--- /dev/null
+From: Carl Huang <cjhuang@codeaurora.org>
+Date: Thu, 3 Dec 2020 05:37:26 -0500
+Subject: [PATCH] nl80211: add common API to configure SAR power limitations
+
+NL80211_CMD_SET_SAR_SPECS is added to configure SAR from
+user space. NL80211_ATTR_SAR_SPEC is used to pass the SAR
+power specification when used with NL80211_CMD_SET_SAR_SPECS.
+
+Wireless driver needs to register SAR type, supported frequency
+ranges to wiphy, so user space can query it. The index in
+frequency range is used to specify which sub band the power
+limitation applies to. The SAR type is for compatibility, so later
+other SAR mechanism can be implemented without breaking the user
+space SAR applications.
+
+Normal process is user space queries the SAR capability, and
+gets the index of supported frequency ranges and associates the
+power limitation with this index and sends to kernel.
+
+Here is an example of message send to kernel:
+8c 00 00 00 08 00 01 00 00 00 00 00 38 00 2b 81
+08 00 01 00 00 00 00 00 2c 00 02 80 14 00 00 80
+08 00 02 00 00 00 00 00 08 00 01 00 38 00 00 00
+14 00 01 80 08 00 02 00 01 00 00 00 08 00 01 00
+48 00 00 00
+
+NL80211_CMD_SET_SAR_SPECS: 0x8c
+NL80211_ATTR_WIPHY: 0x01(phy idx is 0)
+NL80211_ATTR_SAR_SPEC: 0x812b (NLA_NESTED)
+NL80211_SAR_ATTR_TYPE: 0x00 (NL80211_SAR_TYPE_POWER)
+NL80211_SAR_ATTR_SPECS: 0x8002 (NLA_NESTED)
+freq range 0 power: 0x38 in 0.25dbm unit (14dbm)
+freq range 1 power: 0x48 in 0.25dbm unit (18dbm)
+
+Signed-off-by: Carl Huang <cjhuang@codeaurora.org>
+Reviewed-by: Brian Norris <briannorris@chromium.org>
+Reviewed-by: Abhishek Kumar <kuabhs@chromium.org>
+Link: https://lore.kernel.org/r/20201203103728.3034-2-cjhuang@codeaurora.org
+[minor edits, NLA parse cleanups]
+Signed-off-by: Johannes Berg <johannes.berg@intel.com>
+---
+
+--- a/include/net/cfg80211.h
++++ b/include/net/cfg80211.h
+@@ -1737,6 +1737,54 @@ struct station_info {
+ u8 connected_to_as;
+ };
+
++/**
++ * struct cfg80211_sar_sub_specs - sub specs limit
++ * @power: power limitation in 0.25dbm
++ * @freq_range_index: index the power limitation applies to
++ */
++struct cfg80211_sar_sub_specs {
++ s32 power;
++ u32 freq_range_index;
++};
++
++/**
++ * struct cfg80211_sar_specs - sar limit specs
++ * @type: it's set with power in 0.25dbm or other types
++ * @num_sub_specs: number of sar sub specs
++ * @sub_specs: memory to hold the sar sub specs
++ */
++struct cfg80211_sar_specs {
++ enum nl80211_sar_type type;
++ u32 num_sub_specs;
++ struct cfg80211_sar_sub_specs sub_specs[];
++};
++
++
++/**
++ * @struct cfg80211_sar_chan_ranges - sar frequency ranges
++ * @start_freq: start range edge frequency
++ * @end_freq: end range edge frequency
++ */
++struct cfg80211_sar_freq_ranges {
++ u32 start_freq;
++ u32 end_freq;
++};
++
++/**
++ * struct cfg80211_sar_capa - sar limit capability
++ * @type: it's set via power in 0.25dbm or other types
++ * @num_freq_ranges: number of frequency ranges
++ * @freq_ranges: memory to hold the freq ranges.
++ *
++ * Note: WLAN driver may append new ranges or split an existing
++ * range to small ones and then append them.
++ */
++struct cfg80211_sar_capa {
++ enum nl80211_sar_type type;
++ u32 num_freq_ranges;
++ const struct cfg80211_sar_freq_ranges *freq_ranges;
++};
++
+ #if IS_ENABLED(CPTCFG_CFG80211)
+ /**
+ * cfg80211_get_station - retrieve information about a given station
+@@ -4259,6 +4307,8 @@ struct cfg80211_ops {
+ struct cfg80211_tid_config *tid_conf);
+ int (*reset_tid_config)(struct wiphy *wiphy, struct net_device *dev,
+ const u8 *peer, u8 tids);
++ int (*set_sar_specs)(struct wiphy *wiphy,
++ struct cfg80211_sar_specs *sar);
+ };
+
+ /*
+@@ -5030,6 +5080,8 @@ struct wiphy {
+
+ u8 max_data_retry_count;
+
++ const struct cfg80211_sar_capa *sar_capa;
++
+ char priv[] __aligned(NETDEV_ALIGN);
+ };
+
+--- a/net/wireless/nl80211.c
++++ b/net/wireless/nl80211.c
+@@ -405,6 +405,18 @@ nl80211_unsol_bcast_probe_resp_policy[NL
+ .len = IEEE80211_MAX_DATA_LEN }
+ };
+
++static const struct nla_policy
++sar_specs_policy[NL80211_SAR_ATTR_SPECS_MAX + 1] = {
++ [NL80211_SAR_ATTR_SPECS_POWER] = { .type = NLA_S32 },
++ [NL80211_SAR_ATTR_SPECS_RANGE_INDEX] = {.type = NLA_U32 },
++};
++
++static const struct nla_policy
++sar_policy[NL80211_SAR_ATTR_MAX + 1] = {
++ [NL80211_SAR_ATTR_TYPE] = NLA_POLICY_MAX(NLA_U32, NUM_NL80211_SAR_TYPE),
++ [NL80211_SAR_ATTR_SPECS] = NLA_POLICY_NESTED_ARRAY(sar_specs_policy),
++};
++
+ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
+ [0] = { .strict_start_type = NL80211_ATTR_HE_OBSS_PD },
+ [NL80211_ATTR_WIPHY] = { .type = NLA_U32 },
+@@ -739,6 +751,7 @@ static const struct nla_policy nl80211_p
+ [NL80211_ATTR_SAE_PWE] =
+ NLA_POLICY_RANGE(NLA_U8, NL80211_SAE_PWE_HUNT_AND_PECK,
+ NL80211_SAE_PWE_BOTH),
++ [NL80211_ATTR_SAR_SPEC] = NLA_POLICY_NESTED(sar_policy),
+ [NL80211_ATTR_RECONNECT_REQUESTED] = { .type = NLA_REJECT },
+ };
+
+@@ -2117,6 +2130,56 @@ fail:
+ return -ENOBUFS;
+ }
+
++static int
++nl80211_put_sar_specs(struct cfg80211_registered_device *rdev,
++ struct sk_buff *msg)
++{
++ struct nlattr *sar_capa, *specs, *sub_freq_range;
++ u8 num_freq_ranges;
++ int i;
++
++ if (!rdev->wiphy.sar_capa)
++ return 0;
++
++ num_freq_ranges = rdev->wiphy.sar_capa->num_freq_ranges;
++
++ sar_capa = nla_nest_start(msg, NL80211_ATTR_SAR_SPEC);
++ if (!sar_capa)
++ return -ENOSPC;
++
++ if (nla_put_u32(msg, NL80211_SAR_ATTR_TYPE, rdev->wiphy.sar_capa->type))
++ goto fail;
++
++ specs = nla_nest_start(msg, NL80211_SAR_ATTR_SPECS);
++ if (!specs)
++ goto fail;
++
++ /* report supported freq_ranges */
++ for (i = 0; i < num_freq_ranges; i++) {
++ sub_freq_range = nla_nest_start(msg, i + 1);
++ if (!sub_freq_range)
++ goto fail;
++
++ if (nla_put_u32(msg, NL80211_SAR_ATTR_SPECS_START_FREQ,
++ rdev->wiphy.sar_capa->freq_ranges[i].start_freq))
++ goto fail;
++
++ if (nla_put_u32(msg, NL80211_SAR_ATTR_SPECS_END_FREQ,
++ rdev->wiphy.sar_capa->freq_ranges[i].end_freq))
++ goto fail;
++
++ nla_nest_end(msg, sub_freq_range);
++ }
++
++ nla_nest_end(msg, specs);
++ nla_nest_end(msg, sar_capa);
++
++ return 0;
++fail:
++ nla_nest_cancel(msg, sar_capa);
++ return -ENOBUFS;
++}
++
+ struct nl80211_dump_wiphy_state {
+ s64 filter_wiphy;
+ long start;
+@@ -2366,6 +2429,8 @@ static int nl80211_send_wiphy(struct cfg
+ CMD(set_multicast_to_unicast, SET_MULTICAST_TO_UNICAST);
+ CMD(update_connect_params, UPDATE_CONNECT_PARAMS);
+ CMD(update_ft_ies, UPDATE_FT_IES);
++ if (rdev->wiphy.sar_capa)
++ CMD(set_sar_specs, SET_SAR_SPECS);
+ }
+ #undef CMD
+
+@@ -2691,6 +2756,11 @@ static int nl80211_send_wiphy(struct cfg
+
+ if (nl80211_put_tid_config_support(rdev, msg))
+ goto nla_put_failure;
++ state->split_start++;
++ break;
++ case 16:
++ if (nl80211_put_sar_specs(rdev, msg))
++ goto nla_put_failure;
+
+ /* done */
+ state->split_start = 0;
+@@ -14713,6 +14783,111 @@ static void nl80211_post_doit(__genl_con
+ }
+ }
+
++static int nl80211_set_sar_sub_specs(struct cfg80211_registered_device *rdev,
++ struct cfg80211_sar_specs *sar_specs,
++ struct nlattr *spec[], int index)
++{
++ u32 range_index, i;
++
++ if (!sar_specs || !spec)
++ return -EINVAL;
++
++ if (!spec[NL80211_SAR_ATTR_SPECS_POWER] ||
++ !spec[NL80211_SAR_ATTR_SPECS_RANGE_INDEX])
++ return -EINVAL;
++
++ range_index = nla_get_u32(spec[NL80211_SAR_ATTR_SPECS_RANGE_INDEX]);
++
++ /* check if range_index exceeds num_freq_ranges */
++ if (range_index >= rdev->wiphy.sar_capa->num_freq_ranges)
++ return -EINVAL;
++
++ /* check if range_index duplicates */
++ for (i = 0; i < index; i++) {
++ if (sar_specs->sub_specs[i].freq_range_index == range_index)
++ return -EINVAL;
++ }
++
++ sar_specs->sub_specs[index].power =
++ nla_get_s32(spec[NL80211_SAR_ATTR_SPECS_POWER]);
++
++ sar_specs->sub_specs[index].freq_range_index = range_index;
++
++ return 0;
++}
++
++static int nl80211_set_sar_specs(struct sk_buff *skb, struct genl_info *info)
++{
++ struct cfg80211_registered_device *rdev = info->user_ptr[0];
++ struct nlattr *spec[NL80211_SAR_ATTR_SPECS_MAX + 1];
++ struct nlattr *tb[NL80211_SAR_ATTR_MAX + 1];
++ struct cfg80211_sar_specs *sar_spec;
++ enum nl80211_sar_type type;
++ struct nlattr *spec_list;
++ u32 specs;
++ int rem, err;
++
++ if (!rdev->wiphy.sar_capa || !rdev->ops->set_sar_specs)
++ return -EOPNOTSUPP;
++
++ if (!info->attrs[NL80211_ATTR_SAR_SPEC])
++ return -EINVAL;
++
++ nla_parse_nested(tb, NL80211_SAR_ATTR_MAX,
++ info->attrs[NL80211_ATTR_SAR_SPEC],
++ NULL, NULL);
++
++ if (!tb[NL80211_SAR_ATTR_TYPE] || !tb[NL80211_SAR_ATTR_SPECS])
++ return -EINVAL;
++
++ type = nla_get_u32(tb[NL80211_SAR_ATTR_TYPE]);
++ if (type != rdev->wiphy.sar_capa->type)
++ return -EINVAL;
++
++ specs = 0;
++ nla_for_each_nested(spec_list, tb[NL80211_SAR_ATTR_SPECS], rem)
++ specs++;
++
++ if (specs > rdev->wiphy.sar_capa->num_freq_ranges)
++ return -EINVAL;
++
++ sar_spec = kzalloc(sizeof(*sar_spec) +
++ specs * sizeof(struct cfg80211_sar_sub_specs),
++ GFP_KERNEL);
++ if (!sar_spec)
++ return -ENOMEM;
++
++ sar_spec->type = type;
++ specs = 0;
++ nla_for_each_nested(spec_list, tb[NL80211_SAR_ATTR_SPECS], rem) {
++ nla_parse_nested(spec, NL80211_SAR_ATTR_SPECS_MAX,
++ spec_list, NULL, NULL);
++
++ switch (type) {
++ case NL80211_SAR_TYPE_POWER:
++ if (nl80211_set_sar_sub_specs(rdev, sar_spec,
++ spec, specs)) {
++ err = -EINVAL;
++ goto error;
++ }
++ break;
++ default:
++ err = -EINVAL;
++ goto error;
++ }
++ specs++;
++ }
++
++ sar_spec->num_sub_specs = specs;
++
++ rdev->cur_cmd_info = info;
++ err = rdev_set_sar_specs(rdev, sar_spec);
++ rdev->cur_cmd_info = NULL;
++error:
++ kfree(sar_spec);
++ return err;
++}
++
+ static __genl_const struct genl_ops nl80211_ops[] = {
+ {
+ .cmd = NL80211_CMD_GET_WIPHY,
+@@ -15576,6 +15751,14 @@ static const struct genl_small_ops nl802
+ .internal_flags = NL80211_FLAG_NEED_NETDEV |
+ NL80211_FLAG_NEED_RTNL,
+ },
++ {
++ .cmd = NL80211_CMD_SET_SAR_SPECS,
++ .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
++ .doit = nl80211_set_sar_specs,
++ .flags = GENL_UNS_ADMIN_PERM,
++ .internal_flags = NL80211_FLAG_NEED_WIPHY |
++ NL80211_FLAG_NEED_RTNL,
++ },
+ };
+
+ static struct genl_family nl80211_fam __genl_ro_after_init = {
+--- a/net/wireless/rdev-ops.h
++++ b/net/wireless/rdev-ops.h
+@@ -1356,4 +1356,16 @@ static inline int rdev_reset_tid_config(
+ return ret;
+ }
+
++static inline int rdev_set_sar_specs(struct cfg80211_registered_device *rdev,
++ struct cfg80211_sar_specs *sar)
++{
++ int ret;
++
++ trace_rdev_set_sar_specs(&rdev->wiphy, sar);
++ ret = rdev->ops->set_sar_specs(&rdev->wiphy, sar);
++ trace_rdev_return_int(&rdev->wiphy, ret);
++
++ return ret;
++}
++
+ #endif /* __CFG80211_RDEV_OPS */
+--- a/net/wireless/trace.h
++++ b/net/wireless/trace.h
+@@ -3551,6 +3551,25 @@ TRACE_EVENT(rdev_reset_tid_config,
+ TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", peer: " MAC_PR_FMT ", tids: 0x%x",
+ WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(peer), __entry->tids)
+ );
++
++TRACE_EVENT(rdev_set_sar_specs,
++ TP_PROTO(struct wiphy *wiphy, struct cfg80211_sar_specs *sar),
++ TP_ARGS(wiphy, sar),
++ TP_STRUCT__entry(
++ WIPHY_ENTRY
++ __field(u16, type)
++ __field(u16, num)
++ ),
++ TP_fast_assign(
++ WIPHY_ASSIGN;
++ __entry->type = sar->type;
++ __entry->num = sar->num_sub_specs;
++
++ ),
++ TP_printk(WIPHY_PR_FMT ", Set type:%d, num_specs:%d",
++ WIPHY_PR_ARG, __entry->type, __entry->num)
++);
++
+ #endif /* !__RDEV_OPS_TRACE || TRACE_HEADER_MULTI_READ */
+
+ #undef TRACE_INCLUDE_PATH