From 96e3328ac2dc58fb86a0da4ec27a40aa6d41b022 Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Wed, 26 Jun 2019 14:32:31 -0500 Subject: [PATCH] util/vma: Add a function to allocate a particular address range This new function lets you request to remove a specific address range from the allocator. It returns true on success and leaves the allocator unmodified and returns false on failure. It doesn't need to return an offset because, if it succeeds, the offset passed in is the allocated offset. Reviewed-by: Ivan Briano Reviewed-by: Lionel Landwerlin --- src/util/vma.c | 38 ++++++++++++++++++++++++++++++++++++++ src/util/vma.h | 3 +++ 2 files changed, 41 insertions(+) diff --git a/src/util/vma.c b/src/util/vma.c index 4887bdece0c..714ef01b211 100644 --- a/src/util/vma.c +++ b/src/util/vma.c @@ -170,6 +170,44 @@ util_vma_heap_alloc(struct util_vma_heap *heap, return 0; } +bool +util_vma_heap_alloc_addr(struct util_vma_heap *heap, + uint64_t offset, uint64_t size) +{ + /* An offset of 0 is reserved for allocation failure. It is not a valid + * address and cannot be allocated. + */ + assert(offset > 0); + + /* Allocating something with a size of 0 is also not valid. */ + assert(size > 0); + + /* It's possible for offset + size to wrap around if we touch the top of + * the 64-bit address space, but we cannot go any higher than 2^64. + */ + assert(offset + size == 0 || offset + size > offset); + + /* Find the hole if one exists. */ + util_vma_foreach_hole_safe(hole, heap) { + if (hole->offset > offset) + continue; + + /* Holes are ordered high-to-low so the first hole we find with + * hole->offset <= is our hole. If it's not big enough to contain the + * requested range, then the allocation fails. + */ + assert(hole->offset <= offset); + if (hole->size < offset - hole->offset + size) + return false; + + util_vma_hole_alloc(hole, offset, size); + return true; + } + + /* We didn't find a suitable hole */ + return false; +} + void util_vma_heap_free(struct util_vma_heap *heap, uint64_t offset, uint64_t size) diff --git a/src/util/vma.h b/src/util/vma.h index ed69914e4cb..91c7ee6e66a 100644 --- a/src/util/vma.h +++ b/src/util/vma.h @@ -43,6 +43,9 @@ void util_vma_heap_finish(struct util_vma_heap *heap); uint64_t util_vma_heap_alloc(struct util_vma_heap *heap, uint64_t size, uint64_t alignment); +bool util_vma_heap_alloc_addr(struct util_vma_heap *heap, + uint64_t addr, uint64_t size); + void util_vma_heap_free(struct util_vma_heap *heap, uint64_t offset, uint64_t size); -- 2.30.2