search for: dma_zalloc_coherent

...*dma_handle, gfp_t gfp, > + struct dma_attrs *attrs) > +{ > + void *ret; > + > + ret = (void *)__get_free_pages(gfp, get_order(size)); > + if (ret) { > + memset(ret, 0, size); There is no need to zero out the memory here. If the user wants initialized memory it can call dma_zalloc_coherent. Having the memset here means to clear the memory twice in the dma_zalloc_coherent path. Otherwise it looks good. Joerg

...*dma_handle, gfp_t gfp, > + struct dma_attrs *attrs) > +{ > + void *ret; > + > + ret = (void *)__get_free_pages(gfp, get_order(size)); > + if (ret) { > + memset(ret, 0, size); There is no need to zero out the memory here. If the user wants initialized memory it can call dma_zalloc_coherent. Having the memset here means to clear the memory twice in the dma_zalloc_coherent path. Otherwise it looks good. Joerg

...index, > info->num = num; > info->msix_vector = msix_vec; > > - size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN)); > - info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO); > + size = vring_size(num, VIRTIO_PCI_VRING_ALIGN); > + info->queue = dma_zalloc_coherent(vdev->dev.parent, size, > + &info->queue_dma_addr, GFP_KERNEL); > if (info->queue == NULL) { > err = -ENOMEM; > goto out_info; > } > > /* activate the queue */ > - iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT, &...

...index, > info->num = num; > info->msix_vector = msix_vec; > > - size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN)); > - info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO); > + size = vring_size(num, VIRTIO_PCI_VRING_ALIGN); > + info->queue = dma_zalloc_coherent(vdev->dev.parent, size, > + &info->queue_dma_addr, GFP_KERNEL); > if (info->queue == NULL) { > err = -ENOMEM; > goto out_info; > } > > /* activate the queue */ > - iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT, &...

...um & (num - 1)) { > + dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num); > + return NULL; > + } > + > + /* TODO: allocate each queue chunk individually */ > + for (; num && vring_size(num, vring_align) > PAGE_SIZE; num /= 2) { > + queue = dma_zalloc_coherent( > + vdev->dev.parent, vring_size(num, vring_align), > + &dma_addr, GFP_KERNEL|__GFP_NOWARN); I think that we should teach this one to use regular kmalloc if vring_use_dma_api is cleared. Not a must but it seems cleaner at this stage. > + if (queue) > + break; > + } &...

...um & (num - 1)) { > + dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num); > + return NULL; > + } > + > + /* TODO: allocate each queue chunk individually */ > + for (; num && vring_size(num, vring_align) > PAGE_SIZE; num /= 2) { > + queue = dma_zalloc_coherent( > + vdev->dev.parent, vring_size(num, vring_align), > + &dma_addr, GFP_KERNEL|__GFP_NOWARN); I think that we should teach this one to use regular kmalloc if vring_use_dma_api is cleared. Not a must but it seems cleaner at this stage. > + if (queue) > + break; > + } &...

...ume num is a power of 2. */ + if (num & (num - 1)) { + dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num); + return NULL; + } + + /* TODO: allocate each queue chunk individually */ + for (; num && vring_size(num, vring_align) > PAGE_SIZE; num /= 2) { + queue = dma_zalloc_coherent( + vdev->dev.parent, vring_size(num, vring_align), + &dma_addr, GFP_KERNEL|__GFP_NOWARN); + if (queue) + break; + } + + if (!num) + return NULL; + + if (!queue) { + /* Try to get a single page. You are my only hope! */ + queue = dma_zalloc_coherent( + vdev->dev.parent, vring_s...

This switches virtio to use the DMA API unconditionally. I'm sure it breaks things, but it seems to work on x86 using virtio-pci, with and without Xen, and using both the modern 1.0 variant and the legacy variant. This appears to work on native and Xen x86_64 using both modern and legacy virtio-pci. It also appears to work on arm and arm64. It definitely won't work as-is on s390x, and

This switches virtio to use the DMA API unconditionally. I'm sure it breaks things, but it seems to work on x86 using virtio-pci, with and without Xen, and using both the modern 1.0 variant and the legacy variant. This appears to work on native and Xen x86_64 using both modern and legacy virtio-pci. It also appears to work on arm and arm64. It definitely won't work as-is on s390x, and

We can't just do virt_to_phys() on memory that we pass to the device and expect it to work in presence of a virtual IOMMU. We need to add IOMMU mappings for such DMAs to work correctly. Fix that with pci_alloc_consistent() where possible, or pci_map_single() where the mapping is short-lived or we don't control the allocation (netdev). Also fix two small bugs: 1) use after free of

We can't just do virt_to_phys() on memory that we pass to the device and expect it to work in presence of a virtual IOMMU. We need to add IOMMU mappings for such DMAs to work correctly. Fix that with pci_alloc_consistent() where possible, or pci_map_single() where the mapping is short-lived or we don't control the allocation (netdev). Also fix two small bugs: 1) use after free of

...fo->use_dma_api = vp_use_dma_api(); > > - size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN)); > - info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO); > + size = vring_size(num, VIRTIO_PCI_VRING_ALIGN); > + if (info->use_dma_api) { > + info->queue = dma_zalloc_coherent(vdev->dev.parent, size, > + &info->queue_dma_addr, > + GFP_KERNEL); > + } else { > + info->queue = alloc_pages_exact(PAGE_ALIGN(size), > + GFP_KERNEL|__GFP_ZERO); > + info->queue_dma_addr = virt_to_phys(info->queue); > + } > if (info...

...fo->use_dma_api = vp_use_dma_api(); > > - size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN)); > - info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO); > + size = vring_size(num, VIRTIO_PCI_VRING_ALIGN); > + if (info->use_dma_api) { > + info->queue = dma_zalloc_coherent(vdev->dev.parent, size, > + &info->queue_dma_addr, > + GFP_KERNEL); > + } else { > + info->queue = alloc_pages_exact(PAGE_ALIGN(size), > + GFP_KERNEL|__GFP_ZERO); > + info->queue_dma_addr = virt_to_phys(info->queue); > + } > if (info...

...fo->use_dma_api = vp_use_dma_api(); > > - size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN)); > - info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO); > + size = vring_size(num, VIRTIO_PCI_VRING_ALIGN); > + if (info->use_dma_api) { > + info->queue = dma_zalloc_coherent(vdev->dev.parent, size, > + &info->queue_dma_addr, > + GFP_KERNEL); > + } else { > + info->queue = alloc_pages_exact(PAGE_ALIGN(size), > + GFP_KERNEL|__GFP_ZERO); > + info->queue_dma_addr = virt_to_phys(info->queue); > + } > if (info...

...fo->use_dma_api = vp_use_dma_api(); > > - size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN)); > - info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO); > + size = vring_size(num, VIRTIO_PCI_VRING_ALIGN); > + if (info->use_dma_api) { > + info->queue = dma_zalloc_coherent(vdev->dev.parent, size, > + &info->queue_dma_addr, > + GFP_KERNEL); > + } else { > + info->queue = alloc_pages_exact(PAGE_ALIGN(size), > + GFP_KERNEL|__GFP_ZERO); > + info->queue_dma_addr = virt_to_phys(info->queue); > + } > if (info...

...oy() > 2) a cpu_to_le32() that should have been a cpu_to_le64() > > Acked-by: George Zhang <georgezhang at vmware.com> > Acked-by: Aditya Sarwade <asarwade at vmware.com> > Signed-off-by: Andy King <acking at vmware.com> Please use dma_alloc_coherent() (or in fact dma_zalloc_coherent()), dma_map_single() et al., because they are preferred and in particular allow specification of GFP_* flags.

...truct virtio_device *vdev, unsigned index, info->num = num; info->msix_vector = msix_vec; - size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN)); - info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO); + size = vring_size(num, VIRTIO_PCI_VRING_ALIGN); + info->queue = dma_zalloc_coherent(vdev->dev.parent, size, + &info->queue_dma_addr, GFP_KERNEL); if (info->queue == NULL) { err = -ENOMEM; goto out_info; } /* activate the queue */ - iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT, + iowrite32(info->queue_dma_addr >&...

...; info->msix_vector = msix_vec; >> >> - size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN)); >> - info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO); >> + size = vring_size(num, VIRTIO_PCI_VRING_ALIGN); >> + info->queue = dma_zalloc_coherent(vdev->dev.parent, size, >> + &info->queue_dma_addr, GFP_KERNEL); >> if (info->queue == NULL) { >> err = -ENOMEM; >> goto out_info; >> } >> >> /* activate the qu...

here is the 2nd version of providing an DMA API for s390. There are some attempts to unify the dma ops (Christoph) as well as some attempts to make virtio use the dma API (Andy). At kernel summit we concluded that we want to use the same code on all platforms, whereever possible, so having a dummy dma_op might be the easiest solution to keep virtio-ccw as similar as possible to

here is the 2nd version of providing an DMA API for s390. There are some attempts to unify the dma ops (Christoph) as well as some attempts to make virtio use the dma API (Andy). At kernel summit we concluded that we want to use the same code on all platforms, whereever possible, so having a dummy dma_op might be the easiest solution to keep virtio-ccw as similar as possible to