From: FUJITA Tomonori iommu_arena_find_pages duplicates the code to access to the bitmap for free space management. This patch convert the IOMMU code to have only one place to access the bitmap, in the popular way that other IOMMUs (e.g. POWER and SPARC) do. This patch is preparation for modifications to fix the IOMMU segment boundary problem. Signed-off-by: FUJITA Tomonori Cc: Richard Henderson Cc: Ivan Kokshaysky Signed-off-by: Andrew Morton --- arch/alpha/kernel/pci_iommu.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff -puN arch/alpha/kernel/pci_iommu.c~alpha-iommu-had-better-access-to-the-free-space-bitmap-at-only-one-place arch/alpha/kernel/pci_iommu.c --- a/arch/alpha/kernel/pci_iommu.c~alpha-iommu-had-better-access-to-the-free-space-bitmap-at-only-one-place +++ a/arch/alpha/kernel/pci_iommu.c @@ -132,12 +132,15 @@ iommu_arena_find_pages(struct pci_iommu_ { unsigned long *ptes; long i, p, nent; + int pass = 0; /* Search forward for the first mask-aligned sequence of N free ptes */ ptes = arena->ptes; nent = arena->size >> PAGE_SHIFT; p = ALIGN(arena->next_entry, mask + 1); i = 0; + +again: while (i < n && p+i < nent) { if (ptes[p+i]) p = ALIGN(p + i + 1, mask + 1), i = 0; @@ -146,19 +149,18 @@ iommu_arena_find_pages(struct pci_iommu_ } if (i < n) { - /* Reached the end. Flush the TLB and restart the - search from the beginning. */ - alpha_mv.mv_pci_tbi(arena->hose, 0, -1); - - p = 0, i = 0; - while (i < n && p+i < nent) { - if (ptes[p+i]) - p = ALIGN(p + i + 1, mask + 1), i = 0; - else - i = i + 1; - } - - if (i < n) + if (pass < 1) { + /* + * Reached the end. Flush the TLB and restart + * the search from the beginning. + */ + alpha_mv.mv_pci_tbi(arena->hose, 0, -1); + + pass++; + p = 0; + i = 0; + goto again; + } else return -1; } _