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Message-ID: <5fca2448-8ddf-cc64-b68b-5b81bc6f711e@linaro.org>
Date: Fri, 7 Apr 2023 19:32:03 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Mark Yacoub <markyacoub@...omium.org>,
David Airlie <airlied@...il.com>,
Daniel Vetter <daniel@...ll.ch>
Cc: suraj.kandpal@...el.com, Jani Nikula <jani.nikula@...el.com>,
intel-gfx@...ts.freedesktop.org, dianders@...omium.org,
dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
seanpaul@...omium.org, freedreno@...ts.freedesktop.org
Subject: Re: [PATCH v8 04/10] drm/hdcp: Expand HDCP helper library for
enable/disable/check
On 01/04/2023 01:12, Mark Yacoub wrote:
> From: Sean Paul <seanpaul@...omium.org>
>
> Expand upon the HDCP helper library to manage HDCP enable, disable, and check.
>
> Previous to this patch, the majority of the state management and sink
> interaction is tucked inside the Intel driver with the understanding
> that once a new platform supported HDCP we could make good decisions
> about what should be centralized. With the addition of HDCP support
> for Qualcomm, it's time to migrate the protocol-specific bits of HDCP
> authentication, key exchange, and link checks to the HDCP helper.
>
> In terms of functionality, this migration is 1:1 with the Intel driver,
> however things are laid out a bit differently than with intel_hdcp.c,
> which is why this is a separate patch from the i915 transition to the
> helper. On i915, the shim vtable is used to account for HDMI vs. DP
> vs. DP-MST differences whereas the helper library uses a LUT to
> account for the register offsets and a remote read function to route
> the messages. On i915, storing the sink information in the source is
> done inline whereas now we use the new drm_hdcp_helper_funcs vtable
> to store and fetch information to/from source hw. Finally, instead of
> calling enable/disable directly from the driver, we'll leave that
> decision to the helper and by calling drm_hdcp_helper_atomic_commit()
> from the driver. All told, this will centralize the protocol and state
> handling in the helper, ensuring we collect all of our bugs^Wlogic
> in one place.
I have a generic question regarding vtable design. Currently low level
accessors are a part of main helper vtable. They are set by the driver.
But when the driver calls drm_hdcp_helper_initialize_hdmi() or
drm_hdcp_helper_initialize_dp(), we also know, which low level backend
should be used. Can be have a struct describing hdmi vs dp functions and
move that to the helper too?
For the reference: earlier revisions had it in form of if (aux) spread
all over the low level functions. I asked to split those accessors
(thank you!) but I think we can still have them as a set of functions
internal to the helper.
>
> Acked-by: Jani Nikula <jani.nikula@...el.com>
> Signed-off-by: Sean Paul <seanpaul@...omium.org>
> Signed-off-by: Mark Yacoub <markyacoub@...omium.org>
>
> ---
> Changes in v2:
> -Fixed set-but-unused variable identified by 0-day
> Changes in v3:
> -Fixed uninitialized variable warning identified by 0-day
> Changes in v4:
> -None
> Changes in v5:
> -None
> Changes in v6:
> -Fixed typo in function descriptions
> -Rebased: Moved the new code between drm_hdcp.h and drm_hdcp_helper.c/h
> -Add missing headers. Reported-by: kernel test robot <lkp@...el.com>
> Changes in v7:
> - Add a |driver_data| field to some functions in drm_hdcp_helper_funcs
> that are called by the driver so drivers can pass anything they such
> as bridges
> - Isolate all non-common code between HDMI and DP into separate
> functions instead of manually checking for datra->aux
> Changes in v8 (suraj):
> -Try hdcp 1.x if hdcp2_capable returns an error instead of goto out.
> -set the enabled type to either 1 or 0 depending on the prop as hdcp2
> can support either.
>
> drivers/gpu/drm/display/drm_hdcp_helper.c | 1215 +++++++++++++++++++++
> include/drm/display/drm_hdcp.h | 287 +++++
> include/drm/display/drm_hdcp_helper.h | 51 +-
> 3 files changed, 1552 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/display/drm_hdcp_helper.c b/drivers/gpu/drm/display/drm_hdcp_helper.c
> index 3ee1a6ae26c53..3bc0308cc95d8 100644
> --- a/drivers/gpu/drm/display/drm_hdcp_helper.c
> +++ b/drivers/gpu/drm/display/drm_hdcp_helper.c
> @@ -6,13 +6,18 @@
> * Ramalingam C <ramalingam.c@...el.com>
> */
>
> +#include <linux/delay.h>
> #include <linux/device.h>
> #include <linux/err.h>
> #include <linux/gfp.h>
> +#include <linux/i2c.h>
> +#include <linux/iopoll.h>
> #include <linux/export.h>
> #include <linux/slab.h>
> #include <linux/firmware.h>
> +#include <linux/workqueue.h>
>
> +#include <drm/display/drm_dp_helper.h>
> #include <drm/display/drm_hdcp_helper.h>
> #include <drm/drm_sysfs.h>
> #include <drm/drm_print.h>
> @@ -507,3 +512,1213 @@ bool drm_hdcp_has_changed(struct drm_connector *connector,
> return old_hdcp != new_hdcp;
> }
> EXPORT_SYMBOL(drm_hdcp_has_changed);
> +
> +struct drm_hdcp_hdcp1_receiver_reg_lut {
> + unsigned int bksv;
> + unsigned int ri;
> + unsigned int aksv;
> + unsigned int an;
> + unsigned int ainfo;
> + unsigned int v[5];
> + unsigned int bcaps;
> + unsigned int bcaps_mask_repeater_present;
> + unsigned int bstatus;
> +};
> +
> +static const struct drm_hdcp_hdcp1_receiver_reg_lut drm_hdcp_hdcp1_ddc_lut = {
> + .bksv = DRM_HDCP_DDC_BKSV,
> + .ri = DRM_HDCP_DDC_RI_PRIME,
> + .aksv = DRM_HDCP_DDC_AKSV,
> + .an = DRM_HDCP_DDC_AN,
> + .ainfo = DRM_HDCP_DDC_AINFO,
> + .v = { DRM_HDCP_DDC_V_PRIME(0), DRM_HDCP_DDC_V_PRIME(1),
> + DRM_HDCP_DDC_V_PRIME(2), DRM_HDCP_DDC_V_PRIME(3),
> + DRM_HDCP_DDC_V_PRIME(4) },
> + .bcaps = DRM_HDCP_DDC_BCAPS,
> + .bcaps_mask_repeater_present = DRM_HDCP_DDC_BCAPS_REPEATER_PRESENT,
> + .bstatus = DRM_HDCP_DDC_BSTATUS,
> +};
> +
> +static const struct drm_hdcp_hdcp1_receiver_reg_lut drm_hdcp_hdcp1_dpcd_lut = {
> + .bksv = DP_AUX_HDCP_BKSV,
> + .ri = DP_AUX_HDCP_RI_PRIME,
> + .aksv = DP_AUX_HDCP_AKSV,
> + .an = DP_AUX_HDCP_AN,
> + .ainfo = DP_AUX_HDCP_AINFO,
> + .v = { DP_AUX_HDCP_V_PRIME(0), DP_AUX_HDCP_V_PRIME(1),
> + DP_AUX_HDCP_V_PRIME(2), DP_AUX_HDCP_V_PRIME(3),
> + DP_AUX_HDCP_V_PRIME(4) },
> + .bcaps = DP_AUX_HDCP_BCAPS,
> + .bcaps_mask_repeater_present = DP_BCAPS_REPEATER_PRESENT,
> +
> + /*
> + * For some reason the HDMI and DP HDCP specs call this register
> + * definition by different names. In the HDMI spec, it's called BSTATUS,
> + * but in DP it's called BINFO.
> + */
> + .bstatus = DP_AUX_HDCP_BINFO,
> +};
> +
> +/*
> + * Read a DPCD register.
> + *
> + * @data: drm_hdcp_helper_data containing the DisplayPort AUX channel (SST or MST)
> + * @offset: address of the (first) register to read
> + * @value: buffer to store the register values
> + * @len: number of bytes in @value
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +int drm_hdcp_remote_dpcd_read(struct drm_hdcp_helper_data *data,
> + unsigned int offset, u8 *value, size_t len)
> +{
> + ssize_t ret;
> + struct drm_dp_aux *aux = data->aux;
> +
> + ret = drm_dp_dpcd_read(aux, offset, value, len);
> + if (ret != len) {
> + if (ret >= 0)
> + return -EIO;
> + return ret;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_hdcp_remote_dpcd_read);
> +
> +/*
> + * Read a value from a remote DDC bus.
> + *
> + * @data: drm_hdcp_helper_data containing the i2c_adapter.
> + * @offset: Offset of the value to read.
> + * @value: Pointer to the value to read.
> + * @len: Length of the value to read.
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +
> +int drm_hdcp_remote_ddc_read(struct drm_hdcp_helper_data *data,
> + unsigned int offset, u8 *value, size_t len)
> +{
> + int ret;
> + struct i2c_adapter *i2c = data->connector->ddc;
> + u8 start = offset & 0xff;
> + struct i2c_msg msgs[] = { { .addr = DRM_HDCP_DDC_ADDR,
> + .flags = 0,
> + .len = 1,
> + .buf = &start },
> + { .addr = DRM_HDCP_DDC_ADDR,
> + .flags = I2C_M_RD,
> + .len = len,
> + .buf = value } };
> + ret = i2c_transfer(i2c, msgs, ARRAY_SIZE(msgs));
> + if (ret == ARRAY_SIZE(msgs))
> + return 0;
> + return ret >= 0 ? -EIO : ret;
> +}
> +EXPORT_SYMBOL(drm_hdcp_remote_ddc_read);
> +
> +/*
> + * Write to a DPCD register.
> + *
> + * @data: drm_hdcp_helper_data containing the DisplayPort AUX channel (SST or MST)
> + * @offset: Offset of the DPCD register to read from
> + * @value: Pointer to store the DPCD register data
> + * @len: Number of bytes to read
> + *
> + * Returns:
> + * Zero on success or a negative error code on failure
> + */
> +int drm_hdcp_remote_dpcd_write(struct drm_hdcp_helper_data *data,
> + unsigned int offset, u8 *value, size_t len)
> +{
> + ssize_t ret;
> + struct drm_dp_aux *aux = data->aux;
> +
> + ret = drm_dp_dpcd_write(aux, offset, value, len);
> + if (ret != len) {
> + if (ret >= 0)
> + return -EIO;
> + return ret;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_hdcp_remote_dpcd_write);
> +
> +/*
> + * Write data to the HDCP DDC slave device
> + *
> + * @data: drm_hdcp_helper_data containing the i2c_adapter.
> + * @offset: the offset to write to
> + * @buffer: the data to write
> + * @size: the size of the data
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +int drm_hdcp_remote_ddc_write(struct drm_hdcp_helper_data *data,
> + unsigned int offset, u8 *buffer, size_t len)
> +{
> + int ret;
> + u8 *write_buf;
> + struct i2c_msg msg;
> + struct i2c_adapter *i2c = data->connector->ddc;
> +
> + write_buf = kzalloc(len + 1, GFP_KERNEL);
> + if (!write_buf)
> + return -ENOMEM;
> +
> + write_buf[0] = offset & 0xff;
> + memcpy(&write_buf[1], buffer, len);
> +
> + msg.addr = DRM_HDCP_DDC_ADDR;
> + msg.flags = 0, msg.len = len + 1, msg.buf = write_buf;
> +
> + ret = i2c_transfer(i2c, &msg, 1);
> + if (ret == 1)
> + ret = 0;
> + else if (ret >= 0)
> + ret = -EIO;
> +
> + kfree(write_buf);
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_hdcp_remote_ddc_write);
> +
> +static bool drm_hdcp_is_ksv_valid(struct drm_hdcp_ksv *ksv)
> +{
> + /* Valid Ksv has 20 0's and 20 1's */
> + return hweight32(ksv->words[0]) + hweight32(ksv->words[1]) == 20;
> +}
> +
> +static int drm_hdcp_read_valid_bksv(struct drm_hdcp_helper_data *data,
> + struct drm_hdcp_ksv *bksv)
> +{
> + int ret, i, tries = 2;
> +
> + /* HDCP spec states that we must retry the bksv if it is invalid */
> + for (i = 0; i < tries; i++) {
> + ret = data->funcs->remote_read(data, data->hdcp1_lut->bksv,
> + bksv->bytes, DRM_HDCP_KSV_LEN);
> + if (ret)
> + return ret;
> +
> + if (drm_hdcp_is_ksv_valid(bksv))
> + break;
> + }
> + if (i == tries) {
> + drm_dbg_kms(data->connector->dev, "Bksv is invalid %*ph\n",
> + DRM_HDCP_KSV_LEN, bksv->bytes);
> + return -ENODEV;
> + }
> +
> + return 0;
> +}
> +
> +/**
> + * Check if the sink is capable of HDCP 1.x. DisplayPort has a dedicated bit
> + * for this in DPCD.
> + *
> + * @data: pointer to the HDCP helper data.
> + * @capable: pointer to a bool which will contain true if the sink is capable.
> + *
> + * Returns:
> + * -errno if the transacation between source and sink fails.
> + */
> +int drm_hdcp_helper_hdcp1_capable_dp(struct drm_hdcp_helper_data *data,
> + bool *capable)
> +{
> + int ret;
> + u8 bcaps;
> +
> + ret = data->funcs->remote_read(data, data->hdcp1_lut->bcaps, &bcaps, 1);
> + *capable = !ret && (bcaps & DP_BCAPS_HDCP_CAPABLE);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_hdcp1_capable_dp);
> +
> +/**
> + * Check if the sink is capable of HDCP 1.x. HDMI spec states that transmitters
> + * should use bksv to determine capability
> + *
> + * @data: pointer to the HDCP helper data.
> + * @capable: pointer to a bool which will contain true if the sink is capable.
> + *
> + * Returns:
> + * -errno if the transacation between source and sink fails.
> + */
> +int drm_hdcp_helper_hdcp1_capable_hdmi(struct drm_hdcp_helper_data *data,
> + bool *capable)
> +{
> + struct drm_hdcp_ksv bksv;
> + *capable = drm_hdcp_read_valid_bksv(data, &bksv) == 0;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_hdcp1_capable_hdmi);
> +
> +static void drm_hdcp_update_value(struct drm_hdcp_helper_data *data, u64 value,
> + bool update_property)
> +{
> + WARN_ON(!mutex_is_locked(&data->mutex));
> +
> + data->value = value;
> + if (update_property) {
> + drm_connector_get(data->connector);
> + schedule_work(&data->prop_work);
> + }
> +}
> +
> +int drm_hdcp_helper_hdcp1_ksv_fifo_ready_dp(struct drm_hdcp_helper_data *data)
> +{
> + u8 val;
> + u8 mask = DP_BSTATUS_READY;
> + int ret = drm_hdcp_remote_dpcd_read(data, DP_AUX_HDCP_BSTATUS, &val, 1);
> +
> + if (ret)
> + return ret;
> + if (val & mask)
> + return 0;
> +
> + return -EAGAIN;
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_hdcp1_ksv_fifo_ready_dp);
> +
> +int drm_hdcp_helper_hdcp1_ksv_fifo_ready_hdmi(struct drm_hdcp_helper_data *data)
> +{
> + u8 val;
> + u8 mask = DRM_HDCP_DDC_BCAPS_KSV_FIFO_READY;
> + int ret = drm_hdcp_remote_ddc_read(data, DRM_HDCP_DDC_BCAPS, &val, 1);
> +
> + if (ret)
> + return ret;
> + if (val & mask)
> + return 0;
> +
> + return -EAGAIN;
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_hdcp1_ksv_fifo_ready_hdmi);
> +
> +/* Read the KSV FIFO of the HDCP receive of DP.
> + * Read via 15 byte window (3 entries @ 5 bytes each)
> + *
> + * @fifo: buffer to store the KSV FIFO
> + * @num_downstream: number of devices in the KSV FIFO
> + */
> +int drm_hdcp_helper_hdcp1_read_ksv_fifo_dp(struct drm_hdcp_helper_data *data,
> + u8 *fifo, u8 num_downstream)
> +{
> + struct drm_device *dev = data->connector->dev;
> + int i;
> +
> + for (i = 0; i < num_downstream; i += 3) {
> + size_t len = min(num_downstream - i, 3) * DRM_HDCP_KSV_LEN;
> + int ret = drm_hdcp_remote_dpcd_read(data, DP_AUX_HDCP_KSV_FIFO,
> + fifo + i * DRM_HDCP_KSV_LEN,
> + len);
> + if (ret) {
> + drm_err(dev, "Read ksv[%d] from DP/AUX failed (%d)\n",
> + i, ret);
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_hdcp1_read_ksv_fifo_dp);
> +
> +/* Read the KSV FIFO of the HDCP receive of HDMI.
> + * Over HDMI, read the whole thing at once.
> + *
> + * @fifo: buffer to store the KSV FIFO
> + * @num_downstream: number of devices in the KSV FIFO
> + */
> +int drm_hdcp_helper_hdcp1_read_ksv_fifo_hdmi(struct drm_hdcp_helper_data *data,
> + u8 *fifo, u8 num_downstream)
> +{
> + struct drm_device *dev = data->connector->dev;
> +
> + int ret = drm_hdcp_remote_ddc_read(data, DRM_HDCP_DDC_KSV_FIFO, fifo,
> + num_downstream * DRM_HDCP_KSV_LEN);
> + if (ret)
> + drm_err(dev, "DDC ksv fifo read failed (%d)\n", ret);
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_hdcp1_read_ksv_fifo_hdmi);
> +
> +static int drm_hdcp_helper_hdcp1_read_v_prime(struct drm_hdcp_helper_data *data,
> + u32 *v_prime)
> +{
> + struct drm_device *dev = data->connector->dev;
> + int ret, i;
> +
> + for (i = 0; i < DRM_HDCP_V_PRIME_NUM_PARTS; i++) {
> + ret = data->funcs->remote_read(data, data->hdcp1_lut->v[i],
> + (u8 *)&v_prime[i],
> + DRM_HDCP_V_PRIME_PART_LEN);
> + if (ret) {
> + drm_dbg_kms(dev, "Read v'[%d] from failed (%d)\n", i,
> + ret);
> + return ret >= 0 ? -EIO : ret;
> + }
> + }
> + return 0;
> +}
> +
> +static int
> +drm_hdcp_helper_hdcp1_authenticate_downstream(struct drm_hdcp_helper_data *data)
> +{
> + struct drm_connector *connector = data->connector;
> + struct drm_device *dev = connector->dev;
> + u32 v_prime[DRM_HDCP_V_PRIME_NUM_PARTS];
> + u8 bstatus[DRM_HDCP_BSTATUS_LEN];
> + u8 num_downstream, *ksv_fifo;
> + int ret, i, tries = 3;
> +
> + ret = read_poll_timeout(data->funcs->hdcp1_ksv_fifo_ready, ret, !ret,
> + 10 * 1000, 5 * 1000 * 1000, false, data);
> + if (ret) {
> + drm_err(dev, "Failed to poll ksv ready, %d\n", ret);
> + return ret;
> + }
> +
> + ret = data->funcs->remote_read(data, data->hdcp1_lut->bstatus, bstatus,
> + DRM_HDCP_BSTATUS_LEN);
> + if (ret)
> + return ret;
> +
> + /*
> + * When repeater reports 0 device count, HDCP1.4 spec allows disabling
> + * the HDCP encryption. That implies that repeater can't have its own
> + * display. As there is no consumption of encrypted content in the
> + * repeater with 0 downstream devices, we are failing the
> + * authentication.
> + */
> + num_downstream = DRM_HDCP_NUM_DOWNSTREAM(bstatus[0]);
> + if (num_downstream == 0) {
> + drm_err(dev, "Repeater with zero downstream devices, %*ph\n",
> + DRM_HDCP_BSTATUS_LEN, bstatus);
> + return -EINVAL;
> + }
> +
> + ksv_fifo = kcalloc(DRM_HDCP_KSV_LEN, num_downstream, GFP_KERNEL);
> + if (!ksv_fifo)
> + return -ENOMEM;
> +
> + ret = data->funcs->hdcp1_read_ksv_fifo(data, ksv_fifo, num_downstream);
> + if (ret) {
> + drm_err(dev, "Failed to read ksv fifo, %d/%d\n", num_downstream,
> + ret);
> + goto out;
> + }
> +
> + if (drm_hdcp_check_ksvs_revoked(dev, ksv_fifo, num_downstream)) {
> + drm_err(dev, "Revoked Ksv(s) in ksv_fifo\n");
> + ret = -EPERM;
> + goto out;
> + }
> +
> + /*
> + * When V prime mismatches, DP Spec mandates re-read of
> + * V prime at least twice.
> + */
> + for (i = 0; i < tries; i++) {
> + ret = drm_hdcp_helper_hdcp1_read_v_prime(data, v_prime);
> + if (ret)
> + continue;
> +
> + ret = data->funcs->hdcp1_store_ksv_fifo(connector, ksv_fifo,
> + num_downstream, bstatus,
> + v_prime,
> + data->driver_data);
> + if (!ret)
> + break;
> + }
> + if (ret)
> + drm_err(dev, "Could not validate KSV FIFO with V' %d\n", ret);
> +
> +out:
> + if (!ret)
> + drm_dbg_kms(dev, "HDCP is enabled (%d downstream devices)\n",
> + num_downstream);
> +
> + kfree(ksv_fifo);
> + return ret;
> +}
> +
> +static int drm_hdcp_helper_hdcp1_validate_ri(struct drm_hdcp_helper_data *data)
> +{
> + union {
> + u32 word;
> + u8 bytes[DRM_HDCP_RI_LEN];
> + } ri_prime = { .word = 0 };
> + struct drm_connector *connector = data->connector;
> + struct drm_device *dev = connector->dev;
> + int ret;
> +
> + ret = data->funcs->remote_read(data, data->hdcp1_lut->ri,
> + ri_prime.bytes, DRM_HDCP_RI_LEN);
> + if (ret) {
> + drm_err(dev, "Failed to read R0' %d\n", ret);
> + return ret;
> + }
> +
> + return data->funcs->hdcp1_match_ri(connector, ri_prime.word,
> + data->driver_data);
> +}
> +
> +/*
> + * Wait for the DP receiver to set the R0' ready bit in the Bstatus register.
> + * This bit is set to 1 when the receiver has received and validated the
> + * receiver ID list and receiver capability list.
> + * The receiver must set this bit to 1 within 200 ms of the receiver ID
> + * list and receiver capability list being received.
> + *
> + * @data: DRM HDCP helper data structure
> + * @r0_prime_remaining_us: timeout for the R0' ready bit
> + *
> + * Return: 0 on success, error code on failure
> + */
> +int drm_hdcp_helper_wait_r0_dp(struct drm_hdcp_helper_data *data,
> + unsigned long r0_prime_remaining_us)
> +{
> + u8 val;
> + int ret = 0;
> +
> + ret = read_poll_timeout(drm_hdcp_remote_dpcd_read, ret,
> + !ret && (val & DP_BSTATUS_R0_PRIME_READY), 1000,
> + r0_prime_remaining_us, false, data,
> + DP_AUX_HDCP_BSTATUS, &val, 1);
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_wait_r0_dp);
> +
> +/*
> + * drm_hdcp_helper_wait_r0_hdmi - Wait for R0 to be ready on HDMI
> + * @data: DRM HDCP helper data
> + * @r0_prime_remaining_us: Remaining time to wait for R0 in microseconds
> + *
> + * HDMI doesn't have a R0_READY bit, so we just have to wait the remainder of the
> + * 300 ms timeout.
> + *
> + * Returns:
> + * 0 on success, negative error code on failure
> + */
> +
> +int drm_hdcp_helper_wait_r0_hdmi(struct drm_hdcp_helper_data *data,
> + unsigned long r0_prime_remaining_us)
> +{
> + usleep_range(r0_prime_remaining_us, r0_prime_remaining_us + 1000);
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_wait_r0_hdmi);
> +
> +static int drm_hdcp_helper_hdcp1_authenticate(struct drm_hdcp_helper_data *data)
> +{
> + union {
> + u32 word;
> + u8 bytes[DRM_HDCP_BSTATUS_LEN];
> + } bstatus;
> + const struct drm_hdcp_helper_funcs *funcs = data->funcs;
> + struct drm_connector *connector = data->connector;
> + struct drm_device *dev = connector->dev;
> + unsigned long r0_prime_timeout, r0_prime_remaining_us = 0, tmp_jiffies;
> + struct drm_hdcp_ksv aksv;
> + struct drm_hdcp_ksv bksv;
> + struct drm_hdcp_an an;
> + bool repeater_present;
> + int ret, i, tries = 3;
> + u8 bcaps;
> +
> + if (funcs->hdcp1_read_an_aksv) {
> + ret = funcs->hdcp1_read_an_aksv(connector, an.words, aksv.words,
> + data->driver_data);
> + if (ret) {
> + drm_err(dev, "Failed to read An/Aksv values, %d\n",
> + ret);
> + return ret;
> + }
> +
> + ret = funcs->remote_write(data, data->hdcp1_lut->an, an.bytes,
> + DRM_HDCP_AN_LEN);
> + if (ret) {
> + drm_err(dev, "Failed to write An to receiver, %d\n",
> + ret);
> + return ret;
> + }
> +
> + ret = funcs->remote_write(data, data->hdcp1_lut->aksv,
> + aksv.bytes, DRM_HDCP_KSV_LEN);
> + if (ret) {
> + drm_err(dev, "Failed to write Aksv to receiver, %d\n",
> + ret);
> + return ret;
> + }
> + } else {
> + ret = funcs->hdcp1_send_an_aksv(connector, data->driver_data);
> + if (ret) {
> + drm_err(dev, "Failed to read An/Aksv values, %d\n",
> + ret);
> + return ret;
> + }
> + }
> +
> + /*
> + * Timeout for R0' to become available. The spec says 100ms from Aksv,
> + * but some monitors can take longer than this. We'll set the timeout at
> + * 300ms just to be sure.
> + */
> + r0_prime_timeout = jiffies + msecs_to_jiffies(300);
> +
> + memset(&bksv, 0, sizeof(bksv));
> +
> + ret = drm_hdcp_read_valid_bksv(data, &bksv);
> + if (ret < 0)
> + return ret;
> +
> + if (drm_hdcp_check_ksvs_revoked(dev, bksv.bytes, 1)) {
> + drm_err(dev, "BKSV is revoked\n");
> + return -EPERM;
> + }
> +
> + ret = funcs->remote_read(data, data->hdcp1_lut->bcaps, &bcaps, 1);
> + if (ret)
> + return ret;
> +
> + memset(&bstatus, 0, sizeof(bstatus));
> +
> + ret = funcs->remote_read(data, data->hdcp1_lut->bstatus, bstatus.bytes,
> + DRM_HDCP_BSTATUS_LEN);
> + if (ret)
> + return ret;
> +
> + if (DRM_HDCP_MAX_DEVICE_EXCEEDED(bstatus.bytes[0]) ||
> + DRM_HDCP_MAX_CASCADE_EXCEEDED(bstatus.bytes[1])) {
> + drm_err(dev, "Max Topology Limit Exceeded, bstatus=%*ph\n",
> + DRM_HDCP_BSTATUS_LEN, bstatus.bytes);
> + return -EPERM;
> + }
> +
> + repeater_present = bcaps & data->hdcp1_lut->bcaps_mask_repeater_present;
> +
> + ret = funcs->hdcp1_store_receiver_info(connector, bksv.words,
> + bstatus.word, bcaps,
> + repeater_present,
> + data->driver_data);
> + if (ret) {
> + drm_err(dev, "Failed to store bksv, %d\n", ret);
> + return ret;
> + }
> +
> + ret = funcs->hdcp1_enable_encryption(connector, data->driver_data);
> + if (ret)
> + return ret;
> +
> + ret = funcs->hdcp1_wait_for_r0(connector, data->driver_data);
> + if (ret)
> + return ret;
> +
> + tmp_jiffies = jiffies;
> + if (time_before(tmp_jiffies, r0_prime_timeout))
> + r0_prime_remaining_us =
> + jiffies_to_usecs(r0_prime_timeout - tmp_jiffies);
> +
> + ret = funcs->wait_r0(data, r0_prime_remaining_us);
> + if (ret) {
> + drm_err(dev, "R0' did not become ready %d\n", ret);
> + return ret;
> + }
> +
> + /*
> + * DP HDCP Spec mandates the two more reattempt to read R0, in case
> + * of R0 mismatch.
> + */
> + for (i = 0; i < tries; i++) {
> + ret = drm_hdcp_helper_hdcp1_validate_ri(data);
> + if (!ret)
> + break;
> + }
> + if (ret) {
> + drm_err(dev, "Failed to match R0/R0', aborting HDCP %d\n", ret);
> + return ret;
> + }
> +
> + if (repeater_present)
> + return drm_hdcp_helper_hdcp1_authenticate_downstream(data);
> +
> + drm_dbg_kms(dev, "HDCP is enabled (no repeater present)\n");
> + return 0;
> +}
> +
> +static int drm_hdcp_helper_hdcp1_enable(struct drm_hdcp_helper_data *data)
> +{
> + struct drm_connector *connector = data->connector;
> + struct drm_device *dev = connector->dev;
> + int i, ret, tries = 3;
> +
> + drm_dbg_kms(dev, "[%s:%d] HDCP is being enabled...\n", connector->name,
> + connector->base.id);
> +
> + /* In case of authentication failures, HDCP spec expects reauth. */
> + for (i = 0; i < tries; i++) {
> + ret = drm_hdcp_helper_hdcp1_authenticate(data);
> + if (!ret)
> + return 0;
> +
> + drm_dbg_kms(dev, "HDCP Auth failure (%d)\n", ret);
> +
> + /* Ensuring HDCP encryption and signalling are stopped. */
> + data->funcs->hdcp1_disable(data->connector, data->driver_data);
> + }
> +
> + drm_err(dev, "HDCP authentication failed (%d tries/%d)\n", tries, ret);
> + return ret;
> +}
> +
> +static inline void
> +drm_hdcp_helper_driver_lock(struct drm_hdcp_helper_data *data)
> +{
> + if (data->driver_mutex)
> + mutex_lock(data->driver_mutex);
> +}
> +
> +static inline void
> +drm_hdcp_helper_driver_unlock(struct drm_hdcp_helper_data *data)
> +{
> + if (data->driver_mutex)
> + mutex_unlock(data->driver_mutex);
> +}
> +
> +static int drm_hdcp_helper_enable_hdcp(struct drm_hdcp_helper_data *data,
> + struct drm_atomic_state *state,
> + struct mutex *driver_mutex)
> +{
> + struct drm_connector *connector = data->connector;
> + struct drm_connector_state *conn_state;
> + struct drm_device *dev = connector->dev;
> + unsigned long check_link_interval = DRM_HDCP2_CHECK_PERIOD_MS;
> + bool capable;
> + int ret = 0;
> +
> + conn_state = drm_atomic_get_new_connector_state(state, connector);
> +
> + mutex_lock(&data->mutex);
> +
> + if (data->value == DRM_MODE_CONTENT_PROTECTION_ENABLED) {
> + drm_hdcp_update_value(data, DRM_MODE_CONTENT_PROTECTION_ENABLED,
> + true);
> + goto out_data_mutex;
> + }
> +
> + drm_WARN_ON(dev, data->driver_mutex != NULL);
> + data->driver_mutex = driver_mutex;
> +
> + drm_hdcp_helper_driver_lock(data);
> +
> + if (data->funcs->setup) {
> + ret = data->funcs->setup(connector, state, data->driver_data);
> + if (ret) {
> + drm_err(dev, "Failed to setup HDCP %d\n", ret);
> + goto out;
> + }
> + }
> +
> + if (!data->funcs->are_keys_valid ||
> + !data->funcs->are_keys_valid(connector, data->driver_data)) {
> + if (data->funcs->load_keys) {
> + ret = data->funcs->load_keys(connector,
> + data->driver_data);
> + if (ret) {
> + drm_err(dev, "Failed to load HDCP keys %d\n",
> + ret);
> + goto out;
> + }
> + }
> + }
> +
> + /*
> + * Considering that HDCP2.2 is more secure than HDCP1.4, If the setup
> + * is capable of HDCP2.2, it is preferred to use HDCP2.2.
> + */
> + ret = data->funcs->hdcp2_capable(connector, &capable,
> + data->driver_data);
> + if (ret)
> + drm_err(dev, "HDCP 2.x capability check failed %d\n", ret);
> +
> + if (!ret && capable) {
> + if (conn_state->content_type == DRM_MODE_HDCP_CONTENT_TYPE1) {
> + data->enabled_type = DRM_MODE_HDCP_CONTENT_TYPE1;
> + } else {
> + data->enabled_type = DRM_MODE_HDCP_CONTENT_TYPE0;
> + }
> +
> + ret = data->funcs->hdcp2_enable(connector, data->driver_data);
> + if (!ret) {
> + check_link_interval = DRM_HDCP2_CHECK_PERIOD_MS;
> + goto out;
> + }
> + }
> +
> + /*
> + * When HDCP2.2 fails and Content Type is not Type1, HDCP1.4 will
> + * be attempted.
> + */
> + ret = data->funcs->hdcp1_capable(data, &capable);
> + if (ret) {
> + drm_err(dev, "HDCP 1.x capability check failed %d\n", ret);
> + goto out;
> + }
> + if (capable &&
> + conn_state->content_type != DRM_MODE_HDCP_CONTENT_TYPE1) {
> + data->enabled_type = DRM_MODE_HDCP_CONTENT_TYPE0;
> + ret = drm_hdcp_helper_hdcp1_enable(data);
> + if (!ret)
> + check_link_interval = DRM_HDCP_CHECK_PERIOD_MS;
> + }
> +
> +out:
> + if (!ret) {
> + schedule_delayed_work(&data->check_work, check_link_interval);
> + drm_hdcp_update_value(data, DRM_MODE_CONTENT_PROTECTION_ENABLED,
> + true);
> + }
> +
> + drm_hdcp_helper_driver_unlock(data);
> + if (ret)
> + data->driver_mutex = NULL;
> +
> +out_data_mutex:
> + mutex_unlock(&data->mutex);
> + return ret;
> +}
> +
> +static int drm_hdcp_helper_disable_hdcp(struct drm_hdcp_helper_data *data)
> +{
> + int ret = 0;
> +
> + mutex_lock(&data->mutex);
> + drm_hdcp_helper_driver_lock(data);
> +
> + if (data->value == DRM_MODE_CONTENT_PROTECTION_UNDESIRED)
> + goto out;
> +
> + drm_dbg_kms(data->connector->dev, "[%s:%d] HDCP is being disabled...\n",
> + data->connector->name, data->connector->base.id);
> +
> + drm_hdcp_update_value(data, DRM_MODE_CONTENT_PROTECTION_UNDESIRED,
> + true);
> +
> + if (data->enabled_type == DRM_MODE_HDCP_CONTENT_TYPE1)
> + ret = data->funcs->hdcp2_disable(data->connector,
> + data->driver_data);
> + else
> + ret = data->funcs->hdcp1_disable(data->connector,
> + data->driver_data);
> +
> + drm_dbg_kms(data->connector->dev, "HDCP is disabled\n");
> +
> +out:
> + drm_hdcp_helper_driver_unlock(data);
> + data->driver_mutex = NULL;
> + mutex_unlock(&data->mutex);
> + cancel_delayed_work_sync(&data->check_work);
> + return ret;
> +}
> +
> +/**
> + * drm_hdcp_helper_atomic_commit - Helper for drivers to call during commit to
> + * enable/disable HDCP
> + *
> + * @data: pointer to the @drm_hdcp_helper_data for the connector
> + * @state: pointer to the atomic state being committed
> + * @driver_mutex: driver-provided lock to be used while interacting with the driver
> + *
> + * This function can be used by display drivers to determine when HDCP should be
> + * enabled or disabled based on the connector state. It should be called during
> + * steady-state commits as well as connector enable/disable. The function will
> + * handle the HDCP authentication/encryption logic, calling back into the driver
> + * when source operations are necessary.
> + *
> + * @driver_mutex will be retained and used for the duration of the HDCP session
> + * since it will be needed for link checks and retries. This mutex is useful if
> + * the driver has shared resources across connectors which must be serialized.
> + * For example, driver_mutex can be used for MST connectors sharing a common
> + * encoder which should not be accessed/changed concurrently. When the
> + * connector's session is torn down, the mutex will be forgotten by the helper
> + * for this connector until the next session.
> + */
> +void drm_hdcp_helper_atomic_commit(struct drm_hdcp_helper_data *data,
> + struct drm_atomic_state *state,
> + struct mutex *driver_mutex)
> +{
> + struct drm_connector *connector = data->connector;
> + struct drm_connector_state *conn_state;
> + bool type_changed;
> +
> + conn_state = drm_atomic_get_new_connector_state(state, connector);
> + if (!conn_state)
> + return;
> +
> + type_changed = conn_state->hdcp_content_type != data->enabled_type;
> +
> + if (conn_state->content_protection ==
> + DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
> + drm_hdcp_helper_disable_hdcp(data);
> + return;
> + }
> +
> + if (!conn_state->crtc) {
> + drm_hdcp_helper_disable_hdcp(data);
> +
> + /* Restore property to DESIRED so it's retried later */
> + if (conn_state->content_protection ==
> + DRM_MODE_CONTENT_PROTECTION_ENABLED) {
> + mutex_lock(&data->mutex);
> + drm_hdcp_update_value(
> + data, DRM_MODE_CONTENT_PROTECTION_DESIRED,
> + true);
> + mutex_unlock(&data->mutex);
> + }
> + return;
> + }
> +
> + /* Already enabled */
> + if (conn_state->content_protection ==
> + DRM_MODE_CONTENT_PROTECTION_ENABLED)
> + return;
> +
> + /* Disable and re-enable HDCP on content type change */
> + if (type_changed)
> + drm_hdcp_helper_disable_hdcp(data);
> +
> + drm_hdcp_helper_enable_hdcp(data, state, driver_mutex);
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_atomic_commit);
> +
> +static void drm_hdcp_helper_prop_work(struct work_struct *work)
> +{
> + struct drm_hdcp_helper_data *data =
> + container_of(work, struct drm_hdcp_helper_data, prop_work);
> + struct drm_connector *connector = data->connector;
> + struct drm_device *dev = connector->dev;
> +
> + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
> + mutex_lock(&data->mutex);
> +
> + /*
> + * This worker is only used to flip between ENABLED/DESIRED. Either of
> + * those to UNDESIRED is handled by core. If value == UNDESIRED,
> + * we're running just after hdcp has been disabled, so just exit
> + */
> + if (data->value != DRM_MODE_CONTENT_PROTECTION_UNDESIRED)
> + drm_hdcp_update_content_protection(connector, data->value);
> +
> + mutex_unlock(&data->mutex);
> + drm_modeset_unlock(&dev->mode_config.connection_mutex);
> +}
> +
> +/*
> + * Check the link registers for HDCP 1.x for DP.
> + */
> +int drm_hdcp_hdcp1_check_link_registers_dp(struct drm_device *dev,
> + struct drm_hdcp_helper_data *data,
> + bool *shoud_retry)
> +{
> + u8 bstatus;
> + int ret = drm_hdcp_remote_dpcd_read(data, DP_AUX_HDCP_BSTATUS, &bstatus,
> + 1);
> + *shoud_retry = true;
> +
> + if (ret) {
> + *shoud_retry = false;
> + drm_err(dev, "Failed to read dpcd bstatus, %d\n", ret);
> + return ret;
> + }
> + if (bstatus & (DP_BSTATUS_LINK_FAILURE | DP_BSTATUS_REAUTH_REQ))
> + return -EINVAL;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_hdcp_hdcp1_check_link_registers_dp);
> +
> +/*
> + * Check the link registers for HDCP 1.x for HDMI.
> + */
> +int drm_hdcp_hdcp1_check_link_registers_hdmi(struct drm_device *dev,
> + struct drm_hdcp_helper_data *data,
> + bool *shoud_retry)
> +{
> + int ret = drm_hdcp_helper_hdcp1_validate_ri(data);
> + *shoud_retry = true;
> +
> + if (ret)
> + drm_err(dev, "Ri' mismatch, check failed (%d)\n", ret);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_hdcp_hdcp1_check_link_registers_hdmi);
> +
> +static int drm_hdcp_hdcp1_check_link(struct drm_hdcp_helper_data *data)
> +{
> + struct drm_connector *connector = data->connector;
> + struct drm_device *dev = connector->dev;
> + int ret;
> + bool should_retry = false;
> +
> + if (data->funcs->hdcp1_check_link) {
> + ret = data->funcs->hdcp1_check_link(connector,
> + data->driver_data);
> + if (ret)
> + goto retry;
> + }
> +
> + ret = data->funcs->hdcp1_check_link_registers(connector->dev, data,
> + &should_retry);
> + if (!ret)
> + return 0;
> + else if (!should_retry)
> + return ret;
> +
> +retry:
> + drm_err(dev, "[%s:%d] HDCP link failed, retrying authentication\n",
> + connector->name, connector->base.id);
> +
> + ret = data->funcs->hdcp1_disable(connector, data->driver_data);
> + if (ret) {
> + drm_err(dev, "Failed to disable hdcp (%d)\n", ret);
> + drm_hdcp_update_value(data, DRM_MODE_CONTENT_PROTECTION_DESIRED,
> + true);
> + return ret;
> + }
> +
> + ret = drm_hdcp_helper_hdcp1_enable(data);
> + if (ret) {
> + drm_err(dev, "Failed to enable hdcp (%d)\n", ret);
> + drm_hdcp_update_value(data, DRM_MODE_CONTENT_PROTECTION_DESIRED,
> + true);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int drm_hdcp_hdcp2_check_link(struct drm_hdcp_helper_data *data)
> +{
> + struct drm_connector *connector = data->connector;
> + struct drm_device *dev = connector->dev;
> + int ret;
> +
> + ret = data->funcs->hdcp2_check_link(connector, data->driver_data);
> + if (!ret)
> + return 0;
> +
> + drm_err(dev, "[%s:%d] HDCP2 link failed, retrying authentication\n",
> + connector->name, connector->base.id);
> +
> + ret = data->funcs->hdcp2_disable(connector, data->driver_data);
> + if (ret) {
> + drm_err(dev, "Failed to disable hdcp2 (%d)\n", ret);
> + drm_hdcp_update_value(data, DRM_MODE_CONTENT_PROTECTION_DESIRED,
> + true);
> + return ret;
> + }
> +
> + ret = data->funcs->hdcp2_enable(connector, data->driver_data);
> + if (ret) {
> + drm_err(dev, "Failed to enable hdcp2 (%d)\n", ret);
> + drm_hdcp_update_value(data, DRM_MODE_CONTENT_PROTECTION_DESIRED,
> + true);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static void drm_hdcp_helper_check_work(struct work_struct *work)
> +{
> + struct drm_hdcp_helper_data *data = container_of(
> + to_delayed_work(work), struct drm_hdcp_helper_data, check_work);
> + unsigned long check_link_interval;
> +
> + mutex_lock(&data->mutex);
> + if (data->value != DRM_MODE_CONTENT_PROTECTION_ENABLED)
> + goto out_data_mutex;
> +
> + drm_hdcp_helper_driver_lock(data);
> +
> + if (data->enabled_type == DRM_MODE_HDCP_CONTENT_TYPE1) {
> + if (drm_hdcp_hdcp2_check_link(data))
> + goto out;
> + check_link_interval = DRM_HDCP2_CHECK_PERIOD_MS;
> + } else {
> + if (drm_hdcp_hdcp1_check_link(data))
> + goto out;
> + check_link_interval = DRM_HDCP_CHECK_PERIOD_MS;
> + }
> + schedule_delayed_work(&data->check_work, check_link_interval);
> +
> +out:
> + drm_hdcp_helper_driver_unlock(data);
> +out_data_mutex:
> + mutex_unlock(&data->mutex);
> +}
> +
> +/**
> + * drm_hdcp_helper_schedule_hdcp_check - Schedule a check link cycle.
> + *
> + * @data: Pointer to the HDCP helper data.
> + *
> + * This function will kick off a check link cycle on behalf of the caller. This
> + * can be used by DP short hpd interrupt handlers, where the driver must poke
> + * the helper to check the link is still valid.
> + */
> +void drm_hdcp_helper_schedule_hdcp_check(struct drm_hdcp_helper_data *data)
> +{
> + schedule_delayed_work(&data->check_work, 0);
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_schedule_hdcp_check);
> +
> +static struct drm_hdcp_helper_data *
> +drm_hdcp_helper_initialize(struct drm_connector *connector,
> + const struct drm_hdcp_helper_funcs *funcs,
> + bool hdcp_content_type)
> +{
> + struct drm_hdcp_helper_data *out;
> + int ret;
> +
> + out = kzalloc(sizeof(*out), GFP_KERNEL);
> + if (!out)
> + return ERR_PTR(-ENOMEM);
> +
> + out->connector = connector;
> + out->funcs = funcs;
> +
> + mutex_init(&out->mutex);
> + out->value = DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
> +
> + INIT_DELAYED_WORK(&out->check_work, drm_hdcp_helper_check_work);
> + INIT_WORK(&out->prop_work, drm_hdcp_helper_prop_work);
> +
> + ret = drm_connector_attach_content_protection_property(
> + connector, hdcp_content_type);
> + if (ret) {
> + drm_hdcp_helper_destroy(out);
> + return ERR_PTR(ret);
> + }
> +
> + return out;
> +}
> +
> +/**
> + * drm_hdcp_helper_initialize_dp - Initializes the HDCP helpers for a
> + * DisplayPort connector
> + *
> + * @connector: pointer to the DisplayPort connector.
> + * @funcs: pointer to the vtable of HDCP helper funcs for this connector.
> + * @hdcp_content_type: True if the content_type property should be attached.
> + *
> + * This function initializes the HDCP helper for the given DisplayPort connector.
> + * This involves creating the Content Protection property as well as the Content
> + * Type property (if desired). Upon success, it will return a pointer to the
> + * HDCP helper data. Ownership of the underlying memory is ttransferredto the
> + * caller and should be freed using drm_hdcp_helper_destroy().
> + *
> + * Returns:
> + * Pointer to newly created HDCP helper data. PTR_ERR on failure.
> + */
> +struct drm_hdcp_helper_data *drm_hdcp_helper_initialize_dp(
> + struct drm_connector *connector, struct drm_dp_aux *aux,
> + const struct drm_hdcp_helper_funcs *funcs, bool hdcp_content_type)
> +{
> + struct drm_hdcp_helper_data *out;
> +
> + out = drm_hdcp_helper_initialize(connector, funcs, hdcp_content_type);
> + if (IS_ERR(out))
> + return out;
> +
> + out->aux = aux;
> + out->hdcp1_lut = &drm_hdcp_hdcp1_dpcd_lut;
> +
> + return out;
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_initialize_dp);
> +
> +/**
> + * drm_hdcp_helper_initialize_hdmi - Initializes the HDCP helpers for an HDMI
> + * connector
> + *
> + * @connector: pointer to the HDMI connector.
> + * @funcs: pointer to the vtable of HDCP helper funcs for this connector.
> + * @hdcp_content_type: True if the content_type property should be attached.
> + *
> + * This function initializes the HDCP helper for the given HDMI connector. This
> + * involves creating the Content Protection property as well as the Content Type
> + * property (if desired). Upon success, it will return a pointer to the HDCP
> + * helper data. Ownership of the underlying memory is transferred to the caller
> + * and should be freed using drm_hdcp_helper_destroy().
> + *
> + * Returns:
> + * Pointer to newly created HDCP helper data. PTR_ERR on failure.
> + */
> +struct drm_hdcp_helper_data *
> +drm_hdcp_helper_initialize_hdmi(struct drm_connector *connector,
> + const struct drm_hdcp_helper_funcs *funcs,
> + bool hdcp_content_type)
> +{
> + struct drm_hdcp_helper_data *out;
> +
> + out = drm_hdcp_helper_initialize(connector, funcs, hdcp_content_type);
> + if (IS_ERR(out))
> + return out;
> +
> + out->hdcp1_lut = &drm_hdcp_hdcp1_ddc_lut;
> +
> + return out;
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_initialize_hdmi);
> +
> +/**
> + * drm_hdcp_helper_destroy - Destroys the given HDCP helper data.
> + *
> + * @data: Pointer to the HDCP helper data.
> + *
> + * This function cleans up and destroys the HDCP helper data created by
> + * drm_hdcp_helper_initialize_dp() or drm_hdcp_helper_initialize_hdmi().
> + */
> +void drm_hdcp_helper_destroy(struct drm_hdcp_helper_data *data)
> +{
> + struct drm_connector *connector;
> +
> + if (!data)
> + return;
> +
> + connector = data->connector;
> +
> + /*
> + * If the connector is registered, it's possible userspace could kick
> + * off another HDCP enable, which would re-spawn the workers.
> + */
> + drm_WARN_ON(connector->dev,
> + connector->registration_state == DRM_CONNECTOR_REGISTERED);
> +
> + /*
> + * Now that the connector is not registered, check_work won't be run,
> + * but cancel any outstanding instances of it
> + */
> + cancel_delayed_work_sync(&data->check_work);
> +
> + /*
> + * We don't cancel prop_work in the same way as check_work since it
> + * requires connection_mutex which could be held while calling this
> + * function. Instead, we rely on the connector references grabbed before
> + * scheduling prop_work to ensure the connector is alive when prop_work
> + * is run. So if we're in the destroy path (which is where this
> + * function should be called), we're "guaranteed" that prop_work is not
> + * active (tl;dr This Should Never Happen).
> + */
> + drm_WARN_ON(connector->dev, work_pending(&data->prop_work));
> +
> + kfree(data);
> +}
> +EXPORT_SYMBOL(drm_hdcp_helper_destroy);
> diff --git a/include/drm/display/drm_hdcp.h b/include/drm/display/drm_hdcp.h
> index 96a99b1377c0e..6ff28db964f13 100644
> --- a/include/drm/display/drm_hdcp.h
> +++ b/include/drm/display/drm_hdcp.h
> @@ -9,8 +9,12 @@
> #ifndef _DRM_HDCP_H_
> #define _DRM_HDCP_H_
>
> +#include "linux/mutex.h"
> +#include "linux/workqueue.h"
> #include <linux/types.h>
>
> +#include <drm/drm_device.h>
> +
> /* Period of hdcp checks (to ensure we're still authenticated) */
> #define DRM_HDCP_CHECK_PERIOD_MS (128 * 16)
> #define DRM_HDCP2_CHECK_PERIOD_MS 500
> @@ -36,6 +40,7 @@
> #define DRM_HDCP_DDC_BKSV 0x00
> #define DRM_HDCP_DDC_RI_PRIME 0x08
> #define DRM_HDCP_DDC_AKSV 0x10
> +#define DRM_HDCP_DDC_AINFO 0x15
> #define DRM_HDCP_DDC_AN 0x18
> #define DRM_HDCP_DDC_V_PRIME(h) (0x20 + h * 4)
> #define DRM_HDCP_DDC_BCAPS 0x40
> @@ -123,6 +128,19 @@
> #define HDCP_2_2_DEV_COUNT_HI(x) ((x) & BIT(0))
> #define HDCP_2_2_DEPTH(x) (((x) & (0x7 << 1)) >> 1)
>
> +struct drm_hdcp_ksv {
> + union {
> + u32 words[2];
> + u8 bytes[DRM_HDCP_KSV_LEN];
> + };
> +};
> +struct drm_hdcp_an {
> + union {
> + u32 words[2];
> + u8 bytes[DRM_HDCP_AN_LEN];
> + };
> +};
> +
> struct hdcp2_cert_rx {
> u8 receiver_id[HDCP_2_2_RECEIVER_ID_LEN];
> u8 kpub_rx[HDCP_2_2_K_PUB_RX_LEN];
> @@ -295,4 +313,273 @@ struct hdcp_srm_header {
> #define DRM_MODE_HDCP_CONTENT_TYPE0 0
> #define DRM_MODE_HDCP_CONTENT_TYPE1 1
>
> +struct drm_connector;
> +struct drm_atomic_state;
> +
> +struct drm_hdcp_helper_data {
> + struct mutex mutex;
> + struct mutex *driver_mutex;
> +
> + struct drm_connector *connector;
> + const struct drm_hdcp_helper_funcs *funcs;
> +
> + u64 value;
> + unsigned int enabled_type;
> +
> + struct delayed_work check_work;
> + struct work_struct prop_work;
> +
> + struct drm_dp_aux *aux;
> + const struct drm_hdcp_hdcp1_receiver_reg_lut *hdcp1_lut;
> +
> + void *driver_data;
> +};
> +
> +/**
> + * struct drm_hdcp_helper_funcs - A vtable of function hooks for the hdcp helper
> + *
> + * These hooks are used by the hdcp helper to call into the driver/connector
> + * code to read/write to hw.
> + */
> +struct drm_hdcp_helper_funcs {
> + /**
> + * @setup - Performs driver-specific setup before hdcp is enabled
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*setup)(struct drm_connector *connector,
> + struct drm_atomic_state *state, void *driver_data);
> +
> + /**
> + * @are_keys_valid - Checks if the HDCP transmitter keys are valid
> + *
> + * Returns: true if the display controller has valid keys loaded
> + */
> + bool (*are_keys_valid)(struct drm_connector *connector,
> + void *driver_data);
> +
> + /**
> + * @load_keys - Instructs the driver to load its HDCP transmitter keys
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*load_keys)(struct drm_connector *connector, void *driver_data);
> +
> + /**
> + * @hdcp2_capable - Checks if both source and sink support HDCP 2.x
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp2_capable)(struct drm_connector *connector, bool *capable,
> + void *driver_data);
> +
> + /**
> + * @hdcp2_enable - Enables HDCP 2.x on the specified connector
> + *
> + * Since we don't have multiple examples of HDCP 2.x enablement, we
> + * provide the bare minimum support for HDCP 2.x help. Once we have
> + * more examples, perhaps we can be more helpful.
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp2_enable)(struct drm_connector *connector, void *driver_data);
> +
> + /**
> + * @hdcp2_check_link - Checks the HDCP 2.x link on a specified connector
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp2_check_link)(struct drm_connector *connector,
> + void *driver_data);
> +
> + /**
> + * @hdcp2_disable - Disables HDCP 2.x on the specified connector
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp2_disable)(struct drm_connector *connector,
> + void *driver_data);
> +
> + /**
> + * @hdcp1_read_an_aksv - Reads transmitter's An & Aksv from hardware
> + *
> + * Use this function if hardware allows reading the transmitter's An and
> + * Aksv values from the kernel. If your hardware will not allow this,
> + * use hdcp1_send_an_aksv() and implement the transmission in the
> + * driver.
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp1_read_an_aksv)(struct drm_connector *connector, u32 *an,
> + u32 *aksv, void *driver_data);
> +
> + /**
> + * @hdcp1_send_an_aksv - Sends transmitter's An & Aksv to the receiver
> + *
> + * Only implement this on hardware where An or Aksv are not accessible
> + * from the kernel. If these values can be read, use
> + * hdcp1_read_an_aksv() instead.
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp1_send_an_aksv)(struct drm_connector *connector,
> + void *driver_data);
> +
> + /**
> + * @hdcp1_store_receiver_info - Stores the receiver's info in the transmitter
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp1_store_receiver_info)(struct drm_connector *connector,
> + u32 *ksv, u32 status, u8 caps,
> + bool repeater_present,
> + void *driver_data);
> +
> + /**
> + * @hdcp1_enable_encryption - Enables encryption of the outgoing signal
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp1_enable_encryption)(struct drm_connector *connector,
> + void *driver_data);
> +
> + /**
> + * @hdcp1_wait_for_r0 - Wait for transmitter to calculate R0
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp1_wait_for_r0)(struct drm_connector *connector,
> + void *driver_data);
> +
> + /**
> + * @hdcp1_match_ri - Matches the given Ri from the receiver with Ri in
> + * the transmitter
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp1_match_ri)(struct drm_connector *connector, u32 ri_prime,
> + void *driver_data);
> +
> + /**
> + * @hdcp1_post_encryption - Allows the driver to confirm encryption and
> + * perform any post-processing
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp1_post_encryption)(struct drm_connector *connector,
> + void *driver_data);
> +
> + /**
> + * @hdcp1_store_ksv_fifo - Write the receiver's KSV list to transmitter
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp1_store_ksv_fifo)(struct drm_connector *connector,
> + u8 *ksv_fifo, u8 num_downstream,
> + u8 *bstatus, u32 *vprime,
> + void *driver_data);
> +
> + /**
> + * @hdcp1_check_link - Allows the driver to check the HDCP 1.x status
> + * on a specified connector
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp1_check_link)(struct drm_connector *connector,
> + void *driver_data);
> +
> + /**
> + * @hdcp1_disable - Disables HDCP 1.x on the specified connector
> + *
> + * Returns: 0 on success, -errno on failure
> + */
> + int (*hdcp1_disable)(struct drm_connector *connector,
> + void *driver_data);
> +
> + /**
> + * @remote_read - Read HDCP keys from the remote HDCP engine
> +
> + * @data: drm_hdcp_helper_data containing the adapter
> + * @offset: address of the register to read
> + * @value: Pointer to the value to be filled
> + * @len: The length of the data to be read
> + *
> + * Return 0 on success
> + */
> + int (*remote_read)(struct drm_hdcp_helper_data *data,
> + unsigned int offset, u8 *value, size_t len);
> +
> + /**
> + * @remote_write - Write HDCP keys to the remote HDCP engine
> +
> + * @data: drm_hdcp_helper_data containing the adapter
> + * @offset: address of the register to read
> + * @value: Pointer to the value to be filled
> + * @len: The length of the data to be read
> + *
> + * Return 0 on success
> + */
> + int (*remote_write)(struct drm_hdcp_helper_data *data,
> + unsigned int offset, u8 *value, size_t len);
> +
> + /**
> + * @hdcp1_capable - Checks if the sink is capable of HDCP 1.x.
> + *
> + * @data: pointer to the HDCP helper data.
> + * @capable: pointer to a bool which will contain true if the sink is capable.
> + *
> + * Returns:
> + * -errno if the transacation between source and sink fails.
> + */
> + int (*hdcp1_capable)(struct drm_hdcp_helper_data *data, bool *capable);
> +
> + /**
> + * @hdcp1_ksv_fifo_ready - Read KSV FIFO ready bit.
> + *
> + * @data: pointer to the HDCP helper data.
> + *
> + * Returns:
> + * -errno if the transacation between source and sink fails.
> + * 0 on success.
> + * -EAGAIN otherwise.
> + */
> + int (*hdcp1_ksv_fifo_ready)(struct drm_hdcp_helper_data *data);
> +
> + /**
> + * @wait_r0 - Wait for R0' to become available.
> + *
> + * @data: pointer to the HDCP helper data.
> + * @r0_prime_remaining_us: time remaining for R0' to become available.
> + *
> + * Returns 0 on success.
> + */
> + int (*wait_r0)(struct drm_hdcp_helper_data *data,
> + unsigned long r0_prime_remaining_us);
> +
> + /*
> + * @hdcp1_check_link_registers - This function checks the HDCP1
> + * link registers and returns true if the link is valid and false otherwise.
> + *
> + * @dev: DRM device for printing error messages
> + * @data: HDCP helper data
> + * @should_retry: if true, the caller will retry checking the registers
> + *
> + * Returns 0 on success.
> + */
> + int (*hdcp1_check_link_registers)(struct drm_device *dev,
> + struct drm_hdcp_helper_data *data,
> + bool *shoud_retry);
> +
> + /**
> + * @hdcp1_read_ksv_fifo - Read HDCP1.x KSV FIFO
> + * @data: Helper data
> + * @fifo: Buffer to store values
> + * @num_downstream: Number of downstream devices
> + *
> + * Return: Zero on success or negative error code on failure.
> + */
> + int (*hdcp1_read_ksv_fifo)(struct drm_hdcp_helper_data *data, u8 *fifo,
> + u8 num_downstream);
> +};
> +
> #endif
> diff --git a/include/drm/display/drm_hdcp_helper.h b/include/drm/display/drm_hdcp_helper.h
> index 703421fcdf96c..a2e25bad78dbd 100644
> --- a/include/drm/display/drm_hdcp_helper.h
> +++ b/include/drm/display/drm_hdcp_helper.h
> @@ -15,11 +15,60 @@ struct drm_atomic_state;
> struct drm_device;
> struct drm_connector;
>
> +struct drm_hdcp_helper_data;
> +struct drm_dp_aux;
> +struct i2c_adapter;
> +struct mutex;
> +
> 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, u64 val);
> bool drm_hdcp_has_changed(struct drm_connector *connector,
> - struct drm_atomic_state *state);
> + struct drm_atomic_state *state);
> +
> +int drm_hdcp_remote_dpcd_read(struct drm_hdcp_helper_data *data,
> + unsigned int offset, u8 *value, size_t len);
> +int drm_hdcp_remote_ddc_read(struct drm_hdcp_helper_data *data,
> + unsigned int offset, u8 *value, size_t len);
> +int drm_hdcp_remote_dpcd_write(struct drm_hdcp_helper_data *data,
> + unsigned int offset, u8 *value, size_t len);
> +int drm_hdcp_remote_ddc_write(struct drm_hdcp_helper_data *data,
> + unsigned int offset, u8 *buffer, size_t len);
> +
> +int drm_hdcp_helper_hdcp1_capable_dp(struct drm_hdcp_helper_data *data,
> + bool *capable);
> +int drm_hdcp_helper_hdcp1_capable_hdmi(struct drm_hdcp_helper_data *data,
> + bool *capable);
> +int drm_hdcp_helper_hdcp1_ksv_fifo_ready_dp(struct drm_hdcp_helper_data *data);
> +int drm_hdcp_helper_hdcp1_ksv_fifo_ready_hdmi(struct drm_hdcp_helper_data *data);
> +int drm_hdcp_helper_hdcp1_read_ksv_fifo_dp(struct drm_hdcp_helper_data *data,
> + u8 *fifo, u8 num_downstream);
> +int drm_hdcp_helper_hdcp1_read_ksv_fifo_hdmi(struct drm_hdcp_helper_data *data,
> + u8 *fifo, u8 num_downstream);
> +int drm_hdcp_helper_wait_r0_dp(struct drm_hdcp_helper_data *data,
> + unsigned long r0_prime_remaining_us);
> +int drm_hdcp_helper_wait_r0_hdmi(struct drm_hdcp_helper_data *data,
> + unsigned long r0_prime_remaining_us);
> +void drm_hdcp_helper_atomic_commit(struct drm_hdcp_helper_data *data,
> + struct drm_atomic_state *state,
> + struct mutex *driver_mutex);
> +
> +int drm_hdcp_hdcp1_check_link_registers_dp(struct drm_device *dev,
> + struct drm_hdcp_helper_data *data,
> + bool *shoud_retry);
> +int drm_hdcp_hdcp1_check_link_registers_hdmi(struct drm_device *dev,
> + struct drm_hdcp_helper_data *data,
> + bool *shoud_retry);
> +void drm_hdcp_helper_schedule_hdcp_check(struct drm_hdcp_helper_data *data);
> +
> +struct drm_hdcp_helper_data *drm_hdcp_helper_initialize_dp(
> + struct drm_connector *connector, struct drm_dp_aux *aux,
> + const struct drm_hdcp_helper_funcs *funcs, bool hdcp_content_type);
> +struct drm_hdcp_helper_data *
> +drm_hdcp_helper_initialize_hdmi(struct drm_connector *connector,
> + const struct drm_hdcp_helper_funcs *funcs,
> + bool hdcp_content_type);
> +void drm_hdcp_helper_destroy(struct drm_hdcp_helper_data *data);
>
> #endif
--
With best wishes
Dmitry
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