diff options
Diffstat (limited to 'drivers/iommu/iommufd/iova_bitmap.c')
| -rw-r--r-- | drivers/iommu/iommufd/iova_bitmap.c | 68 |
1 files changed, 58 insertions, 10 deletions
diff --git a/drivers/iommu/iommufd/iova_bitmap.c b/drivers/iommu/iommufd/iova_bitmap.c index 0a92c9eeaf7f50..db8c46bee1559a 100644 --- a/drivers/iommu/iommufd/iova_bitmap.c +++ b/drivers/iommu/iommufd/iova_bitmap.c @@ -100,7 +100,7 @@ struct iova_bitmap { struct iova_bitmap_map mapped; /* userspace address of the bitmap */ - u64 __user *bitmap; + u8 __user *bitmap; /* u64 index that @mapped points to */ unsigned long mapped_base_index; @@ -113,6 +113,9 @@ struct iova_bitmap { /* length of the IOVA range for the whole bitmap */ size_t length; + + /* length of the IOVA range set ahead the pinned pages */ + unsigned long set_ahead_length; }; /* @@ -162,7 +165,7 @@ static int iova_bitmap_get(struct iova_bitmap *bitmap) { struct iova_bitmap_map *mapped = &bitmap->mapped; unsigned long npages; - u64 __user *addr; + u8 __user *addr; long ret; /* @@ -176,17 +179,18 @@ static int iova_bitmap_get(struct iova_bitmap *bitmap) sizeof(*bitmap->bitmap), PAGE_SIZE); /* - * We always cap at max number of 'struct page' a base page can fit. - * This is, for example, on x86 means 2M of bitmap data max. - */ - npages = min(npages, PAGE_SIZE / sizeof(struct page *)); - - /* * Bitmap address to be pinned is calculated via pointer arithmetic * with bitmap u64 word index. */ addr = bitmap->bitmap + bitmap->mapped_base_index; + /* + * We always cap at max number of 'struct page' a base page can fit. + * This is, for example, on x86 means 2M of bitmap data max. + */ + npages = min(npages + !!offset_in_page(addr), + PAGE_SIZE / sizeof(struct page *)); + ret = pin_user_pages_fast((unsigned long)addr, npages, FOLL_WRITE, mapped->pages); if (ret <= 0) @@ -247,7 +251,7 @@ struct iova_bitmap *iova_bitmap_alloc(unsigned long iova, size_t length, mapped = &bitmap->mapped; mapped->pgshift = __ffs(page_size); - bitmap->bitmap = data; + bitmap->bitmap = (u8 __user *)data; bitmap->mapped_total_index = iova_bitmap_offset_to_index(bitmap, length - 1) + 1; bitmap->iova = iova; @@ -304,7 +308,7 @@ static unsigned long iova_bitmap_mapped_remaining(struct iova_bitmap *bitmap) remaining = bitmap->mapped_total_index - bitmap->mapped_base_index; remaining = min_t(unsigned long, remaining, - bytes / sizeof(*bitmap->bitmap)); + DIV_ROUND_UP(bytes, sizeof(*bitmap->bitmap))); return remaining; } @@ -341,6 +345,32 @@ static bool iova_bitmap_done(struct iova_bitmap *bitmap) return bitmap->mapped_base_index >= bitmap->mapped_total_index; } +static int iova_bitmap_set_ahead(struct iova_bitmap *bitmap, + size_t set_ahead_length) +{ + int ret = 0; + + while (set_ahead_length > 0 && !iova_bitmap_done(bitmap)) { + unsigned long length = iova_bitmap_mapped_length(bitmap); + unsigned long iova = iova_bitmap_mapped_iova(bitmap); + + ret = iova_bitmap_get(bitmap); + if (ret) + break; + + length = min(length, set_ahead_length); + iova_bitmap_set(bitmap, iova, length); + + set_ahead_length -= length; + bitmap->mapped_base_index += + iova_bitmap_offset_to_index(bitmap, length - 1) + 1; + iova_bitmap_put(bitmap); + } + + bitmap->set_ahead_length = 0; + return ret; +} + /* * Advances to the next range, releases the current pinned * pages and pins the next set of bitmap pages. @@ -357,6 +387,15 @@ static int iova_bitmap_advance(struct iova_bitmap *bitmap) if (iova_bitmap_done(bitmap)) return 0; + /* Iterate, set and skip any bits requested for next iteration */ + if (bitmap->set_ahead_length) { + int ret; + + ret = iova_bitmap_set_ahead(bitmap, bitmap->set_ahead_length); + if (ret) + return ret; + } + /* When advancing the index we pin the next set of bitmap pages */ return iova_bitmap_get(bitmap); } @@ -409,6 +448,7 @@ void iova_bitmap_set(struct iova_bitmap *bitmap, mapped->pgshift) + mapped->pgoff * BITS_PER_BYTE; unsigned long last_bit = (((iova + length - 1) - mapped->iova) >> mapped->pgshift) + mapped->pgoff * BITS_PER_BYTE; + unsigned long last_page_idx = mapped->npages - 1; do { unsigned int page_idx = cur_bit / BITS_PER_PAGE; @@ -417,10 +457,18 @@ void iova_bitmap_set(struct iova_bitmap *bitmap, last_bit - cur_bit + 1); void *kaddr; + if (unlikely(page_idx > last_page_idx)) + break; + kaddr = kmap_local_page(mapped->pages[page_idx]); bitmap_set(kaddr, offset, nbits); kunmap_local(kaddr); cur_bit += nbits; } while (cur_bit <= last_bit); + + if (unlikely(cur_bit <= last_bit)) { + bitmap->set_ahead_length = + ((last_bit - cur_bit + 1) << bitmap->mapped.pgshift); + } } EXPORT_SYMBOL_NS_GPL(iova_bitmap_set, IOMMUFD); |