提交 c85994e4 编写于 作者: D David Woodhouse

intel-iommu: Ensure that PTE writes are 64-bit atomic, even on i386

Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
上级 3238c0c4
......@@ -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) {
......@@ -719,16 +726,16 @@ 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, 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 !=
......
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