diff options
author | Claudio Imbrenda <imbrenda@linux.ibm.com> | 2020-07-06 18:43:24 +0200 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-07-06 13:03:52 -0400 |
commit | 0d622fcb2ba0ac8e9c7f7a282badac694a3592c5 (patch) | |
tree | 47663daadf773b746f457363355dc435f169ea21 | |
parent | 9e801bd9d2d4b37bfad26123bcd58548adb0d82c (diff) | |
download | kvm-unit-tests-0d622fcb2ba0ac8e9c7f7a282badac694a3592c5.tar.gz |
lib/vmalloc: allow vm_memalign with alignment > PAGE_SIZE
Allow allocating aligned virtual memory with alignment larger than only
one page.
Add a check that the backing pages were actually allocated.
Export the alloc_vpages_aligned function to allow users to allocate
non-backed aligned virtual addresses.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-Id: <20200706164324.81123-5-imbrenda@linux.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r-- | lib/vmalloc.c | 35 | ||||
-rw-r--r-- | lib/vmalloc.h | 3 |
2 files changed, 30 insertions, 8 deletions
diff --git a/lib/vmalloc.c b/lib/vmalloc.c index 9237a0f..e0c7b6b 100644 --- a/lib/vmalloc.c +++ b/lib/vmalloc.c @@ -12,19 +12,28 @@ #include "alloc.h" #include "alloc_phys.h" #include "alloc_page.h" +#include <bitops.h> #include "vmalloc.h" static struct spinlock lock; static void *vfree_top = 0; static void *page_root; -void *alloc_vpages(ulong nr) +/* + * Allocate a certain number of pages from the virtual address space (without + * physical backing). + * + * nr is the number of pages to allocate + * alignment_pages is the alignment of the allocation *in pages* + */ +void *alloc_vpages_aligned(ulong nr, unsigned int align_order) { uintptr_t ptr; spin_lock(&lock); ptr = (uintptr_t)vfree_top; ptr -= PAGE_SIZE * nr; + ptr &= GENMASK_ULL(63, PAGE_SHIFT + align_order); vfree_top = (void *)ptr; spin_unlock(&lock); @@ -32,6 +41,11 @@ void *alloc_vpages(ulong nr) return (void *)ptr; } +void *alloc_vpages(ulong nr) +{ + return alloc_vpages_aligned(nr, 0); +} + void *alloc_vpage(void) { return alloc_vpages(1); @@ -55,17 +69,22 @@ void *vmap(phys_addr_t phys, size_t size) return mem; } +/* + * Allocate virtual memory, with the specified minimum alignment. + */ static void *vm_memalign(size_t alignment, size_t size) { + phys_addr_t pa; void *mem, *p; - size_t pages; - assert(alignment <= PAGE_SIZE); - size = PAGE_ALIGN(size); - pages = size / PAGE_SIZE; - mem = p = alloc_vpages(pages); - while (pages--) { - phys_addr_t pa = virt_to_phys(alloc_page()); + assert(is_power_of_2(alignment)); + + size = PAGE_ALIGN(size) / PAGE_SIZE; + alignment = get_order(PAGE_ALIGN(alignment) / PAGE_SIZE); + mem = p = alloc_vpages_aligned(size, alignment); + while (size--) { + pa = virt_to_phys(alloc_page()); + assert(pa); install_page(page_root, pa, p); p += PAGE_SIZE; } diff --git a/lib/vmalloc.h b/lib/vmalloc.h index 2b563f4..8b158f5 100644 --- a/lib/vmalloc.h +++ b/lib/vmalloc.h @@ -5,6 +5,9 @@ /* Allocate consecutive virtual pages (without backing) */ extern void *alloc_vpages(ulong nr); +/* Allocate consecutive and aligned virtual pages (without backing) */ +extern void *alloc_vpages_aligned(ulong nr, unsigned int alignment_order); + /* Allocate one virtual page (without backing) */ extern void *alloc_vpage(void); /* Set the top of the virtual address space */ |