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authorLinus Torvalds <torvalds@linux-foundation.org>2019-09-19 13:27:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-19 13:27:23 -0700
commit671df189537883f36cf9c7d4f9495bfac0f86627 (patch)
tree22e5f598ed1f5d9b2218d85d4426140f804d61e6 /kernel/dma
parentc9fe5630dae1df2328d82042602e2c4d1add8d57 (diff)
parentc7d9eccb3c1e802c5cbb2a764eb0eb9807d9f12e (diff)
Merge tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig: - add dma-mapping and block layer helpers to take care of IOMMU merging for mmc plus subsequent fixups (Yoshihiro Shimoda) - rework handling of the pgprot bits for remapping (me) - take care of the dma direct infrastructure for swiotlb-xen (me) - improve the dma noncoherent remapping infrastructure (me) - better defaults for ->mmap, ->get_sgtable and ->get_required_mask (me) - cleanup mmaping of coherent DMA allocations (me) - various misc cleanups (Andy Shevchenko, me) * tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping: (41 commits) mmc: renesas_sdhi_internal_dmac: Add MMC_CAP2_MERGE_CAPABLE mmc: queue: Fix bigger segments usage arm64: use asm-generic/dma-mapping.h swiotlb-xen: merge xen_unmap_single into xen_swiotlb_unmap_page swiotlb-xen: simplify cache maintainance swiotlb-xen: use the same foreign page check everywhere swiotlb-xen: remove xen_swiotlb_dma_mmap and xen_swiotlb_dma_get_sgtable xen: remove the exports for xen_{create,destroy}_contiguous_region xen/arm: remove xen_dma_ops xen/arm: simplify dma_cache_maint xen/arm: use dev_is_dma_coherent xen/arm: consolidate page-coherent.h xen/arm: use dma-noncoherent.h calls for xen-swiotlb cache maintainance arm: remove wrappers for the generic dma remap helpers dma-mapping: introduce a dma_common_find_pages helper dma-mapping: always use VM_DMA_COHERENT for generic DMA remap vmalloc: lift the arm flag for coherent mappings to common code dma-mapping: provide a better default ->get_required_mask dma-mapping: remove the dma_declare_coherent_memory export remoteproc: don't allow modular build ...
Diffstat (limited to 'kernel/dma')
-rw-r--r--kernel/dma/Kconfig12
-rw-r--r--kernel/dma/coherent.c13
-rw-r--r--kernel/dma/mapping.c105
-rw-r--r--kernel/dma/remap.c51
4 files changed, 115 insertions, 66 deletions
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index 9decbba255fc..73c5c2b8e824 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -20,6 +20,15 @@ config ARCH_HAS_DMA_COHERENCE_H
config ARCH_HAS_DMA_SET_MASK
bool
+#
+# Select this option if the architecture needs special handling for
+# DMA_ATTR_WRITE_COMBINE. Normally the "uncached" mapping should be what
+# people thing of when saying write combine, so very few platforms should
+# need to enable this.
+#
+config ARCH_HAS_DMA_WRITE_COMBINE
+ bool
+
config DMA_DECLARE_COHERENT
bool
@@ -45,9 +54,6 @@ config ARCH_HAS_DMA_PREP_COHERENT
config ARCH_HAS_DMA_COHERENT_TO_PFN
bool
-config ARCH_HAS_DMA_MMAP_PGPROT
- bool
-
config ARCH_HAS_FORCE_DMA_UNENCRYPTED
bool
diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
index 29fd6590dc1e..545e3869b0e3 100644
--- a/kernel/dma/coherent.c
+++ b/kernel/dma/coherent.c
@@ -122,18 +122,6 @@ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
dma_release_coherent_memory(mem);
return ret;
}
-EXPORT_SYMBOL(dma_declare_coherent_memory);
-
-void dma_release_declared_memory(struct device *dev)
-{
- struct dma_coherent_mem *mem = dev->dma_mem;
-
- if (!mem)
- return;
- dma_release_coherent_memory(mem);
- dev->dma_mem = NULL;
-}
-EXPORT_SYMBOL(dma_release_declared_memory);
static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem,
ssize_t size, dma_addr_t *dma_handle)
@@ -288,7 +276,6 @@ int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma,
return __dma_mmap_from_coherent(mem, vma, vaddr, size, ret);
}
-EXPORT_SYMBOL(dma_mmap_from_dev_coherent);
int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr,
size_t size, int *ret)
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index b0038ca3aa92..64a3d294f4b4 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -136,17 +136,29 @@ int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
return ret;
}
+/*
+ * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems
+ * that the intention is to allow exporting memory allocated via the
+ * coherent DMA APIs through the dma_buf API, which only accepts a
+ * scattertable. This presents a couple of problems:
+ * 1. Not all memory allocated via the coherent DMA APIs is backed by
+ * a struct page
+ * 2. Passing coherent DMA memory into the streaming APIs is not allowed
+ * as we will try to flush the memory through a different alias to that
+ * actually being used (and the flushes are redundant.)
+ */
int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
- if (!dma_is_direct(ops) && ops->get_sgtable)
- return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size,
- attrs);
- return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr, size,
- attrs);
+ if (dma_is_direct(ops))
+ return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr,
+ size, attrs);
+ if (!ops->get_sgtable)
+ return -ENXIO;
+ return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size, attrs);
}
EXPORT_SYMBOL(dma_get_sgtable_attrs);
@@ -161,9 +173,11 @@ pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs)
(IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) &&
(attrs & DMA_ATTR_NON_CONSISTENT)))
return prot;
- if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_MMAP_PGPROT))
- return arch_dma_mmap_pgprot(dev, prot, attrs);
- return pgprot_noncached(prot);
+#ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE
+ if (attrs & DMA_ATTR_WRITE_COMBINE)
+ return pgprot_writecombine(prot);
+#endif
+ return pgprot_dmacoherent(prot);
}
#endif /* CONFIG_MMU */
@@ -174,7 +188,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
-#ifndef CONFIG_ARCH_NO_COHERENT_DMA_MMAP
+#ifdef CONFIG_MMU
unsigned long user_count = vma_pages(vma);
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long off = vma->vm_pgoff;
@@ -205,8 +219,29 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
user_count << PAGE_SHIFT, vma->vm_page_prot);
#else
return -ENXIO;
-#endif /* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */
+#endif /* CONFIG_MMU */
+}
+
+/**
+ * dma_can_mmap - check if a given device supports dma_mmap_*
+ * @dev: device to check
+ *
+ * Returns %true if @dev supports dma_mmap_coherent() and dma_mmap_attrs() to
+ * map DMA allocations to userspace.
+ */
+bool dma_can_mmap(struct device *dev)
+{
+ const struct dma_map_ops *ops = get_dma_ops(dev);
+
+ if (dma_is_direct(ops)) {
+ return IS_ENABLED(CONFIG_MMU) &&
+ (dev_is_dma_coherent(dev) ||
+ IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN));
+ }
+
+ return ops->mmap != NULL;
}
+EXPORT_SYMBOL_GPL(dma_can_mmap);
/**
* dma_mmap_attrs - map a coherent DMA allocation into user space
@@ -227,31 +262,15 @@ int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
{
const struct dma_map_ops *ops = get_dma_ops(dev);
- if (!dma_is_direct(ops) && ops->mmap)
- return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
- return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
+ if (dma_is_direct(ops))
+ return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size,
+ attrs);
+ if (!ops->mmap)
+ return -ENXIO;
+ return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
}
EXPORT_SYMBOL(dma_mmap_attrs);
-static u64 dma_default_get_required_mask(struct device *dev)
-{
- u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
- u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
- u64 mask;
-
- if (!high_totalram) {
- /* convert to mask just covering totalram */
- low_totalram = (1 << (fls(low_totalram) - 1));
- low_totalram += low_totalram - 1;
- mask = low_totalram;
- } else {
- high_totalram = (1 << (fls(high_totalram) - 1));
- high_totalram += high_totalram - 1;
- mask = (((u64)high_totalram) << 32) + 0xffffffff;
- }
- return mask;
-}
-
u64 dma_get_required_mask(struct device *dev)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
@@ -260,7 +279,16 @@ u64 dma_get_required_mask(struct device *dev)
return dma_direct_get_required_mask(dev);
if (ops->get_required_mask)
return ops->get_required_mask(dev);
- return dma_default_get_required_mask(dev);
+
+ /*
+ * We require every DMA ops implementation to at least support a 32-bit
+ * DMA mask (and use bounce buffering if that isn't supported in
+ * hardware). As the direct mapping code has its own routine to
+ * actually report an optimal mask we default to 32-bit here as that
+ * is the right thing for most IOMMUs, and at least not actively
+ * harmful in general.
+ */
+ return DMA_BIT_MASK(32);
}
EXPORT_SYMBOL_GPL(dma_get_required_mask);
@@ -405,3 +433,14 @@ size_t dma_max_mapping_size(struct device *dev)
return size;
}
EXPORT_SYMBOL_GPL(dma_max_mapping_size);
+
+unsigned long dma_get_merge_boundary(struct device *dev)
+{
+ const struct dma_map_ops *ops = get_dma_ops(dev);
+
+ if (!ops || !ops->get_merge_boundary)
+ return 0; /* can't merge */
+
+ return ops->get_merge_boundary(dev);
+}
+EXPORT_SYMBOL_GPL(dma_get_merge_boundary);
diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
index ffe78f0b2fe4..ca4e5d44b571 100644
--- a/kernel/dma/remap.c
+++ b/kernel/dma/remap.c
@@ -11,13 +11,21 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
+struct page **dma_common_find_pages(void *cpu_addr)
+{
+ struct vm_struct *area = find_vm_area(cpu_addr);
+
+ if (!area || area->flags != VM_DMA_COHERENT)
+ return NULL;
+ return area->pages;
+}
+
static struct vm_struct *__dma_common_pages_remap(struct page **pages,
- size_t size, unsigned long vm_flags, pgprot_t prot,
- const void *caller)
+ size_t size, pgprot_t prot, const void *caller)
{
struct vm_struct *area;
- area = get_vm_area_caller(size, vm_flags, caller);
+ area = get_vm_area_caller(size, VM_DMA_COHERENT, caller);
if (!area)
return NULL;
@@ -34,12 +42,11 @@ static struct vm_struct *__dma_common_pages_remap(struct page **pages,
* Cannot be used in non-sleeping contexts
*/
void *dma_common_pages_remap(struct page **pages, size_t size,
- unsigned long vm_flags, pgprot_t prot,
- const void *caller)
+ pgprot_t prot, const void *caller)
{
struct vm_struct *area;
- area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
+ area = __dma_common_pages_remap(pages, size, prot, caller);
if (!area)
return NULL;
@@ -53,7 +60,6 @@ void *dma_common_pages_remap(struct page **pages, size_t size,
* Cannot be used in non-sleeping contexts
*/
void *dma_common_contiguous_remap(struct page *page, size_t size,
- unsigned long vm_flags,
pgprot_t prot, const void *caller)
{
int i;
@@ -67,7 +73,7 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
for (i = 0; i < (size >> PAGE_SHIFT); i++)
pages[i] = nth_page(page, i);
- area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
+ area = __dma_common_pages_remap(pages, size, prot, caller);
kfree(pages);
@@ -79,11 +85,11 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
/*
* Unmaps a range previously mapped by dma_common_*_remap
*/
-void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
+void dma_common_free_remap(void *cpu_addr, size_t size)
{
- struct vm_struct *area = find_vm_area(cpu_addr);
+ struct page **pages = dma_common_find_pages(cpu_addr);
- if (!area || (area->flags & vm_flags) != vm_flags) {
+ if (!pages) {
WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
return;
}
@@ -105,7 +111,16 @@ static int __init early_coherent_pool(char *p)
}
early_param("coherent_pool", early_coherent_pool);
-int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot)
+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;
@@ -117,7 +132,7 @@ int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot)
page = dma_alloc_from_contiguous(NULL, nr_pages,
pool_size_order, false);
else
- page = alloc_pages(gfp, pool_size_order);
+ page = alloc_pages(dma_atomic_pool_gfp(), pool_size_order);
if (!page)
goto out;
@@ -127,8 +142,9 @@ int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot)
if (!atomic_pool)
goto free_page;
- addr = dma_common_contiguous_remap(page, atomic_pool_size, VM_USERMAP,
- prot, __builtin_return_address(0));
+ addr = dma_common_contiguous_remap(page, atomic_pool_size,
+ pgprot_dmacoherent(PAGE_KERNEL),
+ __builtin_return_address(0));
if (!addr)
goto destroy_genpool;
@@ -143,7 +159,7 @@ int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot)
return 0;
remove_mapping:
- dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
+ dma_common_free_remap(addr, atomic_pool_size);
destroy_genpool:
gen_pool_destroy(atomic_pool);
atomic_pool = NULL;
@@ -155,6 +171,7 @@ out:
atomic_pool_size / 1024);
return -ENOMEM;
}
+postcore_initcall(dma_atomic_pool_init);
bool dma_in_atomic_pool(void *start, size_t size)
{
@@ -217,7 +234,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
arch_dma_prep_coherent(page, size);
/* create a coherent mapping */
- ret = dma_common_contiguous_remap(page, size, VM_USERMAP,
+ ret = dma_common_contiguous_remap(page, size,
dma_pgprot(dev, PAGE_KERNEL, attrs),
__builtin_return_address(0));
if (!ret) {