From 7ed6f1b85fb613e5e44ef3e14d73f2dc96860935 Mon Sep 17 00:00:00 2001
From: Dave Jiang <dave.jiang@intel.com>
Date: Tue, 14 Dec 2021 13:23:09 -0700
Subject: [PATCH] dmaengine: idxd: change bandwidth token to read buffers
Git-commit: 7ed6f1b85fb613e5e44ef3e14d73f2dc96860935
Patch-mainline: v5.17-rc1
References: jsc#PED-857

DSA spec v1.2 has changed the term of "bandwidth tokens" to "read buffers"
in order to make the concept clearer. Deprecate bandwidth token
naming in the driver and convert to read buffers in order to match with
the spec and reduce confusion when reading the spec.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163951338932.2988321.6162640806935567317.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/dma/idxd/device.c    |   25 ++++++++++++-------------
 drivers/dma/idxd/idxd.h      |   12 ++++++------
 drivers/dma/idxd/init.c      |    6 +++---
 drivers/dma/idxd/registers.h |   14 +++++++-------
 drivers/dma/idxd/sysfs.c     |   42 +++++++++++++++++++++---------------------
 5 files changed, 49 insertions(+), 50 deletions(-)

--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -690,9 +690,9 @@ static void idxd_groups_clear_state(stru
 		memset(&group->grpcfg, 0, sizeof(group->grpcfg));
 		group->num_engines = 0;
 		group->num_wqs = 0;
-		group->use_token_limit = false;
-		group->tokens_allowed = 0;
-		group->tokens_reserved = 0;
+		group->use_rdbuf_limit = false;
+		group->rdbufs_allowed = 0;
+		group->rdbufs_reserved = 0;
 		group->tc_a = -1;
 		group->tc_b = -1;
 	}
@@ -760,10 +760,10 @@ static int idxd_groups_config_write(stru
 	int i;
 	struct device *dev = &idxd->pdev->dev;
 
-	/* Setup bandwidth token limit */
-	if (idxd->hw.gen_cap.config_en && idxd->token_limit) {
+	/* Setup bandwidth rdbuf limit */
+	if (idxd->hw.gen_cap.config_en && idxd->rdbuf_limit) {
 		reg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
-		reg.token_limit = idxd->token_limit;
+		reg.rdbuf_limit = idxd->rdbuf_limit;
 		iowrite32(reg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
 	}
 
@@ -901,13 +901,12 @@ static void idxd_group_flags_setup(struc
 			group->tc_b = group->grpcfg.flags.tc_b = 1;
 		else
 			group->grpcfg.flags.tc_b = group->tc_b;
-		group->grpcfg.flags.use_token_limit = group->use_token_limit;
-		group->grpcfg.flags.tokens_reserved = group->tokens_reserved;
-		if (group->tokens_allowed)
-			group->grpcfg.flags.tokens_allowed =
-				group->tokens_allowed;
+		group->grpcfg.flags.use_rdbuf_limit = group->use_rdbuf_limit;
+		group->grpcfg.flags.rdbufs_reserved = group->rdbufs_reserved;
+		if (group->rdbufs_allowed)
+			group->grpcfg.flags.rdbufs_allowed = group->rdbufs_allowed;
 		else
-			group->grpcfg.flags.tokens_allowed = idxd->max_tokens;
+			group->grpcfg.flags.rdbufs_allowed = idxd->max_rdbufs;
 	}
 }
 
@@ -1100,7 +1099,7 @@ int idxd_device_load_config(struct idxd_
 	int i, rc;
 
 	reg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
-	idxd->token_limit = reg.token_limit;
+	idxd->rdbuf_limit = reg.rdbuf_limit;
 
 	for (i = 0; i < idxd->max_groups; i++) {
 		struct idxd_group *group = idxd->groups[i];
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -90,9 +90,9 @@ struct idxd_group {
 	int id;
 	int num_engines;
 	int num_wqs;
-	bool use_token_limit;
-	u8 tokens_allowed;
-	u8 tokens_reserved;
+	bool use_rdbuf_limit;
+	u8 rdbufs_allowed;
+	u8 rdbufs_reserved;
 	int tc_a;
 	int tc_b;
 };
@@ -294,11 +294,11 @@ struct idxd_device {
 	u32 max_batch_size;
 	int max_groups;
 	int max_engines;
-	int max_tokens;
+	int max_rdbufs;
 	int max_wqs;
 	int max_wq_size;
-	int token_limit;
-	int nr_tokens;		/* non-reserved tokens */
+	int rdbuf_limit;
+	int nr_rdbufs;		/* non-reserved read buffers */
 	unsigned int wqcfg_size;
 
 	union sw_err_reg sw_err;
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -400,9 +400,9 @@ static void idxd_read_caps(struct idxd_d
 	dev_dbg(dev, "group_cap: %#llx\n", idxd->hw.group_cap.bits);
 	idxd->max_groups = idxd->hw.group_cap.num_groups;
 	dev_dbg(dev, "max groups: %u\n", idxd->max_groups);
-	idxd->max_tokens = idxd->hw.group_cap.total_tokens;
-	dev_dbg(dev, "max tokens: %u\n", idxd->max_tokens);
-	idxd->nr_tokens = idxd->max_tokens;
+	idxd->max_rdbufs = idxd->hw.group_cap.total_rdbufs;
+	dev_dbg(dev, "max read buffers: %u\n", idxd->max_rdbufs);
+	idxd->nr_rdbufs = idxd->max_rdbufs;
 
 	/* read engine capabilities */
 	idxd->hw.engine_cap.bits =
--- a/drivers/dma/idxd/registers.h
+++ b/drivers/dma/idxd/registers.h
@@ -65,9 +65,9 @@ union wq_cap_reg {
 union group_cap_reg {
 	struct {
 		u64 num_groups:8;
-		u64 total_tokens:8;
-		u64 token_en:1;
-		u64 token_limit:1;
+		u64 total_rdbufs:8;	/* formerly total_tokens */
+		u64 rdbuf_ctrl:1;	/* formerly token_en */
+		u64 rdbuf_limit:1;	/* formerly token_limit */
 		u64 rsvd:46;
 	};
 	u64 bits;
@@ -111,7 +111,7 @@ union offsets_reg {
 #define IDXD_GENCFG_OFFSET		0x80
 union gencfg_reg {
 	struct {
-		u32 token_limit:8;
+		u32 rdbuf_limit:8;
 		u32 rsvd:4;
 		u32 user_int_en:1;
 		u32 rsvd2:19;
@@ -289,10 +289,10 @@ union group_flags {
 		u32 tc_a:3;
 		u32 tc_b:3;
 		u32 rsvd:1;
-		u32 use_token_limit:1;
-		u32 tokens_reserved:8;
+		u32 use_rdbuf_limit:1;
+		u32 rdbufs_reserved:8;
 		u32 rsvd2:4;
-		u32 tokens_allowed:8;
+		u32 rdbufs_allowed:8;
 		u32 rsvd3:4;
 	};
 	u32 bits;
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -99,17 +99,17 @@ struct device_type idxd_engine_device_ty
 
 /* Group attributes */
 
-static void idxd_set_free_tokens(struct idxd_device *idxd)
+static void idxd_set_free_rdbufs(struct idxd_device *idxd)
 {
-	int i, tokens;
+	int i, rdbufs;
 
-	for (i = 0, tokens = 0; i < idxd->max_groups; i++) {
+	for (i = 0, rdbufs = 0; i < idxd->max_groups; i++) {
 		struct idxd_group *g = idxd->groups[i];
 
-		tokens += g->tokens_reserved;
+		rdbufs += g->rdbufs_reserved;
 	}
 
-	idxd->nr_tokens = idxd->max_tokens - tokens;
+	idxd->nr_rdbufs = idxd->max_rdbufs - rdbufs;
 }
 
 static ssize_t group_tokens_reserved_show(struct device *dev,
@@ -118,7 +118,7 @@ static ssize_t group_tokens_reserved_sho
 {
 	struct idxd_group *group = confdev_to_group(dev);
 
-	return sysfs_emit(buf, "%u\n", group->tokens_reserved);
+	return sysfs_emit(buf, "%u\n", group->rdbufs_reserved);
 }
 
 static ssize_t group_tokens_reserved_store(struct device *dev,
@@ -143,14 +143,14 @@ static ssize_t group_tokens_reserved_sto
 	if (idxd->state == IDXD_DEV_ENABLED)
 		return -EPERM;
 
-	if (val > idxd->max_tokens)
+	if (val > idxd->max_rdbufs)
 		return -EINVAL;
 
-	if (val > idxd->nr_tokens + group->tokens_reserved)
+	if (val > idxd->nr_rdbufs + group->rdbufs_reserved)
 		return -EINVAL;
 
-	group->tokens_reserved = val;
-	idxd_set_free_tokens(idxd);
+	group->rdbufs_reserved = val;
+	idxd_set_free_rdbufs(idxd);
 	return count;
 }
 
@@ -164,7 +164,7 @@ static ssize_t group_tokens_allowed_show
 {
 	struct idxd_group *group = confdev_to_group(dev);
 
-	return sysfs_emit(buf, "%u\n", group->tokens_allowed);
+	return sysfs_emit(buf, "%u\n", group->rdbufs_allowed);
 }
 
 static ssize_t group_tokens_allowed_store(struct device *dev,
@@ -190,10 +190,10 @@ static ssize_t group_tokens_allowed_stor
 		return -EPERM;
 
 	if (val < 4 * group->num_engines ||
-	    val > group->tokens_reserved + idxd->nr_tokens)
+	    val > group->rdbufs_reserved + idxd->nr_rdbufs)
 		return -EINVAL;
 
-	group->tokens_allowed = val;
+	group->rdbufs_allowed = val;
 	return count;
 }
 
@@ -207,7 +207,7 @@ static ssize_t group_use_token_limit_sho
 {
 	struct idxd_group *group = confdev_to_group(dev);
 
-	return sysfs_emit(buf, "%u\n", group->use_token_limit);
+	return sysfs_emit(buf, "%u\n", group->use_rdbuf_limit);
 }
 
 static ssize_t group_use_token_limit_store(struct device *dev,
@@ -232,10 +232,10 @@ static ssize_t group_use_token_limit_sto
 	if (idxd->state == IDXD_DEV_ENABLED)
 		return -EPERM;
 
-	if (idxd->token_limit == 0)
+	if (idxd->rdbuf_limit == 0)
 		return -EPERM;
 
-	group->use_token_limit = !!val;
+	group->use_rdbuf_limit = !!val;
 	return count;
 }
 
@@ -1197,7 +1197,7 @@ static ssize_t max_tokens_show(struct de
 {
 	struct idxd_device *idxd = confdev_to_idxd(dev);
 
-	return sysfs_emit(buf, "%u\n", idxd->max_tokens);
+	return sysfs_emit(buf, "%u\n", idxd->max_rdbufs);
 }
 static DEVICE_ATTR_RO(max_tokens);
 
@@ -1206,7 +1206,7 @@ static ssize_t token_limit_show(struct d
 {
 	struct idxd_device *idxd = confdev_to_idxd(dev);
 
-	return sysfs_emit(buf, "%u\n", idxd->token_limit);
+	return sysfs_emit(buf, "%u\n", idxd->rdbuf_limit);
 }
 
 static ssize_t token_limit_store(struct device *dev,
@@ -1227,13 +1227,13 @@ static ssize_t token_limit_store(struct
 	if (!test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
 		return -EPERM;
 
-	if (!idxd->hw.group_cap.token_limit)
+	if (!idxd->hw.group_cap.rdbuf_limit)
 		return -EPERM;
 
-	if (val > idxd->hw.group_cap.total_tokens)
+	if (val > idxd->hw.group_cap.total_rdbufs)
 		return -EINVAL;
 
-	idxd->token_limit = val;
+	idxd->rdbuf_limit = val;
 	return count;
 }
 static DEVICE_ATTR_RW(token_limit);