| Message ID | 0e877ac0115d37e466ac234f47c51cb1cae7f292.1556043127.git.gustavo.pimentel@synopsys.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | dmaengine: Add Synopsys eDMA IP driver (version 0) | expand |
On 23-04-19, 20:30, Gustavo Pimentel wrote: > Add Synopsys PCIe Endpoint eDMA IP core driver to kernel. Still an RFC ? > +static struct dw_edma_chunk *dw_edma_alloc_chunk(struct dw_edma_desc *desc) > +{ > + struct dw_edma_chan *chan = desc->chan; > + struct dw_edma *dw = chan->chip->dw; > + struct dw_edma_chunk *chunk; > + > + chunk = kzalloc(sizeof(*chunk), GFP_KERNEL); Looking at the code this should be called from one of the device_prep_xxx calls so this should not sleep, so GFP_NOWAIT please (pls audit rest of the mem allocations in the code) > + if (unlikely(!chunk)) > + return NULL; > + > + INIT_LIST_HEAD(&chunk->list); > + chunk->chan = chan; > + chunk->cb = !(desc->chunks_alloc % 2); ? why %2? > +static enum dma_status > +dw_edma_device_tx_status(struct dma_chan *dchan, dma_cookie_t cookie, > + struct dma_tx_state *txstate) > +{ > + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); > + struct dw_edma_desc *desc; > + struct virt_dma_desc *vd; > + unsigned long flags; > + enum dma_status ret; > + u32 residue = 0; > + > + ret = dma_cookie_status(dchan, cookie, txstate); > + if (ret == DMA_COMPLETE) > + return ret; > + > + if (ret == DMA_IN_PROGRESS && chan->status == EDMA_ST_PAUSE) > + ret = DMA_PAUSED; Don't you want to set residue on paused channel, how else will user know the position of pause? > +static struct dma_async_tx_descriptor * > +dw_edma_device_transfer(struct dw_edma_transfer *xfer) > +{ > + struct dw_edma_chan *chan = dchan2dw_edma_chan(xfer->dchan); > + enum dma_transfer_direction direction = xfer->direction; > + phys_addr_t src_addr, dst_addr; > + struct scatterlist *sg = NULL; > + struct dw_edma_chunk *chunk; > + struct dw_edma_burst *burst; > + struct dw_edma_desc *desc; > + u32 cnt; > + int i; > + > + if ((direction == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_WRITE) || > + (direction == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_READ)) > + return NULL; > + > + if (xfer->cyclic) { > + if (!xfer->xfer.cyclic.len || !xfer->xfer.cyclic.cnt) > + return NULL; > + } else { > + if (xfer->xfer.sg.len < 1) > + return NULL; > + } > + > + if (!chan->configured) > + return NULL; > + > + desc = dw_edma_alloc_desc(chan); > + if (unlikely(!desc)) > + goto err_alloc; > + > + chunk = dw_edma_alloc_chunk(desc); > + if (unlikely(!chunk)) > + goto err_alloc; > + > + src_addr = chan->config.src_addr; > + dst_addr = chan->config.dst_addr; > + > + if (xfer->cyclic) { > + cnt = xfer->xfer.cyclic.cnt; > + } else { > + cnt = xfer->xfer.sg.len; > + sg = xfer->xfer.sg.sgl; > + } > + > + for (i = 0; i < cnt; i++) { > + if (!xfer->cyclic && !sg) > + break; > + > + if (chunk->bursts_alloc == chan->ll_max) { > + chunk = dw_edma_alloc_chunk(desc); > + if (unlikely(!chunk)) > + goto err_alloc; > + } > + > + burst = dw_edma_alloc_burst(chunk); > + if (unlikely(!burst)) > + goto err_alloc; > + > + if (xfer->cyclic) > + burst->sz = xfer->xfer.cyclic.len; > + else > + burst->sz = sg_dma_len(sg); > + > + chunk->ll_region.sz += burst->sz; > + desc->alloc_sz += burst->sz; > + > + if (direction == DMA_DEV_TO_MEM) { > + burst->sar = src_addr; We are device to mem, so src is peripheral.. okay > + if (xfer->cyclic) { > + burst->dar = xfer->xfer.cyclic.paddr; > + } else { > + burst->dar = sg_dma_address(sg); > + src_addr += sg_dma_len(sg); and we increment the src, doesn't make sense to me! > + } > + } else { > + burst->dar = dst_addr; > + if (xfer->cyclic) { > + burst->sar = xfer->xfer.cyclic.paddr; > + } else { > + burst->sar = sg_dma_address(sg); > + dst_addr += sg_dma_len(sg); same here as well > +static void dw_edma_done_interrupt(struct dw_edma_chan *chan) > +{ > + struct dw_edma_desc *desc; > + struct virt_dma_desc *vd; > + unsigned long flags; > + > + dw_edma_v0_core_clear_done_int(chan); > + > + spin_lock_irqsave(&chan->vc.lock, flags); > + vd = vchan_next_desc(&chan->vc); > + if (vd) { > + switch (chan->request) { > + case EDMA_REQ_NONE: > + desc = vd2dw_edma_desc(vd); > + if (desc->chunks_alloc) { > + chan->status = EDMA_ST_BUSY; > + dw_edma_start_transfer(chan); > + } else { > + list_del(&vd->node); > + vchan_cookie_complete(vd); > + chan->status = EDMA_ST_IDLE; > + } > + break; Empty line after each break please > + case EDMA_REQ_STOP: > + list_del(&vd->node); > + vchan_cookie_complete(vd); > + chan->request = EDMA_REQ_NONE; > + chan->status = EDMA_ST_IDLE; Why do we need to track request as well as status? > +static int dw_edma_alloc_chan_resources(struct dma_chan *dchan) > +{ > + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); > + > + if (chan->status != EDMA_ST_IDLE) > + return -EBUSY; > + > + dma_cookie_init(dchan); not using vchan_init() you need to do this and init the lists..? > +struct dw_edma_transfer { > + struct dma_chan *dchan; > + union Xfer { no camel case please It would help to run checkpatch with --strict option to find any style issues and fix them as well
Hi Vinod, On Mon, May 6, 2019 at 12:20:1, Vinod Koul <vkoul@kernel.org> wrote: > On 23-04-19, 20:30, Gustavo Pimentel wrote: > > Add Synopsys PCIe Endpoint eDMA IP core driver to kernel. > > Still an RFC ? Yes, it was RFC til I get a formal validation from the HW team. Now that I got it, I can formally submit the very first patch version. > > > +static struct dw_edma_chunk *dw_edma_alloc_chunk(struct dw_edma_desc *desc) > > +{ > > + struct dw_edma_chan *chan = desc->chan; > > + struct dw_edma *dw = chan->chip->dw; > > + struct dw_edma_chunk *chunk; > > + > > + chunk = kzalloc(sizeof(*chunk), GFP_KERNEL); > > Looking at the code this should be called from one of the > device_prep_xxx calls so this should not sleep, so GFP_NOWAIT please > > (pls audit rest of the mem allocations in the code) Ok. Fixed on dw_edma_alloc_burst(), dw_edma_alloc_chunk() and dw_edma_alloc_desc(). The other memory allocations are on probe() and dw_edma_channel_setup() that is called by probe(), that doesn't require to be GFP_NOWAIT. > > > + if (unlikely(!chunk)) > > + return NULL; > > + > > + INIT_LIST_HEAD(&chunk->list); > > + chunk->chan = chan; > > + chunk->cb = !(desc->chunks_alloc % 2); > ? why %2? I think it's explained on the patch description. CB also is known as Change Bit that must be toggled in order to the HW assume a new linked list is available to be consumed. Since desc->chunks_alloc variable is an incremental counter the remainder after division by 2 will be zero (if chunks_alloc is even) or one (if chunks_alloc is odd). > > > +static enum dma_status > > +dw_edma_device_tx_status(struct dma_chan *dchan, dma_cookie_t cookie, > > + struct dma_tx_state *txstate) > > +{ > > + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); > > + struct dw_edma_desc *desc; > > + struct virt_dma_desc *vd; > > + unsigned long flags; > > + enum dma_status ret; > > + u32 residue = 0; > > + > > + ret = dma_cookie_status(dchan, cookie, txstate); > > + if (ret == DMA_COMPLETE) > > + return ret; > > + > > + if (ret == DMA_IN_PROGRESS && chan->status == EDMA_ST_PAUSE) > > + ret = DMA_PAUSED; > > Don't you want to set residue on paused channel, how else will user know > the position of pause? I didn't catch you on this. I'm only setting the dma status here. After this function, the residue is calculated and set, isn't it? > > > +static struct dma_async_tx_descriptor * > > +dw_edma_device_transfer(struct dw_edma_transfer *xfer) > > +{ > > + struct dw_edma_chan *chan = dchan2dw_edma_chan(xfer->dchan); > > + enum dma_transfer_direction direction = xfer->direction; > > + phys_addr_t src_addr, dst_addr; > > + struct scatterlist *sg = NULL; > > + struct dw_edma_chunk *chunk; > > + struct dw_edma_burst *burst; > > + struct dw_edma_desc *desc; > > + u32 cnt; > > + int i; > > + > > + if ((direction == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_WRITE) || > > + (direction == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_READ)) > > + return NULL; > > + > > + if (xfer->cyclic) { > > + if (!xfer->xfer.cyclic.len || !xfer->xfer.cyclic.cnt) > > + return NULL; > > + } else { > > + if (xfer->xfer.sg.len < 1) > > + return NULL; > > + } > > + > > + if (!chan->configured) > > + return NULL; > > + > > + desc = dw_edma_alloc_desc(chan); > > + if (unlikely(!desc)) > > + goto err_alloc; > > + > > + chunk = dw_edma_alloc_chunk(desc); > > + if (unlikely(!chunk)) > > + goto err_alloc; > > + > > + src_addr = chan->config.src_addr; > > + dst_addr = chan->config.dst_addr; > > + > > + if (xfer->cyclic) { > > + cnt = xfer->xfer.cyclic.cnt; > > + } else { > > + cnt = xfer->xfer.sg.len; > > + sg = xfer->xfer.sg.sgl; > > + } > > + > > + for (i = 0; i < cnt; i++) { > > + if (!xfer->cyclic && !sg) > > + break; > > + > > + if (chunk->bursts_alloc == chan->ll_max) { > > + chunk = dw_edma_alloc_chunk(desc); > > + if (unlikely(!chunk)) > > + goto err_alloc; > > + } > > + > > + burst = dw_edma_alloc_burst(chunk); > > + if (unlikely(!burst)) > > + goto err_alloc; > > + > > + if (xfer->cyclic) > > + burst->sz = xfer->xfer.cyclic.len; > > + else > > + burst->sz = sg_dma_len(sg); > > + > > + chunk->ll_region.sz += burst->sz; > > + desc->alloc_sz += burst->sz; > > + > > + if (direction == DMA_DEV_TO_MEM) { > > + burst->sar = src_addr; > > We are device to mem, so src is peripheral.. okay > > > + if (xfer->cyclic) { > > + burst->dar = xfer->xfer.cyclic.paddr; > > + } else { > > + burst->dar = sg_dma_address(sg); > > + src_addr += sg_dma_len(sg); > > and we increment the src, doesn't make sense to me! > > > + } > > + } else { > > + burst->dar = dst_addr; > > + if (xfer->cyclic) { > > + burst->sar = xfer->xfer.cyclic.paddr; > > + } else { > > + burst->sar = sg_dma_address(sg); > > + dst_addr += sg_dma_len(sg); > > same here as well This is hard to explain in words... Well, in my perspective I want to transfer a piece of memory from the peripheral into local RAM Through the DMA client API I'll break this piece of memory in several small parts and add all into a list (scatter-gather), right? Each element of the scatter-gather has the sg_dma_address (in the DMA_DEV_TO_MEM case will be the destination address) and the corresponding size. However, I still need the other address (in the DMA_DEV_TO_MEM case will be the source address) for that small part of memory. Since I get that address from the config, I still need to increment the source address in the same proportion of the destination address, in other words, the increment will be the part size. If there is some way to set and get the address for the source (in this case) into each scatter-gather element, that would be much nicer, is that possible? > > > +static void dw_edma_done_interrupt(struct dw_edma_chan *chan) > > +{ > > + struct dw_edma_desc *desc; > > + struct virt_dma_desc *vd; > > + unsigned long flags; > > + > > + dw_edma_v0_core_clear_done_int(chan); > > + > > + spin_lock_irqsave(&chan->vc.lock, flags); > > + vd = vchan_next_desc(&chan->vc); > > + if (vd) { > > + switch (chan->request) { > > + case EDMA_REQ_NONE: > > + desc = vd2dw_edma_desc(vd); > > + if (desc->chunks_alloc) { > > + chan->status = EDMA_ST_BUSY; > > + dw_edma_start_transfer(chan); > > + } else { > > + list_del(&vd->node); > > + vchan_cookie_complete(vd); > > + chan->status = EDMA_ST_IDLE; > > + } > > + break; > > Empty line after each break please Ok. Done. > > > + case EDMA_REQ_STOP: > > + list_del(&vd->node); > > + vchan_cookie_complete(vd); > > + chan->request = EDMA_REQ_NONE; > > + chan->status = EDMA_ST_IDLE; > > Why do we need to track request as well as status? Since I don't actually have the PAUSE state feature available on HW, I'm emulating it through software. As far as HW is concerned, it thinks that it has transferred everything (no more bursts valid available), but in terms of software, we still have a lot of chunks (each one containing several bursts) to process. > > > +static int dw_edma_alloc_chan_resources(struct dma_chan *dchan) > > +{ > > + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); > > + > > + if (chan->status != EDMA_ST_IDLE) > > + return -EBUSY; > > + > > + dma_cookie_init(dchan); > > not using vchan_init() you need to do this and init the lists..? That's right, vchan_init() already does that. > > > +struct dw_edma_transfer { > > + struct dma_chan *dchan; > > + union Xfer { > > no camel case please Ok. > > It would help to run checkpatch with --strict option to find any style > issues and fix them as well I usually run with that option, but for now, that option is giving some warnings about macro variable names that are pure noise. > -- > ~Vinod Regards, Gustavo
On 06-05-19, 16:42, Gustavo Pimentel wrote: > > > + if (unlikely(!chunk)) > > > + return NULL; > > > + > > > + INIT_LIST_HEAD(&chunk->list); > > > + chunk->chan = chan; > > > + chunk->cb = !(desc->chunks_alloc % 2); > > ? why %2? > > I think it's explained on the patch description. CB also is known as > Change Bit that must be toggled in order to the HW assume a new linked > list is available to be consumed. > Since desc->chunks_alloc variable is an incremental counter the remainder > after division by 2 will be zero (if chunks_alloc is even) or one (if > chunks_alloc is odd). Okay it would be great to add a comment here to explain as well > > > +static enum dma_status > > > +dw_edma_device_tx_status(struct dma_chan *dchan, dma_cookie_t cookie, > > > + struct dma_tx_state *txstate) > > > +{ > > > + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); > > > + struct dw_edma_desc *desc; > > > + struct virt_dma_desc *vd; > > > + unsigned long flags; > > > + enum dma_status ret; > > > + u32 residue = 0; > > > + > > > + ret = dma_cookie_status(dchan, cookie, txstate); > > > + if (ret == DMA_COMPLETE) > > > + return ret; > > > + > > > + if (ret == DMA_IN_PROGRESS && chan->status == EDMA_ST_PAUSE) > > > + ret = DMA_PAUSED; > > > > Don't you want to set residue on paused channel, how else will user know > > the position of pause? > > I didn't catch you on this. I'm only setting the dma status here. After > this function, the residue is calculated and set, isn't it? Hmm I thought you returned for paused case, if not then it is okay > > > +static struct dma_async_tx_descriptor * > > > +dw_edma_device_transfer(struct dw_edma_transfer *xfer) > > > +{ > > > + struct dw_edma_chan *chan = dchan2dw_edma_chan(xfer->dchan); > > > + enum dma_transfer_direction direction = xfer->direction; > > > + phys_addr_t src_addr, dst_addr; > > > + struct scatterlist *sg = NULL; > > > + struct dw_edma_chunk *chunk; > > > + struct dw_edma_burst *burst; > > > + struct dw_edma_desc *desc; > > > + u32 cnt; > > > + int i; > > > + > > > + if ((direction == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_WRITE) || > > > + (direction == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_READ)) > > > + return NULL; > > > + > > > + if (xfer->cyclic) { > > > + if (!xfer->xfer.cyclic.len || !xfer->xfer.cyclic.cnt) > > > + return NULL; > > > + } else { > > > + if (xfer->xfer.sg.len < 1) > > > + return NULL; > > > + } > > > + > > > + if (!chan->configured) > > > + return NULL; > > > + > > > + desc = dw_edma_alloc_desc(chan); > > > + if (unlikely(!desc)) > > > + goto err_alloc; > > > + > > > + chunk = dw_edma_alloc_chunk(desc); > > > + if (unlikely(!chunk)) > > > + goto err_alloc; > > > + > > > + src_addr = chan->config.src_addr; > > > + dst_addr = chan->config.dst_addr; > > > + > > > + if (xfer->cyclic) { > > > + cnt = xfer->xfer.cyclic.cnt; > > > + } else { > > > + cnt = xfer->xfer.sg.len; > > > + sg = xfer->xfer.sg.sgl; > > > + } > > > + > > > + for (i = 0; i < cnt; i++) { > > > + if (!xfer->cyclic && !sg) > > > + break; > > > + > > > + if (chunk->bursts_alloc == chan->ll_max) { > > > + chunk = dw_edma_alloc_chunk(desc); > > > + if (unlikely(!chunk)) > > > + goto err_alloc; > > > + } > > > + > > > + burst = dw_edma_alloc_burst(chunk); > > > + if (unlikely(!burst)) > > > + goto err_alloc; > > > + > > > + if (xfer->cyclic) > > > + burst->sz = xfer->xfer.cyclic.len; > > > + else > > > + burst->sz = sg_dma_len(sg); > > > + > > > + chunk->ll_region.sz += burst->sz; > > > + desc->alloc_sz += burst->sz; > > > + > > > + if (direction == DMA_DEV_TO_MEM) { > > > + burst->sar = src_addr; > > > > We are device to mem, so src is peripheral.. okay > > > > > + if (xfer->cyclic) { > > > + burst->dar = xfer->xfer.cyclic.paddr; > > > + } else { > > > + burst->dar = sg_dma_address(sg); > > > + src_addr += sg_dma_len(sg); > > > > and we increment the src, doesn't make sense to me! > > > > > + } > > > + } else { > > > + burst->dar = dst_addr; > > > + if (xfer->cyclic) { > > > + burst->sar = xfer->xfer.cyclic.paddr; > > > + } else { > > > + burst->sar = sg_dma_address(sg); > > > + dst_addr += sg_dma_len(sg); > > > > same here as well > > This is hard to explain in words... > Well, in my perspective I want to transfer a piece of memory from the > peripheral into local RAM Right and most of the case RAM address (sg) needs to increment whereas peripheral is a constant one > Through the DMA client API I'll break this piece of memory in several > small parts and add all into a list (scatter-gather), right? > Each element of the scatter-gather has the sg_dma_address (in the > DMA_DEV_TO_MEM case will be the destination address) and the > corresponding size. Correct > However, I still need the other address (in the DMA_DEV_TO_MEM case will > be the source address) for that small part of memory. > Since I get that address from the config, I still need to increment the > source address in the same proportion of the destination address, in > other words, the increment will be the part size. I don't think so. Typically the device address is a FIFO, which does not increment and you keep pushing data at same address. It is not a memory > If there is some way to set and get the address for the source (in this > case) into each scatter-gather element, that would be much nicer, is that > possible? > > > + case EDMA_REQ_STOP: > > > + list_del(&vd->node); > > > + vchan_cookie_complete(vd); > > > + chan->request = EDMA_REQ_NONE; > > > + chan->status = EDMA_ST_IDLE; > > > > Why do we need to track request as well as status? > > Since I don't actually have the PAUSE state feature available on HW, I'm > emulating it through software. As far as HW is concerned, it thinks that > it has transferred everything (no more bursts valid available), but in > terms of software, we still have a lot of chunks (each one containing > several bursts) to process. Why do you need to emulate, if HW doesnt support so be it? The applications should handle a device which doesnt support pause and not a low level driver > > > +struct dw_edma_transfer { > > > + struct dma_chan *dchan; > > > + union Xfer { > > > > no camel case please > > Ok. > > > > > It would help to run checkpatch with --strict option to find any style > > issues and fix them as well > > I usually run with that option, but for now, that option is giving some > warnings about macro variable names that are pure noise. yeah that is a *guide* and to be used as guidance. If code looks worse off then it shouldn't be used. But many of the test are helpful. Some macros checks actually make sense, but again use your judgement :)
On Tue, May 7, 2019 at 6:3:10, Vinod Koul <vkoul@kernel.org> wrote: > On 06-05-19, 16:42, Gustavo Pimentel wrote: > > > > > + if (unlikely(!chunk)) > > > > + return NULL; > > > > + > > > > + INIT_LIST_HEAD(&chunk->list); > > > > + chunk->chan = chan; > > > > + chunk->cb = !(desc->chunks_alloc % 2); > > > ? why %2? > > > > I think it's explained on the patch description. CB also is known as > > Change Bit that must be toggled in order to the HW assume a new linked > > list is available to be consumed. > > Since desc->chunks_alloc variable is an incremental counter the remainder > > after division by 2 will be zero (if chunks_alloc is even) or one (if > > chunks_alloc is odd). > > Okay it would be great to add a comment here to explain as well Ok, I'll add it. > > > > > +static enum dma_status > > > > +dw_edma_device_tx_status(struct dma_chan *dchan, dma_cookie_t cookie, > > > > + struct dma_tx_state *txstate) > > > > +{ > > > > + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); > > > > + struct dw_edma_desc *desc; > > > > + struct virt_dma_desc *vd; > > > > + unsigned long flags; > > > > + enum dma_status ret; > > > > + u32 residue = 0; > > > > + > > > > + ret = dma_cookie_status(dchan, cookie, txstate); > > > > + if (ret == DMA_COMPLETE) > > > > + return ret; > > > > + > > > > + if (ret == DMA_IN_PROGRESS && chan->status == EDMA_ST_PAUSE) > > > > + ret = DMA_PAUSED; > > > > > > Don't you want to set residue on paused channel, how else will user know > > > the position of pause? > > > > I didn't catch you on this. I'm only setting the dma status here. After > > this function, the residue is calculated and set, isn't it? > > Hmm I thought you returned for paused case, if not then it is okay No, I'm just setting the dma status in pause case, then I calculate the residue. > > > > > +static struct dma_async_tx_descriptor * > > > > +dw_edma_device_transfer(struct dw_edma_transfer *xfer) > > > > +{ > > > > + struct dw_edma_chan *chan = dchan2dw_edma_chan(xfer->dchan); > > > > + enum dma_transfer_direction direction = xfer->direction; > > > > + phys_addr_t src_addr, dst_addr; > > > > + struct scatterlist *sg = NULL; > > > > + struct dw_edma_chunk *chunk; > > > > + struct dw_edma_burst *burst; > > > > + struct dw_edma_desc *desc; > > > > + u32 cnt; > > > > + int i; > > > > + > > > > + if ((direction == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_WRITE) || > > > > + (direction == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_READ)) > > > > + return NULL; > > > > + > > > > + if (xfer->cyclic) { > > > > + if (!xfer->xfer.cyclic.len || !xfer->xfer.cyclic.cnt) > > > > + return NULL; > > > > + } else { > > > > + if (xfer->xfer.sg.len < 1) > > > > + return NULL; > > > > + } > > > > + > > > > + if (!chan->configured) > > > > + return NULL; > > > > + > > > > + desc = dw_edma_alloc_desc(chan); > > > > + if (unlikely(!desc)) > > > > + goto err_alloc; > > > > + > > > > + chunk = dw_edma_alloc_chunk(desc); > > > > + if (unlikely(!chunk)) > > > > + goto err_alloc; > > > > + > > > > + src_addr = chan->config.src_addr; > > > > + dst_addr = chan->config.dst_addr; > > > > + > > > > + if (xfer->cyclic) { > > > > + cnt = xfer->xfer.cyclic.cnt; > > > > + } else { > > > > + cnt = xfer->xfer.sg.len; > > > > + sg = xfer->xfer.sg.sgl; > > > > + } > > > > + > > > > + for (i = 0; i < cnt; i++) { > > > > + if (!xfer->cyclic && !sg) > > > > + break; > > > > + > > > > + if (chunk->bursts_alloc == chan->ll_max) { > > > > + chunk = dw_edma_alloc_chunk(desc); > > > > + if (unlikely(!chunk)) > > > > + goto err_alloc; > > > > + } > > > > + > > > > + burst = dw_edma_alloc_burst(chunk); > > > > + if (unlikely(!burst)) > > > > + goto err_alloc; > > > > + > > > > + if (xfer->cyclic) > > > > + burst->sz = xfer->xfer.cyclic.len; > > > > + else > > > > + burst->sz = sg_dma_len(sg); > > > > + > > > > + chunk->ll_region.sz += burst->sz; > > > > + desc->alloc_sz += burst->sz; > > > > + > > > > + if (direction == DMA_DEV_TO_MEM) { > > > > + burst->sar = src_addr; > > > > > > We are device to mem, so src is peripheral.. okay > > > > > > > + if (xfer->cyclic) { > > > > + burst->dar = xfer->xfer.cyclic.paddr; > > > > + } else { > > > > + burst->dar = sg_dma_address(sg); > > > > + src_addr += sg_dma_len(sg); > > > > > > and we increment the src, doesn't make sense to me! > > > > > > > + } > > > > + } else { > > > > + burst->dar = dst_addr; > > > > + if (xfer->cyclic) { > > > > + burst->sar = xfer->xfer.cyclic.paddr; > > > > + } else { > > > > + burst->sar = sg_dma_address(sg); > > > > + dst_addr += sg_dma_len(sg); > > > > > > same here as well > > > > This is hard to explain in words... > > Well, in my perspective I want to transfer a piece of memory from the > > peripheral into local RAM > > Right and most of the case RAM address (sg) needs to increment whereas > peripheral is a constant one > > > Through the DMA client API I'll break this piece of memory in several > > small parts and add all into a list (scatter-gather), right? > > Each element of the scatter-gather has the sg_dma_address (in the > > DMA_DEV_TO_MEM case will be the destination address) and the > > corresponding size. > > Correct > > > However, I still need the other address (in the DMA_DEV_TO_MEM case will > > be the source address) for that small part of memory. > > Since I get that address from the config, I still need to increment the > > source address in the same proportion of the destination address, in > > other words, the increment will be the part size. > > I don't think so. Typically the device address is a FIFO, which does not > increment and you keep pushing data at same address. It is not a memory In my use case, it's a memory, perhaps that is what is causing this confusing. I'm copying "plain and flat" data from point A to B, with the particularity that the peripheral memory is always continuous and the CPU memory can be constituted by scatter-gather chunks of contiguous memory > > > If there is some way to set and get the address for the source (in this > > case) into each scatter-gather element, that would be much nicer, is that > > possible? > > > > > + case EDMA_REQ_STOP: > > > > + list_del(&vd->node); > > > > + vchan_cookie_complete(vd); > > > > + chan->request = EDMA_REQ_NONE; > > > > + chan->status = EDMA_ST_IDLE; > > > > > > Why do we need to track request as well as status? > > > > Since I don't actually have the PAUSE state feature available on HW, I'm > > emulating it through software. As far as HW is concerned, it thinks that > > it has transferred everything (no more bursts valid available), but in > > terms of software, we still have a lot of chunks (each one containing > > several bursts) to process. > > Why do you need to emulate, if HW doesnt support so be it? > The applications should handle a device which doesnt support pause and > not a low level driver In this case, since I've to refill the eDMA memory and retrigger the HW block each time the transfer is completed, it's easy to emulate a pause state, by holding or not refilling the eDMA memory. I thought that this could be a nice and easy feature to have. > > > > > +struct dw_edma_transfer { > > > > + struct dma_chan *dchan; > > > > + union Xfer { > > > > > > no camel case please > > > > Ok. > > > > > > > > It would help to run checkpatch with --strict option to find any style > > > issues and fix them as well > > > > I usually run with that option, but for now, that option is giving some > > warnings about macro variable names that are pure noise. > > yeah that is a *guide* and to be used as guidance. If code looks worse > off then it shouldn't be used. But many of the test are helpful. Some > macros checks actually make sense, but again use your judgement :) Sure. > > -- > ~Vinod Regards, Gustavo
On 07-05-19, 09:08, Gustavo Pimentel wrote: > On Tue, May 7, 2019 at 6:3:10, Vinod Koul <vkoul@kernel.org> wrote: > > On 06-05-19, 16:42, Gustavo Pimentel wrote: > > > > > +static struct dma_async_tx_descriptor * > > > > > +dw_edma_device_transfer(struct dw_edma_transfer *xfer) > > > > > +{ > > > > > + struct dw_edma_chan *chan = dchan2dw_edma_chan(xfer->dchan); > > > > > + enum dma_transfer_direction direction = xfer->direction; > > > > > + phys_addr_t src_addr, dst_addr; > > > > > + struct scatterlist *sg = NULL; > > > > > + struct dw_edma_chunk *chunk; > > > > > + struct dw_edma_burst *burst; > > > > > + struct dw_edma_desc *desc; > > > > > + u32 cnt; > > > > > + int i; > > > > > + > > > > > + if ((direction == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_WRITE) || > > > > > + (direction == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_READ)) > > > > > + return NULL; > > > > > + > > > > > + if (xfer->cyclic) { > > > > > + if (!xfer->xfer.cyclic.len || !xfer->xfer.cyclic.cnt) > > > > > + return NULL; > > > > > + } else { > > > > > + if (xfer->xfer.sg.len < 1) > > > > > + return NULL; > > > > > + } > > > > > + > > > > > + if (!chan->configured) > > > > > + return NULL; > > > > > + > > > > > + desc = dw_edma_alloc_desc(chan); > > > > > + if (unlikely(!desc)) > > > > > + goto err_alloc; > > > > > + > > > > > + chunk = dw_edma_alloc_chunk(desc); > > > > > + if (unlikely(!chunk)) > > > > > + goto err_alloc; > > > > > + > > > > > + src_addr = chan->config.src_addr; > > > > > + dst_addr = chan->config.dst_addr; > > > > > + > > > > > + if (xfer->cyclic) { > > > > > + cnt = xfer->xfer.cyclic.cnt; > > > > > + } else { > > > > > + cnt = xfer->xfer.sg.len; > > > > > + sg = xfer->xfer.sg.sgl; > > > > > + } > > > > > + > > > > > + for (i = 0; i < cnt; i++) { > > > > > + if (!xfer->cyclic && !sg) > > > > > + break; > > > > > + > > > > > + if (chunk->bursts_alloc == chan->ll_max) { > > > > > + chunk = dw_edma_alloc_chunk(desc); > > > > > + if (unlikely(!chunk)) > > > > > + goto err_alloc; > > > > > + } > > > > > + > > > > > + burst = dw_edma_alloc_burst(chunk); > > > > > + if (unlikely(!burst)) > > > > > + goto err_alloc; > > > > > + > > > > > + if (xfer->cyclic) > > > > > + burst->sz = xfer->xfer.cyclic.len; > > > > > + else > > > > > + burst->sz = sg_dma_len(sg); > > > > > + > > > > > + chunk->ll_region.sz += burst->sz; > > > > > + desc->alloc_sz += burst->sz; > > > > > + > > > > > + if (direction == DMA_DEV_TO_MEM) { > > > > > + burst->sar = src_addr; > > > > > > > > We are device to mem, so src is peripheral.. okay > > > > > > > > > + if (xfer->cyclic) { > > > > > + burst->dar = xfer->xfer.cyclic.paddr; > > > > > + } else { > > > > > + burst->dar = sg_dma_address(sg); > > > > > + src_addr += sg_dma_len(sg); > > > > > > > > and we increment the src, doesn't make sense to me! > > > > > > > > > + } > > > > > + } else { > > > > > + burst->dar = dst_addr; > > > > > + if (xfer->cyclic) { > > > > > + burst->sar = xfer->xfer.cyclic.paddr; > > > > > + } else { > > > > > + burst->sar = sg_dma_address(sg); > > > > > + dst_addr += sg_dma_len(sg); > > > > > > > > same here as well > > > > > > This is hard to explain in words... > > > Well, in my perspective I want to transfer a piece of memory from the > > > peripheral into local RAM > > > > Right and most of the case RAM address (sg) needs to increment whereas > > peripheral is a constant one > > > > > Through the DMA client API I'll break this piece of memory in several > > > small parts and add all into a list (scatter-gather), right? > > > Each element of the scatter-gather has the sg_dma_address (in the > > > DMA_DEV_TO_MEM case will be the destination address) and the > > > corresponding size. > > > > Correct > > > > > However, I still need the other address (in the DMA_DEV_TO_MEM case will > > > be the source address) for that small part of memory. > > > Since I get that address from the config, I still need to increment the > > > source address in the same proportion of the destination address, in > > > other words, the increment will be the part size. > > > > I don't think so. Typically the device address is a FIFO, which does not > > increment and you keep pushing data at same address. It is not a memory > > In my use case, it's a memory, perhaps that is what is causing this > confusing. > I'm copying "plain and flat" data from point A to B, with the > particularity that the peripheral memory is always continuous and the CPU > memory can be constituted by scatter-gather chunks of contiguous memory Then why should it be slave transfer, it should be treated as memcpy with src and dst sg lists..
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index 0b1dfb5..58b78d2 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -665,6 +665,8 @@ source "drivers/dma/qcom/Kconfig" source "drivers/dma/dw/Kconfig" +source "drivers/dma/dw-edma/Kconfig" + source "drivers/dma/hsu/Kconfig" source "drivers/dma/sh/Kconfig" diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile index 6126e1c..5bddf6f 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_DMA_SUN4I) += sun4i-dma.o obj-$(CONFIG_DMA_SUN6I) += sun6i-dma.o obj-$(CONFIG_DW_AXI_DMAC) += dw-axi-dmac/ obj-$(CONFIG_DW_DMAC_CORE) += dw/ +obj-$(CONFIG_DW_EDMA) += dw-edma/ obj-$(CONFIG_EP93XX_DMA) += ep93xx_dma.o obj-$(CONFIG_FSL_DMA) += fsldma.o obj-$(CONFIG_FSL_EDMA) += fsl-edma.o fsl-edma-common.o diff --git a/drivers/dma/dw-edma/Kconfig b/drivers/dma/dw-edma/Kconfig new file mode 100644 index 0000000..3016bed --- /dev/null +++ b/drivers/dma/dw-edma/Kconfig @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0 + +config DW_EDMA + tristate "Synopsys DesignWare eDMA controller driver" + select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS + help + Support the Synopsys DesignWare eDMA controller, normally + implemented on endpoints SoCs. diff --git a/drivers/dma/dw-edma/Makefile b/drivers/dma/dw-edma/Makefile new file mode 100644 index 0000000..3224010 --- /dev/null +++ b/drivers/dma/dw-edma/Makefile @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_DW_EDMA) += dw-edma.o +dw-edma-objs := dw-edma-core.o diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c new file mode 100644 index 0000000..54cd531 --- /dev/null +++ b/drivers/dma/dw-edma/dw-edma-core.c @@ -0,0 +1,919 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2018-2019 Synopsys, Inc. and/or its affiliates. + * Synopsys DesignWare eDMA core driver + * + * Author: Gustavo Pimentel <gustavo.pimentel@synopsys.com> + */ + +#include <linux/module.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/pm_runtime.h> +#include <linux/dmaengine.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/dma/edma.h> +#include <linux/pci.h> + +#include "dw-edma-core.h" +#include "../dmaengine.h" +#include "../virt-dma.h" + +static inline +struct device *dchan2dev(struct dma_chan *dchan) +{ + return &dchan->dev->device; +} + +static inline +struct device *chan2dev(struct dw_edma_chan *chan) +{ + return &chan->vc.chan.dev->device; +} + +static inline +struct dw_edma_desc *vd2dw_edma_desc(struct virt_dma_desc *vd) +{ + return container_of(vd, struct dw_edma_desc, vd); +} + +static struct dw_edma_burst *dw_edma_alloc_burst(struct dw_edma_chunk *chunk) +{ + struct dw_edma_burst *burst; + + burst = kzalloc(sizeof(*burst), GFP_KERNEL); + if (unlikely(!burst)) + return NULL; + + INIT_LIST_HEAD(&burst->list); + if (chunk->burst) { + /* Create and add new element into the linked list */ + chunk->bursts_alloc++; + list_add_tail(&burst->list, &chunk->burst->list); + } else { + /* List head */ + chunk->bursts_alloc = 0; + chunk->burst = burst; + } + + return burst; +} + +static struct dw_edma_chunk *dw_edma_alloc_chunk(struct dw_edma_desc *desc) +{ + struct dw_edma_chan *chan = desc->chan; + struct dw_edma *dw = chan->chip->dw; + struct dw_edma_chunk *chunk; + + chunk = kzalloc(sizeof(*chunk), GFP_KERNEL); + if (unlikely(!chunk)) + return NULL; + + INIT_LIST_HEAD(&chunk->list); + chunk->chan = chan; + chunk->cb = !(desc->chunks_alloc % 2); + chunk->ll_region.paddr = dw->ll_region.paddr + chan->ll_off; + chunk->ll_region.vaddr = dw->ll_region.vaddr + chan->ll_off; + + if (desc->chunk) { + /* Create and add new element into the linked list */ + desc->chunks_alloc++; + list_add_tail(&chunk->list, &desc->chunk->list); + if (!dw_edma_alloc_burst(chunk)) { + kfree(chunk); + return NULL; + } + } else { + /* List head */ + chunk->burst = NULL; + desc->chunks_alloc = 0; + desc->chunk = chunk; + } + + return chunk; +} + +static struct dw_edma_desc *dw_edma_alloc_desc(struct dw_edma_chan *chan) +{ + struct dw_edma_desc *desc; + + desc = kzalloc(sizeof(*desc), GFP_KERNEL); + if (unlikely(!desc)) + return NULL; + + desc->chan = chan; + if (!dw_edma_alloc_chunk(desc)) { + kfree(desc); + return NULL; + } + + return desc; +} + +static void dw_edma_free_burst(struct dw_edma_chunk *chunk) +{ + struct dw_edma_burst *child, *_next; + + /* Remove all the list elements */ + list_for_each_entry_safe(child, _next, &chunk->burst->list, list) { + list_del(&child->list); + kfree(child); + chunk->bursts_alloc--; + } + + /* Remove the list head */ + kfree(child); + chunk->burst = NULL; +} + +static void dw_edma_free_chunk(struct dw_edma_desc *desc) +{ + struct dw_edma_chunk *child, *_next; + + if (!desc->chunk) + return; + + /* Remove all the list elements */ + list_for_each_entry_safe(child, _next, &desc->chunk->list, list) { + dw_edma_free_burst(child); + list_del(&child->list); + kfree(child); + desc->chunks_alloc--; + } + + /* Remove the list head */ + kfree(child); + desc->chunk = NULL; +} + +static void dw_edma_free_desc(struct dw_edma_desc *desc) +{ + dw_edma_free_chunk(desc); + kfree(desc); +} + +static void vchan_free_desc(struct virt_dma_desc *vdesc) +{ + dw_edma_free_desc(vd2dw_edma_desc(vdesc)); +} + +static void dw_edma_start_transfer(struct dw_edma_chan *chan) +{ + struct dw_edma_chunk *child; + struct dw_edma_desc *desc; + struct virt_dma_desc *vd; + + vd = vchan_next_desc(&chan->vc); + if (!vd) + return; + + desc = vd2dw_edma_desc(vd); + if (!desc) + return; + + child = list_first_entry_or_null(&desc->chunk->list, + struct dw_edma_chunk, list); + if (!child) + return; + + dw_edma_v0_core_start(child, !desc->xfer_sz); + desc->xfer_sz += child->ll_region.sz; + dw_edma_free_burst(child); + list_del(&child->list); + kfree(child); + desc->chunks_alloc--; +} + +static int dw_edma_device_config(struct dma_chan *dchan, + struct dma_slave_config *config) +{ + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); + + memcpy(&chan->config, config, sizeof(*config)); + chan->configured = true; + + return 0; +} + +static int dw_edma_device_pause(struct dma_chan *dchan) +{ + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); + int err = 0; + + if (!chan->configured) + err = -EPERM; + else if (chan->status != EDMA_ST_BUSY) + err = -EPERM; + else if (chan->request != EDMA_REQ_NONE) + err = -EPERM; + else + chan->request = EDMA_REQ_PAUSE; + + return err; +} + +static int dw_edma_device_resume(struct dma_chan *dchan) +{ + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); + int err = 0; + + if (!chan->configured) { + err = -EPERM; + } else if (chan->status != EDMA_ST_PAUSE) { + err = -EPERM; + } else if (chan->request != EDMA_REQ_NONE) { + err = -EPERM; + } else { + chan->status = EDMA_ST_BUSY; + dw_edma_start_transfer(chan); + } + + return err; +} + +static int dw_edma_device_terminate_all(struct dma_chan *dchan) +{ + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); + int err = 0; + LIST_HEAD(head); + + if (!chan->configured) { + /* Do nothing */ + } else if (chan->status == EDMA_ST_PAUSE) { + chan->status = EDMA_ST_IDLE; + chan->configured = false; + } else if (chan->status == EDMA_ST_IDLE) { + chan->configured = false; + } else if (dw_edma_v0_core_ch_status(chan) == DMA_COMPLETE) { + /* + * The channel is in a false BUSY state, probably didn't + * receive or lost an interrupt + */ + chan->status = EDMA_ST_IDLE; + chan->configured = false; + } else if (chan->request > EDMA_REQ_PAUSE) { + err = -EPERM; + } else { + chan->request = EDMA_REQ_STOP; + } + + return err; +} + +static void dw_edma_device_issue_pending(struct dma_chan *dchan) +{ + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); + unsigned long flags; + + spin_lock_irqsave(&chan->vc.lock, flags); + if (chan->configured && chan->request == EDMA_REQ_NONE && + chan->status == EDMA_ST_IDLE && vchan_issue_pending(&chan->vc)) { + chan->status = EDMA_ST_BUSY; + dw_edma_start_transfer(chan); + } + spin_unlock_irqrestore(&chan->vc.lock, flags); +} + +static enum dma_status +dw_edma_device_tx_status(struct dma_chan *dchan, dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); + struct dw_edma_desc *desc; + struct virt_dma_desc *vd; + unsigned long flags; + enum dma_status ret; + u32 residue = 0; + + ret = dma_cookie_status(dchan, cookie, txstate); + if (ret == DMA_COMPLETE) + return ret; + + if (ret == DMA_IN_PROGRESS && chan->status == EDMA_ST_PAUSE) + ret = DMA_PAUSED; + + if (!txstate) + goto ret_residue; + + spin_lock_irqsave(&chan->vc.lock, flags); + vd = vchan_find_desc(&chan->vc, cookie); + if (vd) { + desc = vd2dw_edma_desc(vd); + if (desc) + residue = desc->alloc_sz - desc->xfer_sz; + } + spin_unlock_irqrestore(&chan->vc.lock, flags); + +ret_residue: + dma_set_residue(txstate, residue); + + return ret; +} + +static struct dma_async_tx_descriptor * +dw_edma_device_transfer(struct dw_edma_transfer *xfer) +{ + struct dw_edma_chan *chan = dchan2dw_edma_chan(xfer->dchan); + enum dma_transfer_direction direction = xfer->direction; + phys_addr_t src_addr, dst_addr; + struct scatterlist *sg = NULL; + struct dw_edma_chunk *chunk; + struct dw_edma_burst *burst; + struct dw_edma_desc *desc; + u32 cnt; + int i; + + if ((direction == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_WRITE) || + (direction == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_READ)) + return NULL; + + if (xfer->cyclic) { + if (!xfer->xfer.cyclic.len || !xfer->xfer.cyclic.cnt) + return NULL; + } else { + if (xfer->xfer.sg.len < 1) + return NULL; + } + + if (!chan->configured) + return NULL; + + desc = dw_edma_alloc_desc(chan); + if (unlikely(!desc)) + goto err_alloc; + + chunk = dw_edma_alloc_chunk(desc); + if (unlikely(!chunk)) + goto err_alloc; + + src_addr = chan->config.src_addr; + dst_addr = chan->config.dst_addr; + + if (xfer->cyclic) { + cnt = xfer->xfer.cyclic.cnt; + } else { + cnt = xfer->xfer.sg.len; + sg = xfer->xfer.sg.sgl; + } + + for (i = 0; i < cnt; i++) { + if (!xfer->cyclic && !sg) + break; + + if (chunk->bursts_alloc == chan->ll_max) { + chunk = dw_edma_alloc_chunk(desc); + if (unlikely(!chunk)) + goto err_alloc; + } + + burst = dw_edma_alloc_burst(chunk); + if (unlikely(!burst)) + goto err_alloc; + + if (xfer->cyclic) + burst->sz = xfer->xfer.cyclic.len; + else + burst->sz = sg_dma_len(sg); + + chunk->ll_region.sz += burst->sz; + desc->alloc_sz += burst->sz; + + if (direction == DMA_DEV_TO_MEM) { + burst->sar = src_addr; + if (xfer->cyclic) { + burst->dar = xfer->xfer.cyclic.paddr; + } else { + burst->dar = sg_dma_address(sg); + src_addr += sg_dma_len(sg); + } + } else { + burst->dar = dst_addr; + if (xfer->cyclic) { + burst->sar = xfer->xfer.cyclic.paddr; + } else { + burst->sar = sg_dma_address(sg); + dst_addr += sg_dma_len(sg); + } + } + + if (!xfer->cyclic) + sg = sg_next(sg); + } + + return vchan_tx_prep(&chan->vc, &desc->vd, xfer->flags); + +err_alloc: + if (desc) + dw_edma_free_desc(desc); + + return NULL; +} + +static struct dma_async_tx_descriptor * +dw_edma_device_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl, + unsigned int len, + enum dma_transfer_direction direction, + unsigned long flags, void *context) +{ + struct dw_edma_transfer xfer; + + xfer.dchan = dchan; + xfer.direction = direction; + xfer.xfer.sg.sgl = sgl; + xfer.xfer.sg.len = len; + xfer.flags = flags; + xfer.cyclic = false; + + return dw_edma_device_transfer(&xfer); +} + +static struct dma_async_tx_descriptor * +dw_edma_device_prep_dma_cyclic(struct dma_chan *dchan, dma_addr_t paddr, + size_t len, size_t count, + enum dma_transfer_direction direction, + unsigned long flags) +{ + struct dw_edma_transfer xfer; + + xfer.dchan = dchan; + xfer.direction = direction; + xfer.xfer.cyclic.paddr = paddr; + xfer.xfer.cyclic.len = len; + xfer.xfer.cyclic.cnt = count; + xfer.flags = flags; + xfer.cyclic = true; + + return dw_edma_device_transfer(&xfer); +} + +static void dw_edma_done_interrupt(struct dw_edma_chan *chan) +{ + struct dw_edma_desc *desc; + struct virt_dma_desc *vd; + unsigned long flags; + + dw_edma_v0_core_clear_done_int(chan); + + spin_lock_irqsave(&chan->vc.lock, flags); + vd = vchan_next_desc(&chan->vc); + if (vd) { + switch (chan->request) { + case EDMA_REQ_NONE: + desc = vd2dw_edma_desc(vd); + if (desc->chunks_alloc) { + chan->status = EDMA_ST_BUSY; + dw_edma_start_transfer(chan); + } else { + list_del(&vd->node); + vchan_cookie_complete(vd); + chan->status = EDMA_ST_IDLE; + } + break; + case EDMA_REQ_STOP: + list_del(&vd->node); + vchan_cookie_complete(vd); + chan->request = EDMA_REQ_NONE; + chan->status = EDMA_ST_IDLE; + break; + case EDMA_REQ_PAUSE: + chan->request = EDMA_REQ_NONE; + chan->status = EDMA_ST_PAUSE; + break; + default: + break; + } + } + spin_unlock_irqrestore(&chan->vc.lock, flags); +} + +static void dw_edma_abort_interrupt(struct dw_edma_chan *chan) +{ + struct virt_dma_desc *vd; + unsigned long flags; + + dw_edma_v0_core_clear_abort_int(chan); + + spin_lock_irqsave(&chan->vc.lock, flags); + vd = vchan_next_desc(&chan->vc); + if (vd) { + list_del(&vd->node); + vchan_cookie_complete(vd); + } + spin_unlock_irqrestore(&chan->vc.lock, flags); + chan->request = EDMA_REQ_NONE; + chan->status = EDMA_ST_IDLE; +} + +static irqreturn_t dw_edma_interrupt(int irq, void *data, bool write) +{ + struct dw_edma_irq *dw_irq = data; + struct dw_edma *dw = dw_irq->dw; + unsigned long total, pos, val; + unsigned long off; + u32 mask; + + if (write) { + total = dw->wr_ch_cnt; + off = 0; + mask = dw_irq->wr_mask; + } else { + total = dw->rd_ch_cnt; + off = dw->wr_ch_cnt; + mask = dw_irq->rd_mask; + } + + val = dw_edma_v0_core_status_done_int(dw, write ? + EDMA_DIR_WRITE : + EDMA_DIR_READ); + val &= mask; + for_each_set_bit(pos, &val, total) { + struct dw_edma_chan *chan = &dw->chan[pos + off]; + + dw_edma_done_interrupt(chan); + } + + val = dw_edma_v0_core_status_abort_int(dw, write ? + EDMA_DIR_WRITE : + EDMA_DIR_READ); + val &= mask; + for_each_set_bit(pos, &val, total) { + struct dw_edma_chan *chan = &dw->chan[pos + off]; + + dw_edma_abort_interrupt(chan); + } + + return IRQ_HANDLED; +} + +static inline irqreturn_t dw_edma_interrupt_write(int irq, void *data) +{ + return dw_edma_interrupt(irq, data, true); +} + +static inline irqreturn_t dw_edma_interrupt_read(int irq, void *data) +{ + return dw_edma_interrupt(irq, data, false); +} + +static irqreturn_t dw_edma_interrupt_common(int irq, void *data) +{ + dw_edma_interrupt(irq, data, true); + dw_edma_interrupt(irq, data, false); + + return IRQ_HANDLED; +} + +static int dw_edma_alloc_chan_resources(struct dma_chan *dchan) +{ + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); + + if (chan->status != EDMA_ST_IDLE) + return -EBUSY; + + dma_cookie_init(dchan); + + pm_runtime_get(chan->chip->dev); + + return 0; +} + +static void dw_edma_free_chan_resources(struct dma_chan *dchan) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(5000); + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); + int ret; + + while (time_before(jiffies, timeout)) { + ret = dw_edma_device_terminate_all(dchan); + if (!ret) + break; + + if (time_after_eq(jiffies, timeout)) + return; + + cpu_relax(); + }; + + pm_runtime_put(chan->chip->dev); +} + +static int dw_edma_channel_setup(struct dw_edma_chip *chip, bool write, + u32 wr_alloc, u32 rd_alloc) +{ + struct dw_edma_region *dt_region; + struct device *dev = chip->dev; + struct dw_edma *dw = chip->dw; + struct dw_edma_chan *chan; + size_t ll_chunk, dt_chunk; + struct dw_edma_irq *irq; + struct dma_device *dma; + u32 i, j, cnt, ch_cnt; + u32 alloc, off_alloc; + int err = 0; + u32 pos; + + ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt; + ll_chunk = dw->ll_region.sz; + dt_chunk = dw->dt_region.sz; + + /* Calculate linked list chunk for each channel */ + ll_chunk /= roundup_pow_of_two(ch_cnt); + + /* Calculate linked list chunk for each channel */ + dt_chunk /= roundup_pow_of_two(ch_cnt); + + if (write) { + i = 0; + cnt = dw->wr_ch_cnt; + dma = &dw->wr_edma; + alloc = wr_alloc; + off_alloc = 0; + } else { + i = dw->wr_ch_cnt; + cnt = dw->rd_ch_cnt; + dma = &dw->rd_edma; + alloc = rd_alloc; + off_alloc = wr_alloc; + } + + INIT_LIST_HEAD(&dma->channels); + for (j = 0; (alloc || dw->nr_irqs == 1) && j < cnt; j++, i++) { + chan = &dw->chan[i]; + + dt_region = devm_kzalloc(dev, sizeof(*dt_region), GFP_KERNEL); + if (!dt_region) + return -ENOMEM; + + chan->vc.chan.private = dt_region; + + chan->chip = chip; + chan->id = j; + chan->dir = write ? EDMA_DIR_WRITE : EDMA_DIR_READ; + chan->configured = false; + chan->request = EDMA_REQ_NONE; + chan->status = EDMA_ST_IDLE; + + chan->ll_off = (ll_chunk * i); + chan->ll_max = (ll_chunk / EDMA_LL_SZ) - 1; + + chan->dt_off = (dt_chunk * i); + + dev_vdbg(dev, "L. List:\tChannel %s[%u] off=0x%.8lx, max_cnt=%u\n", + write ? "write" : "read", j, + chan->ll_off, chan->ll_max); + + if (dw->nr_irqs == 1) + pos = 0; + else + pos = off_alloc + (j % alloc); + + irq = &dw->irq[pos]; + + if (write) + irq->wr_mask |= BIT(j); + else + irq->rd_mask |= BIT(j); + + irq->dw = dw; + memcpy(&chan->msi, &irq->msi, sizeof(chan->msi)); + + dev_vdbg(dev, "MSI:\t\tChannel %s[%u] addr=0x%.8x%.8x, data=0x%.8x\n", + write ? "write" : "read", j, + chan->msi.address_hi, chan->msi.address_lo, + chan->msi.data); + + chan->vc.desc_free = vchan_free_desc; + vchan_init(&chan->vc, dma); + + dt_region->paddr = dw->dt_region.paddr + chan->dt_off; + dt_region->vaddr = dw->dt_region.vaddr + chan->dt_off; + dt_region->sz = dt_chunk; + + dev_vdbg(dev, "Data:\tChannel %s[%u] off=0x%.8lx\n", + write ? "write" : "read", j, chan->dt_off); + + dw_edma_v0_core_device_config(chan); + } + + /* Set DMA channel capabilities */ + dma_cap_zero(dma->cap_mask); + dma_cap_set(DMA_SLAVE, dma->cap_mask); + dma_cap_set(DMA_CYCLIC, dma->cap_mask); + dma_cap_set(DMA_PRIVATE, dma->cap_mask); + dma->directions = BIT(write ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV); + dma->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + dma->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + dma->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR; + dma->chancnt = cnt; + + /* Set DMA channel callbacks */ + dma->dev = chip->dev; + dma->device_alloc_chan_resources = dw_edma_alloc_chan_resources; + dma->device_free_chan_resources = dw_edma_free_chan_resources; + dma->device_config = dw_edma_device_config; + dma->device_pause = dw_edma_device_pause; + dma->device_resume = dw_edma_device_resume; + dma->device_terminate_all = dw_edma_device_terminate_all; + dma->device_issue_pending = dw_edma_device_issue_pending; + dma->device_tx_status = dw_edma_device_tx_status; + dma->device_prep_slave_sg = dw_edma_device_prep_slave_sg; + dma->device_prep_dma_cyclic = dw_edma_device_prep_dma_cyclic; + + dma_set_max_seg_size(dma->dev, U32_MAX); + + /* Register DMA device */ + err = dma_async_device_register(dma); + + return err; +} + +static inline void dw_edma_dec_irq_alloc(int *nr_irqs, u32 *alloc, u16 cnt) +{ + if (*nr_irqs && *alloc < cnt) { + (*alloc)++; + (*nr_irqs)--; + } +} + +static inline void dw_edma_add_irq_mask(u32 *mask, u32 alloc, u16 cnt) +{ + while (*mask * alloc < cnt) + (*mask)++; +} + +static int dw_edma_irq_request(struct dw_edma_chip *chip, + u32 *wr_alloc, u32 *rd_alloc) +{ + struct device *dev = chip->dev; + struct dw_edma *dw = chip->dw; + u32 wr_mask = 1; + u32 rd_mask = 1; + int i, err = 0; + u32 ch_cnt; + + ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt; + + if (dw->nr_irqs < 1) + return -EINVAL; + + if (dw->nr_irqs == 1) { + /* Common IRQ shared among all channels */ + err = request_irq(pci_irq_vector(to_pci_dev(dev), 0), + dw_edma_interrupt_common, + IRQF_SHARED, dw->name, &dw->irq[0]); + if (err) { + dw->nr_irqs = 0; + return err; + } + + get_cached_msi_msg(pci_irq_vector(to_pci_dev(dev), 0), + &dw->irq[0].msi); + } else { + /* Distribute IRQs equally among all channels */ + int tmp = dw->nr_irqs; + + while (tmp && (*wr_alloc + *rd_alloc) < ch_cnt) { + dw_edma_dec_irq_alloc(&tmp, wr_alloc, dw->wr_ch_cnt); + dw_edma_dec_irq_alloc(&tmp, rd_alloc, dw->rd_ch_cnt); + } + + dw_edma_add_irq_mask(&wr_mask, *wr_alloc, dw->wr_ch_cnt); + dw_edma_add_irq_mask(&rd_mask, *rd_alloc, dw->rd_ch_cnt); + + for (i = 0; i < (*wr_alloc + *rd_alloc); i++) { + err = request_irq(pci_irq_vector(to_pci_dev(dev), i), + i < *wr_alloc ? + dw_edma_interrupt_write : + dw_edma_interrupt_read, + IRQF_SHARED, dw->name, + &dw->irq[i]); + if (err) { + dw->nr_irqs = i; + return err; + } + + get_cached_msi_msg(pci_irq_vector(to_pci_dev(dev), i), + &dw->irq[i].msi); + } + + dw->nr_irqs = i; + } + + return err; +} + +int dw_edma_probe(struct dw_edma_chip *chip) +{ + struct device *dev = chip->dev; + struct dw_edma *dw = chip->dw; + u32 wr_alloc = 0; + u32 rd_alloc = 0; + int i, err; + + raw_spin_lock_init(&dw->lock); + + /* Find out how many write channels are supported by hardware */ + dw->wr_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_WRITE); + if (!dw->wr_ch_cnt) + return -EINVAL; + + /* Find out how many read channels are supported by hardware */ + dw->rd_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_READ); + if (!dw->rd_ch_cnt) + return -EINVAL; + + dev_vdbg(dev, "Channels:\twrite=%d, read=%d\n", + dw->wr_ch_cnt, dw->rd_ch_cnt); + + /* Allocate channels */ + dw->chan = devm_kcalloc(dev, dw->wr_ch_cnt + dw->rd_ch_cnt, + sizeof(*dw->chan), GFP_KERNEL); + if (!dw->chan) + return -ENOMEM; + + snprintf(dw->name, sizeof(dw->name), "dw-edma-core:%d", chip->id); + + /* Disable eDMA, only to establish the ideal initial conditions */ + dw_edma_v0_core_off(dw); + + /* Request IRQs */ + err = dw_edma_irq_request(chip, &wr_alloc, &rd_alloc); + if (err) + return err; + + /* Setup write channels */ + err = dw_edma_channel_setup(chip, true, wr_alloc, rd_alloc); + if (err) + goto err_irq_free; + + /* Setup read channels */ + err = dw_edma_channel_setup(chip, false, wr_alloc, rd_alloc); + if (err) + goto err_irq_free; + + /* Power management */ + pm_runtime_enable(dev); + + /* Turn debugfs on */ + err = dw_edma_v0_core_debugfs_on(chip); + if (err) + goto err_pm_disable; + + return 0; + +err_pm_disable: + pm_runtime_disable(dev); +err_irq_free: + for (i = (dw->nr_irqs - 1); i >= 0; i--) + free_irq(pci_irq_vector(to_pci_dev(dev), i), &dw->irq[i]); + + dw->nr_irqs = 0; + + return err; +} +EXPORT_SYMBOL_GPL(dw_edma_probe); + +int dw_edma_remove(struct dw_edma_chip *chip) +{ + struct dw_edma_chan *chan, *_chan; + struct device *dev = chip->dev; + struct dw_edma *dw = chip->dw; + int i; + + /* Disable eDMA */ + dw_edma_v0_core_off(dw); + + /* Free irqs */ + for (i = (dw->nr_irqs - 1); i >= 0; i--) + free_irq(pci_irq_vector(to_pci_dev(dev), i), &dw->irq[i]); + + /* Power management */ + pm_runtime_disable(dev); + + list_for_each_entry_safe(chan, _chan, &dw->wr_edma.channels, + vc.chan.device_node) { + list_del(&chan->vc.chan.device_node); + tasklet_kill(&chan->vc.task); + } + + list_for_each_entry_safe(chan, _chan, &dw->rd_edma.channels, + vc.chan.device_node) { + list_del(&chan->vc.chan.device_node); + tasklet_kill(&chan->vc.task); + } + + /* Deregister eDMA device */ + dma_async_device_unregister(&dw->wr_edma); + dma_async_device_unregister(&dw->rd_edma); + + /* Turn debugfs off */ + dw_edma_v0_core_debugfs_off(); + + return 0; +} +EXPORT_SYMBOL_GPL(dw_edma_remove); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Synopsys DesignWare eDMA controller core driver"); +MODULE_AUTHOR("Gustavo Pimentel <gustavo.pimentel@synopsys.com>"); diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h new file mode 100644 index 0000000..8a3a0a4 --- /dev/null +++ b/drivers/dma/dw-edma/dw-edma-core.h @@ -0,0 +1,165 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2018-2019 Synopsys, Inc. and/or its affiliates. + * Synopsys DesignWare eDMA core driver + * + * Author: Gustavo Pimentel <gustavo.pimentel@synopsys.com> + */ + +#ifndef _DW_EDMA_CORE_H +#define _DW_EDMA_CORE_H + +#include <linux/msi.h> +#include <linux/dma/edma.h> + +#include "../virt-dma.h" + +#define EDMA_LL_SZ 24 + +enum dw_edma_dir { + EDMA_DIR_WRITE = 0, + EDMA_DIR_READ +}; + +enum dw_edma_mode { + EDMA_MODE_LEGACY = 0, + EDMA_MODE_UNROLL +}; + +enum dw_edma_request { + EDMA_REQ_NONE = 0, + EDMA_REQ_STOP, + EDMA_REQ_PAUSE +}; + +enum dw_edma_status { + EDMA_ST_IDLE = 0, + EDMA_ST_PAUSE, + EDMA_ST_BUSY +}; + +struct dw_edma_chan; +struct dw_edma_chunk; + +struct dw_edma_burst { + struct list_head list; + u64 sar; + u64 dar; + u32 sz; +}; + +struct dw_edma_region { + phys_addr_t paddr; + dma_addr_t vaddr; + size_t sz; +}; + +struct dw_edma_chunk { + struct list_head list; + struct dw_edma_chan *chan; + struct dw_edma_burst *burst; + + u32 bursts_alloc; + + u8 cb; + struct dw_edma_region ll_region; /* Linked list */ +}; + +struct dw_edma_desc { + struct virt_dma_desc vd; + struct dw_edma_chan *chan; + struct dw_edma_chunk *chunk; + + u32 chunks_alloc; + + u32 alloc_sz; + u32 xfer_sz; +}; + +struct dw_edma_chan { + struct virt_dma_chan vc; + struct dw_edma_chip *chip; + int id; + enum dw_edma_dir dir; + + off_t ll_off; + u32 ll_max; + + off_t dt_off; + + struct msi_msg msi; + + enum dw_edma_request request; + enum dw_edma_status status; + u8 configured; + + struct dma_slave_config config; +}; + +struct dw_edma_irq { + struct msi_msg msi; + u32 wr_mask; + u32 rd_mask; + struct dw_edma *dw; +}; + +struct dw_edma { + char name[20]; + + struct dma_device wr_edma; + u16 wr_ch_cnt; + + struct dma_device rd_edma; + u16 rd_ch_cnt; + + struct dw_edma_region rg_region; /* Registers */ + struct dw_edma_region ll_region; /* Linked list */ + struct dw_edma_region dt_region; /* Data */ + + struct dw_edma_irq *irq; + int nr_irqs; + + u32 version; + enum dw_edma_mode mode; + + struct dw_edma_chan *chan; + const struct dw_edma_core_ops *ops; + + raw_spinlock_t lock; /* Only for legacy */ +}; + +struct dw_edma_sg { + struct scatterlist *sgl; + unsigned int len; +}; + +struct dw_edma_cyclic { + dma_addr_t paddr; + size_t len; + size_t cnt; +}; + +struct dw_edma_transfer { + struct dma_chan *dchan; + union Xfer { + struct dw_edma_sg sg; + struct dw_edma_cyclic cyclic; + } xfer; + enum dma_transfer_direction direction; + unsigned long flags; + bool cyclic; +}; + +static inline +struct dw_edma_chan *vc2dw_edma_chan(struct virt_dma_chan *vc) +{ + return container_of(vc, struct dw_edma_chan, vc); +} + +static inline +struct dw_edma_chan *dchan2dw_edma_chan(struct dma_chan *dchan) +{ + return vc2dw_edma_chan(to_virt_chan(dchan)); +} + +#endif /* _DW_EDMA_CORE_H */ diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h new file mode 100644 index 0000000..cab6e18 --- /dev/null +++ b/include/linux/dma/edma.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2018-2019 Synopsys, Inc. and/or its affiliates. + * Synopsys DesignWare eDMA core driver + * + * Author: Gustavo Pimentel <gustavo.pimentel@synopsys.com> + */ + +#ifndef _DW_EDMA_H +#define _DW_EDMA_H + +#include <linux/device.h> +#include <linux/dmaengine.h> + +struct dw_edma; + +/** + * struct dw_edma_chip - representation of DesignWare eDMA controller hardware + * @dev: struct device of the eDMA controller + * @id: instance ID + * @irq: irq line + * @dw: struct dw_edma that is filed by dw_edma_probe() + */ +struct dw_edma_chip { + struct device *dev; + int id; + int irq; + struct dw_edma *dw; +}; + +/* Export to the platform drivers */ +#if IS_ENABLED(CONFIG_DW_EDMA) +int dw_edma_probe(struct dw_edma_chip *chip); +int dw_edma_remove(struct dw_edma_chip *chip); +#else +static inline int dw_edma_probe(struct dw_edma_chip *chip) +{ + return -ENODEV; +} + +static inline int dw_edma_remove(struct dw_edma_chip *chip) +{ + return 0; +} +#endif /* CONFIG_DW_EDMA */ + +#endif /* _DW_EDMA_H */
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. This patch has a direct dependency of the patch ("[RFC 2/7] dmaengine: Add Synopsys eDMA IP version 0 support"). 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> --- Changes: RFC v1->RFC v2: - Replace comments // (C99 style) by /**/ - Fix the headers of the .c and .h files according to the most recent convention - Fix errors and checks pointed out by checkpatch with --strict option - Replace patch small description tag from dma by dmaengine - Change some dev_info() into dev_dbg() - Remove unnecessary zero initialization after kzalloc - Remove direction validation on config() API, since the direction parameter is deprecated - Refactor code to replace atomic_t by u32 variable type - Replace start_transfer() name by dw_edma_start_transfer() - Add spinlock to dw_edma_device_prep_slave_sg() - Add spinlock to dw_edma_free_chunk() - Simplify switch case into if on dw_edma_device_pause(), dw_edma_device_resume() and dw_edma_device_terminate_all() RFC v2->RFC v3: - Add driver parameter to disable msix feature - Fix printk variable of phys_addr_t type - Fix printk variable of __iomem type - Fix printk variable of size_t type - Add comments or improve existing ones - Add possibility to work with multiple IRQs feature - Fix source and destination addresses - Add define to magic numbers - Add DMA cyclic transfer feature - Rebase to v5.0-rc1 RFC v3->RFC v4: - Remove unnecessary dev_info() calls - Add multiple IRQ automatic adaption feature - Reorder variables declaration in reverse tree order on several functions - Add return check of dw_edma_alloc_burst() in dw_edma_alloc_chunk() - Add return check of dw_edma_alloc_chunk() in dw_edma_alloc_desc() - Remove pm_runtime_get_sync() call in probe() - Fix dma_cyclic() buffer address - Replace devm_*_irq() by *_irq() and recode accordingly - Fix license header - Replace kvzalloc() by kzalloc() and kvfree() by kfree() - Move ops->device_config callback from config() to probe() - Remove restriction to perform operation only in IDLE state on dw_edma_device_config(), dw_edma_device_prep_slave_sg(), dw_edma_device_prep_dma_cyclic() - Recode and simplify slave_sg() and dma_cyclic() - Recode and simplify interrupts and channel setup - Recode dw_edma_device_tx_status() - Move get_cached_msi_msg() to here - Code rewrite to use direct dw-edma-v0-core functions instead of callbacks RFC v4->RFC v5: - Patch resended, forgot to replace of '___' by '---' and to remove duplicate signed-off RFC v5->RFC v6: - Add author on file header - Remove debug prints - Code rewrite following Andy's suggestations drivers/dma/Kconfig | 2 + drivers/dma/Makefile | 1 + drivers/dma/dw-edma/Kconfig | 9 + drivers/dma/dw-edma/Makefile | 4 + drivers/dma/dw-edma/dw-edma-core.c | 919 +++++++++++++++++++++++++++++++++++++ drivers/dma/dw-edma/dw-edma-core.h | 165 +++++++ include/linux/dma/edma.h | 47 ++ 7 files changed, 1147 insertions(+) create mode 100644 drivers/dma/dw-edma/Kconfig create mode 100644 drivers/dma/dw-edma/Makefile create mode 100644 drivers/dma/dw-edma/dw-edma-core.c create mode 100644 drivers/dma/dw-edma/dw-edma-core.h create mode 100644 include/linux/dma/edma.h