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authorJacob Keller <jacob.e.keller@intel.com>2022-11-28 12:36:44 -0800
committerJakub Kicinski <kuba@kernel.org>2022-11-30 20:54:30 -0800
commitaf6397c9ee2b42988c912dcad2fca1f43d5c1c99 (patch)
treee03db8f360ad11aabc59a99489d9fb683c9d5915 /net/core
parent2d4caf0988bd3e9663c300e95cead91f2f954fae (diff)
devlink: support directly reading from region memory
To read from a region, user space must currently request a new snapshot of the region and then read from that snapshot. This can sometimes be overkill if user space only reads a tiny portion. They first create the snapshot, then request a read, then destroy the snapshot. For regions which have a single underlying "contents", it makes sense to allow supporting direct reading of the region data. Extend the DEVLINK_CMD_REGION_READ to allow direct reading from a region if requested via the new DEVLINK_ATTR_REGION_DIRECT. If this attribute is set, then perform a direct read instead of using a snapshot. Direct read is mutually exclusive with DEVLINK_ATTR_REGION_SNAPSHOT_ID, and care is taken to ensure that we reject commands which provide incorrect attributes. Regions must enable support for direct read by implementing the .read() callback function. If a region does not support such direct reads, a suitable extended error message is reported. Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/devlink.c80
1 files changed, 63 insertions, 17 deletions
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 6c05cfaa571d..298041a44aa8 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -6515,6 +6515,26 @@ devlink_region_snapshot_fill(void *cb_priv, u8 *chunk, u32 chunk_size,
return 0;
}
+static int
+devlink_region_port_direct_fill(void *cb_priv, u8 *chunk, u32 chunk_size,
+ u64 curr_offset, struct netlink_ext_ack *extack)
+{
+ struct devlink_region *region = cb_priv;
+
+ return region->port_ops->read(region->port, region->port_ops, extack,
+ curr_offset, chunk_size, chunk);
+}
+
+static int
+devlink_region_direct_fill(void *cb_priv, u8 *chunk, u32 chunk_size,
+ u64 curr_offset, struct netlink_ext_ack *extack)
+{
+ struct devlink_region *region = cb_priv;
+
+ return region->ops->read(region->devlink, region->ops, extack,
+ curr_offset, chunk_size, chunk);
+}
+
static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
struct netlink_callback *cb)
{
@@ -6523,12 +6543,12 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
u64 ret_offset, start_offset, end_offset = U64_MAX;
struct nlattr **attrs = info->attrs;
struct devlink_port *port = NULL;
- struct devlink_snapshot *snapshot;
+ devlink_chunk_fill_t *region_cb;
struct devlink_region *region;
const char *region_name;
struct devlink *devlink;
unsigned int index;
- u32 snapshot_id;
+ void *region_cb_priv;
void *hdr;
int err;
@@ -6546,12 +6566,6 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
goto out_unlock;
}
- if (!attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID]) {
- NL_SET_ERR_MSG(cb->extack, "No snapshot id provided");
- err = -EINVAL;
- goto out_unlock;
- }
-
if (info->attrs[DEVLINK_ATTR_PORT_INDEX]) {
index = nla_get_u32(info->attrs[DEVLINK_ATTR_PORT_INDEX]);
@@ -6577,12 +6591,43 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
}
snapshot_attr = attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID];
- snapshot_id = nla_get_u32(snapshot_attr);
- snapshot = devlink_region_snapshot_get_by_id(region, snapshot_id);
- if (!snapshot) {
- NL_SET_ERR_MSG_ATTR(cb->extack, snapshot_attr, "Requested snapshot does not exist");
- err = -EINVAL;
- goto out_unlock;
+ if (!snapshot_attr) {
+ if (!nla_get_flag(attrs[DEVLINK_ATTR_REGION_DIRECT])) {
+ NL_SET_ERR_MSG(cb->extack, "No snapshot id provided");
+ err = -EINVAL;
+ goto out_unlock;
+ }
+
+ if (!region->ops->read) {
+ NL_SET_ERR_MSG(cb->extack, "Requested region does not support direct read");
+ err = -EOPNOTSUPP;
+ goto out_unlock;
+ }
+
+ if (port)
+ region_cb = &devlink_region_port_direct_fill;
+ else
+ region_cb = &devlink_region_direct_fill;
+ region_cb_priv = region;
+ } else {
+ struct devlink_snapshot *snapshot;
+ u32 snapshot_id;
+
+ if (nla_get_flag(attrs[DEVLINK_ATTR_REGION_DIRECT])) {
+ NL_SET_ERR_MSG_ATTR(cb->extack, snapshot_attr, "Direct region read does not use snapshot");
+ err = -EINVAL;
+ goto out_unlock;
+ }
+
+ snapshot_id = nla_get_u32(snapshot_attr);
+ snapshot = devlink_region_snapshot_get_by_id(region, snapshot_id);
+ if (!snapshot) {
+ NL_SET_ERR_MSG_ATTR(cb->extack, snapshot_attr, "Requested snapshot does not exist");
+ err = -EINVAL;
+ goto out_unlock;
+ }
+ region_cb = &devlink_region_snapshot_fill;
+ region_cb_priv = snapshot;
}
if (attrs[DEVLINK_ATTR_REGION_CHUNK_ADDR] &&
@@ -6633,9 +6678,9 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
goto nla_put_failure;
}
- err = devlink_nl_region_read_fill(skb, &devlink_region_snapshot_fill,
- snapshot, start_offset, end_offset,
- &ret_offset, cb->extack);
+ err = devlink_nl_region_read_fill(skb, region_cb, region_cb_priv,
+ start_offset, end_offset, &ret_offset,
+ cb->extack);
if (err && err != -EMSGSIZE)
goto nla_put_failure;
@@ -9280,6 +9325,7 @@ static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
[DEVLINK_ATTR_SELFTESTS] = { .type = NLA_NESTED },
[DEVLINK_ATTR_RATE_TX_PRIORITY] = { .type = NLA_U32 },
[DEVLINK_ATTR_RATE_TX_WEIGHT] = { .type = NLA_U32 },
+ [DEVLINK_ATTR_REGION_DIRECT] = { .type = NLA_FLAG },
};
static const struct genl_small_ops devlink_nl_ops[] = {