| Message ID | 20210616062157.953777-7-tientzu@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Restricted DMA | expand |
On Wed, 16 Jun 2021, Claire Chang wrote: > Propagate the swiotlb_force into io_tlb_default_mem->force_bounce and > use it to determine whether to bounce the data or not. This will be > useful later to allow for different pools. > > Signed-off-by: Claire Chang <tientzu@chromium.org> > --- > include/linux/swiotlb.h | 11 +++++++++++ > kernel/dma/direct.c | 2 +- > kernel/dma/direct.h | 2 +- > kernel/dma/swiotlb.c | 4 ++++ > 4 files changed, 17 insertions(+), 2 deletions(-) > > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index dd1c30a83058..8d8855c77d9a 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -84,6 +84,7 @@ extern enum swiotlb_force swiotlb_force; > * unmap calls. > * @debugfs: The dentry to debugfs. > * @late_alloc: %true if allocated using the page allocator > + * @force_bounce: %true if swiotlb bouncing is forced > */ > struct io_tlb_mem { > phys_addr_t start; > @@ -94,6 +95,7 @@ struct io_tlb_mem { > spinlock_t lock; > struct dentry *debugfs; > bool late_alloc; > + bool force_bounce; > struct io_tlb_slot { > phys_addr_t orig_addr; > size_t alloc_size; > @@ -109,6 +111,11 @@ static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr) > return mem && paddr >= mem->start && paddr < mem->end; > } > > +static inline bool is_swiotlb_force_bounce(struct device *dev) > +{ > + return dev->dma_io_tlb_mem->force_bounce; > +} > void __init swiotlb_exit(void); > unsigned int swiotlb_max_segment(void); > size_t swiotlb_max_mapping_size(struct device *dev); > @@ -120,6 +127,10 @@ static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr) > { > return false; > } > +static inline bool is_swiotlb_force_bounce(struct device *dev) > +{ > + return false; > +} > static inline void swiotlb_exit(void) > { > } > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > index 7a88c34d0867..a92465b4eb12 100644 > --- a/kernel/dma/direct.c > +++ b/kernel/dma/direct.c > @@ -496,7 +496,7 @@ size_t dma_direct_max_mapping_size(struct device *dev) > { > /* If SWIOTLB is active, use its maximum mapping size */ > if (is_swiotlb_active(dev) && > - (dma_addressing_limited(dev) || swiotlb_force == SWIOTLB_FORCE)) > + (dma_addressing_limited(dev) || is_swiotlb_force_bounce(dev))) > return swiotlb_max_mapping_size(dev); > return SIZE_MAX; > } > diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h > index 13e9e7158d94..4632b0f4f72e 100644 > --- a/kernel/dma/direct.h > +++ b/kernel/dma/direct.h > @@ -87,7 +87,7 @@ 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)) > + if (is_swiotlb_force_bounce(dev)) > return swiotlb_map(dev, phys, size, dir, attrs); > > if (unlikely(!dma_capable(dev, dma_addr, size, true))) { Should we also make the same change in drivers/xen/swiotlb-xen.c:xen_swiotlb_map_page ? If I make that change, I can see that everything is working as expected for a restricted-dma device with Linux running as dom0 on Xen. However, is_swiotlb_force_bounce returns non-zero even for normal non-restricted-dma devices. That shouldn't happen, right? It looks like struct io_tlb_slot is not zeroed on allocation. Adding memset(mem, 0x0, struct_size) in swiotlb_late_init_with_tbl solves the issue. With those two changes, the series passes my tests and you can add my tested-by.
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index dd1c30a83058..8d8855c77d9a 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -84,6 +84,7 @@ extern enum swiotlb_force swiotlb_force; * unmap calls. * @debugfs: The dentry to debugfs. * @late_alloc: %true if allocated using the page allocator + * @force_bounce: %true if swiotlb bouncing is forced */ struct io_tlb_mem { phys_addr_t start; @@ -94,6 +95,7 @@ struct io_tlb_mem { spinlock_t lock; struct dentry *debugfs; bool late_alloc; + bool force_bounce; struct io_tlb_slot { phys_addr_t orig_addr; size_t alloc_size; @@ -109,6 +111,11 @@ static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr) return mem && paddr >= mem->start && paddr < mem->end; } +static inline bool is_swiotlb_force_bounce(struct device *dev) +{ + return dev->dma_io_tlb_mem->force_bounce; +} + void __init swiotlb_exit(void); unsigned int swiotlb_max_segment(void); size_t swiotlb_max_mapping_size(struct device *dev); @@ -120,6 +127,10 @@ static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr) { return false; } +static inline bool is_swiotlb_force_bounce(struct device *dev) +{ + return false; +} static inline void swiotlb_exit(void) { } diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 7a88c34d0867..a92465b4eb12 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -496,7 +496,7 @@ size_t dma_direct_max_mapping_size(struct device *dev) { /* If SWIOTLB is active, use its maximum mapping size */ if (is_swiotlb_active(dev) && - (dma_addressing_limited(dev) || swiotlb_force == SWIOTLB_FORCE)) + (dma_addressing_limited(dev) || is_swiotlb_force_bounce(dev))) return swiotlb_max_mapping_size(dev); return SIZE_MAX; } diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h index 13e9e7158d94..4632b0f4f72e 100644 --- a/kernel/dma/direct.h +++ b/kernel/dma/direct.h @@ -87,7 +87,7 @@ 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)) + if (is_swiotlb_force_bounce(dev)) return swiotlb_map(dev, phys, size, dir, attrs); if (unlikely(!dma_capable(dev, dma_addr, size, true))) { diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 101abeb0a57d..b5a9c4c0b4db 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -179,6 +179,10 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, mem->end = mem->start + bytes; mem->index = 0; mem->late_alloc = late_alloc; + + if (swiotlb_force == SWIOTLB_FORCE) + mem->force_bounce = true; + spin_lock_init(&mem->lock); for (i = 0; i < mem->nslabs; i++) { mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
Propagate the swiotlb_force into io_tlb_default_mem->force_bounce and use it to determine whether to bounce the data or not. This will be useful later to allow for different pools. Signed-off-by: Claire Chang <tientzu@chromium.org> --- include/linux/swiotlb.h | 11 +++++++++++ kernel/dma/direct.c | 2 +- kernel/dma/direct.h | 2 +- kernel/dma/swiotlb.c | 4 ++++ 4 files changed, 17 insertions(+), 2 deletions(-)