core: Move free-list locking to a separate per-region lock

Currently, we have a single lock for the entire mem_region system; this
protects both the global region list, and the allocations from each
region.

This means we can't allocate memory while traversing the global region
list, as any malloc/realloc/free will try to acquire the mem_region lock
again.

This change separates the locking into different functions. We keep the
mem_region_lock to protect the regions list, and introduce a per-region
lock to protect allocations from the regions' free_lists.

Then we remove the open-coded invocations of mem_alloc, where we'd
avoided malloc() due to the above locking issue.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 6 insertions, 6 deletions

diff --git a/core/malloc.c b/core/malloc.c
index 9e715f6..669cc59 100644
--- a/core/malloc.c
+++ b/core/malloc.c
@@ -25,9 +25,9 @@ void *__memalign(size_t blocksize, size_t bytes, const char *location)
 {
 	void *p;
 
-	lock(&mem_region_lock);
+	lock(&skiboot_heap.free_list_lock);
 	p = mem_alloc(&skiboot_heap, bytes, blocksize, location);
-	unlock(&mem_region_lock);
+	unlock(&skiboot_heap.free_list_lock);
 
 	return p;
 }
@@ -39,9 +39,9 @@ void *__malloc(size_t bytes, const char *location)
 
 void __free(void *p, const char *location)
 {
-	lock(&mem_region_lock);
+	lock(&skiboot_heap.free_list_lock);
 	mem_free(&skiboot_heap, p, location);
-	unlock(&mem_region_lock);
+	unlock(&skiboot_heap.free_list_lock);
 }
 
 void *__realloc(void *ptr, size_t size, const char *location)
@@ -56,7 +56,7 @@ void *__realloc(void *ptr, size_t size, const char *location)
 	if (!ptr)
 		return __malloc(size, location);
 
-	lock(&mem_region_lock);
+	lock(&skiboot_heap.free_list_lock);
 	if (mem_resize(&skiboot_heap, ptr, size, location)) {
 		newptr = ptr;
 	} else {
@@ -70,7 +70,7 @@ void *__realloc(void *ptr, size_t size, const char *location)
 			mem_free(&skiboot_heap, ptr, location);
 		}
 	}
-	unlock(&mem_region_lock);
+	unlock(&skiboot_heap.free_list_lock);
 	return newptr;
 }