
@@ -296,12 +345,14 @@ struct page *dma_alloc_from_pool(struct device *dev,
size_t size,
bool dma_free_from_pool(struct device *dev, void *start, size_t size)
{
- struct gen_pool *pool = NULL;
+ struct dma_gen_pool *dma_pool = NULL;
+
+ while ((dma_pool = dma_guess_pool(dma_pool, 0))) {
- while ((pool = dma_guess_pool(pool, 0))) {
- if (!gen_pool_has_addr(pool, (unsigned long)start, size))
+ if (!gen_pool_has_addr(dma_pool->pool, (unsigned long)start,
size))
