drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism

Allocate a multipage object that can be used for input
and output for intel_hdcp_gsc_message so that corruption of
output message can be avoided by the current overwriting method.
Modify intel_gsc_send_sync() to take into account header_out
and addr_out so as to use them to verify the message send status.
Check link for comment and review history
https://patchwork.freedesktop.org/series/118499/

--v2
-Change approach from allocating two objects to just one multipage
object [Daniele]

--v3
-Squash the two patches together [Daniele]
-No need to allocate twice the size of intel_hdcp_gsc_message [Daniele]

Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230602105113.1791104-1-suraj.kandpal@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c b/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c
index 72573ce..ad04053 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c
+++ b/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c
@@ -621,24 +621,26 @@ static int intel_hdcp_gsc_initialize_message(struct drm_i915_private *i915,
        struct intel_gt *gt = i915->media_gt;
        struct drm_i915_gem_object *obj = NULL;
        struct i915_vma *vma = NULL;
-       void *cmd;
+       void *cmd_in, *cmd_out;
        int err;
 
-       /* allocate object of one page for HDCP command memory and store it */
-       obj = i915_gem_object_create_shmem(i915, PAGE_SIZE);
+       /* allocate object of two page for HDCP command memory and store it */
+       obj = i915_gem_object_create_shmem(i915, 2 * PAGE_SIZE);
 
        if (IS_ERR(obj)) {
                drm_err(&i915->drm, "Failed to allocate HDCP streaming command!\n");
                return PTR_ERR(obj);
        }
 
-       cmd = i915_gem_object_pin_map_unlocked(obj, i915_coherent_map_type(i915, obj, true));
-       if (IS_ERR(cmd)) {
+       cmd_in = i915_gem_object_pin_map_unlocked(obj, i915_coherent_map_type(i915, obj, true));
+       if (IS_ERR(cmd_in)) {
                drm_err(&i915->drm, "Failed to map gsc message page!\n");
-               err = PTR_ERR(cmd);
+               err = PTR_ERR(cmd_in);
                goto out_unpin;
        }
 
+       cmd_out = cmd_in + PAGE_SIZE;
+
        vma = i915_vma_instance(obj, &gt->ggtt->vm, NULL);
        if (IS_ERR(vma)) {
                err = PTR_ERR(vma);
@@ -649,9 +651,10 @@ static int intel_hdcp_gsc_initialize_message(struct drm_i915_private *i915,
        if (err)
                goto out_unmap;
 
-       memset(cmd, 0, obj->base.size);
+       memset(cmd_in, 0, obj->base.size);
 
-       hdcp_message->hdcp_cmd = cmd;
+       hdcp_message->hdcp_cmd_in = cmd_in;
+       hdcp_message->hdcp_cmd_out = cmd_out;
        hdcp_message->vma = vma;
 
        return 0;
@@ -691,6 +694,8 @@ static void intel_hdcp_gsc_free_message(struct drm_i915_private *i915)
        struct intel_hdcp_gsc_message *hdcp_message =
                                        i915->display.hdcp.hdcp_message;
 
+       hdcp_message->hdcp_cmd_in = NULL;
+       hdcp_message->hdcp_cmd_out = NULL;
        i915_vma_unpin_and_release(&hdcp_message->vma, I915_VMA_RELEASE_MAP);
        kfree(hdcp_message);
 }
@@ -721,38 +726,42 @@ void intel_hdcp_gsc_fini(struct drm_i915_private *i915)
 }
 
 static int intel_gsc_send_sync(struct drm_i915_private *i915,
-                              struct intel_gsc_mtl_header *header, u64 addr,
+                              struct intel_gsc_mtl_header *header_in,
+                              struct intel_gsc_mtl_header *header_out,
+                              u64 addr_in, u64 addr_out,
                               size_t msg_out_len)
 {
        struct intel_gt *gt = i915->media_gt;
        int ret;
 
-       header->flags = 0;
-       ret = intel_gsc_uc_heci_cmd_submit_packet(&gt->uc.gsc, addr,
-                                                 header->message_size,
-                                                 addr,
-                                                 msg_out_len + sizeof(*header));
+       ret = intel_gsc_uc_heci_cmd_submit_packet(&gt->uc.gsc, addr_in,
+                                                 header_in->message_size,
+                                                 addr_out,
+                                                 msg_out_len + sizeof(*header_out));
        if (ret) {
                drm_err(&i915->drm, "failed to send gsc HDCP msg (%d)\n", ret);
                return ret;
        }
 
        /*
-        * Checking validity marker for memory sanity
+        * Checking validity marker and header status to see if some error has
+        * blocked us from sending message to gsc cs
         */
-       if (header->validity_marker != GSC_HECI_VALIDITY_MARKER) {
+       if (header_out->validity_marker != GSC_HECI_VALIDITY_MARKER) {
                drm_err(&i915->drm, "invalid validity marker\n");
                return -EINVAL;
        }
 
-       if (header->status != 0) {
+       if (header_out->status != 0) {
                drm_err(&i915->drm, "header status indicates error %d\n",
-                       header->status);
+                       header_out->status);
                return -EINVAL;
        }
 
-       if (header->flags & GSC_OUTFLAG_MSG_PENDING)
+       if (header_out->flags & GSC_OUTFLAG_MSG_PENDING) {
+               header_in->gsc_message_handle = header_out->gsc_message_handle;
                return -EAGAIN;
+       }
 
        return 0;
 }
@@ -769,11 +778,11 @@ ssize_t intel_hdcp_gsc_msg_send(struct drm_i915_private *i915, u8 *msg_in,
                                size_t msg_out_len)
 {
        struct intel_gt *gt = i915->media_gt;
-       struct intel_gsc_mtl_header *header;
-       const size_t max_msg_size = PAGE_SIZE - sizeof(*header);
+       struct intel_gsc_mtl_header *header_in, *header_out;
+       const size_t max_msg_size = PAGE_SIZE - sizeof(*header_in);
        struct intel_hdcp_gsc_message *hdcp_message;
-       u64 addr, host_session_id;
-       u32 reply_size, msg_size;
+       u64 addr_in, addr_out, host_session_id;
+       u32 reply_size, msg_size_in, msg_size_out;
        int ret, tries = 0;
 
        if (!intel_uc_uses_gsc_uc(&gt->uc))
@@ -782,16 +791,20 @@ ssize_t intel_hdcp_gsc_msg_send(struct drm_i915_private *i915, u8 *msg_in,
        if (msg_in_len > max_msg_size || msg_out_len > max_msg_size)
                return -ENOSPC;
 
+       msg_size_in = msg_in_len + sizeof(*header_in);
+       msg_size_out = msg_out_len + sizeof(*header_out);
        hdcp_message = i915->display.hdcp.hdcp_message;
-       header = hdcp_message->hdcp_cmd;
-       addr = i915_ggtt_offset(hdcp_message->vma);
+       header_in = hdcp_message->hdcp_cmd_in;
+       header_out = hdcp_message->hdcp_cmd_out;
+       addr_in = i915_ggtt_offset(hdcp_message->vma);
+       addr_out = addr_in + PAGE_SIZE;
 
-       msg_size = msg_in_len + sizeof(*header);
-       memset(header, 0, msg_size);
+       memset(header_in, 0, msg_size_in);
+       memset(header_out, 0, msg_size_out);
        get_random_bytes(&host_session_id, sizeof(u64));
-       intel_gsc_uc_heci_cmd_emit_mtl_header(header, HECI_MEADDRESS_HDCP,
-                                             msg_size, host_session_id);
-       memcpy(hdcp_message->hdcp_cmd + sizeof(*header), msg_in, msg_in_len);
+       intel_gsc_uc_heci_cmd_emit_mtl_header(header_in, HECI_MEADDRESS_HDCP,
+                                             msg_size_in, host_session_id);
+       memcpy(hdcp_message->hdcp_cmd_in + sizeof(*header_in), msg_in, msg_in_len);
 
        /*
         * Keep sending request in case the pending bit is set no need to add
@@ -800,7 +813,8 @@ ssize_t intel_hdcp_gsc_msg_send(struct drm_i915_private *i915, u8 *msg_in,
         * 20 times each message 50 ms apart
         */
        do {
-               ret = intel_gsc_send_sync(i915, header, addr, msg_out_len);
+               ret = intel_gsc_send_sync(i915, header_in, header_out, addr_in,
+                                         addr_out, msg_out_len);
 
                /* Only try again if gsc says so */
                if (ret != -EAGAIN)
@@ -814,7 +828,7 @@ ssize_t intel_hdcp_gsc_msg_send(struct drm_i915_private *i915, u8 *msg_in,
                goto err;
 
        /* we use the same mem for the reply, so header is in the same loc */
-       reply_size = header->message_size - sizeof(*header);
+       reply_size = header_out->message_size - sizeof(*header_out);
        if (reply_size > msg_out_len) {
                drm_warn(&i915->drm, "caller with insufficient HDCP reply size %u (%d)\n",
                         reply_size, (u32)msg_out_len);
@@ -824,7 +838,7 @@ ssize_t intel_hdcp_gsc_msg_send(struct drm_i915_private *i915, u8 *msg_in,
                            reply_size, (u32)msg_out_len);
        }
 
-       memcpy(msg_out, hdcp_message->hdcp_cmd + sizeof(*header), msg_out_len);
+       memcpy(msg_out, hdcp_message->hdcp_cmd_out + sizeof(*header_out), msg_out_len);
 
 err:
        return ret;

diff --git a/drivers/gpu/drm/i915/display/intel_hdcp_gsc.h b/drivers/gpu/drm/i915/display/intel_hdcp_gsc.h
index 5cc9fd2..cbf9655 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_hdcp_gsc.h
+++ b/drivers/gpu/drm/i915/display/intel_hdcp_gsc.h
@@ -13,7 +13,8 @@ struct drm_i915_private;
 
 struct intel_hdcp_gsc_message {
        struct i915_vma *vma;
-       void *hdcp_cmd;
+       void *hdcp_cmd_in;
+       void *hdcp_cmd_out;
 };
 
 bool intel_hdcp_gsc_cs_required(struct drm_i915_private *i915);