[PATCH 2/3] drm/xe/hdcp: Enable HDCP for XE
Daniele Ceraolo Spurio
daniele.ceraolospurio at intel.com
Mon Feb 5 22:50:36 UTC 2024
On 2/2/2024 12:37 AM, Suraj Kandpal wrote:
> Enable HDCP for Xe by defining functions which take care of
> interaction of HDCP as a client with the GSC CS interface.
>
> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> ---
> drivers/gpu/drm/xe/display/xe_hdcp_gsc.c | 188 ++++++++++++++++++++++-
> 1 file changed, 184 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/display/xe_hdcp_gsc.c b/drivers/gpu/drm/xe/display/xe_hdcp_gsc.c
> index 0f11a39333e2..eca941d7b281 100644
> --- a/drivers/gpu/drm/xe/display/xe_hdcp_gsc.c
> +++ b/drivers/gpu/drm/xe/display/xe_hdcp_gsc.c
> @@ -3,8 +3,24 @@
> * Copyright 2023, Intel Corporation.
> */
>
> +#include "abi/gsc_command_header_abi.h"
My original idea was for the users to not include this header and rely
on the size provided by the emit functions. I see you use the check the
input size, which I didn't do on the proxy side because the buffer is
sized to be big enough for all possible commands. Overall not a blocker,
just consider the option.
> #include "i915_drv.h"
Do you actually need i915_drv.h? You shouldn't be using any structure
from i915 here. If you just need it for the pointers to struct
drm_i915_private, just add a forward declaration for the structure.
> #include "intel_hdcp_gsc.h"
> +#include "xe_bo.h"
> +#include "xe_map.h"
> +#include "xe_gsc_submit.h"
> +
> +#define HECI_MEADDRESS_HDCP 18
> +
> +struct intel_hdcp_gsc_message {
> + struct xe_bo *hdcp_bo;
> + u64 hdcp_cmd_in;
> + u64 hdcp_cmd_out;
> +};
> +
> +#define HOST_SESSION_CLIENT_MASK GENMASK_ULL(63, 56)
> +#define HDCP_GSC_MESSAGE_SIZE sizeof(struct intel_hdcp_gsc_message)
this define is unused. Also, intel_hdcp_gsc_message is not the actual
message, but just contains a pointer to the object that holds the message.
> +#define HDCP_GSC_HEADER_SIZE sizeof(struct intel_gsc_mtl_header)
>
> bool intel_hdcp_gsc_cs_required(struct drm_i915_private *i915)
> {
> @@ -13,22 +29,186 @@ bool intel_hdcp_gsc_cs_required(struct drm_i915_private *i915)
>
> bool intel_hdcp_gsc_check_status(struct drm_i915_private *i915)
> {
> - return false;
> + return true;
Shouldn't you actually do a check in here?
> +}
> +
> +/*This function helps allocate memory for the command that we will send to gsc cs */
> +static int intel_hdcp_gsc_initialize_message(struct drm_i915_private *i915,
Having a drm_i915_private here that is actually an xe_device is really
weird. I understand that the aim is to re-use most of the display code
from i915, but if you need to different back-ends maybe just have the
function accept a void pointer and then internally cast it to
drm_i915_private or xe_device based on the driver, or use struct
intel_display and cast it back to i915 or Xe with a container_of. I'll
leave the final comment on this to someone that has more understanding
than me of what's going on on the display side of things.
> + struct intel_hdcp_gsc_message *hdcp_message)
> +{
> + struct xe_bo *bo = NULL;
> + u64 cmd_in, cmd_out;
> + int err, ret = 0;
> +
> + /* allocate object of two page for HDCP command memory and store it */
> +
> + xe_device_mem_access_get(i915);
> + bo = xe_bo_create_pin_map(i915, xe_device_get_root_tile(i915), NULL, PAGE_SIZE * 2,
> + ttm_bo_type_kernel,
> + XE_BO_CREATE_SYSTEM_BIT |
> + XE_BO_CREATE_GGTT_BIT);
> +
> + if (IS_ERR(bo)) {
> + drm_err(&i915->drm, "Failed to allocate bo for HDCP streaming command!\n");
> + ret = err;
> + goto out;
> + }
> +
> + cmd_in = xe_bo_ggtt_addr(bo);
> +
> + if (iosys_map_is_null(&bo->vmap)) {
this can't happen, if the bo fails to map then xe_bo_create_pin_map will
return an error.
> + drm_err(&i915->drm, "Failed to map gsc message page!\n");
> + ret = PTR_ERR(&bo->vmap);
> + goto out;
> + }
> +
> + cmd_out = cmd_in + PAGE_SIZE;
> +
> + xe_map_memset(i915, &bo->vmap, 0, 0, bo->size);
> +
> + hdcp_message->hdcp_bo = bo;
> + hdcp_message->hdcp_cmd_in = cmd_in;
> + hdcp_message->hdcp_cmd_out = cmd_out;
> +out:
> + xe_device_mem_access_put(i915);
> + return ret;
> +}
> +
> +static int intel_hdcp_gsc_hdcp2_init(struct drm_i915_private *i915)
> +{
> + struct intel_hdcp_gsc_message *hdcp_message;
> + int ret;
> +
> + hdcp_message = kzalloc(sizeof(*hdcp_message), GFP_KERNEL);
> +
> + if (!hdcp_message)
> + return -ENOMEM;
> +
> + /*
> + * NOTE: No need to lock the comp mutex here as it is already
> + * going to be taken before this function called
> + */
> + i915->display.hdcp.hdcp_message = hdcp_message;
> + ret = intel_hdcp_gsc_initialize_message(i915, hdcp_message);
> +
> + if (ret)
> + drm_err(&i915->drm, "Could not initialize hdcp_message\n");
Don't you need a kfree in this error path? alternatively you can use
drmm_kzalloc so that it is always automatically freed.
> +
> + return ret;
> }
>
> int intel_hdcp_gsc_init(struct drm_i915_private *i915)
> {
> - drm_info(&i915->drm, "HDCP support not yet implemented\n");
> - return -ENODEV;
> + struct i915_hdcp_arbiter *data;
> + int ret;
> +
> + data = kzalloc(sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + mutex_lock(&i915->display.hdcp.hdcp_mutex);
> + i915->display.hdcp.arbiter = data;
> + i915->display.hdcp.arbiter->hdcp_dev = i915->drm.dev;
> + i915->display.hdcp.arbiter->ops = &gsc_hdcp_ops;
Does this patch compile on its own? As far as I can see gsc_hdcp_ops is
added in the next patch.
> + ret = intel_hdcp_gsc_hdcp2_init(i915);
> + mutex_unlock(&i915->display.hdcp.hdcp_mutex);
> +
> + return ret;
Here as well missing the kfree on error
> }
>
> void intel_hdcp_gsc_fini(struct drm_i915_private *i915)
> {
> + struct intel_hdcp_gsc_message *hdcp_message =
> + i915->display.hdcp.hdcp_message;
> +
> + xe_bo_unpin_map_no_vm(hdcp_message->hdcp_bo);
> + kfree(hdcp_message);
> +
> }
>
> +static int xe_gsc_send_sync(struct drm_i915_private *i915,
> + struct intel_hdcp_gsc_message *hdcp_message,
> + u32 msg_size_in, u32 msg_size_out,
> + u32 addr_in_off, u32 addr_out_off,
Those 2 variables are unused.
> + size_t msg_out_len)
> +{
> + struct xe_gt *gt = hdcp_message->hdcp_bo->tile->media_gt;
> + struct iosys_map *map = &hdcp_message->hdcp_bo->vmap;
> + struct xe_gsc *gsc = >->uc.gsc;
> + int ret;
> +
> + ret = xe_gsc_pkt_submit_kernel(gsc, hdcp_message->hdcp_cmd_in, msg_size_in,
> + hdcp_message->hdcp_cmd_out, msg_size_out);
> + if (ret) {
> + drm_err(&i915->drm, "failed to send gsc HDCP msg (%d)\n", ret);
> + return ret;
> + }
> +
> + ret = xe_gsc_check_and_update_pending(i915, map, 0, map, addr_out_off);
This returns a bool, so you can call it directly inside the if statement
instead of casting the return to int.
> +
> + if (ret)
> + return -EAGAIN;
> +
> + ret = xe_gsc_read_out_header(i915, map, addr_out_off,
> + sizeof(struct hdcp_cmd_header), NULL);
Note that here you're only checking that the message is at least as big
as struct hdcp_cmd_header, but if there was an error and the only thing
in the message was the header it'll still pass. This links with a
comment below.
> +
> + return ret;
> +}
> ssize_t intel_hdcp_gsc_msg_send(struct drm_i915_private *i915, u8 *msg_in,
> size_t msg_in_len, u8 *msg_out,
> size_t msg_out_len)
> {
> - return -ENODEV;
> + const size_t max_msg_size = PAGE_SIZE - HDCP_GSC_HEADER_SIZE;
> + struct intel_hdcp_gsc_message *hdcp_message;
> + u64 host_session_id;
> + u32 msg_size_in, msg_size_out, addr_in_off = 0, addr_out_off;
> + int ret, tries = 0;
> +
> + if (msg_in_len > max_msg_size || msg_out_len > max_msg_size) {
> + ret = -ENOSPC;
> + goto out;
> + }
> +
> + msg_size_in = msg_in_len + HDCP_GSC_HEADER_SIZE;
> + msg_size_out = msg_out_len + HDCP_GSC_HEADER_SIZE;
> + hdcp_message = i915->display.hdcp.hdcp_message;
> + addr_out_off = PAGE_SIZE;
> +
> + get_random_bytes(&host_session_id, sizeof(u64));
> + host_session_id = host_session_id & ~HOST_SESSION_CLIENT_MASK;
Can you move this host session code to a dedicated function in
xe_gsc_submit.c? that way we can re-use it for PXP. You can also drop
the re-definition of HOST_SESSION_CLIENT_MASK because that's already in
that file.
> + xe_device_mem_access_get(i915);
> + addr_in_off = xe_gsc_emit_header(i915, &hdcp_message->hdcp_bo->vmap,
Note that this function does not return the input offset, but the next
writable location (that's why I called it wr_offset in other code)
> + addr_in_off,
> + HECI_MEADDRESS_HDCP, host_session_id,
> + msg_in_len);
> +
> + xe_map_memcpy_to(i915, &hdcp_message->hdcp_bo->vmap, addr_in_off, msg_in, msg_in_len);
> + /*
> + * Keep sending request in case the pending bit is set no need to add
> + * message handle as we are using same address hence loc. of header is
> + * same and it will contain the message handle. we will send the message
> + * 20 times each message 50 ms apart
> + */
> + do {
> + ret = xe_gsc_send_sync(i915, hdcp_message, msg_size_in, msg_size_out,
> + addr_in_off, addr_out_off, msg_out_len);
> +
> + /* Only try again if gsc says so */
> + if (ret != -EAGAIN)
> + break;
> +
> + msleep(50);
> +
> + } while (++tries < 20);
> +
> + if (ret)
> + goto out;
> +
> + xe_map_memcpy_from(i915, msg_out, &hdcp_message->hdcp_bo->vmap,
> + addr_out_off + HDCP_GSC_HEADER_SIZE,
> + msg_out_len);
here you are copying msg_out_len, but you haven't checked if the GSC has
actually written that much, you only checked that you had struct
hdcp_cmd_header.
Daniele
> +
> +out:
> + xe_device_mem_access_put(i915);
> + return ret;
> }
More information about the Intel-xe
mailing list