[kvm-unit-tests PATCH v2 2/6] lib/alloc: improve init

[Andrew Jones <drjones@redhat.com>]

Add some asserts to make sure phys_alloc_init is called only once
and before any other alloc calls. Also require that an alignment
is set up just once and *before* init, or never.

Signed-off-by: Andrew Jones <drjones@redhat.com>
---
 lib/alloc.c         | 26 ++++++++++++++++++--------
 lib/alloc.h         |  7 +++++--
 lib/arm/setup.c     |  2 +-
 lib/powerpc/setup.c |  2 +-
 4 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/lib/alloc.c b/lib/alloc.c
index e1d7b8a380ff..5b3ef5d00f8a 100644
--- a/lib/alloc.c
+++ b/lib/alloc.c
@@ -43,18 +43,28 @@ void phys_alloc_show(void)
 void phys_alloc_init(phys_addr_t base_addr, phys_addr_t size)
 {
 	spin_lock(&lock);
+
+	if (!align_min)
+		align_min = DEFAULT_MINIMUM_ALIGNMENT;
+
+	assert(!top);
+	assert(!(base_addr & (align_min - 1)));
+	assert(size);
+
 	base = base_addr;
 	top = base + size;
-	align_min = DEFAULT_MINIMUM_ALIGNMENT;
-	nr_regions = 0;
+
 	spin_unlock(&lock);
 }
 
 void phys_alloc_set_minimum_alignment(phys_addr_t align)
 {
-	assert(align && !(align & (align - 1)));
 	spin_lock(&lock);
+
+	assert(!align_min);
+	assert(align && !(align & (align - 1)));
 	align_min = align;
+
 	spin_unlock(&lock);
 }
 
@@ -63,14 +73,14 @@ static phys_addr_t phys_alloc_aligned_safe(phys_addr_t size,
 {
 	static bool warned = false;
 	phys_addr_t addr, size_orig = size;
-	u64 top_safe;
+	u64 top_safe = top;
 
-	spin_lock(&lock);
+	if (safe && sizeof(long) == 4)
+		top_safe = MIN(top, 1ULL << 32);
 
-	top_safe = top;
+	assert(top_safe && base < top_safe);
 
-	if (safe && sizeof(long) == 4)
-		top_safe = MIN(top_safe, 1ULL << 32);
+	spin_lock(&lock);
 
 	align = MAX(align, align_min);
 
diff --git a/lib/alloc.h b/lib/alloc.h
index c12bd15f7afc..bd3c4e8ff3f6 100644
--- a/lib/alloc.h
+++ b/lib/alloc.h
@@ -73,13 +73,16 @@ static inline void *memalign(size_t alignment, size_t size)
 
 /*
  * phys_alloc_init creates the initial free memory region of size @size
- * at @base. The minimum alignment is set to DEFAULT_MINIMUM_ALIGNMENT.
+ * at @base. If a minimum alignment has not been set then
+ * DEFAULT_MINIMUM_ALIGNMENT is used. phys_alloc_init may only be called
+ * once.
  */
 extern void phys_alloc_init(phys_addr_t base, phys_addr_t size);
 
 /*
  * phys_alloc_set_minimum_alignment sets the minimum alignment to
- * @align.
+ * @align. phys_alloc_set_minimum_alignment must be called before
+ * phys_alloc_init and only once.
  */
 extern void phys_alloc_set_minimum_alignment(phys_addr_t align);
 
diff --git a/lib/arm/setup.c b/lib/arm/setup.c
index 7e7b39f11dde..d02d1a731d20 100644
--- a/lib/arm/setup.c
+++ b/lib/arm/setup.c
@@ -94,8 +94,8 @@ static void mem_init(phys_addr_t freemem_start)
 	__phys_offset = mem.start;	/* PHYS_OFFSET */
 	__phys_end = mem.end;		/* PHYS_END */
 
-	phys_alloc_init(freemem_start, primary.end - freemem_start);
 	phys_alloc_set_minimum_alignment(SMP_CACHE_BYTES);
+	phys_alloc_init(freemem_start, primary.end - freemem_start);
 
 	mmu_enable_idmap();
 }
diff --git a/lib/powerpc/setup.c b/lib/powerpc/setup.c
index 9153f7bebc6a..b390dadaebbe 100644
--- a/lib/powerpc/setup.c
+++ b/lib/powerpc/setup.c
@@ -146,9 +146,9 @@ static void mem_init(phys_addr_t freemem_start)
 	__physical_start = mem.start;	/* PHYSICAL_START */
 	__physical_end = mem.end;	/* PHYSICAL_END */
 
-	phys_alloc_init(freemem_start, primary.end - freemem_start);
 	phys_alloc_set_minimum_alignment(__icache_bytes > __dcache_bytes
 					 ? __icache_bytes : __dcache_bytes);
+	phys_alloc_init(freemem_start, primary.end - freemem_start);
 }
 
 void setup(const void *fdt)
-- 
2.7.4