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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-06 11:43:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-06 11:43:23 -0700
commit1ee18de92927f37e6948d5a6fc73cbf89f806905 (patch)
tree2521e9884c1349187b9169a5ebf1eead6b6fd66d /kernel/dma
parente542e0dc3ee3eafc46dd8e3073388079d69cace0 (diff)
parent298f3db6ee690259927b105d5ad1079563361323 (diff)
Merge tag 'dma-mapping-5.8' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig: - enhance the dma pool to allow atomic allocation on x86 with AMD SEV (David Rientjes) - two small cleanups (Jason Yan and Peter Collingbourne) * tag 'dma-mapping-5.8' of git://git.infradead.org/users/hch/dma-mapping: dma-contiguous: fix comment for dma_release_from_contiguous dma-pool: scale the default DMA coherent pool size with memory capacity x86/mm: unencrypted non-blocking DMA allocations use coherent pools dma-pool: add pool sizes to debugfs dma-direct: atomic allocations must come from atomic coherent pools dma-pool: dynamically expanding atomic pools dma-pool: add additional coherent pools to map to gfp mask dma-remap: separate DMA atomic pools from direct remap code dma-debug: make __dma_entry_alloc_check_leak() static
Diffstat (limited to 'kernel/dma')
-rw-r--r--kernel/dma/Kconfig6
-rw-r--r--kernel/dma/Makefile1
-rw-r--r--kernel/dma/contiguous.c4
-rw-r--r--kernel/dma/debug.c2
-rw-r--r--kernel/dma/direct.c56
-rw-r--r--kernel/dma/pool.c264
-rw-r--r--kernel/dma/remap.c121
7 files changed, 318 insertions, 136 deletions
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index 4c103a24e380..d006668c0027 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -79,10 +79,14 @@ config DMA_REMAP
select DMA_NONCOHERENT_MMAP
bool
-config DMA_DIRECT_REMAP
+config DMA_COHERENT_POOL
bool
select DMA_REMAP
+config DMA_DIRECT_REMAP
+ bool
+ select DMA_COHERENT_POOL
+
config DMA_CMA
bool "DMA Contiguous Memory Allocator"
depends on HAVE_DMA_CONTIGUOUS && CMA
diff --git a/kernel/dma/Makefile b/kernel/dma/Makefile
index d237cf3dc181..370f63344e9c 100644
--- a/kernel/dma/Makefile
+++ b/kernel/dma/Makefile
@@ -6,4 +6,5 @@ obj-$(CONFIG_DMA_DECLARE_COHERENT) += coherent.o
obj-$(CONFIG_DMA_VIRT_OPS) += virt.o
obj-$(CONFIG_DMA_API_DEBUG) += debug.o
obj-$(CONFIG_SWIOTLB) += swiotlb.o
+obj-$(CONFIG_DMA_COHERENT_POOL) += pool.o
obj-$(CONFIG_DMA_REMAP) += remap.o
diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index 8bc6f2d670f9..15bc5026c485 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -222,8 +222,8 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
* @gfp: Allocation flags.
*
* This function allocates contiguous memory buffer for specified device. It
- * first tries to use device specific contiguous memory area if available or
- * the default global one, then tries a fallback allocation of normal pages.
+ * tries to use device specific contiguous memory area if available, or the
+ * default global one.
*
* Note that it byapss one-page size of allocations from the global area as
* the addresses within one page are always contiguous, so there is no need
diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index 9e1777c81f55..36c962a86bf2 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -656,7 +656,7 @@ static struct dma_debug_entry *__dma_entry_alloc(void)
return entry;
}
-void __dma_entry_alloc_check_leak(void)
+static void __dma_entry_alloc_check_leak(void)
{
u32 tmp = nr_total_entries % nr_prealloc_entries;
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 8f4bbdaf965e..0a4881e59aa7 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -45,8 +45,8 @@ u64 dma_direct_get_required_mask(struct device *dev)
return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;
}
-static gfp_t __dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
- u64 *phys_limit)
+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);
@@ -76,6 +76,39 @@ static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);
}
+/*
+ * Decrypting memory is allowed to block, so if this device requires
+ * unencrypted memory it must come from atomic pools.
+ */
+static inline bool dma_should_alloc_from_pool(struct device *dev, gfp_t gfp,
+ unsigned long attrs)
+{
+ if (!IS_ENABLED(CONFIG_DMA_COHERENT_POOL))
+ return false;
+ if (gfpflags_allow_blocking(gfp))
+ return false;
+ if (force_dma_unencrypted(dev))
+ return true;
+ if (!IS_ENABLED(CONFIG_DMA_DIRECT_REMAP))
+ return false;
+ if (dma_alloc_need_uncached(dev, attrs))
+ return true;
+ return false;
+}
+
+static inline bool dma_should_free_from_pool(struct device *dev,
+ unsigned long attrs)
+{
+ if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL))
+ return true;
+ if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&
+ !force_dma_unencrypted(dev))
+ return false;
+ if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP))
+ return true;
+ return false;
+}
+
struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
gfp_t gfp, unsigned long attrs)
{
@@ -89,8 +122,8 @@ struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
/* we always manually zero the memory once we are done: */
gfp &= ~__GFP_ZERO;
- gfp |= __dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
- &phys_limit);
+ gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
+ &phys_limit);
page = dma_alloc_contiguous(dev, alloc_size, gfp);
if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
dma_free_contiguous(dev, page, alloc_size);
@@ -125,10 +158,8 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size,
struct page *page;
void *ret;
- if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
- dma_alloc_need_uncached(dev, attrs) &&
- !gfpflags_allow_blocking(gfp)) {
- ret = dma_alloc_from_pool(PAGE_ALIGN(size), &page, gfp);
+ if (dma_should_alloc_from_pool(dev, gfp, attrs)) {
+ ret = dma_alloc_from_pool(dev, PAGE_ALIGN(size), &page, gfp);
if (!ret)
return NULL;
goto done;
@@ -204,6 +235,11 @@ void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr,
{
unsigned int page_order = get_order(size);
+ /* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */
+ if (dma_should_free_from_pool(dev, attrs) &&
+ dma_free_from_pool(dev, cpu_addr, PAGE_ALIGN(size)))
+ return;
+
if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&
!force_dma_unencrypted(dev)) {
/* cpu_addr is a struct page cookie, not a kernel address */
@@ -211,10 +247,6 @@ void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr,
return;
}
- if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
- dma_free_from_pool(cpu_addr, PAGE_ALIGN(size)))
- return;
-
if (force_dma_unencrypted(dev))
set_memory_encrypted((unsigned long)cpu_addr, 1 << page_order);
diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
new file mode 100644
index 000000000000..35bb51c31fff
--- /dev/null
+++ b/kernel/dma/pool.c
@@ -0,0 +1,264 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ * Copyright (C) 2020 Google LLC
+ */
+#include <linux/debugfs.h>
+#include <linux/dma-direct.h>
+#include <linux/dma-noncoherent.h>
+#include <linux/dma-contiguous.h>
+#include <linux/init.h>
+#include <linux/genalloc.h>
+#include <linux/set_memory.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+static struct 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 unsigned long pool_size_dma32;
+static struct gen_pool *atomic_pool_kernel __ro_after_init;
+static unsigned long pool_size_kernel;
+
+/* Size can be defined by the coherent_pool command line */
+static size_t atomic_pool_size;
+
+/* Dynamic background expansion when the atomic pool is near capacity */
+static struct work_struct atomic_pool_work;
+
+static int __init early_coherent_pool(char *p)
+{
+ atomic_pool_size = memparse(p, &p);
+ return 0;
+}
+early_param("coherent_pool", early_coherent_pool);
+
+static void __init dma_atomic_pool_debugfs_init(void)
+{
+ struct dentry *root;
+
+ root = debugfs_create_dir("dma_pools", NULL);
+ if (IS_ERR_OR_NULL(root))
+ return;
+
+ debugfs_create_ulong("pool_size_dma", 0400, root, &pool_size_dma);
+ debugfs_create_ulong("pool_size_dma32", 0400, root, &pool_size_dma32);
+ debugfs_create_ulong("pool_size_kernel", 0400, root, &pool_size_kernel);
+}
+
+static void dma_atomic_pool_size_add(gfp_t gfp, size_t size)
+{
+ if (gfp & __GFP_DMA)
+ pool_size_dma += size;
+ else if (gfp & __GFP_DMA32)
+ pool_size_dma32 += size;
+ else
+ pool_size_kernel += size;
+}
+
+static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
+ gfp_t gfp)
+{
+ unsigned int order;
+ struct page *page;
+ void *addr;
+ int ret = -ENOMEM;
+
+ /* Cannot allocate larger than MAX_ORDER-1 */
+ order = min(get_order(pool_size), MAX_ORDER-1);
+
+ do {
+ pool_size = 1 << (PAGE_SHIFT + order);
+
+ if (dev_get_cma_area(NULL))
+ page = dma_alloc_from_contiguous(NULL, 1 << order,
+ order, false);
+ else
+ page = alloc_pages(gfp, order);
+ } while (!page && order-- > 0);
+ if (!page)
+ goto out;
+
+ arch_dma_prep_coherent(page, pool_size);
+
+#ifdef CONFIG_DMA_DIRECT_REMAP
+ addr = dma_common_contiguous_remap(page, pool_size,
+ pgprot_dmacoherent(PAGE_KERNEL),
+ __builtin_return_address(0));
+ if (!addr)
+ goto free_page;
+#else
+ addr = page_to_virt(page);
+#endif
+ /*
+ * Memory in the atomic DMA pools must be unencrypted, the pools do not
+ * shrink so no re-encryption occurs in dma_direct_free_pages().
+ */
+ 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 encrypt_mapping;
+
+ dma_atomic_pool_size_add(gfp, 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;
+ }
+remove_mapping:
+#ifdef CONFIG_DMA_DIRECT_REMAP
+ dma_common_free_remap(addr, pool_size);
+#endif
+free_page: __maybe_unused
+ if (!dma_release_from_contiguous(NULL, page, 1 << order))
+ __free_pages(page, order);
+out:
+ return ret;
+}
+
+static void atomic_pool_resize(struct gen_pool *pool, gfp_t gfp)
+{
+ if (pool && gen_pool_avail(pool) < atomic_pool_size)
+ atomic_pool_expand(pool, gen_pool_size(pool), gfp);
+}
+
+static void atomic_pool_work_fn(struct work_struct *work)
+{
+ if (IS_ENABLED(CONFIG_ZONE_DMA))
+ atomic_pool_resize(atomic_pool_dma,
+ GFP_KERNEL | GFP_DMA);
+ if (IS_ENABLED(CONFIG_ZONE_DMA32))
+ atomic_pool_resize(atomic_pool_dma32,
+ GFP_KERNEL | GFP_DMA32);
+ atomic_pool_resize(atomic_pool_kernel, GFP_KERNEL);
+}
+
+static __init struct gen_pool *__dma_atomic_pool_init(size_t pool_size,
+ gfp_t gfp)
+{
+ struct gen_pool *pool;
+ int ret;
+
+ pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE);
+ if (!pool)
+ return NULL;
+
+ gen_pool_set_algo(pool, gen_pool_first_fit_order_align, NULL);
+
+ ret = atomic_pool_expand(pool, pool_size, gfp);
+ if (ret) {
+ gen_pool_destroy(pool);
+ 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;
+}
+
+static int __init dma_atomic_pool_init(void)
+{
+ int ret = 0;
+
+ /*
+ * If coherent_pool was not used on the command line, default the pool
+ * sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER-1.
+ */
+ if (!atomic_pool_size) {
+ atomic_pool_size = max(totalram_pages() >> PAGE_SHIFT, 1UL) *
+ SZ_128K;
+ atomic_pool_size = min_t(size_t, atomic_pool_size,
+ 1 << (PAGE_SHIFT + MAX_ORDER-1));
+ }
+ INIT_WORK(&atomic_pool_work, atomic_pool_work_fn);
+
+ atomic_pool_kernel = __dma_atomic_pool_init(atomic_pool_size,
+ GFP_KERNEL);
+ if (!atomic_pool_kernel)
+ ret = -ENOMEM;
+ if (IS_ENABLED(CONFIG_ZONE_DMA)) {
+ atomic_pool_dma = __dma_atomic_pool_init(atomic_pool_size,
+ GFP_KERNEL | GFP_DMA);
+ if (!atomic_pool_dma)
+ ret = -ENOMEM;
+ }
+ if (IS_ENABLED(CONFIG_ZONE_DMA32)) {
+ atomic_pool_dma32 = __dma_atomic_pool_init(atomic_pool_size,
+ GFP_KERNEL | GFP_DMA32);
+ if (!atomic_pool_dma32)
+ ret = -ENOMEM;
+ }
+
+ dma_atomic_pool_debugfs_init();
+ return ret;
+}
+postcore_initcall(dma_atomic_pool_init);
+
+static inline struct gen_pool *dev_to_pool(struct device *dev)
+{
+ 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)
+ return atomic_pool_dma;
+ if (IS_ENABLED(CONFIG_ZONE_DMA32) && gfp == GFP_DMA32)
+ return atomic_pool_dma32;
+ return atomic_pool_kernel;
+}
+
+static bool dma_in_atomic_pool(struct device *dev, void *start, size_t size)
+{
+ struct gen_pool *pool = dev_to_pool(dev);
+
+ if (unlikely(!pool))
+ return false;
+ return gen_pool_has_addr(pool, (unsigned long)start, size);
+}
+
+void *dma_alloc_from_pool(struct device *dev, size_t size,
+ struct page **ret_page, gfp_t flags)
+{
+ struct gen_pool *pool = dev_to_pool(dev);
+ unsigned long val;
+ void *ptr = NULL;
+
+ if (!pool) {
+ WARN(1, "%pGg atomic pool not initialised!\n", &flags);
+ return NULL;
+ }
+
+ val = gen_pool_alloc(pool, size);
+ if (val) {
+ phys_addr_t phys = gen_pool_virt_to_phys(pool, val);
+
+ *ret_page = pfn_to_page(__phys_to_pfn(phys));
+ ptr = (void *)val;
+ memset(ptr, 0, size);
+ }
+ if (gen_pool_avail(pool) < atomic_pool_size)
+ schedule_work(&atomic_pool_work);
+
+ return ptr;
+}
+
+bool dma_free_from_pool(struct device *dev, void *start, size_t size)
+{
+ struct gen_pool *pool = dev_to_pool(dev);
+
+ if (!dma_in_atomic_pool(dev, start, size))
+ return false;
+ gen_pool_free(pool, (unsigned long)start, size);
+ return true;
+}
diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
index 914ff5a58dd5..e739a6eea6e7 100644
--- a/kernel/dma/remap.c
+++ b/kernel/dma/remap.c
@@ -1,13 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Copyright (C) 2012 ARM Ltd.
* Copyright (c) 2014 The Linux Foundation
*/
-#include <linux/dma-direct.h>
-#include <linux/dma-noncoherent.h>
-#include <linux/dma-contiguous.h>
-#include <linux/init.h>
-#include <linux/genalloc.h>
+#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
@@ -73,117 +68,3 @@ void dma_common_free_remap(void *cpu_addr, size_t size)
unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size));
vunmap(cpu_addr);
}
-
-#ifdef CONFIG_DMA_DIRECT_REMAP
-static struct gen_pool *atomic_pool __ro_after_init;
-
-#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
-static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE;
-
-static int __init early_coherent_pool(char *p)
-{
- atomic_pool_size = memparse(p, &p);
- return 0;
-}
-early_param("coherent_pool", early_coherent_pool);
-
-static gfp_t dma_atomic_pool_gfp(void)
-{
- if (IS_ENABLED(CONFIG_ZONE_DMA))
- return GFP_DMA;
- if (IS_ENABLED(CONFIG_ZONE_DMA32))
- return GFP_DMA32;
- return GFP_KERNEL;
-}
-
-static int __init dma_atomic_pool_init(void)
-{
- unsigned int pool_size_order = get_order(atomic_pool_size);
- unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
- struct page *page;
- void *addr;
- int ret;
-
- if (dev_get_cma_area(NULL))
- page = dma_alloc_from_contiguous(NULL, nr_pages,
- pool_size_order, false);
- else
- page = alloc_pages(dma_atomic_pool_gfp(), pool_size_order);
- if (!page)
- goto out;
-
- arch_dma_prep_coherent(page, atomic_pool_size);
-
- atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
- if (!atomic_pool)
- goto free_page;
-
- addr = dma_common_contiguous_remap(page, atomic_pool_size,
- pgprot_dmacoherent(PAGE_KERNEL),
- __builtin_return_address(0));
- if (!addr)
- goto destroy_genpool;
-
- ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
- page_to_phys(page), atomic_pool_size, -1);
- if (ret)
- goto remove_mapping;
- gen_pool_set_algo(atomic_pool, gen_pool_first_fit_order_align, NULL);
-
- pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
- atomic_pool_size / 1024);
- return 0;
-
-remove_mapping:
- dma_common_free_remap(addr, atomic_pool_size);
-destroy_genpool:
- gen_pool_destroy(atomic_pool);
- atomic_pool = NULL;
-free_page:
- if (!dma_release_from_contiguous(NULL, page, nr_pages))
- __free_pages(page, pool_size_order);
-out:
- pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
- atomic_pool_size / 1024);
- return -ENOMEM;
-}
-postcore_initcall(dma_atomic_pool_init);
-
-bool dma_in_atomic_pool(void *start, size_t size)
-{
- if (unlikely(!atomic_pool))
- return false;
-
- return gen_pool_has_addr(atomic_pool, (unsigned long)start, size);
-}
-
-void *dma_alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)
-{
- unsigned long val;
- void *ptr = NULL;
-
- if (!atomic_pool) {
- WARN(1, "coherent pool not initialised!\n");
- return NULL;
- }
-
- val = gen_pool_alloc(atomic_pool, size);
- if (val) {
- phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
-
- *ret_page = pfn_to_page(__phys_to_pfn(phys));
- ptr = (void *)val;
- memset(ptr, 0, size);
- }
-
- return ptr;
-}
-
-bool dma_free_from_pool(void *start, size_t size)
-{
- if (!dma_in_atomic_pool(start, size))
- return false;
- gen_pool_free(atomic_pool, (unsigned long)start, size);
- return true;
-}
-#endif /* CONFIG_DMA_DIRECT_REMAP */