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3 Commits
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kbuild test robot
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2b651ecfc3 |
dmaengine: dw-edma: fix semicolon.cocci warnings
drivers/dma/dw-edma/dw-edma-core.c:617:2-3: Unneeded semicolon
Remove unneeded semicolon.
Generated by: scripts/coccinelle/misc/semicolon.cocci
Fixes:
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Gustavo Pimentel
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7e4b8a4fbe |
dmaengine: Add Synopsys eDMA IP version 0 support
Add support for the eDMA IP version 0 driver for both register maps (legacy and unroll). The legacy register mapping was the initial implementation, which consisted in having all registers belonging to channels multiplexed, which could be change anytime (which could led a race-condition) by view port register (access to only one channel available each time). This register mapping is not very effective and efficient in a multithread environment, which has led to the development of unroll registers mapping, which consists of having all channels registers accessible any time by spreading all channels registers by an offset between them. This version supports a maximum of 16 independent channels (8 write + 8 read), which can run simultaneously. Implements a scatter-gather transfer through a linked list, where the size of linked list depends on the allocated memory divided equally among all channels. Each linked list descriptor can transfer from 1 byte to 4 Gbytes and is alignmented to DWORD. Both SAR (Source Address Register) and DAR (Destination Address Register) are alignmented to byte. Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com> Cc: Vinod Koul <vkoul@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Joao Pinto <jpinto@synopsys.com> Signed-off-by: Vinod Koul <vkoul@kernel.org> |
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Gustavo Pimentel
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e63d79d1ff |
dmaengine: Add Synopsys eDMA IP core driver
Add Synopsys PCIe Endpoint eDMA IP core driver to kernel. This IP is generally distributed with Synopsys PCIe Endpoint IP (depends of the use and licensing agreement). This core driver, initializes and configures the eDMA IP using vma-helpers functions and dma-engine subsystem. This driver can be compile as built-in or external module in kernel. To enable this driver just select DW_EDMA option in kernel configuration, however it requires and selects automatically DMA_ENGINE and DMA_VIRTUAL_CHANNELS option too. In order to transfer data from point A to B as fast as possible this IP requires a dedicated memory space containing linked list of elements. All elements of this linked list are continuous and each one describes a data transfer (source and destination addresses, length and a control variable). For the sake of simplicity, lets assume a memory space for channel write 0 which allows about 42 elements. +---------+ | Desc #0 |-+ +---------+ | V +----------+ | Chunk #0 |-+ | CB = 1 | | +----------+ +-----+ +-----------+ +-----+ +----------+ +->| Burst #0 |->| ... |->| Burst #41 |->| llp | | +----------+ +-----+ +-----------+ +-----+ V +----------+ | Chunk #1 |-+ | CB = 0 | | +-----------+ +-----+ +-----------+ +-----+ +----------+ +->| Burst #42 |->| ... |->| Burst #83 |->| llp | | +-----------+ +-----+ +-----------+ +-----+ V +----------+ | Chunk #2 |-+ | CB = 1 | | +-----------+ +-----+ +------------+ +-----+ +----------+ +->| Burst #84 |->| ... |->| Burst #125 |->| llp | | +-----------+ +-----+ +------------+ +-----+ V +----------+ | Chunk #3 |-+ | CB = 0 | | +------------+ +-----+ +------------+ +-----+ +----------+ +->| Burst #126 |->| ... |->| Burst #129 |->| llp | +------------+ +-----+ +------------+ +-----+ Legend: - Linked list, also know as Chunk - Linked list element*, also know as Burst *CB*, also know as Change Bit, it's a control bit (and typically is toggled) that allows to easily identify and differentiate between the current linked list and the previous or the next one. - LLP, is a special element that indicates the end of the linked list element stream also informs that the next CB should be toggle On every last Burst of the Chunk (Burst #41, Burst #83, Burst #125 or even Burst #129) is set some flags on their control variable (RIE and LIE bits) that will trigger the send of "done" interruption. On the interruptions callback, is decided whether to recycle the linked list memory space by writing a new set of Bursts elements (if still exists Chunks to transfer) or is considered completed (if there is no Chunks available to transfer). On scatter-gather transfer mode, the client will submit a scatter-gather list of n (on this case 130) elements, that will be divide in multiple Chunks, each Chunk will have (on this case 42) a limited number of Bursts and after transferring all Bursts, an interrupt will be triggered, which will allow to recycle the all linked list dedicated memory again with the new information relative to the next Chunk and respective Burst associated and repeat the whole cycle again. On cyclic transfer mode, the client will submit a buffer pointer, length of it and number of repetitions, in this case each burst will correspond directly to each repetition. Each Burst can describes a data transfer from point A(source) to point B(destination) with a length that can be from 1 byte up to 4 GB. Since dedicated the memory space where the linked list will reside is limited, the whole n burst elements will be organized in several Chunks, that will be used later to recycle the dedicated memory space to initiate a new sequence of data transfers. The whole transfer is considered has completed when it was transferred all bursts. Currently this IP has a set well-known register map, which includes support for legacy and unroll modes. Legacy mode is version of this register map that has multiplexer register that allows to switch registers between all write and read channels and the unroll modes repeats all write and read channels registers with an offset between them. This register map is called v0. The IP team is creating a new register map more suitable to the latest PCIe features, that very likely will change the map register, which this version will be called v1. As soon as this new version is released by the IP team the support for this version in be included on this driver. According to the logic, patches 1, 2 and 3 should be squashed into 1 unique patch, but for the sake of simplicity of review, it was divided in this 3 patches files. Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com> Cc: Vinod Koul <vkoul@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Joao Pinto <jpinto@synopsys.com> Signed-off-by: Vinod Koul <vkoul@kernel.org> |