From 1b65c4e5a9af1a1c61e792e2d0ed481e0c1f21a9 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Thu, 10 Oct 2013 13:41:10 +0000 Subject: [PATCH] swiotlb-xen: use xen_alloc/free_coherent_pages Use xen_alloc_coherent_pages and xen_free_coherent_pages to allocate or free coherent pages. We need to be careful handling the pointer returned by xen_alloc_coherent_pages, because on ARM the pointer is not equal to phys_to_virt(*dma_handle). In fact virt_to_phys only works for kernel direct mapped RAM memory. In ARM case the pointer could be an ioremap address, therefore passing it to virt_to_phys would give you another physical address that doesn't correspond to it. Make xen_create_contiguous_region take a phys_addr_t as start parameter to avoid the virt_to_phys calls which would be incorrect. Changes in v6: - remove extra spaces. Signed-off-by: Stefano Stabellini Reviewed-by: Konrad Rzeszutek Wilk --- arch/arm/xen/mm.c | 6 +++--- arch/x86/xen/mmu.c | 7 +++++-- drivers/xen/swiotlb-xen.c | 31 +++++++++++++++++++++---------- include/xen/xen-ops.h | 4 ++-- 4 files changed, 31 insertions(+), 17 deletions(-) diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index 0d69b874d249..b0e77de99148 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -16,7 +16,7 @@ #include #include -int xen_create_contiguous_region(unsigned long vstart, unsigned int order, +int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, unsigned int address_bits, dma_addr_t *dma_handle) { @@ -24,12 +24,12 @@ int xen_create_contiguous_region(unsigned long vstart, unsigned int order, return -EINVAL; /* we assume that dom0 is mapped 1:1 for now */ - *dma_handle = virt_to_phys(pstart); + *dma_handle = pstart; return 0; } EXPORT_SYMBOL_GPL(xen_create_contiguous_region); -void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order) +void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) { return; } diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 6c34d7c03d5b..883088368ff0 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -2328,13 +2328,14 @@ static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in, return success; } -int xen_create_contiguous_region(unsigned long vstart, unsigned int order, +int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, unsigned int address_bits, dma_addr_t *dma_handle) { unsigned long *in_frames = discontig_frames, out_frame; unsigned long flags; int success; + unsigned long vstart = (unsigned long)phys_to_virt(pstart); /* * Currently an auto-translated guest will not perform I/O, nor will @@ -2374,11 +2375,12 @@ int xen_create_contiguous_region(unsigned long vstart, unsigned int order, } EXPORT_SYMBOL_GPL(xen_create_contiguous_region); -void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order) +void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) { unsigned long *out_frames = discontig_frames, in_frame; unsigned long flags; int success; + unsigned long vstart; if (xen_feature(XENFEAT_auto_translated_physmap)) return; @@ -2386,6 +2388,7 @@ void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order) if (unlikely(order > MAX_CONTIG_ORDER)) return; + vstart = (unsigned long)phys_to_virt(pstart); memset((void *) vstart, 0, PAGE_SIZE << order); spin_lock_irqsave(&xen_reservation_lock, flags); diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index d8ef0bf577d2..189b8db5c983 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -43,6 +43,7 @@ #include #include #include +#include /* * Used to do a quick range check in swiotlb_tbl_unmap_single and * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this @@ -142,6 +143,7 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs) int i, rc; int dma_bits; dma_addr_t dma_handle; + phys_addr_t p = virt_to_phys(buf); dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT; @@ -151,7 +153,7 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs) do { rc = xen_create_contiguous_region( - (unsigned long)buf + (i << IO_TLB_SHIFT), + p + (i << IO_TLB_SHIFT), get_order(slabs << IO_TLB_SHIFT), dma_bits, &dma_handle); } while (rc && dma_bits++ < max_dma_bits); @@ -279,7 +281,6 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, void *ret; int order = get_order(size); u64 dma_mask = DMA_BIT_MASK(32); - unsigned long vstart; phys_addr_t phys; dma_addr_t dev_addr; @@ -294,8 +295,12 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, if (dma_alloc_from_coherent(hwdev, size, dma_handle, &ret)) return ret; - vstart = __get_free_pages(flags, order); - ret = (void *)vstart; + /* On ARM this function returns an ioremap'ped virtual address for + * which virt_to_phys doesn't return the corresponding physical + * address. In fact on ARM virt_to_phys only works for kernel direct + * mapped RAM memory. Also see comment below. + */ + ret = xen_alloc_coherent_pages(hwdev, size, dma_handle, flags, attrs); if (!ret) return ret; @@ -303,15 +308,19 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, if (hwdev && hwdev->coherent_dma_mask) dma_mask = dma_alloc_coherent_mask(hwdev, flags); - phys = virt_to_phys(ret); + /* At this point dma_handle is the physical address, next we are + * going to set it to the machine address. + * Do not use virt_to_phys(ret) because on ARM it doesn't correspond + * to *dma_handle. */ + phys = *dma_handle; dev_addr = xen_phys_to_bus(phys); if (((dev_addr + size - 1 <= dma_mask)) && !range_straddles_page_boundary(phys, size)) *dma_handle = dev_addr; else { - if (xen_create_contiguous_region(vstart, order, + if (xen_create_contiguous_region(phys, order, fls64(dma_mask), dma_handle) != 0) { - free_pages(vstart, order); + xen_free_coherent_pages(hwdev, size, ret, (dma_addr_t)phys, attrs); return NULL; } } @@ -334,13 +343,15 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, if (hwdev && hwdev->coherent_dma_mask) dma_mask = hwdev->coherent_dma_mask; - phys = virt_to_phys(vaddr); + /* do not use virt_to_phys because on ARM it doesn't return you the + * physical address */ + phys = xen_bus_to_phys(dev_addr); if (((dev_addr + size - 1 > dma_mask)) || range_straddles_page_boundary(phys, size)) - xen_destroy_contiguous_region((unsigned long)vaddr, order); + xen_destroy_contiguous_region(phys, order); - free_pages((unsigned long)vaddr, order); + xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs); } EXPORT_SYMBOL_GPL(xen_swiotlb_free_coherent); diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index 9ef704d3a9dd..fb2ea8f26552 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -19,11 +19,11 @@ void xen_arch_resume(void); int xen_setup_shutdown_event(void); extern unsigned long *xen_contiguous_bitmap; -int xen_create_contiguous_region(unsigned long vstart, unsigned int order, +int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, unsigned int address_bits, dma_addr_t *dma_handle); -void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order); +void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order); struct vm_area_struct; int xen_remap_domain_mfn_range(struct vm_area_struct *vma,