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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-23 13:41:24 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-23 13:41:24 -0700 |
commit | d8133356e99713bd023b229de107ddd6dd6d375a (patch) | |
tree | 3155424b58daff2190ab7aff75ba6204aef692a3 /Documentation/DMA-API.txt | |
parent | 234a56c80a6aa7a05fec05d8b7184354d8765b48 (diff) | |
parent | 207b074f82c6790f008bfe055c37b47047eb2122 (diff) | |
download | linux-d8133356e99713bd023b229de107ddd6dd6d375a.tar.gz linux-d8133356e99713bd023b229de107ddd6dd6d375a.tar.bz2 linux-d8133356e99713bd023b229de107ddd6dd6d375a.zip |
Merge tag 'pci-v4.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:
"PCI changes for the v4.2 merge window:
Enumeration
- Move pci_ari_enabled() to global header (Alex Williamson)
- Account for ARI in _PRT lookups (Alex Williamson)
- Remove unused pci_scan_bus_parented() (Yijing Wang)
Resource management
- Use host bridge _CRS info on systems with >32 bit addressing (Bjorn Helgaas)
- Use host bridge _CRS info on Foxconn K8M890-8237A (Bjorn Helgaas)
- Fix pci_address_to_pio() conversion of CPU address to I/O port (Zhichang Yuan)
- Add pci_bus_addr_t (Yinghai Lu)
PCI device hotplug
- Wait for pciehp command completion where necessary (Alex Williamson)
- Drop pointless ACPI-based "slot detection" check (Rafael J. Wysocki)
- Check ignore_hotplug for all downstream devices (Rafael J. Wysocki)
- Propagate the "ignore hotplug" setting to parent (Rafael J. Wysocki)
- Inline pciehp "handle event" functions into the ISR (Bjorn Helgaas)
- Clean up pciehp debug logging (Bjorn Helgaas)
Power management
- Remove redundant PCIe port type checking (Yijing Wang)
- Add dev->has_secondary_link to track downstream PCIe links (Yijing Wang)
- Use dev->has_secondary_link to find downstream links for ASPM (Yijing Wang)
- Drop __pci_disable_link_state() useless "force" parameter (Bjorn Helgaas)
- Simplify Clock Power Management setting (Bjorn Helgaas)
Virtualization
- Add ACS quirks for Intel 9-series PCH root ports (Alex Williamson)
- Add function 1 DMA alias quirk for Marvell 9120 (Sakari Ailus)
MSI
- Disable MSI at enumeration even if kernel doesn't support MSI (Michael S. Tsirkin)
- Remove unused pci_msi_off() (Bjorn Helgaas)
- Rename msi_set_enable(), msix_clear_and_set_ctrl() (Michael S. Tsirkin)
- Export pci_msi_set_enable(), pci_msix_clear_and_set_ctrl() (Michael S. Tsirkin)
- Drop pci_msi_off() calls during probe (Michael S. Tsirkin)
APM X-Gene host bridge driver
- Add APM X-Gene v1 PCIe MSI/MSIX termination driver (Duc Dang)
- Add APM X-Gene PCIe MSI DTS nodes (Duc Dang)
- Disable Configuration Request Retry Status for v1 silicon (Duc Dang)
- Allow config access to Root Port even when link is down (Duc Dang)
Broadcom iProc host bridge driver
- Allow override of device tree IRQ mapping function (Hauke Mehrtens)
- Add BCMA PCIe driver (Hauke Mehrtens)
- Directly add PCI resources (Hauke Mehrtens)
- Free resource list after registration (Hauke Mehrtens)
Freescale i.MX6 host bridge driver
- Add speed change timeout message (Troy Kisky)
- Rename imx6_pcie_start_link() to imx6_pcie_establish_link() (Bjorn Helgaas)
Freescale Layerscape host bridge driver
- Use dw_pcie_link_up() consistently (Bjorn Helgaas)
- Factor out ls_pcie_establish_link() (Bjorn Helgaas)
Marvell MVEBU host bridge driver
- Remove mvebu_pcie_scan_bus() (Yijing Wang)
NVIDIA Tegra host bridge driver
- Remove tegra_pcie_scan_bus() (Yijing Wang)
Synopsys DesignWare host bridge driver
- Consolidate outbound iATU programming functions (Jisheng Zhang)
- Use iATU0 for cfg and IO, iATU1 for MEM (Jisheng Zhang)
- Add support for x8 links (Zhou Wang)
- Wait for link to come up with consistent style (Bjorn Helgaas)
- Use pci_scan_root_bus() for simplicity (Yijing Wang)
TI DRA7xx host bridge driver
- Use dw_pcie_link_up() consistently (Bjorn Helgaas)
Miscellaneous
- Include <linux/pci.h>, not <asm/pci.h> (Bjorn Helgaas)
- Remove unnecessary #includes of <asm/pci.h> (Bjorn Helgaas)
- Remove unused pcibios_select_root() (again) (Bjorn Helgaas)
- Remove unused pci_dma_burst_advice() (Bjorn Helgaas)
- xen/pcifront: Don't use deprecated function pci_scan_bus_parented() (Arnd Bergmann)"
* tag 'pci-v4.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (58 commits)
PCI: pciehp: Inline the "handle event" functions into the ISR
PCI: pciehp: Rename queue_interrupt_event() to pciehp_queue_interrupt_event()
PCI: pciehp: Make queue_interrupt_event() void
PCI: xgene: Allow config access to Root Port even when link is down
PCI: xgene: Disable Configuration Request Retry Status for v1 silicon
PCI: pciehp: Clean up debug logging
x86/PCI: Use host bridge _CRS info on systems with >32 bit addressing
PCI: imx6: Add #define PCIE_RC_LCSR
PCI: imx6: Use "u32", not "uint32_t"
PCI: Remove unused pci_scan_bus_parented()
xen/pcifront: Don't use deprecated function pci_scan_bus_parented()
PCI: imx6: Add speed change timeout message
PCI/ASPM: Simplify Clock Power Management setting
PCI: designware: Wait for link to come up with consistent style
PCI: layerscape: Factor out ls_pcie_establish_link()
PCI: layerscape: Use dw_pcie_link_up() consistently
PCI: dra7xx: Use dw_pcie_link_up() consistently
x86/PCI: Use host bridge _CRS info on Foxconn K8M890-8237A
PCI: pciehp: Wait for hotplug command completion where necessary
PCI: Remove unused pci_dma_burst_advice()
...
Diffstat (limited to 'Documentation/DMA-API.txt')
-rw-r--r-- | Documentation/DMA-API.txt | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index 52088408668a..7eba542eff7c 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -18,10 +18,10 @@ Part I - dma_ API To get the dma_ API, you must #include <linux/dma-mapping.h>. This provides dma_addr_t and the interfaces described below. -A dma_addr_t can hold any valid DMA or bus address for the platform. It -can be given to a device to use as a DMA source or target. A CPU cannot -reference a dma_addr_t directly because there may be translation between -its physical address space and the bus address space. +A dma_addr_t can hold any valid DMA address for the platform. It can be +given to a device to use as a DMA source or target. A CPU cannot reference +a dma_addr_t directly because there may be translation between its physical +address space and the DMA address space. Part Ia - Using large DMA-coherent buffers ------------------------------------------ @@ -42,7 +42,7 @@ It returns a pointer to the allocated region (in the processor's virtual address space) or NULL if the allocation failed. It also returns a <dma_handle> which may be cast to an unsigned integer the -same width as the bus and given to the device as the bus address base of +same width as the bus and given to the device as the DMA address base of the region. Note: consistent memory can be expensive on some platforms, and the @@ -193,7 +193,7 @@ dma_map_single(struct device *dev, void *cpu_addr, size_t size, enum dma_data_direction direction) Maps a piece of processor virtual memory so it can be accessed by the -device and returns the bus address of the memory. +device and returns the DMA address of the memory. The direction for both APIs may be converted freely by casting. However the dma_ API uses a strongly typed enumerator for its @@ -212,20 +212,20 @@ contiguous piece of memory. For this reason, memory to be mapped by this API should be obtained from sources which guarantee it to be physically contiguous (like kmalloc). -Further, the bus address of the memory must be within the +Further, the DMA address of the memory must be within the dma_mask of the device (the dma_mask is a bit mask of the -addressable region for the device, i.e., if the bus address of -the memory ANDed with the dma_mask is still equal to the bus +addressable region for the device, i.e., if the DMA address of +the memory ANDed with the dma_mask is still equal to the DMA address, then the device can perform DMA to the memory). To ensure that the memory allocated by kmalloc is within the dma_mask, the driver may specify various platform-dependent flags to restrict -the bus address range of the allocation (e.g., on x86, GFP_DMA -guarantees to be within the first 16MB of available bus addresses, +the DMA address range of the allocation (e.g., on x86, GFP_DMA +guarantees to be within the first 16MB of available DMA addresses, as required by ISA devices). Note also that the above constraints on physical contiguity and dma_mask may not apply if the platform has an IOMMU (a device which -maps an I/O bus address to a physical memory address). However, to be +maps an I/O DMA address to a physical memory address). However, to be portable, device driver writers may *not* assume that such an IOMMU exists. @@ -296,7 +296,7 @@ reduce current DMA mapping usage or delay and try again later). dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction direction) -Returns: the number of bus address segments mapped (this may be shorter +Returns: the number of DMA address segments mapped (this may be shorter than <nents> passed in if some elements of the scatter/gather list are physically or virtually adjacent and an IOMMU maps them with a single entry). @@ -340,7 +340,7 @@ must be the same as those and passed in to the scatter/gather mapping API. Note: <nents> must be the number you passed in, *not* the number of -bus address entries returned. +DMA address entries returned. void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, @@ -507,7 +507,7 @@ it's asked for coherent memory for this device. phys_addr is the CPU physical address to which the memory is currently assigned (this will be ioremapped so the CPU can access the region). -device_addr is the bus address the device needs to be programmed +device_addr is the DMA address the device needs to be programmed with to actually address this memory (this will be handed out as the dma_addr_t in dma_alloc_coherent()). |