Skip to content

Commit

Permalink
Merge tag 'for-linus-6.1-rc2-tag' of git://git.kernel.org/pub/scm/lin…
Browse files Browse the repository at this point in the history
…ux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:
 "Just two fixes for the new 'virtio with grants' feature"

* tag 'for-linus-6.1-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/virtio: Convert PAGE_SIZE/PAGE_SHIFT/PFN_UP to Xen counterparts
  xen/virtio: Handle cases when page offset > PAGE_SIZE properly
  • Loading branch information
Linus Torvalds committed Oct 21, 2022
2 parents 0de0b76 + a383dcb commit 1d61754
Showing 1 changed file with 15 additions and 12 deletions.
27 changes: 15 additions & 12 deletions drivers/xen/grant-dma-ops.c
Original file line number Diff line number Diff line change
Expand Up @@ -31,12 +31,12 @@ static DEFINE_XARRAY_FLAGS(xen_grant_dma_devices, XA_FLAGS_LOCK_IRQ);

static inline dma_addr_t grant_to_dma(grant_ref_t grant)
{
return XEN_GRANT_DMA_ADDR_OFF | ((dma_addr_t)grant << PAGE_SHIFT);
return XEN_GRANT_DMA_ADDR_OFF | ((dma_addr_t)grant << XEN_PAGE_SHIFT);
}

static inline grant_ref_t dma_to_grant(dma_addr_t dma)
{
return (grant_ref_t)((dma & ~XEN_GRANT_DMA_ADDR_OFF) >> PAGE_SHIFT);
return (grant_ref_t)((dma & ~XEN_GRANT_DMA_ADDR_OFF) >> XEN_PAGE_SHIFT);
}

static struct xen_grant_dma_data *find_xen_grant_dma_data(struct device *dev)
Expand Down Expand Up @@ -79,7 +79,7 @@ static void *xen_grant_dma_alloc(struct device *dev, size_t size,
unsigned long attrs)
{
struct xen_grant_dma_data *data;
unsigned int i, n_pages = PFN_UP(size);
unsigned int i, n_pages = XEN_PFN_UP(size);
unsigned long pfn;
grant_ref_t grant;
void *ret;
Expand All @@ -91,14 +91,14 @@ static void *xen_grant_dma_alloc(struct device *dev, size_t size,
if (unlikely(data->broken))
return NULL;

ret = alloc_pages_exact(n_pages * PAGE_SIZE, gfp);
ret = alloc_pages_exact(n_pages * XEN_PAGE_SIZE, gfp);
if (!ret)
return NULL;

pfn = virt_to_pfn(ret);

if (gnttab_alloc_grant_reference_seq(n_pages, &grant)) {
free_pages_exact(ret, n_pages * PAGE_SIZE);
free_pages_exact(ret, n_pages * XEN_PAGE_SIZE);
return NULL;
}

Expand All @@ -116,7 +116,7 @@ static void xen_grant_dma_free(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, unsigned long attrs)
{
struct xen_grant_dma_data *data;
unsigned int i, n_pages = PFN_UP(size);
unsigned int i, n_pages = XEN_PFN_UP(size);
grant_ref_t grant;

data = find_xen_grant_dma_data(dev);
Expand All @@ -138,7 +138,7 @@ static void xen_grant_dma_free(struct device *dev, size_t size, void *vaddr,

gnttab_free_grant_reference_seq(grant, n_pages);

free_pages_exact(vaddr, n_pages * PAGE_SIZE);
free_pages_exact(vaddr, n_pages * XEN_PAGE_SIZE);
}

static struct page *xen_grant_dma_alloc_pages(struct device *dev, size_t size,
Expand Down Expand Up @@ -168,7 +168,9 @@ static dma_addr_t xen_grant_dma_map_page(struct device *dev, struct page *page,
unsigned long attrs)
{
struct xen_grant_dma_data *data;
unsigned int i, n_pages = PFN_UP(offset + size);
unsigned long dma_offset = xen_offset_in_page(offset),
pfn_offset = XEN_PFN_DOWN(offset);
unsigned int i, n_pages = XEN_PFN_UP(dma_offset + size);
grant_ref_t grant;
dma_addr_t dma_handle;

Expand All @@ -187,10 +189,11 @@ static dma_addr_t xen_grant_dma_map_page(struct device *dev, struct page *page,

for (i = 0; i < n_pages; i++) {
gnttab_grant_foreign_access_ref(grant + i, data->backend_domid,
xen_page_to_gfn(page) + i, dir == DMA_TO_DEVICE);
pfn_to_gfn(page_to_xen_pfn(page) + i + pfn_offset),
dir == DMA_TO_DEVICE);
}

dma_handle = grant_to_dma(grant) + offset;
dma_handle = grant_to_dma(grant) + dma_offset;

return dma_handle;
}
Expand All @@ -200,8 +203,8 @@ static void xen_grant_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
unsigned long attrs)
{
struct xen_grant_dma_data *data;
unsigned long offset = dma_handle & (PAGE_SIZE - 1);
unsigned int i, n_pages = PFN_UP(offset + size);
unsigned long dma_offset = xen_offset_in_page(dma_handle);
unsigned int i, n_pages = XEN_PFN_UP(dma_offset + size);
grant_ref_t grant;

if (WARN_ON(dir == DMA_NONE))
Expand Down

0 comments on commit 1d61754

Please sign in to comment.