[kvm-unit-tests PATCH v2 5/7] lib/alloc: simplify free and malloc

[Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>]

Remove the size parameter from the various free functions

Since the backends can handle the allocation sizes on their own,
simplify the generic malloc wrappers.

Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
---
 lib/alloc.h      |  2 +-
 lib/alloc_page.h |  6 +++---
 lib/alloc.c      | 42 +++++-------------------------------------
 lib/alloc_page.c |  2 +-
 lib/s390x/smp.c  |  4 ++--
 lib/vmalloc.c    |  2 +-
 s390x/smp.c      |  4 ++--
 7 files changed, 15 insertions(+), 47 deletions(-)

diff --git a/lib/alloc.h b/lib/alloc.h
index c44d459..9b4b634 100644
--- a/lib/alloc.h
+++ b/lib/alloc.h
@@ -24,7 +24,7 @@
 
 struct alloc_ops {
 	void *(*memalign)(size_t alignment, size_t size);
-	void (*free)(void *ptr, size_t size);
+	void (*free)(void *ptr);
 	size_t align_min;
 };
 
diff --git a/lib/alloc_page.h b/lib/alloc_page.h
index 81847ae..6c23018 100644
--- a/lib/alloc_page.h
+++ b/lib/alloc_page.h
@@ -61,18 +61,18 @@ void *alloc_pages(unsigned int order);
  * alloc_pages* functions.
  * The pointer must point to the start of the block.
  */
-void free_pages(void *mem, size_t size);
+void free_pages(void *mem);
 
 /* For backwards compatibility */
 static inline void free_page(void *mem)
 {
-	return free_pages(mem, 1);
+	return free_pages(mem);
 }
 
 /* For backwards compatibility */
 static inline void free_pages_by_order(void *mem, unsigned int order)
 {
-	free_pages(mem, 1ull << order);
+	free_pages(mem);
 }
 
 #endif
diff --git a/lib/alloc.c b/lib/alloc.c
index 9d89d24..a46f464 100644
--- a/lib/alloc.c
+++ b/lib/alloc.c
@@ -50,56 +50,24 @@ void *calloc(size_t nmemb, size_t size)
 	return ptr;
 }
 
-#define METADATA_EXTRA	(2 * sizeof(uintptr_t))
-#define OFS_SLACK	(-2 * sizeof(uintptr_t))
-#define OFS_SIZE	(-sizeof(uintptr_t))
-
-static inline void *block_begin(void *mem)
-{
-	uintptr_t slack = *(uintptr_t *)(mem + OFS_SLACK);
-	return mem - slack;
-}
-
-static inline uintptr_t block_size(void *mem)
-{
-	return *(uintptr_t *)(mem + OFS_SIZE);
-}
-
 void free(void *ptr)
 {
-	if (!alloc_ops->free)
-		return;
-
-	void *base = block_begin(ptr);
-	uintptr_t sz = block_size(ptr);
-
-	alloc_ops->free(base, sz);
+	if (alloc_ops->free)
+		alloc_ops->free(ptr);
 }
 
 void *memalign(size_t alignment, size_t size)
 {
 	void *p;
-	uintptr_t blkalign;
-	uintptr_t mem;
 
 	if (!size)
 		return NULL;
 
-	assert(alignment >= sizeof(void *) && is_power_of_2(alignment));
+	assert(is_power_of_2(alignment));
 	assert(alloc_ops && alloc_ops->memalign);
 
-	size += alignment - 1;
-	blkalign = MAX(alignment, alloc_ops->align_min);
-	size = ALIGN(size + METADATA_EXTRA, alloc_ops->align_min);
-	p = alloc_ops->memalign(blkalign, size);
+	p = alloc_ops->memalign(alignment, size);
 	assert(p);
 
-	/* Leave room for metadata before aligning the result.  */
-	mem = (uintptr_t)p + METADATA_EXTRA;
-	mem = ALIGN(mem, alignment);
-
-	/* Write the metadata */
-	*(uintptr_t *)(mem + OFS_SLACK) = mem - (uintptr_t)p;
-	*(uintptr_t *)(mem + OFS_SIZE) = size;
-	return (void *)mem;
+	return (void *)p;
 }
diff --git a/lib/alloc_page.c b/lib/alloc_page.c
index 29d221f..046082a 100644
--- a/lib/alloc_page.c
+++ b/lib/alloc_page.c
@@ -255,7 +255,7 @@ static void _free_pages(void *mem)
 	} while (coalesce(a, order, pfn, pfn2));
 }
 
-void free_pages(void *mem, size_t size)
+void free_pages(void *mem)
 {
 	spin_lock(&lock);
 	_free_pages(mem);
diff --git a/lib/s390x/smp.c b/lib/s390x/smp.c
index ea93329..77d80ca 100644
--- a/lib/s390x/smp.c
+++ b/lib/s390x/smp.c
@@ -163,8 +163,8 @@ int smp_cpu_destroy(uint16_t addr)
 	rc = smp_cpu_stop_nolock(addr, false);
 	if (!rc) {
 		cpu = smp_cpu_from_addr(addr);
-		free_pages(cpu->lowcore, 2 * PAGE_SIZE);
-		free_pages(cpu->stack, 4 * PAGE_SIZE);
+		free_pages(cpu->lowcore);
+		free_pages(cpu->stack);
 		cpu->lowcore = (void *)-1UL;
 		cpu->stack = (void *)-1UL;
 	}
diff --git a/lib/vmalloc.c b/lib/vmalloc.c
index 3aec5ac..986a34c 100644
--- a/lib/vmalloc.c
+++ b/lib/vmalloc.c
@@ -159,7 +159,7 @@ static void *vm_memalign(size_t alignment, size_t size)
 	return mem;
 }
 
-static void vm_free(void *mem, size_t size)
+static void vm_free(void *mem)
 {
 	struct metadata *m;
 	uintptr_t ptr, end;
diff --git a/s390x/smp.c b/s390x/smp.c
index ad30e3c..4ca1dce 100644
--- a/s390x/smp.c
+++ b/s390x/smp.c
@@ -143,7 +143,7 @@ static void test_store_status(void)
 	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);
 	while (!status->prefix) { mb(); }
 	report(1, "status written");
-	free_pages(status, PAGE_SIZE * 2);
+	free_pages(status);
 	report_prefix_pop();
 	smp_cpu_stop(1);
 
@@ -276,7 +276,7 @@ static void test_reset_initial(void)
 	report_prefix_pop();
 
 	report(smp_cpu_stopped(1), "cpu stopped");
-	free_pages(status, PAGE_SIZE);
+	free_pages(status);
 	report_prefix_pop();
 }
 
-- 
2.26.2