search for: dma_alloc_noncoherent

...rt of the -API at all. +If you don't understand how cache line coherency works between a processor and +an I/O device, you should not be using this part of the API. :: void * - dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, - gfp_t flag, unsigned long attrs) + dma_alloc_noncoherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, enum dma_data_direction dir, + gfp_t gfp) -Identical to dma_alloc_coherent() except that when the -DMA_ATTR_NON_CONSISTENT flags is passed in the attrs argument, the -platform will choose to return either consistent or non-consistent...

...@ -234,8 +234,8 @@ static int sgiwd93_probe(struct platform_device *pdev) hdata = host_to_hostdata(host); hdata->dev = &pdev->dev; - hdata->cpu = dma_alloc_attrs(&pdev->dev, HPC_DMA_SIZE, &hdata->dma, - GFP_KERNEL, DMA_ATTR_NON_CONSISTENT); + hdata->cpu = dma_alloc_noncoherent(&pdev->dev, HPC_DMA_SIZE, + &hdata->dma, DMA_TO_DEVICE, GFP_KERNEL); if (!hdata->cpu) { printk(KERN_WARNING "sgiwd93: Could not allocate memory for " "host %d buffer.\n", unit); @@ -274,8 +274,8 @@ static int sgiwd93_probe(struct platform_devic...

...@@ NCR_700_detect(struct scsi_host_template *tpnt, memory = dma_alloc_coherent(dev, TOTAL_MEM_SIZE, &pScript, GFP_KERNEL); if (!memory) { hostdata->noncoherent = 1; - memory = dma_alloc_attrs(dev, TOTAL_MEM_SIZE, &pScript, - GFP_KERNEL, DMA_ATTR_NON_CONSISTENT); + memory = dma_alloc_noncoherent(dev, TOTAL_MEM_SIZE, &pScript, + DMA_BIDIRECTIONAL, GFP_KERNEL); } if (!memory) { printk(KERN_ERR "53c700: Failed to allocate memory for driver, detaching\n"); @@ -414,8 +421,9 @@ NCR_700_release(struct Scsi_Host *host) (struct NCR_700_Host_Parameters *)host->hostdat...

...c *desc; @@ -449,15 +450,15 @@ static int hal2_alloc_dmabuf(struct snd_hal2 *hal2, struct hal2_codec *codec) int count = H2_BUF_SIZE / H2_BLOCK_SIZE; int i; - codec->buffer = dma_alloc_attrs(dev, H2_BUF_SIZE, &buffer_dma, - GFP_KERNEL, DMA_ATTR_NON_CONSISTENT); + codec->buffer = dma_alloc_noncoherent(dev, H2_BUF_SIZE, &buffer_dma, + buffer_dir, GFP_KERNEL); if (!codec->buffer) return -ENOMEM; - desc = dma_alloc_attrs(dev, count * sizeof(struct hal2_desc), - &desc_dma, GFP_KERNEL, DMA_ATTR_NON_CONSISTENT); + desc = dma_alloc_noncoherent(dev, count * sizeof(struct hal...

...TXCTRL_ACTIVE; @@ -740,8 +748,8 @@ static int sgiseeq_probe(struct platform_device *pdev) sp = netdev_priv(dev); /* Make private data page aligned */ - sr = dma_alloc_attrs(&pdev->dev, sizeof(*sp->srings), &sp->srings_dma, - GFP_KERNEL, DMA_ATTR_NON_CONSISTENT); + sr = dma_alloc_noncoherent(&pdev->dev, sizeof(*sp->srings), + &sp->srings_dma, DMA_BIDIRECTIONAL, GFP_KERNEL); if (!sr) { printk(KERN_ERR "Sgiseeq: Page alloc failed, aborting.\n"); err = -ENOMEM; @@ -802,8 +810,8 @@ static int sgiseeq_probe(struct platform_device *pdev) return 0; er...

On Mon, Sep 14, 2020 at 04:44:27PM +0200, Christoph Hellwig wrote: > drivers/net/ethernet/i825xx/lasi_82596.c | 25 ++--- > drivers/net/ethernet/i825xx/lib82596.c | 114 ++++++++++++++--------- > drivers/net/ethernet/i825xx/sni_82596.c | 4 - > drivers/net/ethernet/seeq/sgiseeq.c | 28 ++++-- > drivers/scsi/53c700.c | 9 +- > 5 files changed, 103

On 2020-09-15 16:51, Christoph Hellwig wrote: [...] > +These APIs allow to allocate pages in the kernel direct mapping that are > +guaranteed to be DMA addressable. This means that unlike dma_alloc_coherent, > +virt_to_page can be called on the resulting address, and the resulting Nit: if we explicitly describe this as if it's a guarantee that can be relied upon... > +struct

...ip(struct parisc_device *dev) lp = netdev_priv(netdevice); lp->options = dev->id.sversion == 0x72 ? OPT_SWAP_PORT : 0; - lp->dma = dma_alloc_attrs(&dev->dev, sizeof(struct i596_dma), - &lp->dma_addr, GFP_KERNEL, - DMA_ATTR_NON_CONSISTENT); + lp->dma = dma_alloc_noncoherent(&dev->dev, + sizeof(struct i596_dma), &lp->dma_addr, + DMA_BIDIRECTIONAL, GFP_KERNEL); if (!lp->dma) goto out_free_netdev; @@ -196,8 +189,8 @@ lan_init_chip(struct parisc_device *dev) return 0; out_free_dma: - dma_free_attrs(&dev->dev, sizeof(struct i596_dma)...

...ip(struct parisc_device *dev) lp = netdev_priv(netdevice); lp->options = dev->id.sversion == 0x72 ? OPT_SWAP_PORT : 0; - lp->dma = dma_alloc_attrs(&dev->dev, sizeof(struct i596_dma), - &lp->dma_addr, GFP_KERNEL, - DMA_ATTR_NON_CONSISTENT); + lp->dma = dma_alloc_noncoherent(&dev->dev, + sizeof(struct i596_dma), &lp->dma_addr, + DMA_BIDIRECTIONAL, GFP_KERNEL); if (!lp->dma) goto out_free_netdev; @@ -196,8 +189,8 @@ lan_init_chip(struct parisc_device *dev) return 0; out_free_dma: - dma_free_attrs(&dev->dev, sizeof(struct i596_dma)...

...plicit handling of the non-IOMMU and IOMMU cases and this is exactly > what we don't want to have in vb2 and what was actually the job of the > DMA API to hide. Is the plan to actually move the IOMMU handling out > of the DMA API? > > Do you think we could instead turn it into a dma_alloc_noncoherent() > helper, which has similar semantics as dma_alloc_attrs() and handles > the various corner cases (e.g. invalidate_kernel_vmap_range and > flush_kernel_vmap_range) to achieve the desired functionality without > delegating the "hell", as you called it, to the users? Yes, I g...

This API is the equivalent of alloc_pages, except that the returned memory is guaranteed to be DMA addressable by the passed in device. The implementation will also be used to provide a more sensible replacement for DMA_ATTR_NON_CONSISTENT flag. Additionally dma_alloc_noncoherent is switched over to use dma_alloc_pages as its backend. Signed-off-by: Christoph Hellwig <hch at lst.de> --- Documentation/core-api/dma-attributes.rst | 8 --- arch/alpha/kernel/pci_iommu.c | 2 + arch/arm/mm/dma-mapping-nommu.c | 2 + arch/arm/mm/dma-mapping.c...

...r non-coherent DMA to pages with incurring bounce buffering over can finally be properly supported. I'm still a little unsure about the API naming, as alloc_pages sort of implies a struct page return value, but we return a kernel virtual address. The other alternative would be to name the API dma_alloc_noncoherent, but the whole non-coherent naming seems to put people off. As a follow up I plan to move the implementation of the DMA_ATTR_NO_KERNEL_MAPPING flag over to this framework as well, given that is also is a fundamentally non coherent allocation. The replacement for that flag would then return a stru...

...e a few macro arguments in 53c700 - pass the right device to the DMA API in the lib82596 drivers - fix memory ownershiptransfers in sgiseeq - better document what a page in the direct kernel mapping means - split into dma_alloc_pages that returns a struct page and is in the direct mapping vs dma_alloc_noncoherent that can be vmapped - conver the firewire ohci driver to dma_alloc_pages Diffstat:

On Wed, Aug 19, 2020 at 03:07:04PM +0100, Robin Murphy wrote: >> FWIW, I asked back in time what the plan is for non-coherent >> allocations and it seemed like DMA_ATTR_NON_CONSISTENT and >> dma_sync_*() was supposed to be the right thing to go with. [2] The >> same thread also explains why dma_alloc_pages() isn't suitable for the >> users of dma_alloc_attrs() and

...6,10 +237,12 @@ nvkm_firmware_ctor(const struct nvkm_firmware_func *func, const char *name, break; case NVKM_FIRMWARE_IMG_DMA: { dma_addr_t addr; - len = ALIGN(fw->len, PAGE_SIZE); - fw->img = dma_alloc_coherent(fw->device->dev, len, &addr, GFP_KERNEL); + fw->img = dma_alloc_noncoherent(fw->device->dev, + len, &addr, + DMA_TO_DEVICE, + GFP_KERNEL); if (fw->img) { memcpy(fw->img, src, fw->len); fw->phys = addr; diff --git a/drivers/gpu/drm/nouveau/nvkm/falcon/fw.c b/drivers/gpu/drm/nouveau/nvkm/falcon/fw.c index 80a480b12174..a1c8545f...

...ith incurring bounce buffering over can finally > be properly supported. > > I'm still a little unsure about the API naming, as alloc_pages sort of > implies a struct page return value, but we return a kernel virtual > address. The other alternative would be to name the API > dma_alloc_noncoherent, but the whole non-coherent naming seems to put > people off. As a follow up I plan to move the implementation of the > DMA_ATTR_NO_KERNEL_MAPPING flag over to this framework as well, given > that is also is a fundamentally non coherent allocation. The replacement > for that flag woul...

...Erm ... dma_alloc_pages() returns a struct page, so is this sentence stale? >From patch 14: +struct page *dma_alloc_pages(struct device *dev, size_t size, + dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp); > The other alternative would be to name the API > dma_alloc_noncoherent, but the whole non-coherent naming seems to put > people off. You say that like it's a bad thing. I think the problem is more that people don't understand what non-coherent means and think they're supporting it when they're not. dma_alloc_manual_flushing()? > As a follow u...

On Thu, Apr 20, 2023 at 06:42:17PM +0200, Alexander Lobakin wrote: > When there's no recycling of pages, then yes. And since recycling is > done asynchronously, sometimes new allocations happen either way. > Anyways, that was roughly a couple years ago right when you introduced > dma_alloc_noncoherent(). Things might've been changed since then. > I could try again while next is closed (i.e. starting this Sunday), the > only thing I'd like to mention: Page Pool allocates pages via > alloc_pages_bulk_array_node(). Bulking helps a lot (and PP uses bulks of > 16 IIRC), explicit n...

...ch is that it requires explicit handling of the non-IOMMU and IOMMU cases and this is exactly what we don't want to have in vb2 and what was actually the job of the DMA API to hide. Is the plan to actually move the IOMMU handling out of the DMA API? Do you think we could instead turn it into a dma_alloc_noncoherent() helper, which has similar semantics as dma_alloc_attrs() and handles the various corner cases (e.g. invalidate_kernel_vmap_range and flush_kernel_vmap_range) to achieve the desired functionality without delegating the "hell", as you called it, to the users? Best regards, Tomasz

...struct nvkm_firmware_func *func, const char *name, > break; > case NVKM_FIRMWARE_IMG_DMA: { > dma_addr_t addr; > - > len = ALIGN(fw->len, PAGE_SIZE); > > - fw->img = dma_alloc_coherent(fw->device->dev, len, &addr, GFP_KERNEL); > + fw->img = dma_alloc_noncoherent(fw->device->dev, > + len, &addr, > + DMA_TO_DEVICE, > + GFP_KERNEL); > if (fw->img) { > memcpy(fw->img, src, fw->len); > fw->phys = addr; > diff --git a/drivers/gpu/drm/nouveau/nvkm/falcon/fw.c b/drivers/gpu/drm/nouveau/nvkm/falco...