From: Dave Jiang <dave.jiang@xxxxxxxxx>
Add sysfs knob to allow control of the number of work descriptors that can
be concurrently processed by an engine in the group as a fraction of the
Maximum Work Descriptors in Progress value specified in ENGCAP register.
This control knob is part of toggle for QoS control.
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Co-developed-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
.../ABI/stable/sysfs-driver-dma-idxd | 12 +++++
drivers/dma/idxd/device.c | 13 +++--
drivers/dma/idxd/idxd.h | 1 +
drivers/dma/idxd/registers.h | 23 ++++----
drivers/dma/idxd/sysfs.c | 53 +++++++++++++++++++
5 files changed, 87 insertions(+), 15 deletions(-)
diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation/ABI/stable/sysfs-driver-dma-idxd
index 3f9f93b5e48c..02a721a8ea68 100644
--- a/Documentation/ABI/stable/sysfs-driver-dma-idxd
+++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd
@@ -266,3 +266,15 @@ Contact: dmaengine@xxxxxxxxxxxxxxx
Description: Indicates the number of Read Buffers reserved for the use of
engines in the group. See DSA spec v1.2 9.2.18 GRPCFG Read Buffers
Reserved.
+
+What: /sys/bus/dsa/devices/group<m>.<n>/desc_progress_limit
+Date: Sept 14, 2022
+KernelVersion: 6.0.0
+Contact: dmaengine@xxxxxxxxxxxxxxx
+Description: Allows control of the number of work descriptors that can be
+ concurrently processed by an engine in the group as a fraction
+ of the Maximum Work Descriptors in Progress value specified in
+ the ENGCAP register. The acceptable values are 0 (default),
+ 1 (1/2 of max value), 2 (1/4 of the max value), and 3 (1/8 of
+ the max value). It's visible only on platforms that support
+ the capability.
diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 81a81b8d769d..3aa583f70312 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -707,6 +707,7 @@ static void idxd_groups_clear_state(struct idxd_device *idxd)
group->tc_a = -1;
group->tc_b = -1;
}
+ group->desc_progress_limit = 0;
}
}
@@ -763,10 +764,10 @@ static void idxd_group_config_write(struct idxd_group *group)
/* setup GRPFLAGS */
grpcfg_offset = GRPFLGCFG_OFFSET(idxd, group->id);
- iowrite32(group->grpcfg.flags.bits, idxd->reg_base + grpcfg_offset);
- dev_dbg(dev, "GRPFLAGS flags[%d: %#x]: %#x\n",
+ iowrite64(group->grpcfg.flags.bits, idxd->reg_base + grpcfg_offset);
+ dev_dbg(dev, "GRPFLAGS flags[%d: %#x]: %#llx\n",
group->id, grpcfg_offset,
- ioread32(idxd->reg_base + grpcfg_offset));
+ ioread64(idxd->reg_base + grpcfg_offset));
}
static int idxd_groups_config_write(struct idxd_device *idxd)
@@ -927,6 +928,8 @@ static void idxd_group_flags_setup(struct idxd_device *idxd)
group->grpcfg.flags.rdbufs_allowed = group->rdbufs_allowed;
else
group->grpcfg.flags.rdbufs_allowed = idxd->max_rdbufs;
+
+ group->grpcfg.flags.desc_progress_limit = group->desc_progress_limit;
}
}
@@ -1109,8 +1112,8 @@ static void idxd_group_load_config(struct idxd_group *group)
}
grpcfg_offset = GRPFLGCFG_OFFSET(idxd, group->id);
- group->grpcfg.flags.bits = ioread32(idxd->reg_base + grpcfg_offset);
- dev_dbg(dev, "GRPFLAGS flags[%d: %#x]: %#x\n",
+ group->grpcfg.flags.bits = ioread64(idxd->reg_base + grpcfg_offset);
+ dev_dbg(dev, "GRPFLAGS flags[%d: %#x]: %#llx\n",
group->id, grpcfg_offset, group->grpcfg.flags.bits);
}
diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index ba877ad31932..058010be0f87 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -95,6 +95,7 @@ struct idxd_group {
u8 rdbufs_reserved;
int tc_a;
int tc_b;
+ int desc_progress_limit;
};
struct idxd_pmu {
diff --git a/drivers/dma/idxd/registers.h b/drivers/dma/idxd/registers.h
index 7b95be8f0f64..2cc2543edd58 100644
--- a/drivers/dma/idxd/registers.h
+++ b/drivers/dma/idxd/registers.h
@@ -68,7 +68,8 @@ union group_cap_reg {
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 progress_limit:1; /* descriptor and batch descriptor */
+ u64 rsvd:45;
};
u64 bits;
} __packed;
@@ -288,16 +289,18 @@ union msix_perm {
union group_flags {
struct {
- u32 tc_a:3;
- u32 tc_b:3;
- u32 rsvd:1;
- u32 use_rdbuf_limit:1;
- u32 rdbufs_reserved:8;
- u32 rsvd2:4;
- u32 rdbufs_allowed:8;
- u32 rsvd3:4;
+ u64 tc_a:3;
+ u64 tc_b:3;
+ u64 rsvd:1;
+ u64 use_rdbuf_limit:1;
+ u64 rdbufs_reserved:8;
+ u64 rsvd2:4;
+ u64 rdbufs_allowed:8;
+ u64 rsvd3:4;
+ u64 desc_progress_limit:2;
+ u64 rsvd4:30;
};
- u32 bits;
+ u64 bits;
} __packed;
struct grpcfg {
diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 3bb1ea02a338..3e655a3a4c7c 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -443,6 +443,37 @@ static struct device_attribute dev_attr_group_traffic_class_b =
__ATTR(traffic_class_b, 0644, group_traffic_class_b_show,
group_traffic_class_b_store);
+static ssize_t group_desc_progress_limit_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct idxd_group *group = confdev_to_group(dev);
+
+ return sysfs_emit(buf, "%d\n", group->desc_progress_limit);
+}
+
+static ssize_t group_desc_progress_limit_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct idxd_group *group = confdev_to_group(dev);
+ int val, rc;
+
+ rc = kstrtoint(buf, 10, &val);
+ if (rc < 0)
+ return -EINVAL;
+
+ if (val & ~GENMASK(1, 0))
+ return -EINVAL;
+
+ group->desc_progress_limit = val;
+ return count;
+}
+
+static struct device_attribute dev_attr_group_desc_progress_limit =
+ __ATTR(desc_progress_limit, 0644, group_desc_progress_limit_show,
+ group_desc_progress_limit_store);
+
static struct attribute *idxd_group_attributes[] = {
&dev_attr_group_work_queues.attr,
&dev_attr_group_engines.attr,
@@ -454,11 +485,33 @@ static struct attribute *idxd_group_attributes[] = {
&dev_attr_group_read_buffers_reserved.attr,
&dev_attr_group_traffic_class_a.attr,
&dev_attr_group_traffic_class_b.attr,
+ &dev_attr_group_desc_progress_limit.attr,
NULL,
};
+static bool idxd_group_attr_progress_limit_invisible(struct attribute *attr,
+ struct idxd_device *idxd)
+{
+ return attr == &dev_attr_group_desc_progress_limit.attr &&
+ !idxd->hw.group_cap.progress_limit;
+}
+
+static umode_t idxd_group_attr_visible(struct kobject *kobj,
+ struct attribute *attr, int n)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct idxd_group *group = confdev_to_group(dev);
+ struct idxd_device *idxd = group->idxd;
+
+ if (idxd_group_attr_progress_limit_invisible(attr, idxd))
+ return 0;
+
+ return attr->mode;
+}
+
static const struct attribute_group idxd_group_attribute_group = {
.attrs = idxd_group_attributes,
+ .is_visible = idxd_group_attr_visible,
};
static const struct attribute_group *idxd_group_attribute_groups[] = {
--
2.32.0
