diff options
Diffstat (limited to 'drivers/gpu/drm/display/drm_hdcp_helper.c')
| -rw-r--r-- | drivers/gpu/drm/display/drm_hdcp_helper.c | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/drivers/gpu/drm/display/drm_hdcp_helper.c b/drivers/gpu/drm/display/drm_hdcp_helper.c new file mode 100644 index 000000000000..e78999c72bd7 --- /dev/null +++ b/drivers/gpu/drm/display/drm_hdcp_helper.c @@ -0,0 +1,421 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 Intel Corporation. + * + * Authors: + * Ramalingam C <[email protected]> + */ + +#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/display/drm_hdcp_helper.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> + +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 in case 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); |