diff options
Diffstat (limited to 'drivers/gpu/drm/drm_hdcp.c')
| -rw-r--r-- | drivers/gpu/drm/drm_hdcp.c | 382 |
1 files changed, 382 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_hdcp.c b/drivers/gpu/drm/drm_hdcp.c new file mode 100644 index 000000000000..cd837bd409f7 --- /dev/null +++ b/drivers/gpu/drm/drm_hdcp.c @@ -0,0 +1,382 @@ +// 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); |