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region.c
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region.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2016 Mellanox Technologies. All rights reserved.
* Copyright (c) 2016 Jiri Pirko <[email protected]>
*/
#include "devl_internal.h"
struct devlink_region {
struct devlink *devlink;
struct devlink_port *port;
struct list_head list;
union {
const struct devlink_region_ops *ops;
const struct devlink_port_region_ops *port_ops;
};
struct mutex snapshot_lock; /* protects snapshot_list,
* max_snapshots and cur_snapshots
* consistency.
*/
struct list_head snapshot_list;
u32 max_snapshots;
u32 cur_snapshots;
u64 size;
};
struct devlink_snapshot {
struct list_head list;
struct devlink_region *region;
u8 *data;
u32 id;
};
static struct devlink_region *
devlink_region_get_by_name(struct devlink *devlink, const char *region_name)
{
struct devlink_region *region;
list_for_each_entry(region, &devlink->region_list, list)
if (!strcmp(region->ops->name, region_name))
return region;
return NULL;
}
static struct devlink_region *
devlink_port_region_get_by_name(struct devlink_port *port,
const char *region_name)
{
struct devlink_region *region;
list_for_each_entry(region, &port->region_list, list)
if (!strcmp(region->ops->name, region_name))
return region;
return NULL;
}
static struct devlink_snapshot *
devlink_region_snapshot_get_by_id(struct devlink_region *region, u32 id)
{
struct devlink_snapshot *snapshot;
list_for_each_entry(snapshot, ®ion->snapshot_list, list)
if (snapshot->id == id)
return snapshot;
return NULL;
}
static int devlink_nl_region_snapshot_id_put(struct sk_buff *msg,
struct devlink *devlink,
struct devlink_snapshot *snapshot)
{
struct nlattr *snap_attr;
int err;
snap_attr = nla_nest_start_noflag(msg, DEVLINK_ATTR_REGION_SNAPSHOT);
if (!snap_attr)
return -EINVAL;
err = nla_put_u32(msg, DEVLINK_ATTR_REGION_SNAPSHOT_ID, snapshot->id);
if (err)
goto nla_put_failure;
nla_nest_end(msg, snap_attr);
return 0;
nla_put_failure:
nla_nest_cancel(msg, snap_attr);
return err;
}
static int devlink_nl_region_snapshots_id_put(struct sk_buff *msg,
struct devlink *devlink,
struct devlink_region *region)
{
struct devlink_snapshot *snapshot;
struct nlattr *snapshots_attr;
int err;
snapshots_attr = nla_nest_start_noflag(msg,
DEVLINK_ATTR_REGION_SNAPSHOTS);
if (!snapshots_attr)
return -EINVAL;
list_for_each_entry(snapshot, ®ion->snapshot_list, list) {
err = devlink_nl_region_snapshot_id_put(msg, devlink, snapshot);
if (err)
goto nla_put_failure;
}
nla_nest_end(msg, snapshots_attr);
return 0;
nla_put_failure:
nla_nest_cancel(msg, snapshots_attr);
return err;
}
static int devlink_nl_region_fill(struct sk_buff *msg, struct devlink *devlink,
enum devlink_command cmd, u32 portid,
u32 seq, int flags,
struct devlink_region *region)
{
void *hdr;
int err;
hdr = genlmsg_put(msg, portid, seq, &devlink_nl_family, flags, cmd);
if (!hdr)
return -EMSGSIZE;
err = devlink_nl_put_handle(msg, devlink);
if (err)
goto nla_put_failure;
if (region->port) {
err = nla_put_u32(msg, DEVLINK_ATTR_PORT_INDEX,
region->port->index);
if (err)
goto nla_put_failure;
}
err = nla_put_string(msg, DEVLINK_ATTR_REGION_NAME, region->ops->name);
if (err)
goto nla_put_failure;
err = nla_put_u64_64bit(msg, DEVLINK_ATTR_REGION_SIZE,
region->size,
DEVLINK_ATTR_PAD);
if (err)
goto nla_put_failure;
err = nla_put_u32(msg, DEVLINK_ATTR_REGION_MAX_SNAPSHOTS,
region->max_snapshots);
if (err)
goto nla_put_failure;
err = devlink_nl_region_snapshots_id_put(msg, devlink, region);
if (err)
goto nla_put_failure;
genlmsg_end(msg, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
return err;
}
static struct sk_buff *
devlink_nl_region_notify_build(struct devlink_region *region,
struct devlink_snapshot *snapshot,
enum devlink_command cmd, u32 portid, u32 seq)
{
struct devlink *devlink = region->devlink;
struct sk_buff *msg;
void *hdr;
int err;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return ERR_PTR(-ENOMEM);
hdr = genlmsg_put(msg, portid, seq, &devlink_nl_family, 0, cmd);
if (!hdr) {
err = -EMSGSIZE;
goto out_free_msg;
}
err = devlink_nl_put_handle(msg, devlink);
if (err)
goto out_cancel_msg;
if (region->port) {
err = nla_put_u32(msg, DEVLINK_ATTR_PORT_INDEX,
region->port->index);
if (err)
goto out_cancel_msg;
}
err = nla_put_string(msg, DEVLINK_ATTR_REGION_NAME,
region->ops->name);
if (err)
goto out_cancel_msg;
if (snapshot) {
err = nla_put_u32(msg, DEVLINK_ATTR_REGION_SNAPSHOT_ID,
snapshot->id);
if (err)
goto out_cancel_msg;
} else {
err = nla_put_u64_64bit(msg, DEVLINK_ATTR_REGION_SIZE,
region->size, DEVLINK_ATTR_PAD);
if (err)
goto out_cancel_msg;
}
genlmsg_end(msg, hdr);
return msg;
out_cancel_msg:
genlmsg_cancel(msg, hdr);
out_free_msg:
nlmsg_free(msg);
return ERR_PTR(err);
}
static void devlink_nl_region_notify(struct devlink_region *region,
struct devlink_snapshot *snapshot,
enum devlink_command cmd)
{
struct devlink *devlink = region->devlink;
struct sk_buff *msg;
WARN_ON(cmd != DEVLINK_CMD_REGION_NEW && cmd != DEVLINK_CMD_REGION_DEL);
if (!__devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
return;
msg = devlink_nl_region_notify_build(region, snapshot, cmd, 0, 0);
if (IS_ERR(msg))
return;
devlink_nl_notify_send(devlink, msg);
}
void devlink_regions_notify_register(struct devlink *devlink)
{
struct devlink_region *region;
list_for_each_entry(region, &devlink->region_list, list)
devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_NEW);
}
void devlink_regions_notify_unregister(struct devlink *devlink)
{
struct devlink_region *region;
list_for_each_entry_reverse(region, &devlink->region_list, list)
devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_DEL);
}
/**
* __devlink_snapshot_id_increment - Increment number of snapshots using an id
* @devlink: devlink instance
* @id: the snapshot id
*
* Track when a new snapshot begins using an id. Load the count for the
* given id from the snapshot xarray, increment it, and store it back.
*
* Called when a new snapshot is created with the given id.
*
* The id *must* have been previously allocated by
* devlink_region_snapshot_id_get().
*
* Returns 0 on success, or an error on failure.
*/
static int __devlink_snapshot_id_increment(struct devlink *devlink, u32 id)
{
unsigned long count;
void *p;
int err;
xa_lock(&devlink->snapshot_ids);
p = xa_load(&devlink->snapshot_ids, id);
if (WARN_ON(!p)) {
err = -EINVAL;
goto unlock;
}
if (WARN_ON(!xa_is_value(p))) {
err = -EINVAL;
goto unlock;
}
count = xa_to_value(p);
count++;
err = xa_err(__xa_store(&devlink->snapshot_ids, id, xa_mk_value(count),
GFP_ATOMIC));
unlock:
xa_unlock(&devlink->snapshot_ids);
return err;
}
/**
* __devlink_snapshot_id_decrement - Decrease number of snapshots using an id
* @devlink: devlink instance
* @id: the snapshot id
*
* Track when a snapshot is deleted and stops using an id. Load the count
* for the given id from the snapshot xarray, decrement it, and store it
* back.
*
* If the count reaches zero, erase this id from the xarray, freeing it
* up for future re-use by devlink_region_snapshot_id_get().
*
* Called when a snapshot using the given id is deleted, and when the
* initial allocator of the id is finished using it.
*/
static void __devlink_snapshot_id_decrement(struct devlink *devlink, u32 id)
{
unsigned long count;
void *p;
xa_lock(&devlink->snapshot_ids);
p = xa_load(&devlink->snapshot_ids, id);
if (WARN_ON(!p))
goto unlock;
if (WARN_ON(!xa_is_value(p)))
goto unlock;
count = xa_to_value(p);
if (count > 1) {
count--;
__xa_store(&devlink->snapshot_ids, id, xa_mk_value(count),
GFP_ATOMIC);
} else {
/* If this was the last user, we can erase this id */
__xa_erase(&devlink->snapshot_ids, id);
}
unlock:
xa_unlock(&devlink->snapshot_ids);
}
/**
* __devlink_snapshot_id_insert - Insert a specific snapshot ID
* @devlink: devlink instance
* @id: the snapshot id
*
* Mark the given snapshot id as used by inserting a zero value into the
* snapshot xarray.
*
* This must be called while holding the devlink instance lock. Unlike
* devlink_snapshot_id_get, the initial reference count is zero, not one.
* It is expected that the id will immediately be used before
* releasing the devlink instance lock.
*
* Returns zero on success, or an error code if the snapshot id could not
* be inserted.
*/
static int __devlink_snapshot_id_insert(struct devlink *devlink, u32 id)
{
int err;
xa_lock(&devlink->snapshot_ids);
if (xa_load(&devlink->snapshot_ids, id)) {
xa_unlock(&devlink->snapshot_ids);
return -EEXIST;
}
err = xa_err(__xa_store(&devlink->snapshot_ids, id, xa_mk_value(0),
GFP_ATOMIC));
xa_unlock(&devlink->snapshot_ids);
return err;
}
/**
* __devlink_region_snapshot_id_get - get snapshot ID
* @devlink: devlink instance
* @id: storage to return snapshot id
*
* Allocates a new snapshot id. Returns zero on success, or a negative
* error on failure. Must be called while holding the devlink instance
* lock.
*
* Snapshot IDs are tracked using an xarray which stores the number of
* users of the snapshot id.
*
* Note that the caller of this function counts as a 'user', in order to
* avoid race conditions. The caller must release its hold on the
* snapshot by using devlink_region_snapshot_id_put.
*/
static int __devlink_region_snapshot_id_get(struct devlink *devlink, u32 *id)
{
return xa_alloc(&devlink->snapshot_ids, id, xa_mk_value(1),
xa_limit_32b, GFP_KERNEL);
}
/**
* __devlink_region_snapshot_create - create a new snapshot
* This will add a new snapshot of a region. The snapshot
* will be stored on the region struct and can be accessed
* from devlink. This is useful for future analyses of snapshots.
* Multiple snapshots can be created on a region.
* The @snapshot_id should be obtained using the getter function.
*
* Must be called only while holding the region snapshot lock.
*
* @region: devlink region of the snapshot
* @data: snapshot data
* @snapshot_id: snapshot id to be created
*/
static int
__devlink_region_snapshot_create(struct devlink_region *region,
u8 *data, u32 snapshot_id)
{
struct devlink *devlink = region->devlink;
struct devlink_snapshot *snapshot;
int err;
lockdep_assert_held(®ion->snapshot_lock);
/* check if region can hold one more snapshot */
if (region->cur_snapshots == region->max_snapshots)
return -ENOSPC;
if (devlink_region_snapshot_get_by_id(region, snapshot_id))
return -EEXIST;
snapshot = kzalloc(sizeof(*snapshot), GFP_KERNEL);
if (!snapshot)
return -ENOMEM;
err = __devlink_snapshot_id_increment(devlink, snapshot_id);
if (err)
goto err_snapshot_id_increment;
snapshot->id = snapshot_id;
snapshot->region = region;
snapshot->data = data;
list_add_tail(&snapshot->list, ®ion->snapshot_list);
region->cur_snapshots++;
devlink_nl_region_notify(region, snapshot, DEVLINK_CMD_REGION_NEW);
return 0;
err_snapshot_id_increment:
kfree(snapshot);
return err;
}
static void devlink_region_snapshot_del(struct devlink_region *region,
struct devlink_snapshot *snapshot)
{
struct devlink *devlink = region->devlink;
lockdep_assert_held(®ion->snapshot_lock);
devlink_nl_region_notify(region, snapshot, DEVLINK_CMD_REGION_DEL);
region->cur_snapshots--;
list_del(&snapshot->list);
region->ops->destructor(snapshot->data);
__devlink_snapshot_id_decrement(devlink, snapshot->id);
kfree(snapshot);
}
int devlink_nl_region_get_doit(struct sk_buff *skb, struct genl_info *info)
{
struct devlink *devlink = info->user_ptr[0];
struct devlink_port *port = NULL;
struct devlink_region *region;
const char *region_name;
struct sk_buff *msg;
unsigned int index;
int err;
if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_REGION_NAME))
return -EINVAL;
if (info->attrs[DEVLINK_ATTR_PORT_INDEX]) {
index = nla_get_u32(info->attrs[DEVLINK_ATTR_PORT_INDEX]);
port = devlink_port_get_by_index(devlink, index);
if (!port)
return -ENODEV;
}
region_name = nla_data(info->attrs[DEVLINK_ATTR_REGION_NAME]);
if (port)
region = devlink_port_region_get_by_name(port, region_name);
else
region = devlink_region_get_by_name(devlink, region_name);
if (!region)
return -EINVAL;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
err = devlink_nl_region_fill(msg, devlink, DEVLINK_CMD_REGION_GET,
info->snd_portid, info->snd_seq, 0,
region);
if (err) {
nlmsg_free(msg);
return err;
}
return genlmsg_reply(msg, info);
}
static int devlink_nl_cmd_region_get_port_dumpit(struct sk_buff *msg,
struct netlink_callback *cb,
struct devlink_port *port,
int *idx, int start, int flags)
{
struct devlink_region *region;
int err = 0;
list_for_each_entry(region, &port->region_list, list) {
if (*idx < start) {
(*idx)++;
continue;
}
err = devlink_nl_region_fill(msg, port->devlink,
DEVLINK_CMD_REGION_GET,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
flags, region);
if (err)
goto out;
(*idx)++;
}
out:
return err;
}
static int devlink_nl_region_get_dump_one(struct sk_buff *msg,
struct devlink *devlink,
struct netlink_callback *cb,
int flags)
{
struct devlink_nl_dump_state *state = devlink_dump_state(cb);
struct devlink_region *region;
struct devlink_port *port;
unsigned long port_index;
int idx = 0;
int err;
list_for_each_entry(region, &devlink->region_list, list) {
if (idx < state->idx) {
idx++;
continue;
}
err = devlink_nl_region_fill(msg, devlink,
DEVLINK_CMD_REGION_GET,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, flags,
region);
if (err) {
state->idx = idx;
return err;
}
idx++;
}
xa_for_each(&devlink->ports, port_index, port) {
err = devlink_nl_cmd_region_get_port_dumpit(msg, cb, port, &idx,
state->idx, flags);
if (err) {
state->idx = idx;
return err;
}
}
return 0;
}
int devlink_nl_region_get_dumpit(struct sk_buff *skb,
struct netlink_callback *cb)
{
return devlink_nl_dumpit(skb, cb, devlink_nl_region_get_dump_one);
}
int devlink_nl_region_del_doit(struct sk_buff *skb, struct genl_info *info)
{
struct devlink *devlink = info->user_ptr[0];
struct devlink_snapshot *snapshot;
struct devlink_port *port = NULL;
struct devlink_region *region;
const char *region_name;
unsigned int index;
u32 snapshot_id;
if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_REGION_NAME) ||
GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_REGION_SNAPSHOT_ID))
return -EINVAL;
region_name = nla_data(info->attrs[DEVLINK_ATTR_REGION_NAME]);
snapshot_id = nla_get_u32(info->attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID]);
if (info->attrs[DEVLINK_ATTR_PORT_INDEX]) {
index = nla_get_u32(info->attrs[DEVLINK_ATTR_PORT_INDEX]);
port = devlink_port_get_by_index(devlink, index);
if (!port)
return -ENODEV;
}
if (port)
region = devlink_port_region_get_by_name(port, region_name);
else
region = devlink_region_get_by_name(devlink, region_name);
if (!region)
return -EINVAL;
mutex_lock(®ion->snapshot_lock);
snapshot = devlink_region_snapshot_get_by_id(region, snapshot_id);
if (!snapshot) {
mutex_unlock(®ion->snapshot_lock);
return -EINVAL;
}
devlink_region_snapshot_del(region, snapshot);
mutex_unlock(®ion->snapshot_lock);
return 0;
}
int devlink_nl_region_new_doit(struct sk_buff *skb, struct genl_info *info)
{
struct devlink *devlink = info->user_ptr[0];
struct devlink_snapshot *snapshot;
struct devlink_port *port = NULL;
struct nlattr *snapshot_id_attr;
struct devlink_region *region;
const char *region_name;
unsigned int index;
u32 snapshot_id;
u8 *data;
int err;
if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_REGION_NAME)) {
NL_SET_ERR_MSG(info->extack, "No region name provided");
return -EINVAL;
}
region_name = nla_data(info->attrs[DEVLINK_ATTR_REGION_NAME]);
if (info->attrs[DEVLINK_ATTR_PORT_INDEX]) {
index = nla_get_u32(info->attrs[DEVLINK_ATTR_PORT_INDEX]);
port = devlink_port_get_by_index(devlink, index);
if (!port)
return -ENODEV;
}
if (port)
region = devlink_port_region_get_by_name(port, region_name);
else
region = devlink_region_get_by_name(devlink, region_name);
if (!region) {
NL_SET_ERR_MSG(info->extack, "The requested region does not exist");
return -EINVAL;
}
if (!region->ops->snapshot) {
NL_SET_ERR_MSG(info->extack, "The requested region does not support taking an immediate snapshot");
return -EOPNOTSUPP;
}
mutex_lock(®ion->snapshot_lock);
if (region->cur_snapshots == region->max_snapshots) {
NL_SET_ERR_MSG(info->extack, "The region has reached the maximum number of stored snapshots");
err = -ENOSPC;
goto unlock;
}
snapshot_id_attr = info->attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID];
if (snapshot_id_attr) {
snapshot_id = nla_get_u32(snapshot_id_attr);
if (devlink_region_snapshot_get_by_id(region, snapshot_id)) {
NL_SET_ERR_MSG(info->extack, "The requested snapshot id is already in use");
err = -EEXIST;
goto unlock;
}
err = __devlink_snapshot_id_insert(devlink, snapshot_id);
if (err)
goto unlock;
} else {
err = __devlink_region_snapshot_id_get(devlink, &snapshot_id);
if (err) {
NL_SET_ERR_MSG(info->extack, "Failed to allocate a new snapshot id");
goto unlock;
}
}
if (port)
err = region->port_ops->snapshot(port, region->port_ops,
info->extack, &data);
else
err = region->ops->snapshot(devlink, region->ops,
info->extack, &data);
if (err)
goto err_snapshot_capture;
err = __devlink_region_snapshot_create(region, data, snapshot_id);
if (err)
goto err_snapshot_create;
if (!snapshot_id_attr) {
struct sk_buff *msg;
snapshot = devlink_region_snapshot_get_by_id(region,
snapshot_id);
if (WARN_ON(!snapshot)) {
err = -EINVAL;
goto unlock;
}
msg = devlink_nl_region_notify_build(region, snapshot,
DEVLINK_CMD_REGION_NEW,
info->snd_portid,
info->snd_seq);
err = PTR_ERR_OR_ZERO(msg);
if (err)
goto err_notify;
err = genlmsg_reply(msg, info);
if (err)
goto err_notify;
}
mutex_unlock(®ion->snapshot_lock);
return 0;
err_snapshot_create:
region->ops->destructor(data);
err_snapshot_capture:
__devlink_snapshot_id_decrement(devlink, snapshot_id);
mutex_unlock(®ion->snapshot_lock);
return err;
err_notify:
devlink_region_snapshot_del(region, snapshot);
unlock:
mutex_unlock(®ion->snapshot_lock);
return err;
}
static int devlink_nl_cmd_region_read_chunk_fill(struct sk_buff *msg,
u8 *chunk, u32 chunk_size,
u64 addr)
{
struct nlattr *chunk_attr;
int err;
chunk_attr = nla_nest_start_noflag(msg, DEVLINK_ATTR_REGION_CHUNK);
if (!chunk_attr)
return -EINVAL;
err = nla_put(msg, DEVLINK_ATTR_REGION_CHUNK_DATA, chunk_size, chunk);
if (err)
goto nla_put_failure;
err = nla_put_u64_64bit(msg, DEVLINK_ATTR_REGION_CHUNK_ADDR, addr,
DEVLINK_ATTR_PAD);
if (err)
goto nla_put_failure;
nla_nest_end(msg, chunk_attr);
return 0;
nla_put_failure:
nla_nest_cancel(msg, chunk_attr);
return err;
}
#define DEVLINK_REGION_READ_CHUNK_SIZE 256
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;
data_size = min_t(u32, end_offset - curr_offset,
DEVLINK_REGION_READ_CHUNK_SIZE);
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;
curr_offset += data_size;
}
*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_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);
}
int devlink_nl_region_read_dumpit(struct sk_buff *skb,
struct netlink_callback *cb)
{
const struct genl_dumpit_info *info = genl_dumpit_info(cb);
struct devlink_nl_dump_state *state = devlink_dump_state(cb);
struct nlattr *chunks_attr, *region_attr, *snapshot_attr;
u64 ret_offset, start_offset, end_offset = U64_MAX;
struct nlattr **attrs = info->info.attrs;
struct devlink_port *port = NULL;
devlink_chunk_fill_t *region_cb;
struct devlink_region *region;
const char *region_name;
struct devlink *devlink;
unsigned int index;
void *region_cb_priv;
void *hdr;
int err;
start_offset = state->start_offset;
devlink = devlink_get_from_attrs_lock(sock_net(cb->skb->sk), attrs,
false);
if (IS_ERR(devlink))
return PTR_ERR(devlink);
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_PORT_INDEX]) {
index = nla_get_u32(attrs[DEVLINK_ATTR_PORT_INDEX]);
port = devlink_port_get_by_index(devlink, index);
if (!port) {
err = -ENODEV;
goto out_unlock;
}
}
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);
else
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;
}
snapshot_attr = attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID];
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] &&
attrs[DEVLINK_ATTR_REGION_CHUNK_LEN]) {
if (!start_offset)
start_offset =
nla_get_u64(attrs[DEVLINK_ATTR_REGION_CHUNK_ADDR]);
end_offset = nla_get_u64(attrs[DEVLINK_ATTR_REGION_CHUNK_ADDR]);
end_offset += nla_get_u64(attrs[DEVLINK_ATTR_REGION_CHUNK_LEN]);
}
if (end_offset > region->size)
end_offset = region->size;
/* return 0 if there is no further data to read */
if (start_offset == end_offset) {
err = 0;
goto out_unlock;
}
hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
&devlink_nl_family, NLM_F_ACK | NLM_F_MULTI,
DEVLINK_CMD_REGION_READ);
if (!hdr) {
err = -EMSGSIZE;
goto out_unlock;
}
err = devlink_nl_put_handle(skb, devlink);
if (err)
goto nla_put_failure;
if (region->port) {
err = nla_put_u32(skb, DEVLINK_ATTR_PORT_INDEX,
region->port->index);
if (err)
goto nla_put_failure;
}
err = nla_put_string(skb, DEVLINK_ATTR_REGION_NAME, region_name);
if (err)