[PATCH 3/5] drm/amd/display: Add sysfs interface for set/get srm
Harry Wentland
hwentlan at amd.com
Wed Jan 22 19:03:46 UTC 2020
On 2020-01-16 3:29 p.m., Bhawanpreet Lakha wrote:
> [Why]
> We need to set/get SRM and linux kernel is not suppose to write to the
"We need to set/get SRM from/to PSP FW..."
> storage, so we need to provide a interface.
>
an interface.
Highlight that we expect these to be exercised by usermode scripts that
run at boot, shutdown, suspend, and resume.
Harry
> [How]
> Provide interface so usermode can set/get srm
>
> Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha at amd.com>
> Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira at amd.com>
> ---
> .../amd/display/amdgpu_dm/amdgpu_dm_hdcp.c | 124 +++++++++++++++++-
> .../amd/display/amdgpu_dm/amdgpu_dm_hdcp.h | 6 +
> 2 files changed, 128 insertions(+), 2 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..a191c84ad8eb 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,
> @@ -302,7 +326,8 @@ void hdcp_destroy(struct hdcp_workqueue *hdcp_work)
> }
>
> kfree(hdcp_work);
> -
> + kfree(hdcp_work->srm);
> + kfree(hdcp_work->srm_temp);
> }
>
> static void update_config(void *handle, struct cp_psp_stream_config *config)
> @@ -338,6 +363,84 @@ 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);
> }
>
> +
> +/*
> + * This can be called twice, because SRM_SIZE > PAGE_SIZE.
> + *
> + * We set the SRM on each call, if SRM_SIZE > PAGE_SIZE, PSP will fail on the
> + * first call but pass on the second call.
> + *
> + * Because of this we are not throwing any errors as it will stop the next call.
> + * So it is a good idea to call the "read" sysfs to verify that the SRM was set
> + *
> + */
> +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;
> +}
> +
> +
> +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)
> {
>
> @@ -348,10 +451,19 @@ struct hdcp_workqueue *hdcp_create_workqueue(struct amdgpu_device *adev, struct
> if (hdcp_work == NULL)
> goto fail_alloc_context;
>
> + 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);
> @@ -371,10 +483,18 @@ 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);
> + kfree(hdcp_work->srm);
> + kfree(hdcp_work->srm_temp);
>
> 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,
>
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