[Intel-gfx] [PATCH v2] drm/hdcp: optimizing the srm handling
Ramalingam C
ramalingam.c at intel.com
Tue Jan 28 05:26:15 UTC 2020
On 2020-01-27 at 16:10:32 -0500, Sean Paul wrote:
> On Mon, Jan 27, 2020 at 11:42:31PM +0530, Ramalingam C wrote:
> > As we are not using the sysfs infrastructure anymore, link to it is
> > removed. And global srm data and mutex to protect it are removed,
> > with required handling at revocation check function.
> >
> > v2:
> > srm_data is dropped and few more comments are addressed.
> >
> > Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> > Suggested-by: Sean Paul <seanpaul at chromium.org>
> > ---
> > drivers/gpu/drm/drm_hdcp.c | 144 ++++++++++++---------------------
> > drivers/gpu/drm/drm_internal.h | 4 -
> > drivers/gpu/drm/drm_sysfs.c | 2 -
> > include/drm/drm_hdcp.h | 4 +-
> > 4 files changed, 55 insertions(+), 99 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_hdcp.c b/drivers/gpu/drm/drm_hdcp.c
> > index 9191633a3c43..30749a13108e 100644
> > --- a/drivers/gpu/drm/drm_hdcp.c
> > +++ b/drivers/gpu/drm/drm_hdcp.c
> > @@ -23,14 +23,6 @@
> >
> > #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",
> > @@ -91,7 +83,8 @@ 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)
> > +static int drm_hdcp_parse_hdcp1_srm(const u8 *buf, size_t count,
> > + u8 *revoked_ksv_list, u32 *revoked_ksv_cnt)
>
> Shouldn't this be u8 **revoked_ksv_list since you want to return the pointer for
> use in the caller? I'm surprised any of this worked when you tested it...
Not tested yet. And forgot to add RFC too. Sorry for wasting your time.
-Ram
>
> > {
> > struct hdcp_srm_header *header;
> > u32 vrl_length, ksv_count;
> > @@ -131,29 +124,28 @@ static int drm_hdcp_parse_hdcp1_srm(const u8 *buf, size_t count)
> > ksv_count = drm_hdcp_get_revoked_ksv_count(buf, vrl_length);
> > if (!ksv_count) {
> > DRM_DEBUG("Revoked KSV count is 0\n");
> > - return count;
> > + return 0;
> > }
> >
> > - 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) {
> > + 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, srm_data->revoked_ksv_list,
> > + if (drm_hdcp_get_revoked_ksvs(buf, revoked_ksv_list,
> > vrl_length) != ksv_count) {
> > - srm_data->revoked_ksv_cnt = 0;
> > - kfree(srm_data->revoked_ksv_list);
> > + *revoked_ksv_cnt = 0;
> > + kfree(revoked_ksv_list);
> > return -EINVAL;
> > }
> >
> > - srm_data->revoked_ksv_cnt = ksv_count;
> > - return count;
> > + *revoked_ksv_cnt = ksv_count;
> > + return 0;
> > }
> >
> > -static int drm_hdcp_parse_hdcp2_srm(const u8 *buf, size_t count)
> > +static int drm_hdcp_parse_hdcp2_srm(const u8 *buf, size_t count,
> > + u8 *revoked_ksv_list, u32 *revoked_ksv_cnt)
>
> Same comment here, this should be u8 **
>
> > {
> > struct hdcp_srm_header *header;
> > u32 vrl_length, ksv_count, ksv_sz;
> > @@ -195,13 +187,11 @@ static int drm_hdcp_parse_hdcp2_srm(const u8 *buf, size_t count)
> > 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;
> > + return 0;
> > }
> >
> > - 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) {
> > + revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, GFP_KERNEL);
> > + if (!revoked_ksv_list) {
> > DRM_ERROR("Out of Memory\n");
> > return -ENOMEM;
> > }
> > @@ -210,10 +200,10 @@ static int drm_hdcp_parse_hdcp2_srm(const u8 *buf, size_t count)
> > 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);
> > + memcpy(revoked_ksv_list, buf, ksv_sz);
> >
> > - srm_data->revoked_ksv_cnt = ksv_count;
> > - return count;
> > + *revoked_ksv_cnt = ksv_count;
> > + return 0;
> > }
> >
> > static inline bool is_srm_version_hdcp1(const u8 *buf)
> > @@ -226,18 +216,22 @@ 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)
> > +static void drm_hdcp_srm_update(const u8 *buf, size_t count,
> > + u8 *revoked_ksv_list, u32 *revoked_ksv_cnt)
>
> and here
>
> > {
> > if (count < sizeof(struct hdcp_srm_header))
> > return;
> >
> > if (is_srm_version_hdcp1(buf))
> > - drm_hdcp_parse_hdcp1_srm(buf, count);
> > + drm_hdcp_parse_hdcp1_srm(buf, count, revoked_ksv_list,
> > + revoked_ksv_cnt);
> > else if (is_srm_version_hdcp2(buf))
> > - drm_hdcp_parse_hdcp2_srm(buf, count);
> > + drm_hdcp_parse_hdcp2_srm(buf, count, revoked_ksv_list,
> > + revoked_ksv_cnt);
> > }
> >
> > -static void drm_hdcp_request_srm(struct drm_device *drm_dev)
> > +static void drm_hdcp_request_srm(struct drm_device *drm_dev,
> > + u8 *revoked_ksv_list, u32 *revoked_ksv_cnt)
>
> and here
>
> > {
> > char fw_name[36] = "display_hdcp_srm.bin";
> > const struct firmware *fw;
> > @@ -250,7 +244,8 @@ static void drm_hdcp_request_srm(struct drm_device *drm_dev)
> > goto exit;
> >
> > if (fw->size && fw->data)
> > - drm_hdcp_srm_update(fw->data, fw->size);
> > + drm_hdcp_srm_update(fw->data, fw->size, revoked_ksv_list,
> > + revoked_ksv_cnt);
> >
> > exit:
> > release_firmware(fw);
> > @@ -279,70 +274,37 @@ static void drm_hdcp_request_srm(struct drm_device *drm_dev)
> > * https://www.digital-cp.com/sites/default/files/specifications/HDCP%20on%20HDMI%20Specification%20Rev2_2_Final1.pdf
> > *
> > * Returns:
> > - * TRUE on any of the KSV is revoked, else FALSE.
> > + * Count of the revoked KSVs.
>
> What about on error?
>
> > */
> > -bool drm_hdcp_check_ksvs_revoked(struct drm_device *drm_dev, u8 *ksvs,
> > - u32 ksv_count)
> > +int drm_hdcp_check_ksvs_revoked(struct drm_device *drm_dev, u8 *ksvs_in,
> > + 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;
> > + u8 *revoked_ksv_list = NULL, *ksvs, *list_itr;
>
> Where is revoked_ksv_list freed?
>
> > + u32 revoked_ksv_cnt = 0, i, j;
> > + int ret = 0;
> > +
> > + drm_hdcp_request_srm(drm_dev, revoked_ksv_list, &revoked_ksv_cnt);
>
> This can't fail?
>
> > + list_itr = revoked_ksv_list;
> > +
> > + for (i = 0; i < revoked_ksv_cnt; i++) {
> > + ksvs = ksvs_in;
> > + for (j = 0; j < ksv_count; j++) {
>
>
> You can save yourself the iterators if you just generate the offsets like:
>
> for (i = 0; i < revoked_ksv_cnt; i++) {
> u8 *a = &ksvs_in[j * DRM_HDCP_KSV_LEN];
> for (j = 0; j < ksv_count; j++) {
> u8 *b = &revoked_ksv_list[i * DRM_HDCP_KSV_LEN];
>
> if (!memcmp(a, b, DRM_HDCP_KSV_LEN)) {
> ...
> }
>
>
>
>
> > + if (!memcmp(ksvs, list_itr, DRM_HDCP_KSV_LEN)) {
> > + DRM_DEBUG("Revoked KSV is ");
> > + drm_hdcp_print_ksv(ksvs);
> > + ret++;
> > + }
> > + /* Iterate to next ksv_offset */
> > + ksvs += DRM_HDCP_KSV_LEN;
> > }
> > -
> > - /* Iterate to next ksv_offset */
> > - ksvs += DRM_HDCP_KSV_LEN;
> > + /* Move the offset to next KSV in the revoked list */
> > + list_itr += 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);
> > - }
> > + 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" },
> > diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
> > index 6937bf923f05..a34c7f8373fa 100644
> > --- a/drivers/gpu/drm/drm_internal.h
> > +++ b/drivers/gpu/drm/drm_internal.h
> > @@ -235,7 +235,3 @@ int drm_syncobj_query_ioctl(struct drm_device *dev, void *data,
> > void drm_framebuffer_print_info(struct drm_printer *p, unsigned int indent,
> > const struct drm_framebuffer *fb);
> > int drm_framebuffer_debugfs_init(struct drm_minor *minor);
> > -
> > -/* drm_hdcp.c */
> > -int drm_setup_hdcp_srm(struct class *drm_class);
> > -void drm_teardown_hdcp_srm(struct class *drm_class);
> > diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
> > index dd2bc85f43cc..2e83c3d72af9 100644
> > --- a/drivers/gpu/drm/drm_sysfs.c
> > +++ b/drivers/gpu/drm/drm_sysfs.c
> > @@ -85,7 +85,6 @@ int drm_sysfs_init(void)
> > }
> >
> > drm_class->devnode = drm_devnode;
> > - drm_setup_hdcp_srm(drm_class);
> > return 0;
> > }
> >
> > @@ -98,7 +97,6 @@ void drm_sysfs_destroy(void)
> > {
> > if (IS_ERR_OR_NULL(drm_class))
> > return;
> > - drm_teardown_hdcp_srm(drm_class);
> > class_remove_file(drm_class, &class_attr_version.attr);
> > class_destroy(drm_class);
> > drm_class = NULL;
> > diff --git a/include/drm/drm_hdcp.h b/include/drm/drm_hdcp.h
> > index 06a11202a097..d512089b873f 100644
> > --- a/include/drm/drm_hdcp.h
> > +++ b/include/drm/drm_hdcp.h
> > @@ -288,8 +288,8 @@ struct hdcp_srm_header {
> > struct drm_device;
> > struct drm_connector;
> >
> > -bool drm_hdcp_check_ksvs_revoked(struct drm_device *dev,
> > - u8 *ksvs, u32 ksv_count);
> > +int drm_hdcp_check_ksvs_revoked(struct drm_device *dev,
> > + u8 *ksvs, u32 ksv_count);
> > int drm_connector_attach_content_protection_property(
> > struct drm_connector *connector, bool hdcp_content_type);
> > void drm_hdcp_update_content_protection(struct drm_connector *connector,
> > --
> > 2.20.1
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Sean Paul, Software Engineer, Google / Chromium OS
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