| // 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 struct hdcp_srm { |
| u32 revoked_ksv_cnt; |
| u8 *revoked_ksv_list; |
| |
| /* Mutex to protect above struct member */ |
| struct mutex mutex; |
| } *srm_data; |
| |
| 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 parsed_bytes = 0, ksv_count = 0; |
| u32 vrl_ksv_cnt, vrl_ksv_sz, vrl_idx = 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, buf, vrl_ksv_sz); |
| |
| ksv_count += vrl_ksv_cnt; |
| revoked_ksv_list += vrl_ksv_sz; |
| 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) |
| { |
| 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 count; |
| } |
| |
| kfree(srm_data->revoked_ksv_list); |
| srm_data->revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, |
| GFP_KERNEL); |
| if (!srm_data->revoked_ksv_list) { |
| DRM_ERROR("Out of Memory\n"); |
| return -ENOMEM; |
| } |
| |
| if (drm_hdcp_get_revoked_ksvs(buf, srm_data->revoked_ksv_list, |
| vrl_length) != ksv_count) { |
| srm_data->revoked_ksv_cnt = 0; |
| kfree(srm_data->revoked_ksv_list); |
| return -EINVAL; |
| } |
| |
| srm_data->revoked_ksv_cnt = ksv_count; |
| return count; |
| } |
| |
| static int drm_hdcp_parse_hdcp2_srm(const u8 *buf, size_t count) |
| { |
| 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 count; |
| } |
| |
| kfree(srm_data->revoked_ksv_list); |
| srm_data->revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, |
| GFP_KERNEL); |
| if (!srm_data->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(srm_data->revoked_ksv_list, buf, ksv_sz); |
| |
| srm_data->revoked_ksv_cnt = ksv_count; |
| return count; |
| } |
| |
| 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 void drm_hdcp_srm_update(const u8 *buf, size_t count) |
| { |
| if (count < sizeof(struct hdcp_srm_header)) |
| return; |
| |
| if (is_srm_version_hdcp1(buf)) |
| drm_hdcp_parse_hdcp1_srm(buf, count); |
| else if (is_srm_version_hdcp2(buf)) |
| drm_hdcp_parse_hdcp2_srm(buf, count); |
| } |
| |
| static void drm_hdcp_request_srm(struct drm_device *drm_dev) |
| { |
| 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) |
| goto exit; |
| |
| if (fw->size && fw->data) |
| drm_hdcp_srm_update(fw->data, fw->size); |
| |
| exit: |
| release_firmware(fw); |
| } |
| |
| /** |
| * 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". |
| * |
| * Returns: |
| * TRUE on any of the KSV is revoked, else FALSE. |
| */ |
| bool drm_hdcp_check_ksvs_revoked(struct drm_device *drm_dev, u8 *ksvs, |
| u32 ksv_count) |
| { |
| u32 rev_ksv_cnt, cnt, i, j; |
| u8 *rev_ksv_list; |
| |
| if (!srm_data) |
| return false; |
| |
| mutex_lock(&srm_data->mutex); |
| drm_hdcp_request_srm(drm_dev); |
| |
| rev_ksv_cnt = srm_data->revoked_ksv_cnt; |
| rev_ksv_list = srm_data->revoked_ksv_list; |
| |
| /* If the Revoked ksv list is empty */ |
| if (!rev_ksv_cnt || !rev_ksv_list) { |
| mutex_unlock(&srm_data->mutex); |
| return false; |
| } |
| |
| for (cnt = 0; cnt < ksv_count; cnt++) { |
| rev_ksv_list = srm_data->revoked_ksv_list; |
| for (i = 0; i < rev_ksv_cnt; i++) { |
| for (j = 0; j < DRM_HDCP_KSV_LEN; j++) |
| if (ksvs[j] != rev_ksv_list[j]) { |
| break; |
| } else if (j == (DRM_HDCP_KSV_LEN - 1)) { |
| DRM_DEBUG("Revoked KSV is "); |
| drm_hdcp_print_ksv(ksvs); |
| mutex_unlock(&srm_data->mutex); |
| return true; |
| } |
| /* Move the offset to next KSV in the revoked list */ |
| rev_ksv_list += DRM_HDCP_KSV_LEN; |
| } |
| |
| /* Iterate to next ksv_offset */ |
| ksvs += DRM_HDCP_KSV_LEN; |
| } |
| mutex_unlock(&srm_data->mutex); |
| return false; |
| } |
| EXPORT_SYMBOL_GPL(drm_hdcp_check_ksvs_revoked); |
| |
| int drm_setup_hdcp_srm(struct class *drm_class) |
| { |
| srm_data = kzalloc(sizeof(*srm_data), GFP_KERNEL); |
| if (!srm_data) |
| return -ENOMEM; |
| mutex_init(&srm_data->mutex); |
| |
| return 0; |
| } |
| |
| void drm_teardown_hdcp_srm(struct class *drm_class) |
| { |
| if (srm_data) { |
| kfree(srm_data->revoked_ksv_list); |
| kfree(srm_data); |
| } |
| } |
| |
| 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) |
| |
| /** |
| * drm_connector_attach_content_protection_property - attach content protection |
| * property |
| * |
| * @connector: connector to attach CP property on. |
| * |
| * 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. |
| * |
| * The content protection will be set to &drm_connector_state.content_protection |
| * |
| * Returns: |
| * Zero on success, negative errno on failure. |
| */ |
| int drm_connector_attach_content_protection_property( |
| struct drm_connector *connector) |
| { |
| 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; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_connector_attach_content_protection_property); |