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>

4 files changed, 17 insertions, 17 deletions

diff --git a/core/test/run-malloc-speed.c b/core/test/run-malloc-speed.c
index 18c0de9..713a74b 100644
--- a/core/test/run-malloc-speed.c
+++ b/core/test/run-malloc-speed.c
@@ -90,7 +90,7 @@ int main(void)
 		       + skiboot_heap.len);
 	}
 	assert(mem_check(&skiboot_heap));
-	assert(mem_region_lock.lock_val == 0);
+	assert(skiboot_heap.free_list_lock.lock_val == 0);
 	free(region_start(&skiboot_heap));
 	real_free(p);
 	return 0;
diff --git a/core/test/run-malloc.c b/core/test/run-malloc.c
index bbd2a48..723cb10 100644
--- a/core/test/run-malloc.c
+++ b/core/test/run-malloc.c
@@ -92,45 +92,45 @@ int main(void)
 		assert(p);
 		assert(p > (char *)test_heap);
 		assert(p + (1ULL << i) <= (char *)test_heap + TEST_HEAP_SIZE);
-		assert(!mem_region_lock.lock_val);
+		assert(!skiboot_heap.free_list_lock.lock_val);
 		free(p);
-		assert(!mem_region_lock.lock_val);
+		assert(!skiboot_heap.free_list_lock.lock_val);
 		assert(heap_empty());
 	}
 
 	/* Realloc as malloc. */
-	mem_region_lock.lock_val = 0;
+	skiboot_heap.free_list_lock.lock_val = 0;
 	p = realloc(NULL, 100);
 	assert(p);
-	assert(!mem_region_lock.lock_val);
+	assert(!skiboot_heap.free_list_lock.lock_val);
 
 	/* Realloc as free. */
 	p = realloc(p, 0);
 	assert(!p);
-	assert(!mem_region_lock.lock_val);
+	assert(!skiboot_heap.free_list_lock.lock_val);
 	assert(heap_empty());
 
 	/* Realloc longer. */
 	p = realloc(NULL, 100);
 	assert(p);
-	assert(!mem_region_lock.lock_val);
+	assert(!skiboot_heap.free_list_lock.lock_val);
 	p2 = realloc(p, 200);
 	assert(p2 == p);
-	assert(!mem_region_lock.lock_val);
+	assert(!skiboot_heap.free_list_lock.lock_val);
 	free(p);
-	assert(!mem_region_lock.lock_val);
+	assert(!skiboot_heap.free_list_lock.lock_val);
 	assert(heap_empty());
 
 	/* Realloc shorter. */
-	mem_region_lock.lock_val = 0;
+	skiboot_heap.free_list_lock.lock_val = 0;
 	p = realloc(NULL, 100);
-	assert(!mem_region_lock.lock_val);
+	assert(!skiboot_heap.free_list_lock.lock_val);
 	assert(p);
 	p2 = realloc(p, 1);
-	assert(!mem_region_lock.lock_val);
+	assert(!skiboot_heap.free_list_lock.lock_val);
 	assert(p2 == p);
 	free(p);
-	assert(!mem_region_lock.lock_val);
+	assert(!skiboot_heap.free_list_lock.lock_val);
 	assert(heap_empty());
 
 	/* zalloc failure */
@@ -152,7 +152,7 @@ int main(void)
 	assert(p2[63] == 'c');
 	free(p2);
 	assert(heap_empty());
-	assert(!mem_region_lock.lock_val);
+	assert(!skiboot_heap.free_list_lock.lock_val);
 
 	/* Realloc with failure to allocate new size */
 	p2 = malloc(TEST_HEAP_SIZE - sizeof(struct alloc_hdr)*2);
@@ -176,7 +176,7 @@ int main(void)
 	free(p);
 	free(p4);
 	assert(heap_empty());
-	assert(!mem_region_lock.lock_val);
+	assert(!skiboot_heap.free_list_lock.lock_val);
 
 	real_free(test_heap);
 	return 0;
diff --git a/core/test/run-mem_region.c b/core/test/run-mem_region.c
index db1ca02..e27459b 100644
--- a/core/test/run-mem_region.c
+++ b/core/test/run-mem_region.c
@@ -244,7 +244,7 @@ int main(void)
 		list_del(&r->list);
 		mem_free(&skiboot_heap, r, __location__);
 	}
-	assert(mem_region_lock.lock_val == 0);
+	assert(skiboot_heap.free_list_lock.lock_val == 0);
 	__free(test_heap, "");
 	return 0;
 }
diff --git a/core/test/run-mem_region_init.c b/core/test/run-mem_region_init.c
index bb606ef..7624057 100644
--- a/core/test/run-mem_region_init.c
+++ b/core/test/run-mem_region_init.c
@@ -177,7 +177,7 @@ int main(void)
 		}
 		assert(mem_check(&skiboot_heap));
 	}
-	assert(mem_region_lock.lock_val == 0);
+	assert(skiboot_heap.free_list_lock.lock_val == 0);
 	real_free(heap);
 	return 0;
 }