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dma-direct: improve swiotlb error reporting 

Untangle the way how dma_direct_map_page calls into swiotlb to be able
to properly report errors where the swiotlb DMA address overflows the
mask separately from overflows in the !swiotlb case.  This means that
siotlb_map now has to do a little more work that duplicates
dma_direct_map_page, but doing so greatly simplifies the calling
convention.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
alistair/sensors
Christoph Hellwig 2020-02-03 14:44:38 +01:00
parent 91ef26f914
commit 4a47cbae04
3 changed files with 33 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
include/linux/swiotlb.h
View File

@ -64,6 +64,9 @@ extern void swiotlb_tbl_sync_single(struct device *hwdev,
size_t size, enum dma_data_direction dir,
enum dma_sync_target target);
dma_addr_t swiotlb_map(struct device *dev, phys_addr_t phys,
size_t size, enum dma_data_direction dir, unsigned long attrs);
#ifdef CONFIG_SWIOTLB
extern enum swiotlb_force swiotlb_force;
extern phys_addr_t io_tlb_start, io_tlb_end;
@ -73,8 +76,6 @@ static inline bool is_swiotlb_buffer(phys_addr_t paddr)
return paddr >= io_tlb_start && paddr < io_tlb_end;
}
bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr,
size_t size, enum dma_data_direction dir, unsigned long attrs);
void __init swiotlb_exit(void);
unsigned int swiotlb_max_segment(void);
size_t swiotlb_max_mapping_size(struct device *dev);
@ -85,12 +86,6 @@ static inline bool is_swiotlb_buffer(phys_addr_t paddr)
{
return false;
}
static inline bool swiotlb_map(struct device *dev, phys_addr_t *phys,
dma_addr_t *dma_addr, size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
return false;
}
static inline void swiotlb_exit(void)
{
}

16
kernel/dma/direct.c
View File

@ -357,13 +357,6 @@ void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
EXPORT_SYMBOL(dma_direct_unmap_sg);
#endif
static inline bool dma_direct_possible(struct device *dev, dma_addr_t dma_addr,
size_t size)
{
return swiotlb_force != SWIOTLB_FORCE &&
dma_capable(dev, dma_addr, size, true);
}
dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
unsigned long attrs)
@ -371,8 +364,13 @@ dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
phys_addr_t phys = page_to_phys(page) + offset;
dma_addr_t dma_addr = phys_to_dma(dev, phys);
if (unlikely(!dma_direct_possible(dev, dma_addr, size)) &&
!swiotlb_map(dev, &phys, &dma_addr, size, dir, attrs)) {
if (unlikely(swiotlb_force == SWIOTLB_FORCE))
return swiotlb_map(dev, phys, size, dir, attrs);
if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
if (swiotlb_force != SWIOTLB_NO_FORCE)
return swiotlb_map(dev, phys, size, dir, attrs);
report_addr(dev, dma_addr, size);
return DMA_MAPPING_ERROR;
}

42
kernel/dma/swiotlb.c
View File

@ -22,6 +22,7 @@
#include <linux/cache.h>
#include <linux/dma-direct.h>
#include <linux/dma-noncoherent.h>
#include <linux/mm.h>
#include <linux/export.h>
#include <linux/spinlock.h>
@ -656,35 +657,38 @@ void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr,
}
/*
* Create a swiotlb mapping for the buffer at @phys, and in case of DMAing
* Create a swiotlb mapping for the buffer at @paddr, and in case of DMAing
* to the device copy the data into it as well.
*/
bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr,
size_t size, enum dma_data_direction dir, unsigned long attrs)
dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size,
enum dma_data_direction dir, unsigned long attrs)
{
trace_swiotlb_bounced(dev, *dma_addr, size, swiotlb_force);
phys_addr_t swiotlb_addr;
dma_addr_t dma_addr;
if (unlikely(swiotlb_force == SWIOTLB_NO_FORCE)) {
dev_warn_ratelimited(dev,
"Cannot do DMA to address %pa\n", phys);
return false;
}
trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size,
swiotlb_force);
/* Oh well, have to allocate and map a bounce buffer. */
*phys = swiotlb_tbl_map_single(dev, __phys_to_dma(dev, io_tlb_start),
*phys, size, size, dir, attrs);
if (*phys == (phys_addr_t)DMA_MAPPING_ERROR)
return false;
swiotlb_addr = swiotlb_tbl_map_single(dev,
__phys_to_dma(dev, io_tlb_start),
paddr, size, size, dir, attrs);
if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR)
return DMA_MAPPING_ERROR;
/* Ensure that the address returned is DMA'ble */
*dma_addr = __phys_to_dma(dev, *phys);
if (unlikely(!dma_capable(dev, *dma_addr, size, true))) {
swiotlb_tbl_unmap_single(dev, *phys, size, size, dir,
dma_addr = __phys_to_dma(dev, swiotlb_addr);
if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
swiotlb_tbl_unmap_single(dev, swiotlb_addr, size, size, dir,
attrs | DMA_ATTR_SKIP_CPU_SYNC);
return false;
dev_WARN_ONCE(dev, 1,
"swiotlb addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
&dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
return DMA_MAPPING_ERROR;
}
return true;
if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
arch_sync_dma_for_device(swiotlb_addr, size, dir);
return dma_addr;
}
size_t swiotlb_max_mapping_size(struct device *dev)