From 28e0c250f17ab3b6eb4dcee1a8208125bc77c61e Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Mon, 28 Nov 2022 12:36:39 -0800 Subject: [PATCH 1/9] devlink: use min_t to calculate data_size The calculation for the data_size in the devlink_nl_read_snapshot_fill function uses an if statement that is better expressed using the min_t macro. Signed-off-by: Jacob Keller Acked-by: Jakub Kicinski Reviewed-by: Jiri Pirko Signed-off-by: Jakub Kicinski --- net/core/devlink.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/core/devlink.c b/net/core/devlink.c index 0e10a8a68c5e..6ef9974f5357 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -6485,10 +6485,8 @@ static int devlink_nl_region_read_snapshot_fill(struct sk_buff *skb, u32 data_size; u8 *data; - if (end_offset - curr_offset < DEVLINK_REGION_READ_CHUNK_SIZE) - data_size = end_offset - curr_offset; - else - data_size = DEVLINK_REGION_READ_CHUNK_SIZE; + data_size = min_t(u32, end_offset - curr_offset, + DEVLINK_REGION_READ_CHUNK_SIZE); data = &snapshot->data[curr_offset]; err = devlink_nl_cmd_region_read_chunk_fill(skb, devlink, From 611fd12ce0fbc809d5e54febb1f39e93532c9deb Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Mon, 28 Nov 2022 12:36:40 -0800 Subject: [PATCH 2/9] devlink: report extended error message in region_read_dumpit() Report extended error details in the devlink_nl_cmd_region_read_dumpit() function, by using the extack structure from the netlink_callback. Signed-off-by: Jacob Keller Acked-by: Jakub Kicinski Reviewed-by: Jiri Pirko Signed-off-by: Jakub Kicinski --- net/core/devlink.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/net/core/devlink.c b/net/core/devlink.c index 6ef9974f5357..fee69280deb4 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -6507,10 +6507,10 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, { const struct genl_dumpit_info *info = genl_dumpit_info(cb); u64 ret_offset, start_offset, end_offset = U64_MAX; + struct nlattr *chunks_attr, *region_attr; struct nlattr **attrs = info->attrs; struct devlink_port *port = NULL; struct devlink_region *region; - struct nlattr *chunks_attr; const char *region_name; struct devlink *devlink; unsigned int index; @@ -6525,8 +6525,14 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, devl_lock(devlink); - if (!attrs[DEVLINK_ATTR_REGION_NAME] || - !attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID]) { + if (!attrs[DEVLINK_ATTR_REGION_NAME]) { + NL_SET_ERR_MSG(cb->extack, "No region name provided"); + err = -EINVAL; + 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; } @@ -6541,7 +6547,8 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, } } - region_name = nla_data(attrs[DEVLINK_ATTR_REGION_NAME]); + region_attr = attrs[DEVLINK_ATTR_REGION_NAME]; + region_name = nla_data(region_attr); if (port) region = devlink_port_region_get_by_name(port, region_name); @@ -6549,6 +6556,7 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, region = devlink_region_get_by_name(devlink, region_name); if (!region) { + NL_SET_ERR_MSG_ATTR(cb->extack, region_attr, "Requested region does not exist"); err = -EINVAL; goto out_unlock; } From e004ea10599d1a8279e959c86e63fc9d0bf2032b Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Mon, 28 Nov 2022 12:36:41 -0800 Subject: [PATCH 3/9] devlink: find snapshot in devlink_nl_cmd_region_read_dumpit The snapshot pointer is obtained inside of the function devlink_nl_region_read_snapshot_fill. Simplify this function by locating the snapshot upfront in devlink_nl_cmd_region_read_dumpit instead. This aligns with how other netlink attributes are handled, and allows us to exit slightly earlier if an invalid snapshot ID is provided. It also allows us to pass the snapshot pointer directly to the devlink_nl_region_read_snapshot_fill, and remove the now unused attrs parameter. Signed-off-by: Jacob Keller Acked-by: Jakub Kicinski Reviewed-by: Jiri Pirko Signed-off-by: Jakub Kicinski --- net/core/devlink.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/net/core/devlink.c b/net/core/devlink.c index fee69280deb4..e3166c9b5954 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -6463,24 +6463,16 @@ nla_put_failure: static int devlink_nl_region_read_snapshot_fill(struct sk_buff *skb, struct devlink *devlink, - struct devlink_region *region, - struct nlattr **attrs, + struct devlink_snapshot *snapshot, u64 start_offset, u64 end_offset, u64 *new_offset) { - struct devlink_snapshot *snapshot; u64 curr_offset = start_offset; - u32 snapshot_id; int err = 0; *new_offset = start_offset; - snapshot_id = nla_get_u32(attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID]); - snapshot = devlink_region_snapshot_get_by_id(region, snapshot_id); - if (!snapshot) - return -EINVAL; - while (curr_offset < end_offset) { u32 data_size; u8 *data; @@ -6506,14 +6498,16 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, struct netlink_callback *cb) { const struct genl_dumpit_info *info = genl_dumpit_info(cb); + struct nlattr *chunks_attr, *region_attr, *snapshot_attr; u64 ret_offset, start_offset, end_offset = U64_MAX; - struct nlattr *chunks_attr, *region_attr; struct nlattr **attrs = info->attrs; struct devlink_port *port = NULL; + struct devlink_snapshot *snapshot; struct devlink_region *region; const char *region_name; struct devlink *devlink; unsigned int index; + u32 snapshot_id; void *hdr; int err; @@ -6561,6 +6555,15 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, goto out_unlock; } + 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 (attrs[DEVLINK_ATTR_REGION_CHUNK_ADDR] && attrs[DEVLINK_ATTR_REGION_CHUNK_LEN]) { if (!start_offset) @@ -6610,7 +6613,7 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, } err = devlink_nl_region_read_snapshot_fill(skb, devlink, - region, attrs, + snapshot, start_offset, end_offset, &ret_offset); From 284e9d1ebbe2944d95120f85054d161a6fccbf7f Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Mon, 28 Nov 2022 12:36:42 -0800 Subject: [PATCH 4/9] devlink: remove unnecessary parameter from chunk_fill function The devlink parameter of the devlink_nl_cmd_region_read_chunk_fill function is not used. Remove it, to simplify the function signature. Once removed, it is also obvious that the devlink parameter is not necessary for the devlink_nl_region_read_snapshot_fill either. Signed-off-by: Jacob Keller Acked-by: Jakub Kicinski Reviewed-by: Jiri Pirko Signed-off-by: Jakub Kicinski --- net/core/devlink.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) diff --git a/net/core/devlink.c b/net/core/devlink.c index e3166c9b5954..5b8a9bdbc13d 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -6431,7 +6431,6 @@ unlock: } static int devlink_nl_cmd_region_read_chunk_fill(struct sk_buff *msg, - struct devlink *devlink, u8 *chunk, u32 chunk_size, u64 addr) { @@ -6462,7 +6461,6 @@ nla_put_failure: #define DEVLINK_REGION_READ_CHUNK_SIZE 256 static int devlink_nl_region_read_snapshot_fill(struct sk_buff *skb, - struct devlink *devlink, struct devlink_snapshot *snapshot, u64 start_offset, u64 end_offset, @@ -6481,9 +6479,7 @@ static int devlink_nl_region_read_snapshot_fill(struct sk_buff *skb, DEVLINK_REGION_READ_CHUNK_SIZE); data = &snapshot->data[curr_offset]; - err = devlink_nl_cmd_region_read_chunk_fill(skb, devlink, - data, data_size, - curr_offset); + err = devlink_nl_cmd_region_read_chunk_fill(skb, data, data_size, curr_offset); if (err) break; @@ -6612,9 +6608,7 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, goto nla_put_failure; } - err = devlink_nl_region_read_snapshot_fill(skb, devlink, - snapshot, - start_offset, + err = devlink_nl_region_read_snapshot_fill(skb, snapshot, start_offset, end_offset, &ret_offset); if (err && err != -EMSGSIZE) From 2d4caf0988bd3e9663c300e95cead91f2f954fae Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Mon, 28 Nov 2022 12:36:43 -0800 Subject: [PATCH 5/9] devlink: refactor region_read_snapshot_fill to use a callback function The devlink_nl_region_read_snapshot_fill is used to copy the contents of a snapshot into a message for reporting to userspace via the DEVLINK_CMG_REGION_READ netlink message. A future change is going to add support for directly reading from a region. Almost all of the logic for this new capability is identical. To help reduce code duplication and make this logic more generic, refactor the function to take a cb and cb_priv pointer for doing the actual copy. Add a devlink_region_snapshot_fill implementation that will simply copy the relevant chunk of the region. This does require allocating some storage for the chunk as opposed to simply passing the correct address forward to the devlink_nl_cmg_region_read_chunk_fill function. A future change to implement support for directly reading from a region without a snapshot will provide a separate implementation that calls the newly added devlink region operation. Signed-off-by: Jacob Keller Acked-by: Jakub Kicinski Reviewed-by: Jiri Pirko Signed-off-by: Jakub Kicinski --- net/core/devlink.c | 44 +++++++++++++++++++++++++++++++++++--------- 1 file changed, 35 insertions(+), 9 deletions(-) diff --git a/net/core/devlink.c b/net/core/devlink.c index 5b8a9bdbc13d..6c05cfaa571d 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -6460,25 +6460,36 @@ nla_put_failure: #define DEVLINK_REGION_READ_CHUNK_SIZE 256 -static int devlink_nl_region_read_snapshot_fill(struct sk_buff *skb, - struct devlink_snapshot *snapshot, - u64 start_offset, - u64 end_offset, - u64 *new_offset) +typedef int devlink_chunk_fill_t(void *cb_priv, u8 *chunk, u32 chunk_size, + u64 curr_offset, + struct netlink_ext_ack *extack); + +static int +devlink_nl_region_read_fill(struct sk_buff *skb, devlink_chunk_fill_t *cb, + void *cb_priv, u64 start_offset, u64 end_offset, + u64 *new_offset, struct netlink_ext_ack *extack) { u64 curr_offset = start_offset; int err = 0; + u8 *data; + + /* Allocate and re-use a single buffer */ + data = kmalloc(DEVLINK_REGION_READ_CHUNK_SIZE, GFP_KERNEL); + if (!data) + return -ENOMEM; *new_offset = start_offset; while (curr_offset < end_offset) { u32 data_size; - u8 *data; data_size = min_t(u32, end_offset - curr_offset, DEVLINK_REGION_READ_CHUNK_SIZE); - data = &snapshot->data[curr_offset]; + err = cb(cb_priv, data, data_size, curr_offset, extack); + if (err) + break; + err = devlink_nl_cmd_region_read_chunk_fill(skb, data, data_size, curr_offset); if (err) break; @@ -6487,9 +6498,23 @@ static int devlink_nl_region_read_snapshot_fill(struct sk_buff *skb, } *new_offset = curr_offset; + kfree(data); + return err; } +static int +devlink_region_snapshot_fill(void *cb_priv, u8 *chunk, u32 chunk_size, + u64 curr_offset, + struct netlink_ext_ack __always_unused *extack) +{ + struct devlink_snapshot *snapshot = cb_priv; + + memcpy(chunk, &snapshot->data[curr_offset], chunk_size); + + return 0; +} + static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, struct netlink_callback *cb) { @@ -6608,8 +6633,9 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, goto nla_put_failure; } - err = devlink_nl_region_read_snapshot_fill(skb, snapshot, start_offset, - end_offset, &ret_offset); + err = devlink_nl_region_read_fill(skb, &devlink_region_snapshot_fill, + snapshot, start_offset, end_offset, + &ret_offset, cb->extack); if (err && err != -EMSGSIZE) goto nla_put_failure; From af6397c9ee2b42988c912dcad2fca1f43d5c1c99 Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Mon, 28 Nov 2022 12:36:44 -0800 Subject: [PATCH 6/9] 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 Reviewed-by: Jiri Pirko Signed-off-by: Jakub Kicinski --- .../networking/devlink/devlink-region.rst | 13 +++ include/net/devlink.h | 16 ++++ include/uapi/linux/devlink.h | 2 + net/core/devlink.c | 80 +++++++++++++++---- 4 files changed, 94 insertions(+), 17 deletions(-) diff --git a/Documentation/networking/devlink/devlink-region.rst b/Documentation/networking/devlink/devlink-region.rst index f06dca9a1eb6..9232cd7da301 100644 --- a/Documentation/networking/devlink/devlink-region.rst +++ b/Documentation/networking/devlink/devlink-region.rst @@ -31,6 +31,15 @@ in its ``devlink_region_ops`` structure. If snapshot id is not set in the ``DEVLINK_CMD_REGION_NEW`` request kernel will allocate one and send the snapshot information to user space. +Regions may optionally allow directly reading from their contents without a +snapshot. Direct read requests are not atomic. In particular a read request +of size 256 bytes or larger will be split into multiple chunks. If atomic +access is required, use a snapshot. A driver wishing to enable this for a +region should implement the ``.read`` callback in the ``devlink_region_ops`` +structure. User space can request a direct read by using the +``DEVLINK_ATTR_REGION_DIRECT`` attribute instead of specifying a snapshot +id. + example usage ------------- @@ -65,6 +74,10 @@ example usage $ devlink region read pci/0000:00:05.0/fw-health snapshot 1 address 0 length 16 0000000000000000 0014 95dc 0014 9514 0035 1670 0034 db30 + # Read from the region without a snapshot + $ devlink region read pci/0000:00:05.0/fw-health address 16 length 16 + 0000000000000010 0000 0000 ffff ff04 0029 8c00 0028 8cc8 + As regions are likely very device or driver specific, no generic regions are defined. See the driver-specific documentation files for information on the specific regions a driver supports. diff --git a/include/net/devlink.h b/include/net/devlink.h index 074a79b8933f..02528f736f65 100644 --- a/include/net/devlink.h +++ b/include/net/devlink.h @@ -650,6 +650,10 @@ struct devlink_info_req; * the data variable must be updated to point to the snapshot data. * The function will be called while the devlink instance lock is * held. + * @read: callback to directly read a portion of the region. On success, + * the data pointer will be updated with the contents of the + * requested portion of the region. The function will be called + * while the devlink instance lock is held. * @priv: Pointer to driver private data for the region operation */ struct devlink_region_ops { @@ -659,6 +663,10 @@ struct devlink_region_ops { const struct devlink_region_ops *ops, struct netlink_ext_ack *extack, u8 **data); + int (*read)(struct devlink *devlink, + const struct devlink_region_ops *ops, + struct netlink_ext_ack *extack, + u64 offset, u32 size, u8 *data); void *priv; }; @@ -670,6 +678,10 @@ struct devlink_region_ops { * the data variable must be updated to point to the snapshot data. * The function will be called while the devlink instance lock is * held. + * @read: callback to directly read a portion of the region. On success, + * the data pointer will be updated with the contents of the + * requested portion of the region. The function will be called + * while the devlink instance lock is held. * @priv: Pointer to driver private data for the region operation */ struct devlink_port_region_ops { @@ -679,6 +691,10 @@ struct devlink_port_region_ops { const struct devlink_port_region_ops *ops, struct netlink_ext_ack *extack, u8 **data); + int (*read)(struct devlink_port *port, + const struct devlink_port_region_ops *ops, + struct netlink_ext_ack *extack, + u64 offset, u32 size, u8 *data); void *priv; }; diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h index 498d0d5d0957..70191d96af89 100644 --- a/include/uapi/linux/devlink.h +++ b/include/uapi/linux/devlink.h @@ -610,6 +610,8 @@ enum devlink_attr { DEVLINK_ATTR_RATE_TX_PRIORITY, /* u32 */ DEVLINK_ATTR_RATE_TX_WEIGHT, /* u32 */ + DEVLINK_ATTR_REGION_DIRECT, /* flag */ + /* add new attributes above here, update the policy in devlink.c */ __DEVLINK_ATTR_MAX, 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[] = { From ed23debec5d197956fbda4ad8fad66d910c6a6b6 Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Mon, 28 Nov 2022 12:36:45 -0800 Subject: [PATCH 7/9] ice: use same function to snapshot both NVM and Shadow RAM The ice driver supports a region for both the flat NVM contents as well as the Shadow RAM which is a layer built on top of the flash during device initialization. These regions use an almost identical read function, except that the NVM needs to set the direct flag when reading, while Shadow RAM needs to read without the direct flag set. They each call ice_read_flat_nvm with the only difference being whether to set the direct flash flag. The NVM region read function also was fixed to read the NVM in blocks to avoid a situation where the firmware reclaims the lock due to taking too long. Note that the region snapshot function takes the ops pointer so the function can easily determine which region to read. Make use of this and re-use the NVM snapshot function for both the NVM and Shadow RAM regions. This makes Shadow RAM benefit from the same block approach as the NVM region. It also reduces code in the ice driver. Signed-off-by: Jacob Keller Acked-by: Jakub Kicinski Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/intel/ice/ice_devlink.c | 95 +++++--------------- 1 file changed, 23 insertions(+), 72 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_devlink.c b/drivers/net/ethernet/intel/ice/ice_devlink.c index 1d638216484d..9d3500291d2e 100644 --- a/drivers/net/ethernet/intel/ice/ice_devlink.c +++ b/drivers/net/ethernet/intel/ice/ice_devlink.c @@ -1596,21 +1596,22 @@ void ice_devlink_destroy_vf_port(struct ice_vf *vf) #define ICE_DEVLINK_READ_BLK_SIZE (1024 * 1024) +static const struct devlink_region_ops ice_nvm_region_ops; +static const struct devlink_region_ops ice_sram_region_ops; + /** * ice_devlink_nvm_snapshot - Capture a snapshot of the NVM flash contents * @devlink: the devlink instance - * @ops: the devlink region being snapshotted + * @ops: the devlink region to snapshot * @extack: extended ACK response structure * @data: on exit points to snapshot data buffer * - * This function is called in response to the DEVLINK_CMD_REGION_TRIGGER for - * the nvm-flash devlink region. It captures a snapshot of the full NVM flash - * contents, including both banks of flash. This snapshot can later be viewed - * via the devlink-region interface. + * This function is called in response to a DEVLINK_CMD_REGION_NEW for either + * the nvm-flash or shadow-ram region. * - * It captures the flash using the FLASH_ONLY bit set when reading via - * firmware, so it does not read the current Shadow RAM contents. For that, - * use the shadow-ram region. + * It captures a snapshot of the NVM or Shadow RAM flash contents. This + * snapshot can then later be viewed via the DEVLINK_CMD_REGION_READ netlink + * interface. * * @returns zero on success, and updates the data pointer. Returns a non-zero * error code on failure. @@ -1622,17 +1623,27 @@ static int ice_devlink_nvm_snapshot(struct devlink *devlink, struct ice_pf *pf = devlink_priv(devlink); struct device *dev = ice_pf_to_dev(pf); struct ice_hw *hw = &pf->hw; + bool read_shadow_ram; u8 *nvm_data, *tmp, i; u32 nvm_size, left; s8 num_blks; int status; - nvm_size = hw->flash.flash_size; + if (ops == &ice_nvm_region_ops) { + read_shadow_ram = false; + nvm_size = hw->flash.flash_size; + } else if (ops == &ice_sram_region_ops) { + read_shadow_ram = true; + nvm_size = hw->flash.sr_words * 2u; + } else { + NL_SET_ERR_MSG_MOD(extack, "Unexpected region in snapshot function"); + return -EOPNOTSUPP; + } + nvm_data = vzalloc(nvm_size); if (!nvm_data) return -ENOMEM; - num_blks = DIV_ROUND_UP(nvm_size, ICE_DEVLINK_READ_BLK_SIZE); tmp = nvm_data; left = nvm_size; @@ -1656,7 +1667,7 @@ static int ice_devlink_nvm_snapshot(struct devlink *devlink, } status = ice_read_flat_nvm(hw, i * ICE_DEVLINK_READ_BLK_SIZE, - &read_sz, tmp, false); + &read_sz, tmp, read_shadow_ram); if (status) { dev_dbg(dev, "ice_read_flat_nvm failed after reading %u bytes, err %d aq_err %d\n", read_sz, status, hw->adminq.sq_last_status); @@ -1676,66 +1687,6 @@ static int ice_devlink_nvm_snapshot(struct devlink *devlink, return 0; } -/** - * ice_devlink_sram_snapshot - Capture a snapshot of the Shadow RAM contents - * @devlink: the devlink instance - * @ops: the devlink region being snapshotted - * @extack: extended ACK response structure - * @data: on exit points to snapshot data buffer - * - * This function is called in response to the DEVLINK_CMD_REGION_TRIGGER for - * the shadow-ram devlink region. It captures a snapshot of the shadow ram - * contents. This snapshot can later be viewed via the devlink-region - * interface. - * - * @returns zero on success, and updates the data pointer. Returns a non-zero - * error code on failure. - */ -static int -ice_devlink_sram_snapshot(struct devlink *devlink, - const struct devlink_region_ops __always_unused *ops, - struct netlink_ext_ack *extack, u8 **data) -{ - struct ice_pf *pf = devlink_priv(devlink); - struct device *dev = ice_pf_to_dev(pf); - struct ice_hw *hw = &pf->hw; - u8 *sram_data; - u32 sram_size; - int err; - - sram_size = hw->flash.sr_words * 2u; - sram_data = vzalloc(sram_size); - if (!sram_data) - return -ENOMEM; - - err = ice_acquire_nvm(hw, ICE_RES_READ); - if (err) { - dev_dbg(dev, "ice_acquire_nvm failed, err %d aq_err %d\n", - err, hw->adminq.sq_last_status); - NL_SET_ERR_MSG_MOD(extack, "Failed to acquire NVM semaphore"); - vfree(sram_data); - return err; - } - - /* Read from the Shadow RAM, rather than directly from NVM */ - err = ice_read_flat_nvm(hw, 0, &sram_size, sram_data, true); - if (err) { - dev_dbg(dev, "ice_read_flat_nvm failed after reading %u bytes, err %d aq_err %d\n", - sram_size, err, hw->adminq.sq_last_status); - NL_SET_ERR_MSG_MOD(extack, - "Failed to read Shadow RAM contents"); - ice_release_nvm(hw); - vfree(sram_data); - return err; - } - - ice_release_nvm(hw); - - *data = sram_data; - - return 0; -} - /** * ice_devlink_devcaps_snapshot - Capture snapshot of device capabilities * @devlink: the devlink instance @@ -1789,7 +1740,7 @@ static const struct devlink_region_ops ice_nvm_region_ops = { static const struct devlink_region_ops ice_sram_region_ops = { .name = "shadow-ram", .destructor = vfree, - .snapshot = ice_devlink_sram_snapshot, + .snapshot = ice_devlink_nvm_snapshot, }; static const struct devlink_region_ops ice_devcaps_region_ops = { From 2d0197843f9e23c72e3c34303c3a4832bd81b3c3 Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Mon, 28 Nov 2022 12:36:46 -0800 Subject: [PATCH 8/9] ice: document 'shadow-ram' devlink region 78ad87da9978 ("ice: devlink: add shadow-ram region to snapshot Shadow RAM") added support for the 'shadow-ram' devlink region, but did not document it in the ice devlink documentation. Fix this. Signed-off-by: Jacob Keller Acked-by: Jakub Kicinski Signed-off-by: Jakub Kicinski --- Documentation/networking/devlink/ice.rst | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Documentation/networking/devlink/ice.rst b/Documentation/networking/devlink/ice.rst index 890062da7820..bcd4839fbf79 100644 --- a/Documentation/networking/devlink/ice.rst +++ b/Documentation/networking/devlink/ice.rst @@ -189,6 +189,11 @@ device data. * - ``nvm-flash`` - The contents of the entire flash chip, sometimes referred to as the device's Non Volatile Memory. + * - ``shadow-ram`` + - The contents of the Shadow RAM, which is loaded from the beginning + of the flash. Although the contents are primarily from the flash, + this area also contains data generated during device boot which is + not stored in flash. * - ``device-caps`` - The contents of the device firmware's capabilities buffer. Useful to determine the current state and configuration of the device. From 3af4b40b0f2f194d32e90cc5d25ebb3daa96cd1f Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Mon, 28 Nov 2022 12:36:47 -0800 Subject: [PATCH 9/9] ice: implement direct read for NVM and Shadow RAM regions Implement the .read handler for the NVM and Shadow RAM regions. This enables user space to read a small chunk of the flash without needing the overhead of creating a full snapshot. Update the documentation for ice to detail which regions have direct read support. Signed-off-by: Jacob Keller Acked-by: Jakub Kicinski Signed-off-by: Jakub Kicinski --- Documentation/networking/devlink/ice.rst | 8 ++- drivers/net/ethernet/intel/ice/ice_devlink.c | 69 ++++++++++++++++++++ 2 files changed, 75 insertions(+), 2 deletions(-) diff --git a/Documentation/networking/devlink/ice.rst b/Documentation/networking/devlink/ice.rst index bcd4839fbf79..625efb3777d5 100644 --- a/Documentation/networking/devlink/ice.rst +++ b/Documentation/networking/devlink/ice.rst @@ -198,8 +198,12 @@ device data. - The contents of the device firmware's capabilities buffer. Useful to determine the current state and configuration of the device. -Users can request an immediate capture of a snapshot via the -``DEVLINK_CMD_REGION_NEW`` +Both the ``nvm-flash`` and ``shadow-ram`` regions can be accessed without a +snapshot. The ``device-caps`` region requires a snapshot as the contents are +sent by firmware and can't be split into separate reads. + +Users can request an immediate capture of a snapshot for all three regions +via the ``DEVLINK_CMD_REGION_NEW`` command. .. code:: shell diff --git a/drivers/net/ethernet/intel/ice/ice_devlink.c b/drivers/net/ethernet/intel/ice/ice_devlink.c index 9d3500291d2e..946d64e577c9 100644 --- a/drivers/net/ethernet/intel/ice/ice_devlink.c +++ b/drivers/net/ethernet/intel/ice/ice_devlink.c @@ -1687,6 +1687,73 @@ static int ice_devlink_nvm_snapshot(struct devlink *devlink, return 0; } +/** + * ice_devlink_nvm_read - Read a portion of NVM flash contents + * @devlink: the devlink instance + * @ops: the devlink region to snapshot + * @extack: extended ACK response structure + * @offset: the offset to start at + * @size: the amount to read + * @data: the data buffer to read into + * + * This function is called in response to DEVLINK_CMD_REGION_READ to directly + * read a section of the NVM contents. + * + * It reads from either the nvm-flash or shadow-ram region contents. + * + * @returns zero on success, and updates the data pointer. Returns a non-zero + * error code on failure. + */ +static int ice_devlink_nvm_read(struct devlink *devlink, + const struct devlink_region_ops *ops, + struct netlink_ext_ack *extack, + u64 offset, u32 size, u8 *data) +{ + struct ice_pf *pf = devlink_priv(devlink); + struct device *dev = ice_pf_to_dev(pf); + struct ice_hw *hw = &pf->hw; + bool read_shadow_ram; + u64 nvm_size; + int status; + + if (ops == &ice_nvm_region_ops) { + read_shadow_ram = false; + nvm_size = hw->flash.flash_size; + } else if (ops == &ice_sram_region_ops) { + read_shadow_ram = true; + nvm_size = hw->flash.sr_words * 2u; + } else { + NL_SET_ERR_MSG_MOD(extack, "Unexpected region in snapshot function"); + return -EOPNOTSUPP; + } + + if (offset + size >= nvm_size) { + NL_SET_ERR_MSG_MOD(extack, "Cannot read beyond the region size"); + return -ERANGE; + } + + status = ice_acquire_nvm(hw, ICE_RES_READ); + if (status) { + dev_dbg(dev, "ice_acquire_nvm failed, err %d aq_err %d\n", + status, hw->adminq.sq_last_status); + NL_SET_ERR_MSG_MOD(extack, "Failed to acquire NVM semaphore"); + return -EIO; + } + + status = ice_read_flat_nvm(hw, (u32)offset, &size, data, + read_shadow_ram); + if (status) { + dev_dbg(dev, "ice_read_flat_nvm failed after reading %u bytes, err %d aq_err %d\n", + size, status, hw->adminq.sq_last_status); + NL_SET_ERR_MSG_MOD(extack, "Failed to read NVM contents"); + ice_release_nvm(hw); + return -EIO; + } + ice_release_nvm(hw); + + return 0; +} + /** * ice_devlink_devcaps_snapshot - Capture snapshot of device capabilities * @devlink: the devlink instance @@ -1735,12 +1802,14 @@ static const struct devlink_region_ops ice_nvm_region_ops = { .name = "nvm-flash", .destructor = vfree, .snapshot = ice_devlink_nvm_snapshot, + .read = ice_devlink_nvm_read, }; static const struct devlink_region_ops ice_sram_region_ops = { .name = "shadow-ram", .destructor = vfree, .snapshot = ice_devlink_nvm_snapshot, + .read = ice_devlink_nvm_read, }; static const struct devlink_region_ops ice_devcaps_region_ops = {