cxl: Add support to handle user feature commands for set feature

Add helper function to parse the user data from fwctl RPC ioctl and
send the parsed input parameters to cxl_set_feature() call.

Link: https://patch.msgid.link/r/20250307205648.1021626-6-dave.jiang@intel.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/cxl/core/features.c b/drivers/cxl/core/features.c
index 88aceb3c8bec867fa4e60b7c98f45c0cc64e8e5c..f4daefe3180e52318827a0e7c02d6a27d810fb32 100644 (file)
--- a/drivers/cxl/core/features.c
+++ b/drivers/cxl/core/features.c
@@ -21,16 +21,21 @@ static const uuid_t cxl_exclusive_feats[] = {
        CXL_FEAT_RANK_SPARING_UUID,
 };
 
-static bool is_cxl_feature_exclusive(struct cxl_feat_entry *entry)
+static bool is_cxl_feature_exclusive_by_uuid(const uuid_t *uuid)
 {
        for (int i = 0; i < ARRAY_SIZE(cxl_exclusive_feats); i++) {
-               if (uuid_equal(&entry->uuid, &cxl_exclusive_feats[i]))
+               if (uuid_equal(uuid, &cxl_exclusive_feats[i]))
                        return true;
        }
 
        return false;
 }
 
+static bool is_cxl_feature_exclusive(struct cxl_feat_entry *entry)
+{
+       return is_cxl_feature_exclusive_by_uuid(&entry->uuid);
+}
+
 inline struct cxl_features_state *to_cxlfs(struct cxl_dev_state *cxlds)
 {
        return cxlds->cxlfs;
@@ -350,6 +355,27 @@ static void cxlctl_close_uctx(struct fwctl_uctx *uctx)
 {
 }
 
+static struct cxl_feat_entry *
+get_support_feature_info(struct cxl_features_state *cxlfs,
+                        const struct fwctl_rpc_cxl *rpc_in)
+{
+       struct cxl_feat_entry *feat;
+       const uuid_t *uuid;
+
+       if (rpc_in->op_size < sizeof(uuid))
+               return ERR_PTR(-EINVAL);
+
+       uuid = &rpc_in->set_feat_in.uuid;
+
+       for (int i = 0; i < cxlfs->entries->num_features; i++) {
+               feat = &cxlfs->entries->ent[i];
+               if (uuid_equal(uuid, &feat->uuid))
+                       return feat;
+       }
+
+       return ERR_PTR(-EINVAL);
+}
+
 static void *cxlctl_get_supported_features(struct cxl_features_state *cxlfs,
                                           const struct fwctl_rpc_cxl *rpc_in,
                                           size_t *out_len)
@@ -468,6 +494,116 @@ static void *cxlctl_get_feature(struct cxl_features_state *cxlfs,
        return no_free_ptr(rpc_out);
 }
 
+static void *cxlctl_set_feature(struct cxl_features_state *cxlfs,
+                               const struct fwctl_rpc_cxl *rpc_in,
+                               size_t *out_len)
+{
+       struct cxl_mailbox *cxl_mbox = &cxlfs->cxlds->cxl_mbox;
+       const struct cxl_mbox_set_feat_in *feat_in;
+       size_t out_size, data_size;
+       u16 offset, return_code;
+       u32 flags;
+       int rc;
+
+       if (rpc_in->op_size <= sizeof(feat_in->hdr))
+               return ERR_PTR(-EINVAL);
+
+       feat_in = &rpc_in->set_feat_in;
+
+       if (is_cxl_feature_exclusive_by_uuid(&feat_in->uuid))
+               return ERR_PTR(-EPERM);
+
+       offset = le16_to_cpu(feat_in->offset);
+       flags = le32_to_cpu(feat_in->flags);
+       out_size = *out_len;
+
+       struct fwctl_rpc_cxl_out *rpc_out __free(kvfree) =
+               kvzalloc(out_size, GFP_KERNEL);
+       if (!rpc_out)
+               return ERR_PTR(-ENOMEM);
+
+       rpc_out->size = 0;
+
+       data_size = rpc_in->op_size - sizeof(feat_in->hdr);
+       rc = cxl_set_feature(cxl_mbox, &feat_in->uuid,
+                            feat_in->version, feat_in->feat_data,
+                            data_size, flags, offset, &return_code);
+       if (rc) {
+               rpc_out->retval = return_code;
+               return no_free_ptr(rpc_out);
+       }
+
+       rpc_out->retval = CXL_MBOX_CMD_RC_SUCCESS;
+       *out_len = sizeof(*rpc_out);
+
+       return no_free_ptr(rpc_out);
+}
+
+static bool cxlctl_validate_set_features(struct cxl_features_state *cxlfs,
+                                        const struct fwctl_rpc_cxl *rpc_in,
+                                        enum fwctl_rpc_scope scope)
+{
+       u16 effects, imm_mask, reset_mask;
+       struct cxl_feat_entry *feat;
+       u32 flags;
+
+       feat = get_support_feature_info(cxlfs, rpc_in);
+       if (IS_ERR(feat))
+               return false;
+
+       /* Ensure that the attribute is changeable */
+       flags = le32_to_cpu(feat->flags);
+       if (!(flags & CXL_FEATURE_F_CHANGEABLE))
+               return false;
+
+       effects = le16_to_cpu(feat->effects);
+
+       /*
+        * Reserved bits are set, rejecting since the effects is not
+        * comprehended by the driver.
+        */
+       if (effects & CXL_CMD_EFFECTS_RESERVED) {
+               dev_warn_once(cxlfs->cxlds->dev,
+                             "Reserved bits set in the Feature effects field!\n");
+               return false;
+       }
+
+       /* Currently no user background command support */
+       if (effects & CXL_CMD_BACKGROUND)
+               return false;
+
+       /* Effects cause immediate change, highest security scope is needed */
+       imm_mask = CXL_CMD_CONFIG_CHANGE_IMMEDIATE |
+                  CXL_CMD_DATA_CHANGE_IMMEDIATE |
+                  CXL_CMD_POLICY_CHANGE_IMMEDIATE |
+                  CXL_CMD_LOG_CHANGE_IMMEDIATE;
+
+       reset_mask = CXL_CMD_CONFIG_CHANGE_COLD_RESET |
+                    CXL_CMD_CONFIG_CHANGE_CONV_RESET |
+                    CXL_CMD_CONFIG_CHANGE_CXL_RESET;
+
+       /* If no immediate or reset effect set, The hardware has a bug */
+       if (!(effects & imm_mask) && !(effects & reset_mask))
+               return false;
+
+       /*
+        * If the Feature setting causes immediate configuration change
+        * then we need the full write permission policy.
+        */
+       if (effects & imm_mask && scope >= FWCTL_RPC_DEBUG_WRITE_FULL)
+               return true;
+
+       /*
+        * If the Feature setting only causes configuration change
+        * after a reset, then the lesser level of write permission
+        * policy is ok.
+        */
+       if (!(effects & imm_mask) && scope >= FWCTL_RPC_DEBUG_WRITE)
+               return true;
+
+       return false;
+}
+
 static bool cxlctl_validate_hw_command(struct cxl_features_state *cxlfs,
                                       const struct fwctl_rpc_cxl *rpc_in,
                                       enum fwctl_rpc_scope scope,
@@ -483,6 +619,10 @@ static bool cxlctl_validate_hw_command(struct cxl_features_state *cxlfs,
                if (scope >= FWCTL_RPC_CONFIGURATION)
                        return true;
                return false;
+       case CXL_MBOX_OP_SET_FEATURE:
+               if (cxl_mbox->feat_cap < CXL_FEATURES_RW)
+                       return false;
+               return cxlctl_validate_set_features(cxlfs, rpc_in, scope);
        default:
                return false;
        }
@@ -497,6 +637,8 @@ static void *cxlctl_handle_commands(struct cxl_features_state *cxlfs,
                return cxlctl_get_supported_features(cxlfs, rpc_in, out_len);
        case CXL_MBOX_OP_GET_FEATURE:
                return cxlctl_get_feature(cxlfs, rpc_in, out_len);
+       case CXL_MBOX_OP_SET_FEATURE:
+               return cxlctl_set_feature(cxlfs, rpc_in, out_len);
        default:
                return ERR_PTR(-EOPNOTSUPP);
        }

diff --git a/include/uapi/fwctl/cxl.h b/include/uapi/fwctl/cxl.h
index f589bfb774266bca42d9bb64d8a52e0849df365e..43f522f0cdcd0bf6d99f5622648c9bf5fd6147a2 100644 (file)
--- a/include/uapi/fwctl/cxl.h
+++ b/include/uapi/fwctl/cxl.h
@@ -19,6 +19,7 @@
  * @reserved1: Reserved. Must be 0s.
  * @get_sup_feats_in: Get Supported Features input
  * @get_feat_in: Get Feature input
+ * @set_feat_in: Set Feature input
  */
 struct fwctl_rpc_cxl {
        __struct_group(fwctl_rpc_cxl_hdr, hdr, /* no attrs */,
@@ -30,6 +31,7 @@ struct fwctl_rpc_cxl {
        union {
                struct cxl_mbox_get_sup_feats_in get_sup_feats_in;
                struct cxl_mbox_get_feat_in get_feat_in;
+               struct cxl_mbox_set_feat_in set_feat_in;
        };
 };