From 6c654b5fdf093cd05f35f7c9c2a00182fa5636dc Mon Sep 17 00:00:00 2001 From: "John W. Linville" Date: Thu, 29 Sep 2005 14:42:42 -0700 Subject: [PATCH 1/7] [PATCH] swiotlb: move from arch/ia64/lib/ to lib/ The swiotlb implementation is shared by both IA-64 and EM64T. However, the source itself lives under arch/ia64. This patch moves swiotlb.c from arch/ia64/lib to lib/ and fixes-up the appropriate Makefile and Kconfig files. No actual changes are made to swiotlb.c. Signed-off-by: John W. Linville Signed-off-by: Tony Luck --- arch/ia64/Kconfig | 4 ++++ arch/ia64/lib/Makefile | 2 +- arch/x86_64/kernel/Makefile | 2 -- lib/Makefile | 2 ++ {arch/ia64/lib => lib}/swiotlb.c | 0 5 files changed, 7 insertions(+), 3 deletions(-) rename {arch/ia64/lib => lib}/swiotlb.c (100%) diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index ed25d66c8d50..ea4a889d8196 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -26,6 +26,10 @@ config MMU bool default y +config SWIOTLB + bool + default y + config RWSEM_XCHGADD_ALGORITHM bool default y diff --git a/arch/ia64/lib/Makefile b/arch/ia64/lib/Makefile index 799407e7726f..4be1546e1726 100644 --- a/arch/ia64/lib/Makefile +++ b/arch/ia64/lib/Makefile @@ -9,7 +9,7 @@ lib-y := __divsi3.o __udivsi3.o __modsi3.o __umodsi3.o \ bitop.o checksum.o clear_page.o csum_partial_copy.o \ clear_user.o strncpy_from_user.o strlen_user.o strnlen_user.o \ flush.o ip_fast_csum.o do_csum.o \ - memset.o strlen.o swiotlb.o + memset.o strlen.o lib-$(CONFIG_ITANIUM) += copy_page.o copy_user.o memcpy.o lib-$(CONFIG_MCKINLEY) += copy_page_mck.o memcpy_mck.o diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile index bcdd0a805fe7..14328cab5d3a 100644 --- a/arch/x86_64/kernel/Makefile +++ b/arch/x86_64/kernel/Makefile @@ -27,7 +27,6 @@ obj-$(CONFIG_CPU_FREQ) += cpufreq/ obj-$(CONFIG_EARLY_PRINTK) += early_printk.o obj-$(CONFIG_GART_IOMMU) += pci-gart.o aperture.o obj-$(CONFIG_DUMMY_IOMMU) += pci-nommu.o pci-dma.o -obj-$(CONFIG_SWIOTLB) += swiotlb.o obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_X86_PM_TIMER) += pmtimer.o @@ -41,7 +40,6 @@ CFLAGS_vsyscall.o := $(PROFILING) -g0 bootflag-y += ../../i386/kernel/bootflag.o cpuid-$(subst m,y,$(CONFIG_X86_CPUID)) += ../../i386/kernel/cpuid.o topology-y += ../../i386/mach-default/topology.o -swiotlb-$(CONFIG_SWIOTLB) += ../../ia64/lib/swiotlb.o microcode-$(subst m,y,$(CONFIG_MICROCODE)) += ../../i386/kernel/microcode.o intel_cacheinfo-y += ../../i386/kernel/cpu/intel_cacheinfo.o quirks-y += ../../i386/kernel/quirks.o diff --git a/lib/Makefile b/lib/Makefile index 44a46750690a..8535f4d7d1c3 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -44,6 +44,8 @@ obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o obj-$(CONFIG_TEXTSEARCH_BM) += ts_bm.o obj-$(CONFIG_TEXTSEARCH_FSM) += ts_fsm.o +obj-$(CONFIG_SWIOTLB) += swiotlb.o + hostprogs-y := gen_crc32table clean-files := crc32table.h diff --git a/arch/ia64/lib/swiotlb.c b/lib/swiotlb.c similarity index 100% rename from arch/ia64/lib/swiotlb.c rename to lib/swiotlb.c From 8270f3f1a605c83b3aa516c1eaed209fe0884e84 Mon Sep 17 00:00:00 2001 From: "John W. Linville" Date: Thu, 29 Sep 2005 14:43:32 -0700 Subject: [PATCH 2/7] [PATCH] swiotlb: cleanup some code duplication cruft The implementations of swiotlb_sync_single_for_{cpu,device} are identical. Likewise for swiotlb_syng_sg_for_{cpu,device}. This patch move the guts of those functions to two new inline functions, and calls the appropriate one from the bodies of those functions. Signed-off-by: John W. Linville Signed-off-by: Tony Luck --- lib/swiotlb.c | 45 ++++++++++++++++++++++----------------------- 1 file changed, 22 insertions(+), 23 deletions(-) diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 875b0c16250c..9719a14649e7 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -594,9 +594,9 @@ swiotlb_unmap_single(struct device *hwdev, dma_addr_t dev_addr, size_t size, * address back to the card, you must first perform a * swiotlb_dma_sync_for_device, and then the device again owns the buffer */ -void -swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, - size_t size, int dir) +static inline void +swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr, + size_t size, int dir) { char *dma_addr = phys_to_virt(dev_addr); @@ -608,18 +608,18 @@ swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, mark_clean(dma_addr, size); } +void +swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, + size_t size, int dir) +{ + swiotlb_sync_single(hwdev, dev_addr, size, dir); +} + void swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, size_t size, int dir) { - char *dma_addr = phys_to_virt(dev_addr); - - if (dir == DMA_NONE) - BUG(); - if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end) - sync_single(hwdev, dma_addr, size, dir); - else if (dir == DMA_FROM_DEVICE) - mark_clean(dma_addr, size); + swiotlb_sync_single(hwdev, dev_addr, size, dir); } /* @@ -696,9 +696,9 @@ swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nelems, * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules * and usage. */ -void -swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, - int nelems, int dir) +static inline void +swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sg, + int nelems, int dir) { int i; @@ -711,19 +711,18 @@ swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, sg->dma_length, dir); } +void +swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, + int nelems, int dir) +{ + swiotlb_sync_sg(hwdev, sg, nelems, dir); +} + void swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg, int nelems, int dir) { - int i; - - if (dir == DMA_NONE) - BUG(); - - for (i = 0; i < nelems; i++, sg++) - if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg)) - sync_single(hwdev, (void *) sg->dma_address, - sg->dma_length, dir); + swiotlb_sync_sg(hwdev, sg, nelems, dir); } int From 878a97cfd7014b01285db09f52f9881ffe4cb608 Mon Sep 17 00:00:00 2001 From: "John W. Linville" Date: Thu, 29 Sep 2005 14:44:23 -0700 Subject: [PATCH 3/7] [PATCH] swiotlb: support syncing sub-ranges of mappings This patch implements swiotlb_sync_single_range_for_{cpu,device}. This is intended to support an x86_64 implementation of dma_sync_single_range_for_{cpu,device}. Signed-off-by: John W. Linville Signed-off-by: Tony Luck --- include/asm-x86_64/swiotlb.h | 8 ++++++++ lib/swiotlb.c | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/include/asm-x86_64/swiotlb.h b/include/asm-x86_64/swiotlb.h index 36293061f4ed..9b011dd8d19d 100644 --- a/include/asm-x86_64/swiotlb.h +++ b/include/asm-x86_64/swiotlb.h @@ -15,6 +15,14 @@ extern void swiotlb_sync_single_for_cpu(struct device *hwdev, extern void swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, size_t size, int dir); +extern void swiotlb_sync_single_range_for_cpu(struct device *hwdev, + dma_addr_t dev_addr, + unsigned long offset, + size_t size, int dir); +extern void swiotlb_sync_single_range_for_device(struct device *hwdev, + dma_addr_t dev_addr, + unsigned long offset, + size_t size, int dir); extern void swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, int nelems, int dir); diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 9719a14649e7..566791b3f583 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -622,6 +622,37 @@ swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, swiotlb_sync_single(hwdev, dev_addr, size, dir); } +/* + * Same as above, but for a sub-range of the mapping. + */ +static inline void +swiotlb_sync_single_range(struct device *hwdev, dma_addr_t dev_addr, + unsigned long offset, size_t size, int dir) +{ + char *dma_addr = phys_to_virt(dev_addr) + offset; + + if (dir == DMA_NONE) + BUG(); + if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end) + sync_single(hwdev, dma_addr, size, dir); + else if (dir == DMA_FROM_DEVICE) + mark_clean(dma_addr, size); +} + +void +swiotlb_sync_single_range_for_cpu(struct device *hwdev, dma_addr_t dev_addr, + unsigned long offset, size_t size, int dir) +{ + swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir); +} + +void +swiotlb_sync_single_range_for_device(struct device *hwdev, dma_addr_t dev_addr, + unsigned long offset, size_t size, int dir) +{ + swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir); +} + /* * Map a set of buffers described by scatterlist in streaming mode for DMA. * This is the scatter-gather version of the above swiotlb_map_single @@ -750,6 +781,8 @@ EXPORT_SYMBOL(swiotlb_map_sg); EXPORT_SYMBOL(swiotlb_unmap_sg); EXPORT_SYMBOL(swiotlb_sync_single_for_cpu); EXPORT_SYMBOL(swiotlb_sync_single_for_device); +EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_cpu); +EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_device); EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu); EXPORT_SYMBOL(swiotlb_sync_sg_for_device); EXPORT_SYMBOL(swiotlb_dma_mapping_error); From de69e0f0b38a467d881e138a302b005bf31c8400 Mon Sep 17 00:00:00 2001 From: "John W. Linville" Date: Thu, 29 Sep 2005 14:44:57 -0700 Subject: [PATCH 4/7] [PATCH] swiotlb: support syncing DMA_BIDIRECTIONAL mappings The current implementation of sync_single in swiotlb.c chokes on DMA_BIDIRECTIONAL mappings. This patch adds the capability to sync those mappings, and optimizes other syncs by accounting for the sync target (i.e. cpu or device) in addition to the DMA direction of the mapping. Signed-off-by: John W. Linville Signed-off-by: Tony Luck --- lib/swiotlb.c | 62 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 40 insertions(+), 22 deletions(-) diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 566791b3f583..a1a6d6bf87b4 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -58,6 +58,14 @@ */ #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT) +/* + * Enumeration for sync targets + */ +enum dma_sync_target { + SYNC_FOR_CPU = 0, + SYNC_FOR_DEVICE = 1, +}; + int swiotlb_force; /* @@ -397,21 +405,28 @@ unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir) } static void -sync_single(struct device *hwdev, char *dma_addr, size_t size, int dir) +sync_single(struct device *hwdev, char *dma_addr, size_t size, + int dir, int target) { int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT; char *buffer = io_tlb_orig_addr[index]; - /* - * bounce... copy the data back into/from the original buffer - * XXX How do you handle DMA_BIDIRECTIONAL here ? - */ - if (dir == DMA_FROM_DEVICE) - memcpy(buffer, dma_addr, size); - else if (dir == DMA_TO_DEVICE) - memcpy(dma_addr, buffer, size); - else + switch (target) { + case SYNC_FOR_CPU: + if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)) + memcpy(buffer, dma_addr, size); + else if (dir != DMA_TO_DEVICE) + BUG(); + break; + case SYNC_FOR_DEVICE: + if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) + memcpy(dma_addr, buffer, size); + else if (dir != DMA_FROM_DEVICE) + BUG(); + break; + default: BUG(); + } } void * @@ -596,14 +611,14 @@ swiotlb_unmap_single(struct device *hwdev, dma_addr_t dev_addr, size_t size, */ static inline void swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr, - size_t size, int dir) + size_t size, int dir, int target) { char *dma_addr = phys_to_virt(dev_addr); if (dir == DMA_NONE) BUG(); if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end) - sync_single(hwdev, dma_addr, size, dir); + sync_single(hwdev, dma_addr, size, dir, target); else if (dir == DMA_FROM_DEVICE) mark_clean(dma_addr, size); } @@ -612,14 +627,14 @@ void swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, size_t size, int dir) { - swiotlb_sync_single(hwdev, dev_addr, size, dir); + swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU); } void swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, size_t size, int dir) { - swiotlb_sync_single(hwdev, dev_addr, size, dir); + swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE); } /* @@ -627,14 +642,15 @@ swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, */ static inline void swiotlb_sync_single_range(struct device *hwdev, dma_addr_t dev_addr, - unsigned long offset, size_t size, int dir) + unsigned long offset, size_t size, + int dir, int target) { char *dma_addr = phys_to_virt(dev_addr) + offset; if (dir == DMA_NONE) BUG(); if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end) - sync_single(hwdev, dma_addr, size, dir); + sync_single(hwdev, dma_addr, size, dir, target); else if (dir == DMA_FROM_DEVICE) mark_clean(dma_addr, size); } @@ -643,14 +659,16 @@ void swiotlb_sync_single_range_for_cpu(struct device *hwdev, dma_addr_t dev_addr, unsigned long offset, size_t size, int dir) { - swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir); + swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir, + SYNC_FOR_CPU); } void swiotlb_sync_single_range_for_device(struct device *hwdev, dma_addr_t dev_addr, unsigned long offset, size_t size, int dir) { - swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir); + swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir, + SYNC_FOR_DEVICE); } /* @@ -729,7 +747,7 @@ swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nelems, */ static inline void swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sg, - int nelems, int dir) + int nelems, int dir, int target) { int i; @@ -739,21 +757,21 @@ swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sg, for (i = 0; i < nelems; i++, sg++) if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg)) sync_single(hwdev, (void *) sg->dma_address, - sg->dma_length, dir); + sg->dma_length, dir, target); } void swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, int nelems, int dir) { - swiotlb_sync_sg(hwdev, sg, nelems, dir); + swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU); } void swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg, int nelems, int dir) { - swiotlb_sync_sg(hwdev, sg, nelems, dir); + swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE); } int From 569c8bf5d8eeeeb9f5250d5b7991007874f0fef2 Mon Sep 17 00:00:00 2001 From: "John W. Linville" Date: Thu, 29 Sep 2005 14:45:24 -0700 Subject: [PATCH 5/7] [PATCH] swiotlb: file header comments Change comment at top of swiotlb.c to reflect that the code is shared with EM64T (i.e. Intel x86_64). Also add an entry for myself so that if I "broke it", everyone knows who "bought it"... :-) Signed-off-by: John W. Linville Signed-off-by: Tony Luck --- lib/swiotlb.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/lib/swiotlb.c b/lib/swiotlb.c index a1a6d6bf87b4..cae806d1ef12 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -1,7 +1,7 @@ /* * Dynamic DMA mapping support. * - * This implementation is for IA-64 platforms that do not support + * This implementation is for IA-64 and EM64T platforms that do not support * I/O TLBs (aka DMA address translation hardware). * Copyright (C) 2000 Asit Mallick * Copyright (C) 2000 Goutham Rao @@ -11,7 +11,9 @@ * 03/05/07 davidm Switch from PCI-DMA to generic device DMA API. * 00/12/13 davidm Rename to swiotlb.c and add mark_clean() to avoid * unnecessary i-cache flushing. - * 04/07/.. ak Better overflow handling. Assorted fixes. + * 04/07/.. ak Better overflow handling. Assorted fixes. + * 05/09/10 linville Add support for syncing ranges, support syncing for + * DMA_BIDIRECTIONAL mappings, miscellaneous cleanup. */ #include From 8d15d19e44d2e903d00ae4b70da917ac77921239 Mon Sep 17 00:00:00 2001 From: "John W. Linville" Date: Thu, 29 Sep 2005 14:45:52 -0700 Subject: [PATCH 6/7] [PATCH] x86_64: implement dma_sync_single_range_for_{cpu,device} Re-implement dma_sync_single_range_for_{cpu,device} for x86_64 using swiotlb_sync_single_range_for_{cpu,device}. Signed-off-by: John W. Linville Signed-off-by: Tony Luck --- include/asm-x86_64/dma-mapping.h | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/include/asm-x86_64/dma-mapping.h b/include/asm-x86_64/dma-mapping.h index e784fdc524f1..45ca88c875c0 100644 --- a/include/asm-x86_64/dma-mapping.h +++ b/include/asm-x86_64/dma-mapping.h @@ -85,10 +85,33 @@ static inline void dma_sync_single_for_device(struct device *hwdev, flush_write_buffers(); } -#define dma_sync_single_range_for_cpu(dev, dma_handle, offset, size, dir) \ - dma_sync_single_for_cpu(dev, dma_handle, size, dir) -#define dma_sync_single_range_for_device(dev, dma_handle, offset, size, dir) \ - dma_sync_single_for_device(dev, dma_handle, size, dir) +static inline void dma_sync_single_range_for_cpu(struct device *hwdev, + dma_addr_t dma_handle, + unsigned long offset, + size_t size, int direction) +{ + if (direction == DMA_NONE) + out_of_line_bug(); + + if (swiotlb) + return swiotlb_sync_single_range_for_cpu(hwdev,dma_handle,offset,size,direction); + + flush_write_buffers(); +} + +static inline void dma_sync_single_range_for_device(struct device *hwdev, + dma_addr_t dma_handle, + unsigned long offset, + size_t size, int direction) +{ + if (direction == DMA_NONE) + out_of_line_bug(); + + if (swiotlb) + return swiotlb_sync_single_range_for_device(hwdev,dma_handle,offset,size,direction); + + flush_write_buffers(); +} static inline void dma_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, From 17e5ad6c0ce5a970e2830d0de8bdd60a2f077d38 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Thu, 29 Sep 2005 15:52:13 -0700 Subject: [PATCH 7/7] [PATCH] Removed remaining PCI specific references from swiotlb.c Matthew Wilcox pointed out that swiotlb.c implements a generic interface that is not tied to just PCI. Remove includes of , . Fix comments and printk() messages to no longer refer to PCI. Signed-off-by: Tony Luck --- lib/swiotlb.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/lib/swiotlb.c b/lib/swiotlb.c index cae806d1ef12..c2fc470b6ed8 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -17,17 +17,17 @@ */ #include +#include #include #include -#include #include #include #include #include #include -#include #include +#include #include #include @@ -127,7 +127,7 @@ __setup("swiotlb=", setup_io_tlb_npages); /* * Statically reserve bounce buffer space and initialize bounce buffer data - * structures for the software IO TLB used to implement the PCI DMA API. + * structures for the software IO TLB used to implement the DMA API. */ void swiotlb_init_with_default_size (size_t default_size) @@ -502,24 +502,24 @@ swiotlb_full(struct device *dev, size_t size, int dir, int do_panic) /* * Ran out of IOMMU space for this operation. This is very bad. * Unfortunately the drivers cannot handle this operation properly. - * unless they check for pci_dma_mapping_error (most don't) + * unless they check for dma_mapping_error (most don't) * When the mapping is small enough return a static buffer to limit * the damage, or panic when the transfer is too big. */ - printk(KERN_ERR "PCI-DMA: Out of SW-IOMMU space for %lu bytes at " + printk(KERN_ERR "DMA: Out of SW-IOMMU space for %lu bytes at " "device %s\n", size, dev ? dev->bus_id : "?"); if (size > io_tlb_overflow && do_panic) { - if (dir == PCI_DMA_FROMDEVICE || dir == PCI_DMA_BIDIRECTIONAL) - panic("PCI-DMA: Memory would be corrupted\n"); - if (dir == PCI_DMA_TODEVICE || dir == PCI_DMA_BIDIRECTIONAL) - panic("PCI-DMA: Random memory would be DMAed\n"); + if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) + panic("DMA: Memory would be corrupted\n"); + if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) + panic("DMA: Random memory would be DMAed\n"); } } /* * Map a single buffer of the indicated size for DMA in streaming mode. The - * PCI address to use is returned. + * physical address to use is returned. * * Once the device is given the dma address, the device owns this memory until * either swiotlb_unmap_single or swiotlb_dma_sync_single is performed. @@ -606,8 +606,8 @@ swiotlb_unmap_single(struct device *hwdev, dma_addr_t dev_addr, size_t size, * after a transfer. * * If you perform a swiotlb_map_single() but wish to interrogate the buffer - * using the cpu, yet do not wish to teardown the PCI dma mapping, you must - * call this function before doing so. At the next point you give the PCI dma + * using the cpu, yet do not wish to teardown the dma mapping, you must + * call this function before doing so. At the next point you give the dma * address back to the card, you must first perform a * swiotlb_dma_sync_for_device, and then the device again owns the buffer */ @@ -783,9 +783,9 @@ swiotlb_dma_mapping_error(dma_addr_t dma_addr) } /* - * Return whether the given PCI device DMA address mask can be supported + * Return whether the given device DMA address mask can be supported * properly. For example, if your device can only drive the low 24-bits - * during PCI bus mastering, then you would pass 0x00ffffff as the mask to + * during bus mastering, then you would pass 0x00ffffff as the mask to * this function. */ int