// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019 Intel Corporation.
*
* Authors:
* Ramalingam C <ramalingam.c@intel.com>
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/gfp.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/firmware.h>
#include <drm/drm_hdcp.h>
#include <drm/drm_sysfs.h>
#include <drm/drm_print.h>
#include <drm/drm_device.h>
#include <drm/drm_property.h>
#include <drm/drm_mode_object.h>
#include <drm/drm_connector.h>
#include "drm_internal.h"
static inline void drm_hdcp_print_ksv(const u8 *ksv)
{
DRM_DEBUG("\t%#02x, %#02x, %#02x, %#02x, %#02x\n",
ksv[0], ksv[1], ksv[2], ksv[3], ksv[4]);
}
static u32 drm_hdcp_get_revoked_ksv_count(const u8 *buf, u32 vrls_length)
{
u32 parsed_bytes = 0, ksv_count = 0, vrl_ksv_cnt, vrl_sz;
while (parsed_bytes < vrls_length) {
vrl_ksv_cnt = *buf;
ksv_count += vrl_ksv_cnt;
vrl_sz = (vrl_ksv_cnt * DRM_HDCP_KSV_LEN) + 1;
buf += vrl_sz;
parsed_bytes += vrl_sz;
}
/*
* When vrls are not valid, ksvs are not considered.
* Hence SRM will be discarded.
*/
if (parsed_bytes != vrls_length)
ksv_count = 0;
return ksv_count;
}
static u32 drm_hdcp_get_revoked_ksvs(const u8 *buf, u8 **revoked_ksv_list,
u32 vrls_length)
{
u32 vrl_ksv_cnt, vrl_ksv_sz, vrl_idx = 0;
u32 parsed_bytes = 0, ksv_count = 0;
do {
vrl_ksv_cnt = *buf;
vrl_ksv_sz = vrl_ksv_cnt * DRM_HDCP_KSV_LEN;
buf++;
DRM_DEBUG("vrl: %d, Revoked KSVs: %d\n", vrl_idx++,
vrl_ksv_cnt);
memcpy((*revoked_ksv_list) + (ksv_count * DRM_HDCP_KSV_LEN),
buf, vrl_ksv_sz);
ksv_count += vrl_ksv_cnt;
buf += vrl_ksv_sz;
parsed_bytes += (vrl_ksv_sz + 1);
} while (parsed_bytes < vrls_length);
return ksv_count;
}
static inline u32 get_vrl_length(const u8 *buf)
{
return drm_hdcp_be24_to_cpu(buf);
}
static int drm_hdcp_parse_hdcp1_srm(const u8 *buf, size_t count,
u8 **revoked_ksv_list, u32 *revoked_ksv_cnt)
{
struct hdcp_srm_header *header;
u32 vrl_length, ksv_count;
if (count < (sizeof(struct hdcp_srm_header) +
DRM_HDCP_1_4_VRL_LENGTH_SIZE + DRM_HDCP_1_4_DCP_SIG_SIZE)) {
DRM_ERROR("Invalid blob length\n");
return -EINVAL;
}
header = (struct hdcp_srm_header *)buf;
DRM_DEBUG("SRM ID: 0x%x, SRM Ver: 0x%x, SRM Gen No: 0x%x\n",
header->srm_id,
be16_to_cpu(header->srm_version), header->srm_gen_no);
WARN_ON(header->reserved);
buf = buf + sizeof(*header);
vrl_length = get_vrl_length(buf);
if (count < (sizeof(struct hdcp_srm_header) + vrl_length) ||
vrl_length < (DRM_HDCP_1_4_VRL_LENGTH_SIZE +
DRM_HDCP_1_4_DCP_SIG_SIZE)) {
DRM_ERROR("Invalid blob length or vrl length\n");
return -EINVAL;
}
/* Length of the all vrls combined */
vrl_length -= (DRM_HDCP_1_4_VRL_LENGTH_SIZE +
DRM_HDCP_1_4_DCP_SIG_SIZE);
if (!vrl_length) {
DRM_ERROR("No vrl found\n");
return -EINVAL;
}
buf += DRM_HDCP_1_4_VRL_LENGTH_SIZE;
ksv_count = drm_hdcp_get_revoked_ksv_count(buf, vrl_length);
if (!ksv_count) {
DRM_DEBUG("Revoked KSV count is 0\n");
return 0;
}
*revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, GFP_KERNEL);
if (!*revoked_ksv_list) {
DRM_ERROR("Out of Memory\n");
return -ENOMEM;
}
if (drm_hdcp_get_revoked_ksvs(buf, revoked_ksv_list,
vrl_length) != ksv_count) {
*revoked_ksv_cnt = 0;
kfree(*revoked_ksv_list);
return -EINVAL;
}
*revoked_ksv_cnt = ksv_count;
return 0;
}
static int drm_hdcp_parse_hdcp2_srm(const u8 *buf, size_t count,
u8 **revoked_ksv_list, u32 *revoked_ksv_cnt)
{
struct hdcp_srm_header *header;
u32 vrl_length, ksv_count, ksv_sz;
if (count < (sizeof(struct hdcp_srm_header) +
DRM_HDCP_2_VRL_LENGTH_SIZE + DRM_HDCP_2_DCP_SIG_SIZE)) {
DRM_ERROR("Invalid blob length\n");
return -EINVAL;
}
header = (struct hdcp_srm_header *)buf;
DRM_DEBUG("SRM ID: 0x%x, SRM Ver: 0x%x, SRM Gen No: 0x%x\n",
header->srm_id & DRM_HDCP_SRM_ID_MASK,
be16_to_cpu(header->srm_version), header->srm_gen_no);
if (header->reserved)
return -EINVAL;
buf = buf + sizeof(*header);
vrl_length = get_vrl_length(buf);
if (count < (sizeof(struct hdcp_srm_header) + vrl_length) ||
vrl_length < (DRM_HDCP_2_VRL_LENGTH_SIZE +
DRM_HDCP_2_DCP_SIG_SIZE)) {
DRM_ERROR("Invalid blob length or vrl length\n");
return -EINVAL;
}
/* Length of the all vrls combined */
vrl_length -= (DRM_HDCP_2_VRL_LENGTH_SIZE +
DRM_HDCP_2_DCP_SIG_SIZE);
if (!vrl_length) {
DRM_ERROR("No vrl found\n");
return -EINVAL;
}
buf += DRM_HDCP_2_VRL_LENGTH_SIZE;
ksv_count = (*buf << 2) | DRM_HDCP_2_KSV_COUNT_2_LSBITS(*(buf + 1));
if (!ksv_count) {
DRM_DEBUG("Revoked KSV count is 0\n");
return 0;
}
*revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, GFP_KERNEL);
if (!*revoked_ksv_list) {
DRM_ERROR("Out of Memory\n");
return -ENOMEM;
}
ksv_sz = ksv_count * DRM_HDCP_KSV_LEN;
buf += DRM_HDCP_2_NO_OF_DEV_PLUS_RESERVED_SZ;
DRM_DEBUG("Revoked KSVs: %d\n", ksv_count);
memcpy(*revoked_ksv_list, buf, ksv_sz);
*revoked_ksv_cnt = ksv_count;
return 0;
}
static inline bool is_srm_version_hdcp1(const u8 *buf)
{
return *buf == (u8)(DRM_HDCP_1_4_SRM_ID << 4);
}
static inline bool is_srm_version_hdcp2(const u8 *buf)
{
return *buf == (u8)(DRM_HDCP_2_SRM_ID << 4 | DRM_HDCP_2_INDICATOR);
}
static int drm_hdcp_srm_update(const u8 *buf, size_t count,
u8 **revoked_ksv_list, u32 *revoked_ksv_cnt)
{
if (count < sizeof(struct hdcp_srm_header))
return -EINVAL;
if (is_srm_version_hdcp1(buf))
return drm_hdcp_parse_hdcp1_srm(buf, count, revoked_ksv_list,
revoked_ksv_cnt);
else if (is_srm_version_hdcp2(buf))
return drm_hdcp_parse_hdcp2_srm(buf, count, revoked_ksv_list,
revoked_ksv_cnt);
else
return -EINVAL;
}
static int drm_hdcp_request_srm(struct drm_device *drm_dev,
u8 **revoked_ksv_list, u32 *revoked_ksv_cnt)
{
char fw_name[36] = "display_hdcp_srm.bin";
const struct firmware *fw;
int ret;
ret = request_firmware_direct(&fw, (const char *)fw_name,
drm_dev->dev);
if (ret < 0) {
*revoked_ksv_cnt = 0;
*revoked_ksv_list = NULL;
ret = 0;
goto exit;
}
if (fw->size && fw->data)
ret = drm_hdcp_srm_update(fw->data, fw->size, revoked_ksv_list,
revoked_ksv_cnt);
exit:
release_firmware(fw);
return ret;
}
/**
* drm_hdcp_check_ksvs_revoked - Check the revoked status of the IDs
*
* @drm_dev: drm_device for which HDCP revocation check is requested
* @ksvs: List of KSVs (HDCP receiver IDs)
* @ksv_count: KSV count passed in through @ksvs
*
* This function reads the HDCP System renewability Message(SRM Table)
* from userspace as a firmware and parses it for the revoked HDCP
* KSVs(Receiver IDs) detected by DCP LLC. Once the revoked KSVs are known,
* revoked state of the KSVs in the list passed in by display drivers are
* decided and response is sent.
*
* SRM should be presented in the name of "display_hdcp_srm.bin".
*
* Format of the SRM table, that userspace needs to write into the binary file,
* is defined at:
* 1. Renewability chapter on 55th page of HDCP 1.4 specification
* https://www.digital-cp.com/sites/default/files/specifications/HDCP%20Specification%20Rev1_4_Secure.pdf
* 2. Renewability chapter on 63rd page of HDCP 2.2 specification
* https://www.digital-cp.com/sites/default/files/specifications/HDCP%20on%20HDMI%20Specification%20Rev2_2_Final1.pdf
*
* Returns:
* Count of the revoked KSVs or -ve error number incase of the failure.
*/
int drm_hdcp_check_ksvs_revoked(struct drm_device *drm_dev, u8 *ksvs,
u32 ksv_count)
{
u32 revoked_ksv_cnt = 0, i, j;
u8 *revoked_ksv_list = NULL;
int ret = 0;
ret = drm_hdcp_request_srm(drm_dev, &revoked_ksv_list,
&revoked_ksv_cnt);
if (ret)
return ret;
/* revoked_ksv_cnt will be zero when above function failed */
for (i = 0; i < revoked_ksv_cnt; i++)
for (j = 0; j < ksv_count; j++)
if (!memcmp(&ksvs[j * DRM_HDCP_KSV_LEN],
&revoked_ksv_list[i * DRM_HDCP_KSV_LEN],
DRM_HDCP_KSV_LEN)) {
DRM_DEBUG("Revoked KSV is ");
drm_hdcp_print_ksv(&ksvs[j * DRM_HDCP_KSV_LEN]);
ret++;
}
kfree(revoked_ksv_list);
return ret;
}
EXPORT_SYMBOL_GPL(drm_hdcp_check_ksvs_revoked);
static struct drm_prop_enum_list drm_cp_enum_list[] = {
{ DRM_MODE_CONTENT_PROTECTION_UNDESIRED, "Undesired" },
{ DRM_MODE_CONTENT_PROTECTION_DESIRED, "Desired" },
{ DRM_MODE_CONTENT_PROTECTION_ENABLED, "Enabled" },
};
DRM_ENUM_NAME_FN(drm_get_content_protection_name, drm_cp_enum_list)
static struct drm_prop_enum_list drm_hdcp_content_type_enum_list[] = {
{ DRM_MODE_HDCP_CONTENT_TYPE0, "HDCP Type0" },
{ DRM_MODE_HDCP_CONTENT_TYPE1, "HDCP Type1" },
};
DRM_ENUM_NAME_FN(drm_get_hdcp_content_type_name,
drm_hdcp_content_type_enum_list)
/**
* drm_connector_attach_content_protection_property - attach content protection
* property
*
* @connector: connector to attach CP property on.
* @hdcp_content_type: is HDCP Content Type property needed for connector
*
* This is used to add support for content protection on select connectors.
* Content Protection is intentionally vague to allow for different underlying
* technologies, however it is most implemented by HDCP.
*
* When hdcp_content_type is true enum property called HDCP Content Type is
* created (if it is not already) and attached to the connector.
*
* This property is used for sending the protected content's stream type
* from userspace to kernel on selected connectors. Protected content provider
* will decide their type of their content and declare the same to kernel.
*
* Content type will be used during the HDCP 2.2 authentication.
* Content type will be set to &drm_connector_state.hdcp_content_type.
*
* The content protection will be set to &drm_connector_state.content_protection
*
* When kernel triggered content protection state change like DESIRED->ENABLED
* and ENABLED->DESIRED, will use drm_hdcp_update_content_protection() to update
* the content protection state of a connector.
*
* Returns:
* Zero on success, negative errno on failure.
*/
int drm_connector_attach_content_protection_property(
struct drm_connector *connector, bool hdcp_content_type)
{
struct drm_device *dev = connector->dev;
struct drm_property *prop =
dev->mode_config.content_protection_property;
if (!prop)
prop = drm_property_create_enum(dev, 0, "Content Protection",
drm_cp_enum_list,
ARRAY_SIZE(drm_cp_enum_list));
if (!prop)
return -ENOMEM;
drm_object_attach_property(&connector->base, prop,
DRM_MODE_CONTENT_PROTECTION_UNDESIRED);
dev->mode_config.content_protection_property = prop;
if (!hdcp_content_type)
return 0;
prop = dev->mode_config.hdcp_content_type_property;
if (!prop)
prop = drm_property_create_enum(dev, 0, "HDCP Content Type",
drm_hdcp_content_type_enum_list,
ARRAY_SIZE(
drm_hdcp_content_type_enum_list));
if (!prop)
return -ENOMEM;
drm_object_attach_property(&connector->base, prop,
DRM_MODE_HDCP_CONTENT_TYPE0);
dev->mode_config.hdcp_content_type_property = prop;
return 0;
}
EXPORT_SYMBOL(drm_connector_attach_content_protection_property);
/**
* drm_hdcp_update_content_protection - Updates the content protection state
* of a connector
*
* @connector: drm_connector on which content protection state needs an update
* @val: New state of the content protection property
*
* This function can be used by display drivers, to update the kernel triggered
* content protection state changes of a drm_connector such as DESIRED->ENABLED
* and ENABLED->DESIRED. No uevent for DESIRED->UNDESIRED or ENABLED->UNDESIRED,
* as userspace is triggering such state change and kernel performs it without
* fail.This function update the new state of the property into the connector's
* state and generate an uevent to notify the userspace.
*/
void drm_hdcp_update_content_protection(struct drm_connector *connector,
u64 val)
{
struct drm_device *dev = connector->dev;
struct drm_connector_state *state = connector->state;
WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
if (state->content_protection == val)
return;
state->content_protection = val;
drm_sysfs_connector_status_event(connector,
dev->mode_config.content_protection_property);
}
EXPORT_SYMBOL(drm_hdcp_update_content_protection);
