From 9e8aa6b5461be50197e0bebc040e9fb6029a3d6b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 21 Nov 2018 19:20:44 +0100 Subject: [PATCH] x86/amd_gart: remove the mapping_error dma_map_ops method Return DMA_MAPPING_ERROR instead of the magic bad_dma_addr on a dma mapping failure and let the core dma-mapping code handle the rest. Remove the magic EMERGENCY_PAGES that the bad_dma_addr gets redirected to. Signed-off-by: Christoph Hellwig Acked-by: Linus Torvalds --- arch/x86/kernel/amd_gart_64.c | 40 ++++++----------------------------- 1 file changed, 6 insertions(+), 34 deletions(-) diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c index 3f9d1b4019bb..ad84f13d0c1f 100644 --- a/arch/x86/kernel/amd_gart_64.c +++ b/arch/x86/kernel/amd_gart_64.c @@ -50,8 +50,6 @@ static unsigned long iommu_pages; /* .. and in pages */ static u32 *iommu_gatt_base; /* Remapping table */ -static dma_addr_t bad_dma_addr; - /* * If this is disabled the IOMMU will use an optimized flushing strategy * of only flushing when an mapping is reused. With it true the GART is @@ -74,8 +72,6 @@ static u32 gart_unmapped_entry; (((x) & 0xfffff000) | (((x) >> 32) << 4) | GPTE_VALID | GPTE_COHERENT) #define GPTE_DECODE(x) (((x) & 0xfffff000) | (((u64)(x) & 0xff0) << 28)) -#define EMERGENCY_PAGES 32 /* = 128KB */ - #ifdef CONFIG_AGP #define AGPEXTERN extern #else @@ -184,14 +180,6 @@ static void iommu_full(struct device *dev, size_t size, int dir) */ dev_err(dev, "PCI-DMA: Out of IOMMU space for %lu bytes\n", size); - - if (size > PAGE_SIZE*EMERGENCY_PAGES) { - if (dir == PCI_DMA_FROMDEVICE || dir == PCI_DMA_BIDIRECTIONAL) - panic("PCI-DMA: Memory would be corrupted\n"); - if (dir == PCI_DMA_TODEVICE || dir == PCI_DMA_BIDIRECTIONAL) - panic(KERN_ERR - "PCI-DMA: Random memory would be DMAed\n"); - } #ifdef CONFIG_IOMMU_LEAK dump_leak(); #endif @@ -220,7 +208,7 @@ static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem, int i; if (unlikely(phys_mem + size > GART_MAX_PHYS_ADDR)) - return bad_dma_addr; + return DMA_MAPPING_ERROR; iommu_page = alloc_iommu(dev, npages, align_mask); if (iommu_page == -1) { @@ -229,7 +217,7 @@ static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem, if (panic_on_overflow) panic("dma_map_area overflow %lu bytes\n", size); iommu_full(dev, size, dir); - return bad_dma_addr; + return DMA_MAPPING_ERROR; } for (i = 0; i < npages; i++) { @@ -271,7 +259,7 @@ static void gart_unmap_page(struct device *dev, dma_addr_t dma_addr, int npages; int i; - if (dma_addr < iommu_bus_base + EMERGENCY_PAGES*PAGE_SIZE || + if (dma_addr == DMA_MAPPING_ERROR || dma_addr >= iommu_bus_base + iommu_size) return; @@ -315,7 +303,7 @@ static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg, if (nonforced_iommu(dev, addr, s->length)) { addr = dma_map_area(dev, addr, s->length, dir, 0); - if (addr == bad_dma_addr) { + if (addr == DMA_MAPPING_ERROR) { if (i > 0) gart_unmap_sg(dev, sg, i, dir, 0); nents = 0; @@ -471,7 +459,7 @@ error: iommu_full(dev, pages << PAGE_SHIFT, dir); for_each_sg(sg, s, nents, i) - s->dma_address = bad_dma_addr; + s->dma_address = DMA_MAPPING_ERROR; return 0; } @@ -490,7 +478,7 @@ gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr, *dma_addr = dma_map_area(dev, virt_to_phys(vaddr), size, DMA_BIDIRECTIONAL, (1UL << get_order(size)) - 1); flush_gart(); - if (unlikely(*dma_addr == bad_dma_addr)) + if (unlikely(*dma_addr == DMA_MAPPING_ERROR)) goto out_free; return vaddr; out_free: @@ -507,11 +495,6 @@ gart_free_coherent(struct device *dev, size_t size, void *vaddr, dma_direct_free_pages(dev, size, vaddr, dma_addr, attrs); } -static int gart_mapping_error(struct device *dev, dma_addr_t dma_addr) -{ - return (dma_addr == bad_dma_addr); -} - static int no_agp; static __init unsigned long check_iommu_size(unsigned long aper, u64 aper_size) @@ -695,7 +678,6 @@ static const struct dma_map_ops gart_dma_ops = { .unmap_page = gart_unmap_page, .alloc = gart_alloc_coherent, .free = gart_free_coherent, - .mapping_error = gart_mapping_error, .dma_supported = dma_direct_supported, }; @@ -730,7 +712,6 @@ int __init gart_iommu_init(void) unsigned long aper_base, aper_size; unsigned long start_pfn, end_pfn; unsigned long scratch; - long i; if (!amd_nb_has_feature(AMD_NB_GART)) return 0; @@ -784,19 +765,12 @@ int __init gart_iommu_init(void) } #endif - /* - * Out of IOMMU space handling. - * Reserve some invalid pages at the beginning of the GART. - */ - bitmap_set(iommu_gart_bitmap, 0, EMERGENCY_PAGES); - pr_info("PCI-DMA: Reserving %luMB of IOMMU area in the AGP aperture\n", iommu_size >> 20); agp_memory_reserved = iommu_size; iommu_start = aper_size - iommu_size; iommu_bus_base = info.aper_base + iommu_start; - bad_dma_addr = iommu_bus_base; iommu_gatt_base = agp_gatt_table + (iommu_start>>PAGE_SHIFT); /* @@ -838,8 +812,6 @@ int __init gart_iommu_init(void) if (!scratch) panic("Cannot allocate iommu scratch page"); gart_unmapped_entry = GPTE_ENCODE(__pa(scratch)); - for (i = EMERGENCY_PAGES; i < iommu_pages; i++) - iommu_gatt_base[i] = gart_unmapped_entry; flush_gart(); dma_ops = &gart_dma_ops;