diff options
| author | David Woodhouse <David.Woodhouse@intel.com> | 2009-07-01 19:21:24 +0100 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2009-07-01 19:21:24 +0100 |
| commit | c85994e4771025ef2a66533eb1a4c6c2217b9cda (patch) | |
| tree | 9f827d5587a5cac2c8a412317e2997b8add67b9a | |
| parent | 3238c0c4d68d9a9022b411a11a4b933fbdb53a14 (diff) | |
intel-iommu: Ensure that PTE writes are 64-bit atomic, even on i386
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
| -rw-r--r-- | drivers/pci/intel-iommu.c | 37 |
1 files changed, 23 insertions, 14 deletions
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index ec7e032d5ab5..eea1006c860a 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -222,7 +222,12 @@ static inline void dma_set_pte_prot(struct dma_pte *pte, unsigned long prot) static inline u64 dma_pte_addr(struct dma_pte *pte) { - return (pte->val & VTD_PAGE_MASK); +#ifdef CONFIG_64BIT + return pte->val & VTD_PAGE_MASK; +#else + /* Must have a full atomic 64-bit read */ + return __cmpxchg64(pte, 0ULL, 0ULL) & VTD_PAGE_MASK; +#endif } static inline void dma_set_pte_pfn(struct dma_pte *pte, unsigned long pfn) @@ -712,6 +717,8 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain, break; if (!dma_pte_present(pte)) { + uint64_t pteval; + tmp_page = alloc_pgtable_page(); if (!tmp_page) { @@ -719,15 +726,15 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain, flags); return NULL; } - domain_flush_cache(domain, tmp_page, PAGE_SIZE); - dma_set_pte_pfn(pte, virt_to_dma_pfn(tmp_page)); - /* - * high level table always sets r/w, last level page - * table control read/write - */ - dma_set_pte_readable(pte); - dma_set_pte_writable(pte); - domain_flush_cache(domain, pte, sizeof(*pte)); + domain_flush_cache(domain, tmp_page, VTD_PAGE_SIZE); + pteval = (virt_to_dma_pfn(tmp_page) << VTD_PAGE_SHIFT) | DMA_PTE_READ | DMA_PTE_WRITE; + if (cmpxchg64(&pte->val, 0ULL, pteval)) { + /* Someone else set it while we were thinking; use theirs. */ + free_pgtable_page(tmp_page); + } else { + dma_pte_addr(pte); + domain_flush_cache(domain, pte, sizeof(*pte)); + } } parent = phys_to_virt(dma_pte_addr(pte)); level--; @@ -1666,6 +1673,8 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn, } while (nr_pages--) { + uint64_t tmp; + if (!sg_res) { sg_res = (sg->offset + sg->length + VTD_PAGE_SIZE - 1) >> VTD_PAGE_SHIFT; sg->dma_address = ((dma_addr_t)iov_pfn << VTD_PAGE_SHIFT) + sg->offset; @@ -1680,17 +1689,17 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn, /* We don't need lock here, nobody else * touches the iova range */ - if (unlikely(dma_pte_addr(pte))) { + tmp = cmpxchg64(&pte->val, 0ULL, pteval); + if (tmp) { static int dumps = 5; - printk(KERN_CRIT "ERROR: DMA PTE for vPFN 0x%lx already set (to %llx)\n", - iov_pfn, pte->val); + printk(KERN_CRIT "ERROR: DMA PTE for vPFN 0x%lx already set (to %llx not %llx)\n", + iov_pfn, tmp, (unsigned long long)pteval); if (dumps) { dumps--; debug_dma_dump_mappings(NULL); } WARN_ON(1); } - pte->val = pteval; pte++; if (!nr_pages || (unsigned long)pte >> VTD_PAGE_SHIFT != |