From: Christoph Hellwig <hch@xxxxxx> Subject: dma-mapping: use vmap insted of reimplementing it Replace the open coded instance of vmap with the actual function. In the non-contiguous (IOMMU) case this requires an extra find_vm_area, but given that this isn't a fast path function that is a small price to pay. Link: http://lkml.kernel.org/r/20200414131348.444715-6-hch@xxxxxx Signed-off-by: Christoph Hellwig <hch@xxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: David Airlie <airlied@xxxxxxxx> Cc: Gao Xiang <xiang@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx> Cc: Laura Abbott <labbott@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Michael Kelley <mikelley@xxxxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Nitin Gupta <ngupta@xxxxxxxxxx> Cc: Robin Murphy <robin.murphy@xxxxxxx> Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx> Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx> Cc: Wei Liu <wei.liu@xxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/dma/remap.c | 48 ++++++++++--------------------------------- 1 file changed, 12 insertions(+), 36 deletions(-) --- a/kernel/dma/remap.c~dma-mapping-use-vmap-insted-of-reimplementing-it +++ a/kernel/dma/remap.c @@ -20,23 +20,6 @@ struct page **dma_common_find_pages(void return area->pages; } -static struct vm_struct *__dma_common_pages_remap(struct page **pages, - size_t size, pgprot_t prot, const void *caller) -{ - struct vm_struct *area; - - area = get_vm_area_caller(size, VM_DMA_COHERENT, caller); - if (!area) - return NULL; - - if (map_vm_area(area, prot, pages)) { - vunmap(area->addr); - return NULL; - } - - return area; -} - /* * Remaps an array of PAGE_SIZE pages into another vm_area. * Cannot be used in non-sleeping contexts @@ -44,15 +27,12 @@ static struct vm_struct *__dma_common_pa void *dma_common_pages_remap(struct page **pages, size_t size, pgprot_t prot, const void *caller) { - struct vm_struct *area; + void *vaddr; - area = __dma_common_pages_remap(pages, size, prot, caller); - if (!area) - return NULL; - - area->pages = pages; - - return area->addr; + vaddr = vmap(pages, size >> PAGE_SHIFT, VM_DMA_COHERENT, prot); + if (vaddr) + find_vm_area(vaddr)->pages = pages; + return vaddr; } /* @@ -62,24 +42,20 @@ void *dma_common_pages_remap(struct page void *dma_common_contiguous_remap(struct page *page, size_t size, pgprot_t prot, const void *caller) { - int i; + int count = size >> PAGE_SHIFT; struct page **pages; - struct vm_struct *area; + void *vaddr; + int i; - pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL); + pages = kmalloc_array(count, sizeof(struct page *), GFP_KERNEL); if (!pages) return NULL; - - for (i = 0; i < (size >> PAGE_SHIFT); i++) + for (i = 0; i < count; i++) pages[i] = nth_page(page, i); - - area = __dma_common_pages_remap(pages, size, prot, caller); - + vaddr = vmap(pages, count, VM_DMA_COHERENT, prot); kfree(pages); - if (!area) - return NULL; - return area->addr; + return vaddr; } /* _
