diff options
| author | David Woodhouse <David.Woodhouse@intel.com> | 2009-07-02 11:21:16 +0100 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2009-07-02 11:27:13 +0100 |
| commit | 75e6bf9638992dfc0fec9c3ca10444c8e0d6a638 (patch) | |
| tree | bdbabd91d77edb3d623292ea97b17d88d053816e | |
| parent | 7766a3fb905f0b078b05f5d6a6be8df4c64b9f51 (diff) | |
intel-iommu: Introduce first_pte_in_page() to simplify PTE-setting loops
On Wed, 2009-07-01 at 16:59 -0700, Linus Torvalds wrote:
> I also _really_ hate how you do
>
> (unsigned long)pte >> VTD_PAGE_SHIFT ==
> (unsigned long)first_pte >> VTD_PAGE_SHIFT
Kill this, in favour of just looking to see if the incremented pte
pointer has 'wrapped' onto the next page. Which means we have to check
it _after_ incrementing it, not before.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
| -rw-r--r-- | drivers/pci/intel-iommu.c | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index 2c1b2babfdc..dcf0295a9b6 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -240,6 +240,11 @@ static inline bool dma_pte_present(struct dma_pte *pte) return (pte->val & 3) != 0; } +static inline int first_pte_in_page(struct dma_pte *pte) +{ + return !((unsigned long)pte & ~VTD_PAGE_MASK); +} + /* * This domain is a statically identity mapping domain. * 1. This domain creats a static 1:1 mapping to all usable memory. @@ -780,13 +785,12 @@ static void dma_pte_clear_range(struct dmar_domain *domain, start_pfn = align_to_level(start_pfn + 1, 2); continue; } - while (start_pfn <= last_pfn && - (unsigned long)pte >> VTD_PAGE_SHIFT == - (unsigned long)first_pte >> VTD_PAGE_SHIFT) { + do { dma_clear_pte(pte); start_pfn++; pte++; - } + } while (start_pfn <= last_pfn && !first_pte_in_page(pte)); + domain_flush_cache(domain, first_pte, (void *)pte - (void *)first_pte); } @@ -821,14 +825,14 @@ static void dma_pte_free_pagetable(struct dmar_domain *domain, tmp = align_to_level(tmp + 1, level + 1); continue; } - while (tmp + level_size(level) - 1 <= last_pfn && - (unsigned long)pte >> VTD_PAGE_SHIFT == - (unsigned long)first_pte >> VTD_PAGE_SHIFT) { + do { free_pgtable_page(phys_to_virt(dma_pte_addr(pte))); dma_clear_pte(pte); pte++; tmp += level_size(level); - } + } while (!first_pte_in_page(pte) && + tmp + level_size(level) - 1 <= last_pfn); + domain_flush_cache(domain, first_pte, (void *)pte - (void *)first_pte); @@ -1694,9 +1698,7 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn, WARN_ON(1); } pte++; - if (!nr_pages || - (unsigned long)pte >> VTD_PAGE_SHIFT != - (unsigned long)first_pte >> VTD_PAGE_SHIFT) { + if (!nr_pages || first_pte_in_page(pte)) { domain_flush_cache(domain, first_pte, (void *)pte - (void *)first_pte); pte = NULL; |