On 17:16 Tue 12 Mar , Dave Stevenson wrote: > Hi Andrea > > On Tue, 12 Mar 2024 at 09:12, Andrea della Porta <andrea.porta@xxxxxxxx> wrote: > > > > * Spam * > > The BCM2711 has 4 DMA channels with a 40-bit address range, allowing them > > to access the full 4GB of memory on a Pi 4. > > This patchset aims to update the dma engine for BCM* chipset with respect > > to current advancements in downstream vendor tree. In particular, it > > supports the BCM2711 DMA engine in terms of extended DMA addressing to 40 bit. > > > > Changes with respect to the first version (see [1]) of this patchset: > > > > * dropped support of the new BCM2712. It will be the focus of a subsequent > > patch. > > > > * merged patchset from Stefan Wahren [2] to support newer chipset with a > > platform agnostic design, while also retaining the new features added > > from downstream [1], as follows: > > > > - patches from 1 to 5 are preparatory, adding some features and bugfix > > common to all chipsets. > > - patches from 6 to 12 add hw abstraction > > - patches 13 to 15 eventually add 40 bit and BCM2711 support > > > > * fixed a couple of bugs from [2] relative to address shifting on 40 bit > > support specific code > > > > * added the relevant entries in the dts and DT binding that was missing > > in the first patch > > > > * used FIELD_PREP() wherever appropriate as advised in [3] > > > > * of_match_node() has been replaced by the more generic device_get_match_data(), > > as per [4] > > > > * fixed several errors and warnings from checkpatch > > > > > > Please note that there is still a pending discussion around here [5]: > > this patch still use the current approach (used in both downstream > > code and in Stefan's redesigned patchset) of getting the address as it is > > (dma_addr_t) and just add the relevant offset when needed (on 40 bit > > channel, see .addr_offset in struct bcm2835_dma_cfg). This is not > > optimal but still deemed as less hacky than using DMA internals (see > > [6]). As soon as there will be guidelines for [5] or dma_map_resource() > > will take care of dma_ranges, a subsequent patch will adjust accordingly. > > > > Since there is an ongoing effort from Dave Stevenson to upstream a > > patchset with similar goals, I'm adding him to the email loop in order > > seek for collaboration. > > Please hold fire on these patches until we resolve the dma-ranges question. > If the dma-ranges are defined correctly, then the cb_offset is not > required as the mapping deals with it. > > At present we have a mess with the 32bit DMA controllers, and need to > clean it up whilst still having old DT files work. Fixing it up also > requires fixing the DMA users (primarily MMC, SPI, and vc4 HDMI > audio), so will need some care over patch ordering to avoid > regressions. > If at all possible then I would like to avoid the same mess on the 40 > bit controllers too. > I agree with you: I've just sent the entire patchset again for consistency since I had an unlucky issue with the internal imap server that results in the patchset to be splitted and to be *not* received by all intended recipients. I saw that you were one of those so I apologize for the inconvenience. I'll wait for any guidelines regarding dmap_map_resource() and how to proceed about that. Many thanks, Andrea > Thanks > Dave > > FWIW my work in progress branch is currently > https://github.com/6by9/linux/tree/mainline_2712_rp1_dma_vc4_rc5, > which includes my fixed up set of Stefan's patches, as well as all the > other patches that need working on for Pi5 support upstream. > > > Many thanks, > > > > Andrea > > > > Links: > > [1] https://lore.kernel.org/linux-arm-kernel/cover.1706948717.git.andrea.porta@xxxxxxxx/ > > [2] https://lore.kernel.org/linux-arm-kernel/13ec386b-2305-27da-9765-8fa3ad71146c@xxxxxxxx/T/ > > [3] https://lore.kernel.org/linux-arm-kernel/YguMW8n1q0ZV5tKH@matsya/ > > [4] https://lore.kernel.org/linux-arm-kernel/1e71c153-e482-409c-b229-9b9c0662b67e@xxxxxxx/ > > [5] https://lore.kernel.org/all/CAPY8ntByJYzSv0kTAc1kY0Dp=vwrzcA0oWiPpyg7x7_BQwGSnA@xxxxxxxxxxxxxx/ > > [6] https://lkml.org/lkml/2024/2/5/1161 > > > > Andrea della Porta (11): > > dmaengine: bcm2835: Fix several spellos > > dmaengine: bcm2835: Support common dma-channel-mask > > dmaengine: bcm2835: move CB info generation into separate function > > dmaengine: bcm2835: move CB final extra info generation into function > > dmaengine: bcm2835: make address increment platform independent > > dmaengine: bcm2385: drop info parameters > > dmaengine: bcm2835: pass dma_chan to generic functions > > dmaengine: bcm2835: introduce multi platform support > > dt-bindings: dma: Added bcm2711-dma > > dmaengine: bcm2835: Add BCM2711 40-bit DMA support > > ARM: dts: bcm2711: add bcm2711-dma node > > > > Dom Cobley (2): > > dmaengine: bcm2835: Support dma flags for multi-beat burst > > dmaengine: bcm2835: Fixes for dma_abort > > > > Phil Elwell (2): > > dmaengine: bcm2835: Add support for per-channel flags > > dmaengine: bcm2835: Add NO_WAIT_RESP, DMA_WIDE_SOURCE and > > DMA_WIDE_DEST flag > > > > .../bindings/dma/brcm,bcm2835-dma.yaml | 4 +- > > arch/arm/boot/dts/broadcom/bcm2711.dtsi | 16 + > > drivers/dma/bcm2835-dma.c | 1084 +++++++++++++---- > > 3 files changed, 892 insertions(+), 212 deletions(-) > > > > -- > > 2.35.3 > > > >
