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authorBjorn Helgaas <bhelgaas@google.com>2014-05-20 18:56:27 -0400
committerBjorn Helgaas <bhelgaas@google.com>2014-05-26 19:28:27 -0400
commitf311a724a79669ac0336932d0361325afdb54279 (patch)
tree1f86a93a676d25961f692ca5966ea1decb0a867f
parentace4b3fd67e771951d495aa1f1b1000984083362 (diff)
DMA-API: Capitalize "CPU" consistently
Sometimes we used "cpu," other times "CPU." Use "CPU" consistently. Suggested-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
-rw-r--r--Documentation/DMA-API-HOWTO.txt8
-rw-r--r--Documentation/DMA-API.txt12
2 files changed, 10 insertions, 10 deletions
diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt
index fd3727b94ac2..f59955303475 100644
--- a/Documentation/DMA-API-HOWTO.txt
+++ b/Documentation/DMA-API-HOWTO.txt
@@ -575,10 +575,10 @@ Incorrect example 2:
575You should call dma_unmap_single() when the DMA activity is finished, e.g., 575You should call dma_unmap_single() when the DMA activity is finished, e.g.,
576from the interrupt which told you that the DMA transfer is done. 576from the interrupt which told you that the DMA transfer is done.
577 577
578Using cpu pointers like this for single mappings has a disadvantage: 578Using CPU pointers like this for single mappings has a disadvantage:
579you cannot reference HIGHMEM memory in this way. Thus, there is a 579you cannot reference HIGHMEM memory in this way. Thus, there is a
580map/unmap interface pair akin to dma_{map,unmap}_single(). These 580map/unmap interface pair akin to dma_{map,unmap}_single(). These
581interfaces deal with page/offset pairs instead of cpu pointers. 581interfaces deal with page/offset pairs instead of CPU pointers.
582Specifically: 582Specifically:
583 583
584 struct device *dev = &my_dev->dev; 584 struct device *dev = &my_dev->dev;
@@ -650,7 +650,7 @@ you could render the machine unusable by consuming all bus addresses.
650 650
651If you need to use the same streaming DMA region multiple times and touch 651If you need to use the same streaming DMA region multiple times and touch
652the data in between the DMA transfers, the buffer needs to be synced 652the data in between the DMA transfers, the buffer needs to be synced
653properly in order for the cpu and device to see the most up-to-date and 653properly in order for the CPU and device to see the most up-to-date and
654correct copy of the DMA buffer. 654correct copy of the DMA buffer.
655 655
656So, firstly, just map it with dma_map_{single,sg}(), and after each DMA 656So, firstly, just map it with dma_map_{single,sg}(), and after each DMA
@@ -665,7 +665,7 @@ or:
665as appropriate. 665as appropriate.
666 666
667Then, if you wish to let the device get at the DMA area again, 667Then, if you wish to let the device get at the DMA area again,
668finish accessing the data with the cpu, and then before actually 668finish accessing the data with the CPU, and then before actually
669giving the buffer to the hardware call either: 669giving the buffer to the hardware call either:
670 670
671 dma_sync_single_for_device(dev, dma_handle, size, direction); 671 dma_sync_single_for_device(dev, dma_handle, size, direction);
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index 4f1cdc5febd1..52088408668a 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -19,7 +19,7 @@ To get the dma_ API, you must #include <linux/dma-mapping.h>. This
19provides dma_addr_t and the interfaces described below. 19provides dma_addr_t and the interfaces described below.
20 20
21A dma_addr_t can hold any valid DMA or bus address for the platform. It 21A dma_addr_t can hold any valid DMA or bus address for the platform. It
22can be given to a device to use as a DMA source or target. A cpu cannot 22can be given to a device to use as a DMA source or target. A CPU cannot
23reference a dma_addr_t directly because there may be translation between 23reference a dma_addr_t directly because there may be translation between
24its physical address space and the bus address space. 24its physical address space and the bus address space.
25 25
@@ -112,7 +112,7 @@ size and alignment requirements specified at creation time. Pass
112GFP_ATOMIC to prevent blocking, or if it's permitted (not 112GFP_ATOMIC to prevent blocking, or if it's permitted (not
113in_interrupt, not holding SMP locks), pass GFP_KERNEL to allow 113in_interrupt, not holding SMP locks), pass GFP_KERNEL to allow
114blocking. Like dma_alloc_coherent(), this returns two values: an 114blocking. Like dma_alloc_coherent(), this returns two values: an
115address usable by the cpu, and the DMA address usable by the pool's 115address usable by the CPU, and the DMA address usable by the pool's
116device. 116device.
117 117
118 118
@@ -120,7 +120,7 @@ device.
120 dma_addr_t addr); 120 dma_addr_t addr);
121 121
122This puts memory back into the pool. The pool is what was passed to 122This puts memory back into the pool. The pool is what was passed to
123dma_pool_alloc(); the cpu (vaddr) and DMA addresses are what 123dma_pool_alloc(); the CPU (vaddr) and DMA addresses are what
124were returned when that routine allocated the memory being freed. 124were returned when that routine allocated the memory being freed.
125 125
126 126
@@ -355,7 +355,7 @@ void
355dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems, 355dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems,
356 enum dma_data_direction direction) 356 enum dma_data_direction direction)
357 357
358Synchronise a single contiguous or scatter/gather mapping for the cpu 358Synchronise a single contiguous or scatter/gather mapping for the CPU
359and device. With the sync_sg API, all the parameters must be the same 359and device. With the sync_sg API, all the parameters must be the same
360as those passed into the single mapping API. With the sync_single API, 360as those passed into the single mapping API. With the sync_single API,
361you can use dma_handle and size parameters that aren't identical to 361you can use dma_handle and size parameters that aren't identical to
@@ -504,8 +504,8 @@ dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
504Declare region of memory to be handed out by dma_alloc_coherent() when 504Declare region of memory to be handed out by dma_alloc_coherent() when
505it's asked for coherent memory for this device. 505it's asked for coherent memory for this device.
506 506
507phys_addr is the cpu physical address to which the memory is currently 507phys_addr is the CPU physical address to which the memory is currently
508assigned (this will be ioremapped so the cpu can access the region). 508assigned (this will be ioremapped so the CPU can access the region).
509 509
510device_addr is the bus address the device needs to be programmed 510device_addr is the bus address the device needs to be programmed
511with to actually address this memory (this will be handed out as the 511with to actually address this memory (this will be handed out as the