Re: [Intel-gfx] [PATCH v2 13/13] drm/msm: Implement HDCP 1.x using the new drm HDCP helpers

Stephen Boyd
2021-09-17T06:00:35Z

Quoting Sean Paul (2021-09-15 13:38:32)
> diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi b/arch/arm64/boot/dts/qcom/sc7180.dtsi
> index c8921e2d6480..3ae6fc7a2c01 100644
> --- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
> @@ -3088,7 +3088,9 @@ mdss_dp: displayport-controller@ae90000 {
> compatible = "qcom,sc7180-dp";
> status = "disabled";
>
> - reg = <0 0x0ae90000 0 0x1400>;
> + reg = <0 0x0ae90000 0 0x1400>,
> + <0 0x0aed1000 0 0x174>,
> + <0 0x0aee1000 0 0x2c>;
>

I suspect we'll still want this hunk of the patch to be split off and go
through arm-soc tree.

> interrupt-parent = <&mdss>;
> interrupts = <12>;
> diff --git a/drivers/gpu/drm/msm/dp/dp_debug.c b/drivers/gpu/drm/msm/dp/dp_debug.c
> index 2f6247e80e9d..de16fca8782a 100644
> --- a/drivers/gpu/drm/msm/dp/dp_debug.c
> +++ b/drivers/gpu/drm/msm/dp/dp_debug.c
> @@ -8,6 +8,7 @@
> #include <linux/debugfs.h>
> #include <drm/drm_connector.h>
> #include <drm/drm_file.h>
> +#include <drm/drm_hdcp.h>
>
> #include "dp_parser.h"
> #include "dp_catalog.h"
> @@ -15,6 +16,7 @@
> #include "dp_ctrl.h"
> #include "dp_debug.h"
> #include "dp_display.h"
> +#include "dp_hdcp.h"
>
> #define DEBUG_NAME "msm_dp"
>
> @@ -24,6 +26,7 @@ struct dp_debug_private {
> struct dp_usbpd *usbpd;
> struct dp_link *link;
> struct dp_panel *panel;
> + struct dp_hdcp *hdcp;
> struct drm_connector **connector;
> struct device *dev;
> struct drm_device *drm_dev;
> @@ -349,6 +352,38 @@ static int dp_test_active_open(struct inode *inode,
> inode->i_private);
> }
>
> +static ssize_t dp_hdcp_key_write(struct file *file, const char __user *ubuf,

Is this the API that userspace is going to use to set the key? Or a
simple debug interface that's used to test this code out? I hope it's a
debugging aid and not the normal flow given that it's through debugfs.

> + size_t len, loff_t *offp)
> +{
> + char *input_buffer;
> + int ret = 0;

Please don't assign variables and then overwrite without testing the
variable.

> + struct dp_debug_private *debug = file->private_data;
> + struct drm_device *dev;
> +
> + dev = debug->drm_dev;
> +
> + if (len != (DRM_HDCP_KSV_LEN + DP_HDCP_NUM_KEYS * DP_HDCP_KEY_LEN))
> + return -EINVAL;
> +
> + if (!debug->hdcp)
> + return -ENOENT;
> +
> + input_buffer = memdup_user_nul(ubuf, len);
> + if (IS_ERR(input_buffer))
> + return PTR_ERR(input_buffer);
> +
> + ret = dp_hdcp_ingest_key(debug->hdcp, input_buffer, len);
> +
> + kfree(input_buffer);
> + if (ret < 0) {
> + DRM_ERROR("Could not ingest HDCP key, ret=%d\n", ret);
> + return ret;
> + }
> +
> + *offp += len;
> + return len;
> +}
> +
> static const struct file_operations dp_debug_fops = {
> .open = simple_open,
> .read = dp_debug_read_info,
> @@ -363,6 +398,12 @@ static const struct file_operations test_active_fops = {
> .write = dp_test_active_write
> };
>
> +static const struct file_operations dp_hdcp_key_fops = {
> + .owner = THIS_MODULE,
> + .open = simple_open,
> + .write = dp_hdcp_key_write,
> +};
> +
> static int dp_debug_init(struct dp_debug *dp_debug, struct drm_minor *minor)
> {
> int rc = 0;
> @@ -384,6 +425,10 @@ static int dp_debug_init(struct dp_debug *dp_debug, struct drm_minor *minor)
> minor->debugfs_root,
> debug, &dp_test_type_fops);
>
> + debugfs_create_file("msm_dp_hdcp_key", 0222,
> + minor->debugfs_root,
> + debug, &dp_hdcp_key_fops);
> +
> debug->root = minor->debugfs_root;
>
> return rc;
> @@ -391,7 +436,8 @@ static int dp_debug_init(struct dp_debug *dp_debug, struct drm_minor *minor)
>
> struct dp_debug *dp_debug_get(struct device *dev, struct dp_panel *panel,
> struct dp_usbpd *usbpd, struct dp_link *link,
> - struct drm_connector **connector, struct drm_minor *minor)
> + struct dp_hdcp *hdcp, struct drm_connector **connector,
> + struct drm_minor *minor)
> {
> int rc = 0;
> struct dp_debug_private *debug;
> @@ -413,6 +459,7 @@ struct dp_debug *dp_debug_get(struct device *dev, struct dp_panel *panel,
> debug->usbpd = usbpd;
> debug->link = link;
> debug->panel = panel;
> + debug->hdcp = hdcp;
> debug->dev = dev;
> debug->drm_dev = minor->dev;
> debug->connector = connector;
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
> index 8b47cdabb67e..421268e47f30 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.h
> +++ b/drivers/gpu/drm/msm/dp/dp_display.h
> @@ -27,8 +27,13 @@ struct msm_dp {
> struct dp_audio *dp_audio;
> };
>
> +struct drm_atomic_state;
> +
> int dp_display_set_plugged_cb(struct msm_dp *dp_display,
> hdmi_codec_plugged_cb fn, struct device *codec_dev);
> +struct dp_hdcp *dp_display_connector_to_hdcp(struct drm_connector *connector);
> +void dp_display_hdcp_commit(struct msm_dp *dp_display,
> + struct drm_atomic_state *state);
> int dp_display_validate_mode(struct msm_dp *dp_display, u32 mode_pclk_khz);
> int dp_display_get_modes(struct msm_dp *dp_display,
> struct dp_display_mode *dp_mode);
> diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
> index 764f4b81017e..8e62558b4fc3 100644
> --- a/drivers/gpu/drm/msm/dp/dp_drm.c
> +++ b/drivers/gpu/drm/msm/dp/dp_drm.c
> @@ -5,11 +5,20 @@
>
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_atomic.h>
> +#include <drm/drm_connector.h>
> #include <drm/drm_crtc.h>
> +#include <drm/drm_hdcp.h>
>
> #include "msm_drv.h"
> #include "msm_kms.h"
> #include "dp_drm.h"
> +#include "dp_hdcp.h"
> +
> +struct dp_connector_state {
> + struct drm_connector_state base;
> + bool hdcp_transition;
> +};
> +#define to_dp_connector_state(x) container_of(x, struct dp_connector_state, base)
>
> struct dp_connector {
> struct drm_connector base;
> @@ -17,6 +26,11 @@ struct dp_connector {
> };
> #define to_dp_connector(x) container_of(x, struct dp_connector, base)
>
> +struct msm_dp *msm_dp_from_connector(struct drm_connector *connector)
> +{
> + return to_dp_connector(connector)->dp_display;
> +}
> +
> /**
> * dp_connector_detect - callback to determine if connector is connected
> * @conn: Pointer to drm connector structure
> @@ -114,20 +128,72 @@ static enum drm_mode_status dp_connector_mode_valid(
> return dp_display_validate_mode(dp_disp, mode->clock);
> }
>
> +static int dp_connector_atomic_check(struct drm_connector *connector,
> + struct drm_atomic_state *state)
> +{
> + struct drm_connector_state *conn_state;
> + struct dp_connector_state *dp_state;
> +
> + conn_state = drm_atomic_get_new_connector_state(state, connector);
> + dp_state = to_dp_connector_state(conn_state);
> +
> + dp_state->hdcp_transition = drm_hdcp_atomic_check(connector, state);
> +
> + return 0;
> +}
> +
> +static struct drm_connector_state *
> +dp_connector_atomic_duplicate_state(struct drm_connector *connector)
> +{
> + struct dp_connector_state *state;
> +
> + state = kzalloc(sizeof(*state), GFP_KERNEL);
> + if (!state)
> + return NULL;
> +
> + state->hdcp_transition = false;
> +
> + __drm_atomic_helper_connector_duplicate_state(connector, &state->base);
> + return &state->base;
> +}
> +
> static const struct drm_connector_funcs dp_connector_funcs = {
> .detect = dp_connector_detect,
> .fill_modes = drm_helper_probe_single_connector_modes,
> .destroy = drm_connector_cleanup,
> .reset = drm_atomic_helper_connector_reset,
> - .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> + .atomic_duplicate_state = dp_connector_atomic_duplicate_state,
> .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> };
>
> static const struct drm_connector_helper_funcs dp_connector_helper_funcs = {
> .get_modes = dp_connector_get_modes,
> .mode_valid = dp_connector_mode_valid,
> + .atomic_check = dp_connector_atomic_check,
> };
>
> +bool dp_drm_is_connector_msm_dp(struct drm_connector *connector)
> +{
> + return connector->funcs == &dp_connector_funcs;
> +}
> +
> +void dp_drm_atomic_commit(struct drm_connector *connector,
> + struct drm_connector_state *conn_state,
> + struct drm_atomic_state *state)
> +{
> + struct dp_connector_state *dp_state;
> + struct msm_dp *dp_disp;
> +
> + dp_state = to_dp_connector_state(conn_state);
> +
> + if (!dp_state->hdcp_transition)
> + return;
> +
> + dp_disp = msm_dp_from_connector(connector);
> +
> + dp_display_hdcp_commit(dp_disp, state);
> +}
> +
> /* connector initialization */
> struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display)
> {
> diff --git a/drivers/gpu/drm/msm/dp/dp_drm.h b/drivers/gpu/drm/msm/dp/dp_drm.h
> index c27bfceefdf0..a5d95c6acd67 100644
> --- a/drivers/gpu/drm/msm/dp/dp_drm.h
> +++ b/drivers/gpu/drm/msm/dp/dp_drm.h
> @@ -14,5 +14,10 @@
> #include "dp_display.h"
>
> struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display);
> +struct msm_dp *msm_dp_from_connector(struct drm_connector *connector);
> +bool dp_drm_is_connector_msm_dp(struct drm_connector *connector);
> +void dp_drm_atomic_commit(struct drm_connector *connector,
> + struct drm_connector_state *conn_state,
> + struct drm_atomic_state *state);
>
> #endif /* _DP_DRM_H_ */
> diff --git a/drivers/gpu/drm/msm/dp/dp_hdcp.c b/drivers/gpu/drm/msm/dp/dp_hdcp.c
> new file mode 100644
> index 000000000000..07d2a1f04d97
> --- /dev/null
> +++ b/drivers/gpu/drm/msm/dp/dp_hdcp.c
> @@ -0,0 +1,433 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright (C) 2021 Google, Inc.
> + *
> + * Authors:
> + * Sean Paul <seanpaul@chromium.org>
> + */
> +
> +#include "dp_display.h"
> +#include "dp_drm.h"
> +#include "dp_hdcp.h"
> +#include "dp_reg.h"
> +
> +#include <drm/drm_connector.h>
> +#include <drm/drm_device.h>
> +#include <drm/drm_dp_helper.h>
> +#include <drm/drm_hdcp.h>
> +#include <drm/drm_print.h>
> +
> +#include <linux/bitfield.h>
> +#include <linux/bits.h>
> +#include <linux/iopoll.h>
> +#include <linux/mutex.h>
> +#include <linux/random.h>
> +#include <linux/slab.h>
> +
> +/* Offsets based on hdcp_ksv mmio */
> +#define DP_HDCP_KSV_AN_LSB 0x0
> +#define DP_HDCP_KSV_AN_MSB 0x4
> +#define DP_HDCP_KSV_AKSV_MSB 0x1D8
> +#define DP_HDCP_KSV_AKSV_LSB 0x1DC
> +
> +/* Key offsets based on hdcp_key mmio */
> +#define DP_HDCP_KEY_BASE 0x30
> +#define DP_HDCP_KEY_MSB(x) (DP_HDCP_KEY_BASE + (x * 8))
> +#define DP_HDCP_KEY_LSB(x) (DP_HDCP_KEY_MSB(x) + 4)
> +#define DP_HDCP_KEY_VALID 0x170
> +#define DP_HDCP_SW_KEY_VALID BIT(0)
> +
> +/*
> + * dp_hdcp_key - structure which contains an HDCP key set
> + * @ksv: The key selection vector
> + * @keys: Contains 40 keys
> + */
> +struct dp_hdcp_key {
> + struct drm_hdcp_ksv ksv;
> + union {
> + u32 words[2];
> + u8 bytes[DP_HDCP_KEY_LEN];
> + } keys[DP_HDCP_NUM_KEYS];
> + bool valid;
> +};
> +
> +struct dp_hdcp {
> + struct drm_device *dev;
> + struct drm_connector *connector;
> +
> + struct drm_dp_aux *aux;
> + struct dp_parser *parser;
> +
> + struct drm_hdcp_helper_data *helper_data;
> +
> + struct mutex key_lock;
> + struct dp_hdcp_key *key;

Is there a reason this is a pointer vs. a plain struct member?

> +};
> +
> +static inline void dp_hdcp_write_dp(struct dp_hdcp *hdcp, u32 offset, u32 val)
> +{
> + writel(val, hdcp->parser->io.dp_controller.base + offset);
> +}
> +
> +static inline u32 dp_hdcp_read_dp(struct dp_hdcp *hdcp, u32 offset)
> +{
> + return readl(hdcp->parser->io.dp_controller.base + offset);
> +}
> +
> +static inline void dp_hdcp_write_hdcp(struct dp_hdcp *hdcp, u32 offset, u32 val)
> +{
> + writel(val, hdcp->parser->io.hdcp_key.base + offset);
> +}
> +
> +static inline u32 dp_hdcp_read_hdcp(struct dp_hdcp *hdcp, u32 offset)
> +{
> + return readl(hdcp->parser->io.hdcp_key.base + offset);
> +}
> +
> +static inline void dp_hdcp_write_tz(struct dp_hdcp *hdcp, u32 offset, u32 val)
> +{
> + writel(val, hdcp->parser->io.hdcp_tz.base + offset);
> +}
> +
> +static inline u32 dp_hdcp_read_tz(struct dp_hdcp *hdcp, u32 offset)
> +{
> + return readl(hdcp->parser->io.hdcp_tz.base + offset);
> +}
> +
> +int dp_hdcp_ingest_key(struct dp_hdcp *hdcp, const u8 *raw_key, int raw_len)
> +{
> + struct dp_hdcp_key *key;
> + const u8 *ptr = raw_key;

Why have the local variable when raw_key will do?

> + unsigned int ksv_weight;
> + int i, ret = 0;
> +
> + mutex_lock(&hdcp->key_lock);

This can move after the length check?

> +
> + if (raw_len != (DRM_HDCP_KSV_LEN + DP_HDCP_NUM_KEYS * DP_HDCP_KEY_LEN)) {
> + DRM_ERROR("Invalid HDCP key length expected=%d actual=%d\n",
> + (DRM_HDCP_KSV_LEN + DP_HDCP_NUM_KEYS * DP_HDCP_KEY_LEN),
> + raw_len);
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + key = hdcp->key;
> +
> + memcpy(key->ksv.bytes, ptr, DRM_HDCP_KSV_LEN);
> + ksv_weight = hweight32(key->ksv.words[0]) + hweight32(key->ksv.words[1]);
> + if (ksv_weight != 20) {
> + DRM_ERROR("Invalid ksv weight, expected=20 actual=%d\n",
> + ksv_weight);
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + ptr += DRM_HDCP_KSV_LEN;
> + for (i = 0; i < DP_HDCP_NUM_KEYS; i++) {
> + memcpy(key->keys[i].bytes, ptr, DP_HDCP_KEY_LEN);
> + ptr += DP_HDCP_KEY_LEN;
> + }
> +
> + DRM_DEBUG_DRIVER("Successfully ingested HDCP key\n");
> + hdcp->key->valid = true;
> +
> +out:
> + mutex_unlock(&hdcp->key_lock);
> + return ret;
> +}
> +
> +static bool dp_hdcp_are_keys_valid(struct drm_connector *connector)
> +{
> + struct dp_hdcp *hdcp = dp_display_connector_to_hdcp(connector);
> + u32 val;
> +
> + val = dp_hdcp_read_dp(hdcp, DP_HDCP_STATUS);
> + return FIELD_GET(DP_HDCP_KEY_STATUS, val) == DP_HDCP_KEY_STATUS_VALID;
> +}
> +
> +static int dp_hdcp_load_keys(struct drm_connector *connector)
> +{
> + struct dp_hdcp *hdcp = dp_display_connector_to_hdcp(connector);
> + struct dp_hdcp_key *key;
> + int i, ret = 0;
> +
> + mutex_lock(&hdcp->key_lock);
> +
> + key = hdcp->key;
> +
> + if (!key->valid) {
> + ret = -ENOENT;
> + goto out;
> + }
> +
> + dp_hdcp_write_dp(hdcp, DP_HDCP_SW_LOWER_AKSV, key->ksv.words[0]);
> + dp_hdcp_write_dp(hdcp, DP_HDCP_SW_UPPER_AKSV, key->ksv.words[1]);
> +
> + for (i = 0; i < DP_HDCP_NUM_KEYS; i++) {
> + dp_hdcp_write_hdcp(hdcp, DP_HDCP_KEY_LSB(i),
> + key->keys[i].words[0]);
> + dp_hdcp_write_hdcp(hdcp, DP_HDCP_KEY_MSB(i),
> + key->keys[i].words[1]);
> + }
> +
> + dp_hdcp_write_hdcp(hdcp, DP_HDCP_KEY_VALID, DP_HDCP_SW_KEY_VALID);
> + wmb();

What are the wmb()s for? Can you add a comment indicating what we're
trying to fix by having them?

> +
> + dp_hdcp_write_dp(hdcp, DP_HDCP_ENTROPY_CTRL0, get_random_u32());
> + dp_hdcp_write_dp(hdcp, DP_HDCP_ENTROPY_CTRL1, get_random_u32());

Can we call get_random_u64() at the start of this function outside the
mutex lock and then use the upper and lower halves for these two lines
above?

> + wmb();
> +
> +out:
> + mutex_unlock(&hdcp->key_lock);
> + return ret;
> +}
> +
> +static int dp_hdcp_hdcp2_capable(struct drm_connector *connector, bool *capable)
> +{
> + *capable = false;
> + return 0;
> +}
> +
> +static int dp_hdcp_hdcp1_read_an_aksv(struct drm_connector *connector,
> + u32 *an, u32 *aksv)
> +{
> + struct dp_hdcp *hdcp = dp_display_connector_to_hdcp(connector);
> + bool keys_valid;
> + int ret;
> + u32 val;
> +
> + dp_hdcp_write_dp(hdcp, DP_HDCP_CTRL, 1);
> +
> + ret = read_poll_timeout(dp_hdcp_are_keys_valid, keys_valid, keys_valid,
> + 20 * 1000, 10 * 1000, false, connector);
> + if (ret) {
> + drm_err(hdcp->dev, "HDCP keys invalid %d\n", ret);
> + return ret;
> + }
> +
> + /* Clear AInfo */
> + dp_hdcp_write_dp(hdcp, DP_HDCP_RCVPORT_DATA4, 0);
> +
> + aksv[0] = dp_hdcp_read_dp(hdcp, DP_HDCP_RCVPORT_DATA3);
> + aksv[1] = GENMASK(7, 0) & dp_hdcp_read_dp(hdcp, DP_HDCP_RCVPORT_DATA4);
> +
> + ret = read_poll_timeout(dp_hdcp_read_dp, val,
> + (val & DP_HDCP_AN_READY_MASK) == DP_HDCP_AN_READY_MASK,
> + 100, 10 * 1000, false, hdcp, DP_HDCP_STATUS);
> + if (ret) {
> + drm_err(hdcp->dev, "AN failed to become ready %x/%d\n", val, ret);
> + return ret;
> + }
> +
> + /*
> + * Get An from hardware, for unknown reasons we need to read the reg
> + * twice to get valid data.

That's annoying.

> + */
> + dp_hdcp_read_dp(hdcp, DP_HDCP_RCVPORT_DATA5);
> + an[0] = dp_hdcp_read_dp(hdcp, DP_HDCP_RCVPORT_DATA5);
> +
> + dp_hdcp_read_dp(hdcp, DP_HDCP_RCVPORT_DATA6);
> + an[1] = dp_hdcp_read_dp(hdcp, DP_HDCP_RCVPORT_DATA6);
> +
> + return 0;
> +}
> +
> +static int dp_hdcp_hdcp1_store_receiver_info(struct drm_connector *connector,
> + u32 *ksv, u32 status, u8 bcaps,
> + bool is_repeater)
> +{
> + struct dp_hdcp *hdcp = dp_display_connector_to_hdcp(connector);
> + u32 val;
> +
> + dp_hdcp_write_tz(hdcp, HDCP_SEC_DP_TZ_HV_HLOS_HDCP_RCVPORT_DATA0,
> + ksv[0]);
> + dp_hdcp_write_tz(hdcp, HDCP_SEC_DP_TZ_HV_HLOS_HDCP_RCVPORT_DATA1,
> + ksv[1]);
> +
> + val = ((status & GENMASK(15, 0)) << 8) | (bcaps & GENMASK(7, 0));

Nitpick: Can this use FIELD_PREP() too?

> +
> + dp_hdcp_write_tz(hdcp, HDCP_SEC_DP_TZ_HV_HLOS_HDCP_RCVPORT_DATA12, val);
> +
> + return 0;
> +}
> +
> +static int dp_hdcp_hdcp1_enable_encryption(struct drm_connector *connector)
> +{
> + return 0;
> +}
> +
> +static int dp_hdcp_hdcp1_wait_for_r0(struct drm_connector *connector)
> +{
> + struct dp_hdcp *hdcp = dp_display_connector_to_hdcp(connector);
> + int ret;
> + u32 val;
> +
> + ret = read_poll_timeout(dp_hdcp_read_dp, val, (val & DP_HDCP_R0_READY),
> + 100, 1000, false, hdcp,
> + DP_HDCP_STATUS);
> + if (ret) {
> + drm_err(hdcp->dev, "HDCP R0 not ready %x/%d\n", val, ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int dp_hdcp_hdcp1_match_ri(struct drm_connector *connector, u32 ri_prime)
> +{
> + struct dp_hdcp *hdcp = dp_display_connector_to_hdcp(connector);
> + int ret;
> + u32 val;
> +
> + dp_hdcp_write_dp(hdcp, DP_HDCP_RCVPORT_DATA2_0, ri_prime);
> +
> + ret = read_poll_timeout(dp_hdcp_read_dp, val, (val & DP_HDCP_RI_MATCH),
> + 20 * 1000, 100 * 1000, false, hdcp,

Maybe 20 * 1000 and 100 * 1000 should be some defines at the top of this
file?

> + DP_HDCP_STATUS);
> + if (ret) {
> + drm_err(hdcp->dev, "Failed to match Ri and Ri` (%08x) %08x/%d\n",
> + ri_prime, val, ret);
> + return ret;
> + }
> + return 0;
> +}
> +
> +static int dp_hdcp_hdcp1_store_ksv_fifo(struct drm_connector *connector,
> + u8 *ksv_fifo, u8 num_downstream,
> + u8 *bstatus, u32 *vprime)
> +{
> + struct dp_hdcp *hdcp = dp_display_connector_to_hdcp(connector);
> + int num_bytes = (num_downstream * DRM_HDCP_KSV_LEN);

Nitpick: Why the parenthesis?

> + int ret, i;
> + u32 val;
> +
> + /* Reset the SHA computation block */
> + dp_hdcp_write_tz(hdcp, HDCP_SEC_DP_TZ_HV_HLOS_HDCP_SHA_CTRL,
> + DP_HDCP_SHA_CTRL_RESET);
> + dp_hdcp_write_tz(hdcp, HDCP_SEC_DP_TZ_HV_HLOS_HDCP_SHA_CTRL, 0);
> +
> + /*
> + * KSV info gets written a byte at a time in the same order it was
> + * received. Every 64 bytes, we need to wait for the SHA_BLOCK_DONE
> + * bit to be set in SHA_CTRL.
> + */
> + for (i = 0; i < num_bytes; i++) {
> + val = FIELD_PREP(DP_HDCP_SHA_DATA_MASK, ksv_fifo[i]);
> +
> + if (i == (num_bytes - 1))
> + val |= DP_HDCP_SHA_DATA_DONE;
> +
> + dp_hdcp_write_tz(hdcp, HDCP_SEC_DP_TZ_HV_HLOS_HDCP_SHA_DATA,
> + val);
> +
> + if (((i + 1) % 64) != 0)
> + continue;
> +
> + ret = read_poll_timeout(dp_hdcp_read_dp, val,
> + (val & DP_HDCP_SHA_DONE), 100,
> + 100 * 1000, false, hdcp,
> + DP_HDCP_SHA_STATUS);
> + if (ret) {
> + drm_err(hdcp->dev, "SHA block incomplete %d\n", ret);
> + return ret;
> + }
> + }
> +
> + ret = read_poll_timeout(dp_hdcp_read_dp, val,
> + (val & DP_HDCP_SHA_COMP_DONE), 100, 100 * 1000,
> + false, hdcp, DP_HDCP_SHA_STATUS);
> + if (ret) {
> + drm_err(hdcp->dev, "SHA computation incomplete %d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int dp_hdcp_hdcp1_disable(struct drm_connector *connector)
> +{
> + struct dp_hdcp *hdcp = dp_display_connector_to_hdcp(connector);
> + u32 val;
> +
> + val = dp_hdcp_read_dp(hdcp, REG_DP_SW_RESET);
> + dp_hdcp_write_dp(hdcp, REG_DP_SW_RESET, val | DP_HDCP_SW_RESET);
> +
> + /* Disable encryption and disable the HDCP block */
> + dp_hdcp_write_dp(hdcp, DP_HDCP_CTRL, 0);
> +
> + dp_hdcp_write_dp(hdcp, REG_DP_SW_RESET, val);
> +
> + return 0;
> +}
> +
> +void dp_hdcp_commit(struct dp_hdcp *hdcp, struct drm_atomic_state *state)
> +{
> + drm_hdcp_helper_atomic_commit(hdcp->helper_data, state, NULL);
> +}
> +
> +static const struct drm_hdcp_helper_funcs dp_hdcp_funcs = {
> + .are_keys_valid = dp_hdcp_are_keys_valid,
> + .load_keys = dp_hdcp_load_keys,
> + .hdcp2_capable = dp_hdcp_hdcp2_capable,
> + .hdcp1_read_an_aksv = dp_hdcp_hdcp1_read_an_aksv,
> + .hdcp1_store_receiver_info = dp_hdcp_hdcp1_store_receiver_info,
> + .hdcp1_enable_encryption = dp_hdcp_hdcp1_enable_encryption,
> + .hdcp1_wait_for_r0 = dp_hdcp_hdcp1_wait_for_r0,
> + .hdcp1_match_ri = dp_hdcp_hdcp1_match_ri,
> + .hdcp1_store_ksv_fifo = dp_hdcp_hdcp1_store_ksv_fifo,
> + .hdcp1_disable = dp_hdcp_hdcp1_disable,
> +};
> +
> +int dp_hdcp_attach(struct dp_hdcp *hdcp, struct drm_connector *connector)
> +{
> + struct drm_device *dev = connector->dev;
> + struct drm_hdcp_helper_data *helper_data;
> + int ret;
> +
> + /* HDCP is not configured for this device */
> + if (!hdcp || !hdcp->parser || hdcp->parser->io.hdcp_key.len == 0)
> + return 0;
> +
> + helper_data = drm_hdcp_helper_initialize_dp(connector, hdcp->aux,
> + &dp_hdcp_funcs, false);
> + if (IS_ERR_OR_NULL(helper_data))
> + return PTR_ERR(helper_data);
> +
> + ret = drm_connector_attach_content_protection_property(connector, false);
> + if (ret) {
> + drm_hdcp_helper_destroy(helper_data);
> + drm_err(dev, "Failed to attach content protection prop %d\n", ret);
> + return ret;
> + }
> +
> + hdcp->dev = connector->dev;
> + hdcp->connector = connector;
> + hdcp->helper_data = helper_data;
> +
> + return 0;
> +}
> +
> +struct dp_hdcp *dp_hdcp_get(struct dp_parser *parser, struct drm_dp_aux *aux)
> +{
> + struct dp_hdcp *hdcp;
> +
> + hdcp = devm_kzalloc(&parser->pdev->dev, sizeof(*hdcp), GFP_KERNEL);
> + if (!hdcp)
> + return ERR_PTR(-ENOMEM);
> +
> + hdcp->key = devm_kzalloc(&parser->pdev->dev, sizeof(*hdcp->key), GFP_KERNEL);
> + if (!hdcp->key)
> + return ERR_PTR(-ENOMEM);
> +
> + hdcp->parser = parser;
> + hdcp->aux = aux;
> +
> + mutex_init(&hdcp->key_lock);
> +
> + return hdcp;
> +}
> +
> +void dp_hdcp_put(struct dp_hdcp *hdcp)
> +{
> + drm_hdcp_helper_destroy(hdcp->helper_data);
> +}
> diff --git a/drivers/gpu/drm/msm/dp/dp_hdcp.h b/drivers/gpu/drm/msm/dp/dp_hdcp.h
> new file mode 100644
> index 000000000000..5637a9b0dea2
> --- /dev/null
> +++ b/drivers/gpu/drm/msm/dp/dp_hdcp.h
> @@ -0,0 +1,27 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright (C) 2021 Google, Inc.
> + *
> + * Authors:
> + * Sean Paul <seanpaul@chromium.org>
> + */
> +
> +#ifndef DP_HDCP_H_
> +#define DP_HDCP_H_
> +
> +#define DP_HDCP_KEY_LEN 7
> +#define DP_HDCP_NUM_KEYS 40
> +
> +struct dp_hdcp;
> +struct dp_parser;
> +struct drm_atomic_state;
> +struct drm_dp_aux;
> +
> +struct dp_hdcp *dp_hdcp_get(struct dp_parser *parser, struct drm_dp_aux *aux);
> +void dp_hdcp_put(struct dp_hdcp *hdcp);
> +
> +int dp_hdcp_attach(struct dp_hdcp *hdcp, struct drm_connector *connector);
> +int dp_hdcp_ingest_key(struct dp_hdcp *hdcp, const u8 *raw_key, int raw_len);
> +void dp_hdcp_commit(struct dp_hdcp *hdcp, struct drm_atomic_state *state);
> +
> +#endif
> diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c b/drivers/gpu/drm/msm/dp/dp_parser.c
> index 0519dd3ac3c3..75a163b0b5af 100644
> --- a/drivers/gpu/drm/msm/dp/dp_parser.c
> +++ b/drivers/gpu/drm/msm/dp/dp_parser.c
> @@ -20,11 +20,11 @@ static const struct dp_regulator_cfg sdm845_dp_reg_cfg = {
> };
>
> static int msm_dss_ioremap(struct platform_device *pdev,
> - struct dss_io_data *io_data)
> + struct dss_io_data *io_data, int idx)
> {
> struct resource *res = NULL;
>
> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + res = platform_get_resource(pdev, IORESOURCE_MEM, idx);
> if (!res) {
> DRM_ERROR("%pS->%s: msm_dss_get_res failed\n",
> __builtin_return_address(0), __func__);

We should remove this error message. It's confusing now that some
resources are optional.

> @@ -55,6 +55,8 @@ static void dp_parser_unmap_io_resources(struct dp_parser *parser)
> {
> struct dp_io *io = &parser->io;
>
> + msm_dss_iounmap(&io->hdcp_tz);
> + msm_dss_iounmap(&io->hdcp_key);
> msm_dss_iounmap(&io->dp_controller);
> }
>
> @@ -64,10 +66,20 @@ static int dp_parser_ctrl_res(struct dp_parser *parser)
> struct platform_device *pdev = parser->pdev;
> struct dp_io *io = &parser->io;
>
> - rc = msm_dss_ioremap(pdev, &io->dp_controller);
> - if (rc) {
> - DRM_ERROR("unable to remap dp io resources, rc=%d\n", rc);
> + rc = msm_dss_ioremap(pdev, &io->dp_controller, 0);
> + if (rc)
> goto err;
> +
> + rc = msm_dss_ioremap(pdev, &io->hdcp_key, 1);
> + if (rc) {
> + io->hdcp_key.base = NULL;
> + io->hdcp_key.len = 0;
> + }
> +
> + rc = msm_dss_ioremap(pdev, &io->hdcp_tz, 2);
> + if (rc) {
> + io->hdcp_tz.base = NULL;
> + io->hdcp_tz.len = 0;

Bjorn is trying to split the single io region apart into 4 different
regions[1]. This would add two more io regions. Maybe this should come
after those patches and be indexed later? I worry about needing to add
more register properties later on though. Maybe a better approach would
be to make them mandatory for certain compatible strings instead.

[1] https://lore.kernel.org/r/20210825222557.1499104-6-bjorn.andersson@linaro.org

> }
>
> io->phy = devm_phy_get(&pdev->dev, "dp");