mlxsw: spectrum: Change KVD linear parts from list to array

The parts info is array. The parts copy this info array, yet they are a
list. So make the indexing according to the id and change the list of
parts into array of parts. This helps to eliminate lookups and
constructs like mlxsw_sp_kvdl_part_update() (took me some non-trivial
time to figure out what is going on there).
Alongside with that, introduce a helper macro to define the parts infos.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 92 insertions, 143 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.c
index 201825c0019b..7b28f65d6407 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.c
@@ -55,24 +55,47 @@
 #define MLXSW_SP_KVDL_LARGE_CHUNKS_END \
 	(MLXSW_SP_KVDL_LARGE_CHUNKS_SIZE + MLXSW_SP_KVDL_LARGE_CHUNKS_BASE - 1)
 
-#define MLXSW_SP_CHUNK_MAX 32
-#define MLXSW_SP_LARGE_CHUNK_MAX 512
+#define MLXSW_SP_KVDL_SINGLE_ALLOC_SIZE 1
+#define MLXSW_SP_KVDL_CHUNKS_ALLOC_SIZE 32
+#define MLXSW_SP_KVDL_LARGE_CHUNKS_ALLOC_SIZE 512
 
 struct mlxsw_sp_kvdl_part_info {
 	unsigned int part_index;
 	unsigned int start_index;
 	unsigned int end_index;
 	unsigned int alloc_size;
+	enum mlxsw_sp_resource_id resource_id;
+};
+
+enum mlxsw_sp_kvdl_part_id {
+	MLXSW_SP_KVDL_PART_ID_SINGLE,
+	MLXSW_SP_KVDL_PART_ID_CHUNKS,
+	MLXSW_SP_KVDL_PART_ID_LARGE_CHUNKS,
 };
 
+#define MLXSW_SP_KVDL_PART_INFO(id)				\
+[MLXSW_SP_KVDL_PART_ID_##id] = {				\
+	.start_index = MLXSW_SP_KVDL_##id##_BASE,		\
+	.end_index = MLXSW_SP_KVDL_##id##_END,			\
+	.alloc_size = MLXSW_SP_KVDL_##id##_ALLOC_SIZE,		\
+	.resource_id = MLXSW_SP_RESOURCE_KVD_LINEAR_##id,	\
+}
+
+static const struct mlxsw_sp_kvdl_part_info mlxsw_sp_kvdl_parts_info[] = {
+	MLXSW_SP_KVDL_PART_INFO(SINGLE),
+	MLXSW_SP_KVDL_PART_INFO(CHUNKS),
+	MLXSW_SP_KVDL_PART_INFO(LARGE_CHUNKS),
+};
+
+#define MLXSW_SP_KVDL_PARTS_INFO_LEN ARRAY_SIZE(mlxsw_sp_kvdl_parts_info)
+
 struct mlxsw_sp_kvdl_part {
-	struct list_head list;
-	struct mlxsw_sp_kvdl_part_info *info;
+	struct mlxsw_sp_kvdl_part_info info;
 	unsigned long usage[0];	/* Entries */
 };
 
 struct mlxsw_sp_kvdl {
-	struct list_head parts_list;
+	struct mlxsw_sp_kvdl_part *parts[MLXSW_SP_KVDL_PARTS_INFO_LEN];
 };
 
 static struct mlxsw_sp_kvdl_part *
@@ -80,11 +103,13 @@ mlxsw_sp_kvdl_alloc_size_part(struct mlxsw_sp_kvdl *kvdl,
 			      unsigned int alloc_size)
 {
 	struct mlxsw_sp_kvdl_part *part, *min_part = NULL;
+	int i;
 
-	list_for_each_entry(part, &kvdl->parts_list, list) {
-		if (alloc_size <= part->info->alloc_size &&
+	for (i = 0; i < MLXSW_SP_KVDL_PARTS_INFO_LEN; i++) {
+		part = kvdl->parts[i];
+		if (alloc_size <= part->info.alloc_size &&
 		    (!min_part ||
-		     part->info->alloc_size <= min_part->info->alloc_size))
+		     part->info.alloc_size <= min_part->info.alloc_size))
 			min_part = part;
 	}
 
@@ -95,10 +120,12 @@ static struct mlxsw_sp_kvdl_part *
 mlxsw_sp_kvdl_index_part(struct mlxsw_sp_kvdl *kvdl, u32 kvdl_index)
 {
 	struct mlxsw_sp_kvdl_part *part;
+	int i;
 
-	list_for_each_entry(part, &kvdl->parts_list, list) {
-		if (kvdl_index >= part->info->start_index &&
-		    kvdl_index <= part->info->end_index)
+	for (i = 0; i < MLXSW_SP_KVDL_PARTS_INFO_LEN; i++) {
+		part = kvdl->parts[i];
+		if (kvdl_index >= part->info.start_index &&
+		    kvdl_index <= part->info.end_index)
 			return part;
 	}
 
@@ -122,7 +149,7 @@ mlxsw_sp_kvdl_index_entry_index(const struct mlxsw_sp_kvdl_part_info *info,
 static int mlxsw_sp_kvdl_part_alloc(struct mlxsw_sp_kvdl_part *part,
 				    u32 *p_kvdl_index)
 {
-	const struct mlxsw_sp_kvdl_part_info *info = part->info;
+	const struct mlxsw_sp_kvdl_part_info *info = &part->info;
 	unsigned int entry_index, nr_entries;
 
 	nr_entries = (info->end_index - info->start_index + 1) /
@@ -132,8 +159,7 @@ static int mlxsw_sp_kvdl_part_alloc(struct mlxsw_sp_kvdl_part *part,
 		return -ENOBUFS;
 	__set_bit(entry_index, part->usage);
 
-	*p_kvdl_index = mlxsw_sp_entry_index_kvdl_index(part->info,
-							entry_index);
+	*p_kvdl_index = mlxsw_sp_entry_index_kvdl_index(info, entry_index);
 
 	return 0;
 }
@@ -141,10 +167,10 @@ static int mlxsw_sp_kvdl_part_alloc(struct mlxsw_sp_kvdl_part *part,
 static void mlxsw_sp_kvdl_part_free(struct mlxsw_sp_kvdl_part *part,
 				    u32 kvdl_index)
 {
+	const struct mlxsw_sp_kvdl_part_info *info = &part->info;
 	unsigned int entry_index;
 
-	entry_index = mlxsw_sp_kvdl_index_entry_index(part->info,
-						      kvdl_index);
+	entry_index = mlxsw_sp_kvdl_index_entry_index(info, kvdl_index);
 	__clear_bit(entry_index, part->usage);
 }
 
@@ -183,74 +209,30 @@ int mlxsw_sp_kvdl_alloc_size_query(struct mlxsw_sp *mlxsw_sp,
 	if (IS_ERR(part))
 		return PTR_ERR(part);
 
-	*p_alloc_size = part->info->alloc_size;
+	*p_alloc_size = part->info.alloc_size;
 
 	return 0;
 }
 
-enum mlxsw_sp_kvdl_part_id {
-	MLXSW_SP_KVDL_PART_SINGLE,
-	MLXSW_SP_KVDL_PART_CHUNKS,
-	MLXSW_SP_KVDL_PART_LARGE_CHUNKS,
-};
-
-static const struct mlxsw_sp_kvdl_part_info kvdl_parts_info[] = {
-	{
-		.part_index	= MLXSW_SP_KVDL_PART_SINGLE,
-		.start_index	= MLXSW_SP_KVDL_SINGLE_BASE,
-		.end_index	= MLXSW_SP_KVDL_SINGLE_END,
-		.alloc_size	= 1,
-	},
-	{
-		.part_index	= MLXSW_SP_KVDL_PART_CHUNKS,
-		.start_index	= MLXSW_SP_KVDL_CHUNKS_BASE,
-		.end_index	= MLXSW_SP_KVDL_CHUNKS_END,
-		.alloc_size	= MLXSW_SP_CHUNK_MAX,
-	},
-	{
-		.part_index	= MLXSW_SP_KVDL_PART_LARGE_CHUNKS,
-		.start_index	= MLXSW_SP_KVDL_LARGE_CHUNKS_BASE,
-		.end_index	= MLXSW_SP_KVDL_LARGE_CHUNKS_END,
-		.alloc_size	= MLXSW_SP_LARGE_CHUNK_MAX,
-	},
-};
-
-static struct mlxsw_sp_kvdl_part *
-mlxsw_sp_kvdl_part_find(struct mlxsw_sp *mlxsw_sp, unsigned int part_index)
-{
-	struct mlxsw_sp_kvdl_part *part;
-
-	list_for_each_entry(part, &mlxsw_sp->kvdl->parts_list, list) {
-		if (part->info->part_index == part_index)
-			return part;
-	}
-
-	return NULL;
-}
-
-static void
-mlxsw_sp_kvdl_part_update(struct mlxsw_sp *mlxsw_sp,
-			  struct mlxsw_sp_kvdl_part *part, unsigned int size)
+static void mlxsw_sp_kvdl_part_update(struct mlxsw_sp_kvdl_part *part,
+				      struct mlxsw_sp_kvdl_part *part_prev,
+				      unsigned int size)
 {
-	struct mlxsw_sp_kvdl_part_info *info = part->info;
-
-	if (list_is_last(&part->list, &mlxsw_sp->kvdl->parts_list)) {
-		info->end_index = size - 1;
-	} else  {
-		struct mlxsw_sp_kvdl_part *last_part;
 
-		last_part = list_next_entry(part, list);
-		info->start_index = last_part->info->end_index + 1;
-		info->end_index = info->start_index + size - 1;
+	if (!part_prev) {
+		part->info.end_index = size - 1;
+	} else {
+		part->info.start_index = part_prev->info.end_index + 1;
+		part->info.end_index = part->info.start_index + size - 1;
 	}
 }
 
-static int mlxsw_sp_kvdl_part_init(struct mlxsw_sp *mlxsw_sp,
-				   unsigned int part_index)
+static struct mlxsw_sp_kvdl_part *
+mlxsw_sp_kvdl_part_init(struct mlxsw_sp *mlxsw_sp,
+			const struct mlxsw_sp_kvdl_part_info *info,
+			struct mlxsw_sp_kvdl_part *part_prev)
 {
 	struct devlink *devlink = priv_to_devlink(mlxsw_sp->core);
-	const struct mlxsw_sp_kvdl_part_info *info;
-	enum mlxsw_sp_resource_id resource_id;
 	struct mlxsw_sp_kvdl_part *part;
 	bool need_update = true;
 	unsigned int nr_entries;
@@ -258,23 +240,8 @@ static int mlxsw_sp_kvdl_part_init(struct mlxsw_sp *mlxsw_sp,
 	u64 resource_size;
 	int err;
 
-	info = &kvdl_parts_info[part_index];
-
-	switch (part_index) {
-	case MLXSW_SP_KVDL_PART_SINGLE:
-		resource_id = MLXSW_SP_RESOURCE_KVD_LINEAR_SINGLE;
-		break;
-	case MLXSW_SP_KVDL_PART_CHUNKS:
-		resource_id = MLXSW_SP_RESOURCE_KVD_LINEAR_CHUNKS;
-		break;
-	case MLXSW_SP_KVDL_PART_LARGE_CHUNKS:
-		resource_id = MLXSW_SP_RESOURCE_KVD_LINEAR_LARGE_CHUNKS;
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	err = devlink_resource_size_get(devlink, resource_id, &resource_size);
+	err = devlink_resource_size_get(devlink, info->resource_id,
+					&resource_size);
 	if (err) {
 		need_update = false;
 		resource_size = info->end_index - info->start_index + 1;
@@ -284,86 +251,77 @@ static int mlxsw_sp_kvdl_part_init(struct mlxsw_sp *mlxsw_sp,
 	usage_size = BITS_TO_LONGS(nr_entries) * sizeof(unsigned long);
 	part = kzalloc(sizeof(*part) + usage_size, GFP_KERNEL);
 	if (!part)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
-	part->info = kmemdup(info, sizeof(*part->info), GFP_KERNEL);
-	if (!part->info)
-		goto err_part_info_alloc;
+	memcpy(&part->info, info, sizeof(part->info));
 
-	list_add(&part->list, &mlxsw_sp->kvdl->parts_list);
 	if (need_update)
-		mlxsw_sp_kvdl_part_update(mlxsw_sp, part, resource_size);
-	return 0;
-
-err_part_info_alloc:
-	kfree(part);
-	return -ENOMEM;
+		mlxsw_sp_kvdl_part_update(part, part_prev, resource_size);
+	return part;
 }
 
-static void mlxsw_sp_kvdl_part_fini(struct mlxsw_sp *mlxsw_sp,
-				    unsigned int part_index)
+static void mlxsw_sp_kvdl_part_fini(struct mlxsw_sp_kvdl_part *part)
 {
-	struct mlxsw_sp_kvdl_part *part;
-
-	part = mlxsw_sp_kvdl_part_find(mlxsw_sp, part_index);
-	if (!part)
-		return;
-
-	list_del(&part->list);
-	kfree(part->info);
 	kfree(part);
 }
 
 static int mlxsw_sp_kvdl_parts_init(struct mlxsw_sp *mlxsw_sp)
 {
+	struct mlxsw_sp_kvdl *kvdl = mlxsw_sp->kvdl;
+	const struct mlxsw_sp_kvdl_part_info *info;
+	struct mlxsw_sp_kvdl_part *part_prev = NULL;
 	int err, i;
 
-	INIT_LIST_HEAD(&mlxsw_sp->kvdl->parts_list);
-
-	for (i = 0; i < ARRAY_SIZE(kvdl_parts_info); i++) {
-		err = mlxsw_sp_kvdl_part_init(mlxsw_sp, i);
-		if (err)
+	for (i = 0; i < MLXSW_SP_KVDL_PARTS_INFO_LEN; i++) {
+		info = &mlxsw_sp_kvdl_parts_info[i];
+		kvdl->parts[i] = mlxsw_sp_kvdl_part_init(mlxsw_sp, info,
+							 part_prev);
+		if (IS_ERR(kvdl->parts[i])) {
+			err = PTR_ERR(kvdl->parts[i]);
 			goto err_kvdl_part_init;
+		}
+		part_prev = kvdl->parts[i];
 	}
-
 	return 0;
 
 err_kvdl_part_init:
 	for (i--; i >= 0; i--)
-		mlxsw_sp_kvdl_part_fini(mlxsw_sp, i);
+		mlxsw_sp_kvdl_part_fini(kvdl->parts[i]);
 	return err;
 }
 
 static void mlxsw_sp_kvdl_parts_fini(struct mlxsw_sp *mlxsw_sp)
 {
+	struct mlxsw_sp_kvdl *kvdl = mlxsw_sp->kvdl;
 	int i;
 
-	for (i = ARRAY_SIZE(kvdl_parts_info) - 1; i >= 0; i--)
-		mlxsw_sp_kvdl_part_fini(mlxsw_sp, i);
+	for (i = 0; i < MLXSW_SP_KVDL_PARTS_INFO_LEN; i++)
+		mlxsw_sp_kvdl_part_fini(kvdl->parts[i]);
 }
 
 static u64 mlxsw_sp_kvdl_part_occ(struct mlxsw_sp_kvdl_part *part)
 {
+	const struct mlxsw_sp_kvdl_part_info *info = &part->info;
 	unsigned int nr_entries;
 	int bit = -1;
 	u64 occ = 0;
 
-	nr_entries = (part->info->end_index -
-		      part->info->start_index + 1) /
-		      part->info->alloc_size;
+	nr_entries = (info->end_index -
+		      info->start_index + 1) /
+		      info->alloc_size;
 	while ((bit = find_next_bit(part->usage, nr_entries, bit + 1))
 		< nr_entries)
-		occ += part->info->alloc_size;
+		occ += info->alloc_size;
 	return occ;
 }
 
 u64 mlxsw_sp_kvdl_occ_get(const struct mlxsw_sp *mlxsw_sp)
 {
-	struct mlxsw_sp_kvdl_part *part;
 	u64 occ = 0;
+	int i;
 
-	list_for_each_entry(part, &mlxsw_sp->kvdl->parts_list, list)
-		occ += mlxsw_sp_kvdl_part_occ(part);
+	for (i = 0; i < MLXSW_SP_KVDL_PARTS_INFO_LEN; i++)
+		occ += mlxsw_sp_kvdl_part_occ(mlxsw_sp->kvdl->parts[i]);
 
 	return occ;
 }
@@ -374,10 +332,7 @@ static u64 mlxsw_sp_kvdl_single_occ_get(struct devlink *devlink)
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
 	struct mlxsw_sp_kvdl_part *part;
 
-	part = mlxsw_sp_kvdl_part_find(mlxsw_sp, MLXSW_SP_KVDL_PART_SINGLE);
-	if (!part)
-		return -EINVAL;
-
+	part = mlxsw_sp->kvdl->parts[MLXSW_SP_KVDL_PART_ID_SINGLE];
 	return mlxsw_sp_kvdl_part_occ(part);
 }
 
@@ -387,10 +342,7 @@ static u64 mlxsw_sp_kvdl_chunks_occ_get(struct devlink *devlink)
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
 	struct mlxsw_sp_kvdl_part *part;
 
-	part = mlxsw_sp_kvdl_part_find(mlxsw_sp, MLXSW_SP_KVDL_PART_CHUNKS);
-	if (!part)
-		return -EINVAL;
-
+	part = mlxsw_sp->kvdl->parts[MLXSW_SP_KVDL_PART_ID_CHUNKS];
 	return mlxsw_sp_kvdl_part_occ(part);
 }
 
@@ -400,11 +352,7 @@ static u64 mlxsw_sp_kvdl_large_chunks_occ_get(struct devlink *devlink)
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
 	struct mlxsw_sp_kvdl_part *part;
 
-	part = mlxsw_sp_kvdl_part_find(mlxsw_sp,
-				       MLXSW_SP_KVDL_PART_LARGE_CHUNKS);
-	if (!part)
-		return -EINVAL;
-
+	part = mlxsw_sp->kvdl->parts[MLXSW_SP_KVDL_PART_ID_LARGE_CHUNKS];
 	return mlxsw_sp_kvdl_part_occ(part);
 }
 
@@ -431,7 +379,8 @@ int mlxsw_sp_kvdl_resources_register(struct devlink *devlink)
 			MLXSW_CORE_RES_GET(mlxsw_core, KVD_SINGLE_MIN_SIZE) -
 			MLXSW_CORE_RES_GET(mlxsw_core, KVD_DOUBLE_MIN_SIZE);
 
-	devlink_resource_size_params_init(&size_params, 0, kvdl_max_size, 1,
+	devlink_resource_size_params_init(&size_params, 0, kvdl_max_size,
+					  MLXSW_SP_KVDL_SINGLE_ALLOC_SIZE,
 					  DEVLINK_RESOURCE_UNIT_ENTRY);
 	err = devlink_resource_register(devlink, MLXSW_SP_RESOURCE_NAME_KVD_LINEAR_SINGLES,
 					MLXSW_SP_KVDL_SINGLE_SIZE,
@@ -443,7 +392,7 @@ int mlxsw_sp_kvdl_resources_register(struct devlink *devlink)
 		return err;
 
 	devlink_resource_size_params_init(&size_params, 0, kvdl_max_size,
-					  MLXSW_SP_CHUNK_MAX,
+					  MLXSW_SP_KVDL_CHUNKS_ALLOC_SIZE,
 					  DEVLINK_RESOURCE_UNIT_ENTRY);
 	err = devlink_resource_register(devlink, MLXSW_SP_RESOURCE_NAME_KVD_LINEAR_CHUNKS,
 					MLXSW_SP_KVDL_CHUNKS_SIZE,
@@ -455,7 +404,7 @@ int mlxsw_sp_kvdl_resources_register(struct devlink *devlink)
 		return err;
 
 	devlink_resource_size_params_init(&size_params, 0, kvdl_max_size,
-					  MLXSW_SP_LARGE_CHUNK_MAX,
+					  MLXSW_SP_KVDL_LARGE_CHUNKS_ALLOC_SIZE,
 					  DEVLINK_RESOURCE_UNIT_ENTRY);
 	err = devlink_resource_register(devlink, MLXSW_SP_RESOURCE_NAME_KVD_LINEAR_LARGE_CHUNKS,
 					MLXSW_SP_KVDL_LARGE_CHUNKS_SIZE,