diff options
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c | 182 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.h | 6 |
2 files changed, 185 insertions, 3 deletions
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c index a269916f7dd6..221abee517ee 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c @@ -28,6 +28,8 @@ #include "amdgpu_dm.h" #include "dm_helpers.h" #include <drm/drm_hdcp.h> +#include "hdcp_psp.h" + static bool lp_write_i2c(void *handle, uint32_t address, const uint8_t *data, uint32_t size) @@ -67,6 +69,16 @@ lp_read_dpcd(void *handle, uint32_t address, uint8_t *data, uint32_t size) return dm_helpers_dp_read_dpcd(link->ctx, link, address, data, size); } +static uint8_t *psp_get_srm(struct psp_context *psp, uint32_t *srm_version, uint32_t *srm_size) +{ + return NULL; +} + +static int psp_set_srm(struct psp_context *psp, uint8_t *srm, uint32_t srm_size, uint32_t *srm_version) +{ + return 0; +} + static void process_output(struct hdcp_workqueue *hdcp_work) { struct mod_hdcp_output output = hdcp_work->output; @@ -88,6 +100,18 @@ static void process_output(struct hdcp_workqueue *hdcp_work) schedule_delayed_work(&hdcp_work->property_validate_dwork, msecs_to_jiffies(0)); } +static void link_lock(struct hdcp_workqueue *work, bool lock) +{ + + int i = 0; + + for (i = 0; i < work->max_link; i++) { + if (lock) + mutex_lock(&work[i].mutex); + else + mutex_unlock(&work[i].mutex); + } +} void hdcp_update_display(struct hdcp_workqueue *hdcp_work, unsigned int link_index, struct amdgpu_dm_connector *aconnector, @@ -301,8 +325,9 @@ void hdcp_destroy(struct hdcp_workqueue *hdcp_work) cancel_delayed_work_sync(&hdcp_work[i].watchdog_timer_dwork); } + kfree(hdcp_work->srm); + kfree(hdcp_work->srm_temp); kfree(hdcp_work); - } static void update_config(void *handle, struct cp_psp_stream_config *config) @@ -338,20 +363,163 @@ static void update_config(void *handle, struct cp_psp_stream_config *config) hdcp_update_display(hdcp_work, link_index, aconnector, DRM_MODE_HDCP_CONTENT_TYPE0, false); } + +/* NOTE: From the usermodes prospective you only need to call write *ONCE*, the kernel + * will automatically call once or twice depending on the size + * + * call: "cat file > /sys/class/drm/card0/device/hdcp_srm" from usermode no matter what the size is + * + * The kernel can only send PAGE_SIZE at once and since MAX_SRM_FILE(5120) > PAGE_SIZE(4096), + * srm_data_write can be called multiple times. + * + * sysfs interface doesn't tell us the size we will get so we are sending partial SRMs to psp and on + * the last call we will send the full SRM. PSP will fail on every call before the last. + * + * This means we don't know if the SRM is good until the last call. And because of this limitation we + * cannot throw errors early as it will stop the kernel from writing to sysfs + * + * Example 1: + * Good SRM size = 5096 + * first call to write 4096 -> PSP fails + * Second call to write 1000 -> PSP Pass -> SRM is set + * + * Example 2: + * Bad SRM size = 4096 + * first call to write 4096 -> PSP fails (This is the same as above, but we don't know if this + * is the last call) + * + * Solution?: + * 1: Parse the SRM? -> It is signed so we don't know the EOF + * 2: We can have another sysfs that passes the size before calling set. -> simpler solution + * below + * + * Easy Solution: + * Always call get after Set to verify if set was successful. + * +----------------------+ + * | Why it works: | + * +----------------------+ + * PSP will only update its srm if its older than the one we are trying to load. + * Always do set first than get. + * -if we try to "1. SET" a older version PSP will reject it and we can "2. GET" the newer + * version and save it + * + * -if we try to "1. SET" a newer version PSP will accept it and we can "2. GET" the + * same(newer) version back and save it + * + * -if we try to "1. SET" a newer version and PSP rejects it. That means the format is + * incorrect/corrupted and we should correct our SRM by getting it from PSP + */ +static ssize_t srm_data_write(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, + loff_t pos, size_t count) +{ + struct hdcp_workqueue *work; + uint32_t srm_version = 0; + + work = container_of(bin_attr, struct hdcp_workqueue, attr); + link_lock(work, true); + + memcpy(work->srm_temp + pos, buffer, count); + + if (!psp_set_srm(work->hdcp.config.psp.handle, work->srm_temp, pos + count, &srm_version)) { + DRM_DEBUG_DRIVER("HDCP SRM SET version 0x%X", srm_version); + memcpy(work->srm, work->srm_temp, pos + count); + work->srm_size = pos + count; + work->srm_version = srm_version; + } + + + link_lock(work, false); + + return count; +} + +static ssize_t srm_data_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, + loff_t pos, size_t count) +{ + struct hdcp_workqueue *work; + uint8_t *srm = NULL; + uint32_t srm_version; + uint32_t srm_size; + size_t ret = count; + + work = container_of(bin_attr, struct hdcp_workqueue, attr); + + link_lock(work, true); + + srm = psp_get_srm(work->hdcp.config.psp.handle, &srm_version, &srm_size); + + if (!srm) + return -EINVAL; + + if (pos >= srm_size) + ret = 0; + + if (srm_size - pos < count) { + memcpy(buffer, srm + pos, srm_size - pos); + ret = srm_size - pos; + goto ret; + } + + memcpy(buffer, srm + pos, count); + +ret: + link_lock(work, false); + return ret; +} + +/* From the hdcp spec (5.Renewability) SRM needs to be stored in a non-volatile memory. + * + * For example, + * if Application "A" sets the SRM (ver 2) and we reboot/suspend and later when Application "B" + * needs to use HDCP, the version in PSP should be SRM(ver 2). So SRM should be persistent + * across boot/reboots/suspend/resume/shutdown + * + * Currently when the system goes down (suspend/shutdown) the SRM is cleared from PSP. For HDCP we need + * to make the SRM persistent. + * + * -PSP owns the checking of SRM but doesn't have the ability to store it in a non-volatile memory. + * -The kernel cannot write to the file systems. + * -So we need usermode to do this for us, which is why an interface for usermode is needed + * + * + * + * Usermode can read/write to/from PSP using the sysfs interface + * For example: + * to save SRM from PSP to storage : cat /sys/class/drm/card0/device/hdcp_srm > srmfile + * to load from storage to PSP: cat srmfile > /sys/class/drm/card0/device/hdcp_srm + */ +static const struct bin_attribute data_attr = { + .attr = {.name = "hdcp_srm", .mode = 0664}, + .size = PSP_HDCP_SRM_FIRST_GEN_MAX_SIZE, /* Limit SRM size */ + .write = srm_data_write, + .read = srm_data_read, +}; + + struct hdcp_workqueue *hdcp_create_workqueue(struct amdgpu_device *adev, struct cp_psp *cp_psp, struct dc *dc) { int max_caps = dc->caps.max_links; - struct hdcp_workqueue *hdcp_work = kzalloc(max_caps*sizeof(*hdcp_work), GFP_KERNEL); + struct hdcp_workqueue *hdcp_work; int i = 0; + hdcp_work = kcalloc(max_caps, sizeof(*hdcp_work), GFP_KERNEL); if (hdcp_work == NULL) + return NULL; + + hdcp_work->srm = kcalloc(PSP_HDCP_SRM_FIRST_GEN_MAX_SIZE, sizeof(*hdcp_work->srm), GFP_KERNEL); + + if (hdcp_work->srm == NULL) + goto fail_alloc_context; + + hdcp_work->srm_temp = kcalloc(PSP_HDCP_SRM_FIRST_GEN_MAX_SIZE, sizeof(*hdcp_work->srm_temp), GFP_KERNEL); + + if (hdcp_work->srm_temp == NULL) goto fail_alloc_context; hdcp_work->max_link = max_caps; for (i = 0; i < max_caps; i++) { - mutex_init(&hdcp_work[i].mutex); INIT_WORK(&hdcp_work[i].cpirq_work, event_cpirq); @@ -371,9 +539,17 @@ struct hdcp_workqueue *hdcp_create_workqueue(struct amdgpu_device *adev, struct cp_psp->funcs.update_stream_config = update_config; cp_psp->handle = hdcp_work; + /* File created at /sys/class/drm/card0/device/hdcp_srm*/ + hdcp_work[0].attr = data_attr; + + if (sysfs_create_bin_file(&adev->dev->kobj, &hdcp_work[0].attr)) + DRM_WARN("Failed to create device file hdcp_srm"); + return hdcp_work; fail_alloc_context: + kfree(hdcp_work->srm); + kfree(hdcp_work->srm_temp); kfree(hdcp_work); return NULL; diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.h index 331b50825510..5159b3a5e5b0 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.h +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.h @@ -53,6 +53,12 @@ struct hdcp_workqueue { enum mod_hdcp_encryption_status encryption_status; uint8_t max_link; + + uint8_t *srm; + uint8_t *srm_temp; + uint32_t srm_version; + uint32_t srm_size; + struct bin_attribute attr; }; void hdcp_update_display(struct hdcp_workqueue *hdcp_work, |