---

yaml
---
r: 202988
b: refs/heads/master
c: f4989d9
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4de57826810fd2cfeb2ab5c7d003ff9116b8f7ee
+refs/heads/master: f4989d9befbeeaa2c070fc251edd75e8ffc6deef

trunk/Documentation/ABI/testing/sysfs-bus-pci

@@ -133,46 +133,6 @@ Description:
 		The symbolic link points to the PCI device sysfs entry of the
 		Physical Function this device associates with.
 
-
-What:		/sys/bus/pci/slots/...
-Date:		April 2005 (possibly older)
-KernelVersion:	2.6.12 (possibly older)
-Contact:	linux-pci@vger.kernel.org
-Description:
-		When the appropriate driver is loaded, it will create a
-		directory per claimed physical PCI slot in
-		/sys/bus/pci/slots/.  The names of these directories are
-		specific to the driver, which in turn, are specific to the
-		platform, but in general, should match the label on the
-		machine's physical chassis.
-
-		The drivers that can create slot directories include the
-		PCI hotplug drivers, and as of 2.6.27, the pci_slot driver.
-
-		The slot directories contain, at a minimum, a file named
-		'address' which contains the PCI bus:device:function tuple.
-		Other files may appear as well, but are specific to the
-		driver.
-
-What:		/sys/bus/pci/slots/.../function[0-7]
-Date:		March 2010
-KernelVersion:	2.6.35
-Contact:	linux-pci@vger.kernel.org
-Description:
-		If PCI slot directories (as described above) are created,
-		and the physical slot is actually populated with a device,
-		symbolic links in the slot directory pointing to the
-		device's PCI functions are created as well.
-
-What:		/sys/bus/pci/devices/.../slot
-Date:		March 2010
-KernelVersion:	2.6.35
-Contact:	linux-pci@vger.kernel.org
-Description:
-		If PCI slot directories (as described above) are created,
-		a symbolic link pointing to the slot directory will be
-		created as well.
-
 What:		/sys/bus/pci/slots/.../module
 Date:		June 2009
 Contact:	linux-pci@vger.kernel.org

trunk/Documentation/DMA-API-HOWTO.txt

@@ -639,36 +639,6 @@ is planned to completely remove virt_to_bus() and bus_to_virt() as
 they are entirely deprecated.  Some ports already do not provide these
 as it is impossible to correctly support them.
 
-			Handling Errors
-
-DMA address space is limited on some architectures and an allocation
-failure can be determined by:
-
-- checking if dma_alloc_coherent returns NULL or dma_map_sg returns 0
-
-- checking the returned dma_addr_t of dma_map_single and dma_map_page
-  by using dma_mapping_error():
-
-	dma_addr_t dma_handle;
-
-	dma_handle = dma_map_single(dev, addr, size, direction);
-	if (dma_mapping_error(dev, dma_handle)) {
-		/*
-		 * reduce current DMA mapping usage,
-		 * delay and try again later or
-		 * reset driver.
-		 */
-	}
-
-Networking drivers must call dev_kfree_skb to free the socket buffer
-and return NETDEV_TX_OK if the DMA mapping fails on the transmit hook
-(ndo_start_xmit). This means that the socket buffer is just dropped in
-the failure case.
-
-SCSI drivers must return SCSI_MLQUEUE_HOST_BUSY if the DMA mapping
-fails in the queuecommand hook. This means that the SCSI subsystem
-passes the command to the driver again later.
-
 		Optimizing Unmap State Space Consumption
 
 On many platforms, dma_unmap_{single,page}() is simply a nop.
@@ -733,25 +703,42 @@ to "Closing".
 
 1) Struct scatterlist requirements.
 
-   Don't invent the architecture specific struct scatterlist; just use
-   <asm-generic/scatterlist.h>. You need to enable
-   CONFIG_NEED_SG_DMA_LENGTH if the architecture supports IOMMUs
-   (including software IOMMU).
-
-2) ARCH_KMALLOC_MINALIGN
-
-   Architectures must ensure that kmalloc'ed buffer is
-   DMA-safe. Drivers and subsystems depend on it. If an architecture
-   isn't fully DMA-coherent (i.e. hardware doesn't ensure that data in
-   the CPU cache is identical to data in main memory),
-   ARCH_KMALLOC_MINALIGN must be set so that the memory allocator
-   makes sure that kmalloc'ed buffer doesn't share a cache line with
-   the others. See arch/arm/include/asm/cache.h as an example.
-
-   Note that ARCH_KMALLOC_MINALIGN is about DMA memory alignment
-   constraints. You don't need to worry about the architecture data
-   alignment constraints (e.g. the alignment constraints about 64-bit
-   objects).
+   Struct scatterlist must contain, at a minimum, the following
+   members:
+
+	struct page *page;
+	unsigned int offset;
+	unsigned int length;
+
+   The base address is specified by a "page+offset" pair.
+
+   Previous versions of struct scatterlist contained a "void *address"
+   field that was sometimes used instead of page+offset.  As of Linux
+   2.5., page+offset is always used, and the "address" field has been
+   deleted.
+
+2) More to come...
+
+			Handling Errors
+
+DMA address space is limited on some architectures and an allocation
+failure can be determined by:
+
+- checking if dma_alloc_coherent returns NULL or dma_map_sg returns 0
+
+- checking the returned dma_addr_t of dma_map_single and dma_map_page
+  by using dma_mapping_error():
+
+	dma_addr_t dma_handle;
+
+	dma_handle = dma_map_single(dev, addr, size, direction);
+	if (dma_mapping_error(dev, dma_handle)) {
+		/*
+		 * reduce current DMA mapping usage,
+		 * delay and try again later or
+		 * reset driver.
+		 */
+	}
 
 			   Closing