[1/4] regmap: clean up regmap allocation

Message ID 1524019125-26287-2-git-send-email-yamada.masahiro@socionext.com
State New
Headers show
Series
  • Add Linux-compatible syscon_to_regmap API
Related show

Commit Message

Masahiro Yamada April 18, 2018, 2:38 a.m.
Putting zero length array at the end of struct is a common technique
to embed arbitrary length of members.  There is no good reason to let
regmap_alloc_count() branch by "if (count <= 1)".

As far as I understood the code, regmap->base is an alias of
regmap->ranges[0].start, but it is not helpful but make the code
just ugly.

Rename regmap_alloc_count() to regmap_alloc() because the _count
suffix seems pointless.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 drivers/core/regmap.c | 31 +++++++++----------------------
 include/regmap.h      |  7 ++-----
 2 files changed, 11 insertions(+), 27 deletions(-)

Comments

Simon Glass April 22, 2018, 8:11 p.m. | #1
Hi Masahiro,

On 17 April 2018 at 20:38, Masahiro Yamada <yamada.masahiro@socionext.com>
wrote:
> Putting zero length array at the end of struct is a common technique
> to embed arbitrary length of members.  There is no good reason to let
> regmap_alloc_count() branch by "if (count <= 1)".
>
> As far as I understood the code, regmap->base is an alias of
> regmap->ranges[0].start, but it is not helpful but make the code
> just ugly.
>
> Rename regmap_alloc_count() to regmap_alloc() because the _count
> suffix seems pointless.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
>
>  drivers/core/regmap.c | 31 +++++++++----------------------
>  include/regmap.h      |  7 ++-----
>  2 files changed, 11 insertions(+), 27 deletions(-)

This seems fine to me and does not increase the number of allocations.

Reviewed-by: Simon Glass <sjg@chromium.org>

Regards,
Simon

Patch

diff --git a/drivers/core/regmap.c b/drivers/core/regmap.c
index 8a0e00f..6c3dbe9 100644
--- a/drivers/core/regmap.c
+++ b/drivers/core/regmap.c
@@ -18,22 +18,13 @@ 
 
 DECLARE_GLOBAL_DATA_PTR;
 
-static struct regmap *regmap_alloc_count(int count)
+static struct regmap *regmap_alloc(int count)
 {
 	struct regmap *map;
 
-	map = malloc(sizeof(struct regmap));
+	map = malloc(sizeof(*map) + sizeof(map->ranges[0]) * count);
 	if (!map)
 		return NULL;
-	if (count <= 1) {
-		map->range = &map->base_range;
-	} else {
-		map->range = malloc(count * sizeof(struct regmap_range));
-		if (!map->range) {
-			free(map);
-			return NULL;
-		}
-	}
 	map->range_count = count;
 
 	return map;
@@ -46,12 +37,11 @@  int regmap_init_mem_platdata(struct udevice *dev, fdt_val_t *reg, int count,
 	struct regmap_range *range;
 	struct regmap *map;
 
-	map = regmap_alloc_count(count);
+	map = regmap_alloc(count);
 	if (!map)
 		return -ENOMEM;
 
-	map->base = *reg;
-	for (range = map->range; count > 0; reg += 2, range++, count--) {
+	for (range = map->ranges; count > 0; reg += 2, range++, count--) {
 		range->start = *reg;
 		range->size = reg[1];
 	}
@@ -84,11 +74,11 @@  int regmap_init_mem(struct udevice *dev, struct regmap **mapp)
 	if (!count)
 		return -EINVAL;
 
-	map = regmap_alloc_count(count);
+	map = regmap_alloc(count);
 	if (!map)
 		return -ENOMEM;
 
-	for (range = map->range, index = 0; count > 0;
+	for (range = map->ranges, index = 0; count > 0;
 	     count--, range++, index++) {
 		fdt_size_t sz;
 		if (of_live_active()) {
@@ -102,7 +92,6 @@  int regmap_init_mem(struct udevice *dev, struct regmap **mapp)
 			range->size = sz;
 		}
 	}
-	map->base = map->range[0].start;
 
 	*mapp = map;
 
@@ -116,15 +105,13 @@  void *regmap_get_range(struct regmap *map, unsigned int range_num)
 
 	if (range_num >= map->range_count)
 		return NULL;
-	range = &map->range[range_num];
+	range = &map->ranges[range_num];
 
 	return map_sysmem(range->start, range->size);
 }
 
 int regmap_uninit(struct regmap *map)
 {
-	if (map->range_count > 1)
-		free(map->range);
 	free(map);
 
 	return 0;
@@ -132,7 +119,7 @@  int regmap_uninit(struct regmap *map)
 
 int regmap_read(struct regmap *map, uint offset, uint *valp)
 {
-	uint32_t *ptr = map_physmem(map->base + offset, 4, MAP_NOCACHE);
+	u32 *ptr = map_physmem(map->ranges[0].start + offset, 4, MAP_NOCACHE);
 
 	*valp = le32_to_cpu(readl(ptr));
 
@@ -141,7 +128,7 @@  int regmap_read(struct regmap *map, uint offset, uint *valp)
 
 int regmap_write(struct regmap *map, uint offset, uint val)
 {
-	uint32_t *ptr = map_physmem(map->base + offset, 4, MAP_NOCACHE);
+	u32 *ptr = map_physmem(map->ranges[0].start + offset, 4, MAP_NOCACHE);
 
 	writel(cpu_to_le32(val), ptr);
 
diff --git a/include/regmap.h b/include/regmap.h
index 493a5d8..858aa7e 100644
--- a/include/regmap.h
+++ b/include/regmap.h
@@ -22,15 +22,12 @@  struct regmap_range {
 /**
  * struct regmap - a way of accessing hardware/bus registers
  *
- * @base:	Base address of register map
  * @range_count: Number of ranges available within the map
- * @range:	Pointer to the list of ranges, allocated if @range_count > 1
- * @base_range:	If @range_count is <= 1, @range points here
+ * @ranges:	Array of ranges
  */
 struct regmap {
-	phys_addr_t base;
 	int range_count;
-	struct regmap_range *range, base_range;
+	struct regmap_range ranges[];
 };
 
 /*