[RFC PATCH v3 3/6] swiotlb: Use restricted DMA pool if available
Claire Chang
tientzu at chromium.org
Wed Jan 6 14:41:21 AEDT 2021
Regardless of swiotlb setting, the restricted DMA pool is preferred if
available.
The restricted DMA pools provide a basic level of protection against
the DMA overwriting buffer contents at unexpected times. However, to
protect against general data leakage and system memory corruption, the
system needs to provide a way to restrict the DMA to a predefined memory
region.
Signed-off-by: Claire Chang <tientzu at chromium.org>
---
drivers/iommu/dma-iommu.c | 12 ++++++------
include/linux/swiotlb.h | 17 +++++++++++------
kernel/dma/direct.c | 8 ++++----
kernel/dma/direct.h | 10 ++++++----
kernel/dma/swiotlb.c | 13 ++++++-------
5 files changed, 33 insertions(+), 27 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index f0305e6aac1b..1343cc2ef27a 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -516,7 +516,7 @@ static void __iommu_dma_unmap_swiotlb(struct device *dev, dma_addr_t dma_addr,
__iommu_dma_unmap(dev, dma_addr, size);
- if (unlikely(is_swiotlb_buffer(phys)))
+ if (unlikely(is_swiotlb_buffer(dev, phys)))
swiotlb_tbl_unmap_single(dev, phys, size,
iova_align(iovad, size), dir, attrs);
}
@@ -592,7 +592,7 @@ static dma_addr_t __iommu_dma_map_swiotlb(struct device *dev, phys_addr_t phys,
}
iova = __iommu_dma_map(dev, phys, aligned_size, prot, dma_mask);
- if ((iova == DMA_MAPPING_ERROR) && is_swiotlb_buffer(phys))
+ if ((iova == DMA_MAPPING_ERROR) && is_swiotlb_buffer(dev, phys))
swiotlb_tbl_unmap_single(dev, phys, org_size,
aligned_size, dir, attrs);
@@ -764,7 +764,7 @@ static void iommu_dma_sync_single_for_cpu(struct device *dev,
if (!dev_is_dma_coherent(dev))
arch_sync_dma_for_cpu(phys, size, dir);
- if (is_swiotlb_buffer(phys))
+ if (is_swiotlb_buffer(dev, phys))
swiotlb_tbl_sync_single(dev, phys, size, dir, SYNC_FOR_CPU);
}
@@ -777,7 +777,7 @@ static void iommu_dma_sync_single_for_device(struct device *dev,
return;
phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dma_handle);
- if (is_swiotlb_buffer(phys))
+ if (is_swiotlb_buffer(dev, phys))
swiotlb_tbl_sync_single(dev, phys, size, dir, SYNC_FOR_DEVICE);
if (!dev_is_dma_coherent(dev))
@@ -798,7 +798,7 @@ static void iommu_dma_sync_sg_for_cpu(struct device *dev,
if (!dev_is_dma_coherent(dev))
arch_sync_dma_for_cpu(sg_phys(sg), sg->length, dir);
- if (is_swiotlb_buffer(sg_phys(sg)))
+ if (is_swiotlb_buffer(dev, sg_phys(sg)))
swiotlb_tbl_sync_single(dev, sg_phys(sg), sg->length,
dir, SYNC_FOR_CPU);
}
@@ -815,7 +815,7 @@ static void iommu_dma_sync_sg_for_device(struct device *dev,
return;
for_each_sg(sgl, sg, nelems, i) {
- if (is_swiotlb_buffer(sg_phys(sg)))
+ if (is_swiotlb_buffer(dev, sg_phys(sg)))
swiotlb_tbl_sync_single(dev, sg_phys(sg), sg->length,
dir, SYNC_FOR_DEVICE);
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index a1bbd7788885..5135e5636042 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -2,12 +2,12 @@
#ifndef __LINUX_SWIOTLB_H
#define __LINUX_SWIOTLB_H
+#include <linux/device.h>
#include <linux/dma-direction.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/limits.h>
-struct device;
struct page;
struct scatterlist;
@@ -106,9 +106,14 @@ struct io_tlb_mem {
};
extern struct io_tlb_mem io_tlb_default_mem;
-static inline bool is_swiotlb_buffer(phys_addr_t paddr)
+static inline struct io_tlb_mem *get_io_tlb_mem(struct device *dev)
{
- struct io_tlb_mem *mem = &io_tlb_default_mem;
+ return dev->dma_io_tlb_mem ? dev->dma_io_tlb_mem : &io_tlb_default_mem;
+}
+
+static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
+{
+ struct io_tlb_mem *mem = get_io_tlb_mem(dev);
return paddr >= mem->start && paddr < mem->end;
}
@@ -116,11 +121,11 @@ static inline bool is_swiotlb_buffer(phys_addr_t paddr)
void __init swiotlb_exit(void);
unsigned int swiotlb_max_segment(void);
size_t swiotlb_max_mapping_size(struct device *dev);
-bool is_swiotlb_active(void);
+bool is_swiotlb_active(struct device *dev);
void __init swiotlb_adjust_size(unsigned long new_size);
#else
#define swiotlb_force SWIOTLB_NO_FORCE
-static inline bool is_swiotlb_buffer(phys_addr_t paddr)
+static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
{
return false;
}
@@ -136,7 +141,7 @@ static inline size_t swiotlb_max_mapping_size(struct device *dev)
return SIZE_MAX;
}
-static inline bool is_swiotlb_active(void)
+static inline bool is_swiotlb_active(struct device *dev)
{
return false;
}
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 002268262c9a..30ccbc08e229 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -343,7 +343,7 @@ void dma_direct_sync_sg_for_device(struct device *dev,
for_each_sg(sgl, sg, nents, i) {
phys_addr_t paddr = dma_to_phys(dev, sg_dma_address(sg));
- if (unlikely(is_swiotlb_buffer(paddr)))
+ if (unlikely(is_swiotlb_buffer(dev, paddr)))
swiotlb_tbl_sync_single(dev, paddr, sg->length,
dir, SYNC_FOR_DEVICE);
@@ -369,7 +369,7 @@ void dma_direct_sync_sg_for_cpu(struct device *dev,
if (!dev_is_dma_coherent(dev))
arch_sync_dma_for_cpu(paddr, sg->length, dir);
- if (unlikely(is_swiotlb_buffer(paddr)))
+ if (unlikely(is_swiotlb_buffer(dev, paddr)))
swiotlb_tbl_sync_single(dev, paddr, sg->length, dir,
SYNC_FOR_CPU);
@@ -495,7 +495,7 @@ int dma_direct_supported(struct device *dev, u64 mask)
size_t dma_direct_max_mapping_size(struct device *dev)
{
/* If SWIOTLB is active, use its maximum mapping size */
- if (is_swiotlb_active() &&
+ if (is_swiotlb_active(dev) &&
(dma_addressing_limited(dev) || swiotlb_force == SWIOTLB_FORCE))
return swiotlb_max_mapping_size(dev);
return SIZE_MAX;
@@ -504,7 +504,7 @@ size_t dma_direct_max_mapping_size(struct device *dev)
bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr)
{
return !dev_is_dma_coherent(dev) ||
- is_swiotlb_buffer(dma_to_phys(dev, dma_addr));
+ is_swiotlb_buffer(dev, dma_to_phys(dev, dma_addr));
}
/**
diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h
index b98615578737..7188834cc4c7 100644
--- a/kernel/dma/direct.h
+++ b/kernel/dma/direct.h
@@ -56,7 +56,7 @@ static inline void dma_direct_sync_single_for_device(struct device *dev,
{
phys_addr_t paddr = dma_to_phys(dev, addr);
- if (unlikely(is_swiotlb_buffer(paddr)))
+ if (unlikely(is_swiotlb_buffer(dev, paddr)))
swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_DEVICE);
if (!dev_is_dma_coherent(dev))
@@ -73,7 +73,7 @@ static inline void dma_direct_sync_single_for_cpu(struct device *dev,
arch_sync_dma_for_cpu_all();
}
- if (unlikely(is_swiotlb_buffer(paddr)))
+ if (unlikely(is_swiotlb_buffer(dev, paddr)))
swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_CPU);
if (dir == DMA_FROM_DEVICE)
@@ -87,8 +87,10 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev,
phys_addr_t phys = page_to_phys(page) + offset;
dma_addr_t dma_addr = phys_to_dma(dev, phys);
- if (unlikely(swiotlb_force == SWIOTLB_FORCE))
+#ifdef CONFIG_SWIOTLB
+ if (unlikely(swiotlb_force == SWIOTLB_FORCE) || dev->dma_io_tlb_mem)
return swiotlb_map(dev, phys, size, dir, attrs);
+#endif
if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
if (swiotlb_force != SWIOTLB_NO_FORCE)
@@ -113,7 +115,7 @@ static inline void dma_direct_unmap_page(struct device *dev, dma_addr_t addr,
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
dma_direct_sync_single_for_cpu(dev, addr, size, dir);
- if (unlikely(is_swiotlb_buffer(phys)))
+ if (unlikely(is_swiotlb_buffer(dev, phys)))
swiotlb_tbl_unmap_single(dev, phys, size, size, dir, attrs);
}
#endif /* _KERNEL_DMA_DIRECT_H */
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 7fb2ac087d23..1f05af09e61a 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -222,7 +222,6 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
mem->orig_addr[i] = INVALID_PHYS_ADDR;
}
mem->index = 0;
- no_iotlb_memory = false;
if (verbose)
swiotlb_print_info();
@@ -464,7 +463,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr,
size_t mapping_size, size_t alloc_size,
enum dma_data_direction dir, unsigned long attrs)
{
- struct io_tlb_mem *mem = &io_tlb_default_mem;
+ struct io_tlb_mem *mem = get_io_tlb_mem(hwdev);
dma_addr_t tbl_dma_addr = phys_to_dma_unencrypted(hwdev, mem->start);
unsigned long flags;
phys_addr_t tlb_addr;
@@ -475,7 +474,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr,
unsigned long max_slots;
unsigned long tmp_io_tlb_used;
- if (no_iotlb_memory)
+ if (no_iotlb_memory && !hwdev->dma_io_tlb_mem)
panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer");
if (mem_encrypt_active())
@@ -597,7 +596,7 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,
size_t mapping_size, size_t alloc_size,
enum dma_data_direction dir, unsigned long attrs)
{
- struct io_tlb_mem *mem = &io_tlb_default_mem;
+ struct io_tlb_mem *mem = get_io_tlb_mem(hwdev);
unsigned long flags;
int i, count, nslots = ALIGN(alloc_size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
int index = (tlb_addr - mem->start) >> IO_TLB_SHIFT;
@@ -645,7 +644,7 @@ void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr,
size_t size, enum dma_data_direction dir,
enum dma_sync_target target)
{
- struct io_tlb_mem *mem = &io_tlb_default_mem;
+ struct io_tlb_mem *mem = get_io_tlb_mem(hwdev);
int index = (tlb_addr - mem->start) >> IO_TLB_SHIFT;
phys_addr_t orig_addr = mem->orig_addr[index];
@@ -712,13 +711,13 @@ size_t swiotlb_max_mapping_size(struct device *dev)
return ((size_t)1 << IO_TLB_SHIFT) * IO_TLB_SEGSIZE;
}
-bool is_swiotlb_active(void)
+bool is_swiotlb_active(struct device *dev)
{
/*
* When SWIOTLB is initialized, even if mem->start points to physical
* address zero, mem->end surely doesn't.
*/
- return io_tlb_default_mem.end != 0;
+ return io_tlb_default_mem.end != 0 || dev->dma_io_tlb_mem;
}
#ifdef CONFIG_DEBUG_FS
--
2.29.2.729.g45daf8777d-goog
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