dmaengine: idxd: change bandwidth token to read buffers

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 <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/idxd/device.c

···
 		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;
 	}
···
 	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);
 	}
 
···
 			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;
 	}
 }
 
···
 	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];

drivers/dma/idxd/idxd.h

···
 	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;
 };
···
 	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;

drivers/dma/idxd/init.c

···
 	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 =

drivers/dma/idxd/registers.h

···
 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;
···
 #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;
···
 		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;

drivers/dma/idxd/sysfs.c

···
 
 /* 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,
···
 {
 	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,
···
 	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;
 }
 
···
 {
 	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,
···
 		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;
 }
 
···
 {
 	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,
···
 	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;
 }
 
···
 {
 	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);
 
···
 {
 	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,
···
 	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);