<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p><tt>As v3 implementation removes the mode set from the path of
HDCP state change,</tt></p>
<p><tt>IMO that would have been preferred until we have the ville's
changes mentioned by daniel.</tt></p>
<p><tt>Now once again modeset is brought back :(</tt></p>
<p><tt><br>
</tt></p>
<p><tt>And have we already thought about holding the modeset lock
for 5+ Sec for HDCP authentication completion?</tt></p>
<p><tt>we might want to move the hdcp authentication itself to a
deferred work, just to return the atomic_commit_tail call
soon...</tt></p>
<p><tt>Of course even if this change is preferred, can be planned
for phase2 too...</tt></p>
<p><tt><br>
</tt></p>
<p><tt>With this change looks good to me.</tt></p>
<p><tt>Reviewed-by: Ramalingam C </tt><tt><a
class="moz-txt-link-rfc2396E"
href="mailto:ramalingm.c@intel.com"><ramalingm.c@intel.com></a></tt></p>
--Ram<br>
<br>
<div class="moz-cite-prefix">On Thursday 07 December 2017 05:30 AM,
Sean Paul wrote:<br>
</div>
<blockquote type="cite"
cite="mid:20171207000014.10083-6-seanpaul@chromium.org">
<pre wrap="">This patch adds the framework required to add HDCP support to intel
connectors. It implements Aksv loading from fuse, and parts 1/2/3
of the HDCP authentication scheme.
Note that without shim implementations, this does not actually implement
HDCP. That will come in subsequent patches.
Changes in v2:
- Don't open code wait_fors (Chris)
- drm_hdcp.c under MIT license (Daniel)
- Move intel_hdcp_disable() call above ddi_disable (Ram)
- Fix // comments (I wore a cone of shame for 12 hours to atone) (Daniel)
- Justify intel_hdcp_shim with comments (Daniel)
- Fixed async locking issues by adding hdcp_mutex (Daniel)
- Don't alter connector_state in enable/disable (Daniel)
Changes in v3:
- Added hdcp_mutex/hdcp_value to make async reasonable
- Added hdcp_prop_work to separate link checking & property setting
- Added new helper for atomic_check state tracking (Daniel)
- Moved enable/disable into atomic_commit with matching helpers
- Moved intel_hdcp_check_link out of all locks when called from dp
- Bumped up ksv_fifo timeout (noticed failure on one of my dongles)
Changes in v4:
- Remove SKL_ prefix from most register names (Daniel)
- Move enable/disable back to modeset path (Daniel)
- s/get_random_long/get_random_u32/ (Daniel)
- Remove mode_config.mutex lock in prop_work (Daniel)
- Add intel_hdcp_init to handle init of conn components (Daniel)
- Actually check return value of attach_property
- Check Bksv is valid before trying to authenticate (Ram)
Cc: Chris Wilson <a class="moz-txt-link-rfc2396E" href="mailto:chris@chris-wilson.co.uk"><chris@chris-wilson.co.uk></a>
Cc: Ramalingam C <a class="moz-txt-link-rfc2396E" href="mailto:ramalingam.c@intel.com"><ramalingam.c@intel.com></a>
Reviewed-by: Daniel Vetter <a class="moz-txt-link-rfc2396E" href="mailto:daniel.vetter@ffwll.ch"><daniel.vetter@ffwll.ch></a>
Signed-off-by: Sean Paul <a class="moz-txt-link-rfc2396E" href="mailto:seanpaul@chromium.org"><seanpaul@chromium.org></a>
---
drivers/gpu/drm/i915/Makefile | 1 +
drivers/gpu/drm/i915/i915_reg.h | 83 ++++
drivers/gpu/drm/i915/intel_atomic.c | 2 +
drivers/gpu/drm/i915/intel_ddi.c | 7 +
drivers/gpu/drm/i915/intel_display.c | 4 +
drivers/gpu/drm/i915/intel_drv.h | 85 ++++
drivers/gpu/drm/i915/intel_hdcp.c | 735 +++++++++++++++++++++++++++++++++++
7 files changed, 917 insertions(+)
create mode 100644 drivers/gpu/drm/i915/intel_hdcp.c
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 42bc8bd4ff06..3facea4eefdb 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -107,6 +107,7 @@ i915-y += intel_audio.o \
intel_fbc.o \
intel_fifo_underrun.o \
intel_frontbuffer.o \
+ intel_hdcp.o \
intel_hotplug.o \
intel_modes.o \
intel_overlay.o \
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 09bf043c1c2e..4d66651219e3 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8034,6 +8034,7 @@ enum {
#define GEN9_MEM_LATENCY_LEVEL_1_5_SHIFT 8
#define GEN9_MEM_LATENCY_LEVEL_2_6_SHIFT 16
#define GEN9_MEM_LATENCY_LEVEL_3_7_SHIFT 24
+#define SKL_PCODE_LOAD_HDCP_KEYS 0x5
#define SKL_PCODE_CDCLK_CONTROL 0x7
#define SKL_CDCLK_PREPARE_FOR_CHANGE 0x3
#define SKL_CDCLK_READY_FOR_CHANGE 0x1
@@ -8335,6 +8336,88 @@ enum skl_power_gate {
#define SKL_PW_TO_PG(pw) ((pw) - SKL_DISP_PW_1 + SKL_PG1)
#define SKL_FUSE_PG_DIST_STATUS(pg) (1 << (27 - (pg)))
+
+/* HDCP Key Registers */
+#define HDCP_KEY_CONF _MMIO(0x66c00)
+#define HDCP_AKSV_SEND_TRIGGER BIT(31)
+#define HDCP_CLEAR_KEYS_TRIGGER BIT(30)
+#define HDCP_KEY_STATUS _MMIO(0x66c04)
+#define HDCP_FUSE_IN_PROGRESS BIT(7)
+#define HDCP_FUSE_ERROR BIT(6)
+#define HDCP_FUSE_DONE BIT(5)
+#define HDCP_KEY_LOAD_STATUS BIT(1)
+#define HDCP_KEY_LOAD_DONE BIT(0)
+#define HDCP_AKSV_LO _MMIO(0x66c10)
+#define HDCP_AKSV_HI _MMIO(0x66c14)
+
+/* HDCP Repeater Registers */
+#define HDCP_REP_CTL _MMIO(0x66d00)
+#define HDCP_DDIB_REP_PRESENT BIT(30)
+#define HDCP_DDIA_REP_PRESENT BIT(29)
+#define HDCP_DDIC_REP_PRESENT BIT(28)
+#define HDCP_DDID_REP_PRESENT BIT(27)
+#define HDCP_DDIF_REP_PRESENT BIT(26)
+#define HDCP_DDIE_REP_PRESENT BIT(25)
+#define HDCP_DDIB_SHA1_M0 (1 << 20)
+#define HDCP_DDIA_SHA1_M0 (2 << 20)
+#define HDCP_DDIC_SHA1_M0 (3 << 20)
+#define HDCP_DDID_SHA1_M0 (4 << 20)
+#define HDCP_DDIF_SHA1_M0 (5 << 20)
+#define HDCP_DDIE_SHA1_M0 (6 << 20) /* Bspec says 5? */
+#define HDCP_SHA1_BUSY BIT(16)
+#define HDCP_SHA1_READY BIT(17)
+#define HDCP_SHA1_COMPLETE BIT(18)
+#define HDCP_SHA1_V_MATCH BIT(19)
+#define HDCP_SHA1_TEXT_32 (1 << 1)
+#define HDCP_SHA1_COMPLETE_HASH (2 << 1)
+#define HDCP_SHA1_TEXT_24 (4 << 1)
+#define HDCP_SHA1_TEXT_16 (5 << 1)
+#define HDCP_SHA1_TEXT_8 (6 << 1)
+#define HDCP_SHA1_TEXT_0 (7 << 1)
+#define HDCP_SHA_V_PRIME_H0 _MMIO(0x66d04)
+#define HDCP_SHA_V_PRIME_H1 _MMIO(0x66d08)
+#define HDCP_SHA_V_PRIME_H2 _MMIO(0x66d0C)
+#define HDCP_SHA_V_PRIME_H3 _MMIO(0x66d10)
+#define HDCP_SHA_V_PRIME_H4 _MMIO(0x66d14)
+#define HDCP_SHA_V_PRIME(h) _MMIO((0x66d04 + h * 4))
+#define HDCP_SHA_TEXT _MMIO(0x66d18)
+
+/* HDCP Auth Registers */
+#define _PORTA_HDCP_AUTHENC 0x66800
+#define _PORTB_HDCP_AUTHENC 0x66500
+#define _PORTC_HDCP_AUTHENC 0x66600
+#define _PORTD_HDCP_AUTHENC 0x66700
+#define _PORTE_HDCP_AUTHENC 0x66A00
+#define _PORTF_HDCP_AUTHENC 0x66900
+#define _PORT_HDCP_AUTHENC(port, x) _MMIO(_PICK(port, \
+ _PORTA_HDCP_AUTHENC, \
+ _PORTB_HDCP_AUTHENC, \
+ _PORTC_HDCP_AUTHENC, \
+ _PORTD_HDCP_AUTHENC, \
+ _PORTE_HDCP_AUTHENC, \
+ _PORTF_HDCP_AUTHENC) + x)
+#define PORT_HDCP_CONF(port) _PORT_HDCP_AUTHENC(port, 0x0)
+#define HDCP_CONF_CAPTURE_AN BIT(0)
+#define HDCP_CONF_AUTH_AND_ENC (BIT(1) | BIT(0))
+#define PORT_HDCP_ANINIT(port) _PORT_HDCP_AUTHENC(port, 0x4)
+#define PORT_HDCP_ANLO(port) _PORT_HDCP_AUTHENC(port, 0x8)
+#define PORT_HDCP_ANHI(port) _PORT_HDCP_AUTHENC(port, 0xC)
+#define PORT_HDCP_BKSVLO(port) _PORT_HDCP_AUTHENC(port, 0x10)
+#define PORT_HDCP_BKSVHI(port) _PORT_HDCP_AUTHENC(port, 0x14)
+#define PORT_HDCP_RPRIME(port) _PORT_HDCP_AUTHENC(port, 0x18)
+#define PORT_HDCP_STATUS(port) _PORT_HDCP_AUTHENC(port, 0x1C)
+#define HDCP_STATUS_STREAM_A_ENC BIT(31)
+#define HDCP_STATUS_STREAM_B_ENC BIT(30)
+#define HDCP_STATUS_STREAM_C_ENC BIT(29)
+#define HDCP_STATUS_STREAM_D_ENC BIT(28)
+#define HDCP_STATUS_AUTH BIT(21)
+#define HDCP_STATUS_ENC BIT(20)
+#define HDCP_STATUS_RI_MATCH BIT(19)
+#define HDCP_STATUS_R0_READY BIT(18)
+#define HDCP_STATUS_AN_READY BIT(17)
+#define HDCP_STATUS_CIPHER BIT(16)
+#define HDCP_STATUS_FRAME_CNT(x) ((x >> 8) & 0xff)
+
/* Per-pipe DDI Function Control */
#define _TRANS_DDI_FUNC_CTL_A 0x60400
#define _TRANS_DDI_FUNC_CTL_B 0x61400
diff --git a/drivers/gpu/drm/i915/intel_atomic.c b/drivers/gpu/drm/i915/intel_atomic.c
index 36d4e635e4ce..d452c327dc1d 100644
--- a/drivers/gpu/drm/i915/intel_atomic.c
+++ b/drivers/gpu/drm/i915/intel_atomic.c
@@ -110,6 +110,8 @@ int intel_digital_connector_atomic_check(struct drm_connector *conn,
to_intel_digital_connector_state(old_state);
struct drm_crtc_state *crtc_state;
+ intel_hdcp_atomic_check(conn, old_state, new_state);
+
if (!new_state->crtc)
return 0;
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index eff3b51872eb..ab727f0b2696 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -2418,6 +2418,11 @@ static void intel_enable_ddi(struct intel_encoder *encoder,
intel_enable_ddi_hdmi(encoder, crtc_state, conn_state);
else
intel_enable_ddi_dp(encoder, crtc_state, conn_state);
+
+ /* Enable hdcp if it's desired */
+ if (conn_state->content_protection ==
+ DRM_MODE_CONTENT_PROTECTION_DESIRED)
+ intel_hdcp_enable(to_intel_connector(conn_state->connector));
}
static void intel_disable_ddi_dp(struct intel_encoder *encoder,
@@ -2452,6 +2457,8 @@ static void intel_disable_ddi(struct intel_encoder *encoder,
const struct intel_crtc_state *old_crtc_state,
const struct drm_connector_state *old_conn_state)
{
+ intel_hdcp_disable(to_intel_connector(old_conn_state->connector));
+
if (intel_crtc_has_type(old_crtc_state, INTEL_OUTPUT_HDMI))
intel_disable_ddi_hdmi(encoder, old_crtc_state, old_conn_state);
else
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 601c23be8264..a5fef3abca64 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -15322,6 +15322,10 @@ static void intel_hpd_poll_fini(struct drm_device *dev)
for_each_intel_connector_iter(connector, &conn_iter) {
if (connector->modeset_retry_work.func)
cancel_work_sync(&connector->modeset_retry_work);
+ if (connector->hdcp_shim) {
+ cancel_delayed_work_sync(&connector->hdcp_check_work);
+ cancel_work_sync(&connector->hdcp_prop_work);
+ }
}
drm_connector_list_iter_end(&conn_iter);
}
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index cbfe306cc5b7..3351785af867 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -301,6 +301,76 @@ struct intel_panel {
} backlight;
};
+/*
+ * This structure serves as a translation layer between the generic HDCP code
+ * and the bus-specific code. What that means is that HDCP over HDMI differs
+ * from HDCP over DP, so to account for these differences, we need to
+ * communicate with the receiver through this shim.
+ *
+ * For completeness, the 2 buses differ in the following ways:
+ * - DP AUX vs. DDC
+ * HDCP registers on the receiver are set via DP AUX for DP, and
+ * they are set via DDC for HDMI.
+ * - Receiver register offsets
+ * The offsets of the registers are different for DP vs. HDMI
+ * - Receiver register masks/offsets
+ * For instance, the ready bit for the KSV fifo is in a different
+ * place on DP vs HDMI
+ * - Receiver register names
+ * Seriously. In the DP spec, the 16-bit register containing
+ * downstream information is called BINFO, on HDMI it's called
+ * BSTATUS. To confuse matters further, DP has a BSTATUS register
+ * with a completely different definition.
+ * - KSV FIFO
+ * On HDMI, the ksv fifo is read all at once, whereas on DP it must
+ * be read 3 keys at a time
+ * - Aksv output
+ * Since Aksv is hidden in hardware, there's different procedures
+ * to send it over DP AUX vs DDC
+ */
+struct intel_hdcp_shim {
+ /* Outputs the transmitter's An and Aksv values to the receiver. */
+ int (*write_an_aksv)(struct intel_digital_port *intel_dig_port, u8 *an);
+
+ /* Reads the receiver's key selection vector */
+ int (*read_bksv)(struct intel_digital_port *intel_dig_port, u8 *bksv);
+
+ /*
+ * Reads BINFO from DP receivers and BSTATUS from HDMI receivers. The
+ * definitions are the same in the respective specs, but the names are
+ * different. Call it BSTATUS since that's the name the HDMI spec
+ * uses and it was there first.
+ */
+ int (*read_bstatus)(struct intel_digital_port *intel_dig_port,
+ u8 *bstatus);
+
+ /* Determines whether a repeater is present downstream */
+ int (*repeater_present)(struct intel_digital_port *intel_dig_port,
+ bool *repeater_present);
+
+ /* Reads the receiver's Ri' value */
+ int (*read_ri_prime)(struct intel_digital_port *intel_dig_port, u8 *ri);
+
+ /* Determines if the receiver's KSV FIFO is ready for consumption */
+ int (*read_ksv_ready)(struct intel_digital_port *intel_dig_port,
+ bool *ksv_ready);
+
+ /* Reads the ksv fifo for num_downstream devices */
+ int (*read_ksv_fifo)(struct intel_digital_port *intel_dig_port,
+ int num_downstream, u8 *ksv_fifo);
+
+ /* Reads a 32-bit part of V' from the receiver */
+ int (*read_v_prime_part)(struct intel_digital_port *intel_dig_port,
+ int i, u32 *part);
+
+ /* Enables HDCP signalling on the port */
+ int (*toggle_signalling)(struct intel_digital_port *intel_dig_port,
+ bool enable);
+
+ /* Ensures the link is still protected */
+ bool (*check_link)(struct intel_digital_port *intel_dig_port);
+};
+
struct intel_connector {
struct drm_connector base;
/*
@@ -332,6 +402,12 @@ struct intel_connector {
/* Work struct to schedule a uevent on link train failure */
struct work_struct modeset_retry_work;
+
+ const struct intel_hdcp_shim *hdcp_shim;
+ struct mutex hdcp_mutex;
+ uint64_t hdcp_value; /* protected by hdcp_mutex */
+ struct delayed_work hdcp_check_work;
+ struct work_struct hdcp_prop_work;
};
struct intel_digital_connector_state {
@@ -1763,6 +1839,15 @@ static inline void intel_backlight_device_unregister(struct intel_connector *con
}
#endif /* CONFIG_BACKLIGHT_CLASS_DEVICE */
+/* intel_hdcp.c */
+void intel_hdcp_atomic_check(struct drm_connector *connector,
+ struct drm_connector_state *old_state,
+ struct drm_connector_state *new_state);
+int intel_hdcp_init(struct intel_connector *connector,
+ const struct intel_hdcp_shim *hdcp_shim);
+int intel_hdcp_enable(struct intel_connector *connector);
+int intel_hdcp_disable(struct intel_connector *connector);
+int intel_hdcp_check_link(struct intel_connector *connector);
/* intel_psr.c */
void intel_psr_enable(struct intel_dp *intel_dp,
diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
new file mode 100644
index 000000000000..0d003de8e99c
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -0,0 +1,735 @@
+/*
+ * Copyright (C) 2017 Google, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ * Sean Paul <a class="moz-txt-link-rfc2396E" href="mailto:seanpaul@chromium.org"><seanpaul@chromium.org></a>
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_hdcp.h>
+#include <linux/i2c.h>
+#include <linux/random.h>
+
+#include "intel_drv.h"
+#include "i915_reg.h"
+
+#define KEY_LOAD_TRIES 5
+
+static int intel_hdcp_poll_ksv_fifo(struct intel_digital_port *intel_dig_port,
+ const struct intel_hdcp_shim *shim)
+{
+ int ret, read_ret;
+ bool ksv_ready;
+
+ ret = __wait_for(read_ret = shim->read_ksv_ready(intel_dig_port,
+ &ksv_ready),
+ read_ret || ksv_ready, 1500 * 1000, 1000, 100 * 1000);
+ if (ret)
+ return ret;
+ if (read_ret)
+ return read_ret;
+ if (!ksv_ready)
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static void intel_hdcp_clear_keys(struct drm_i915_private *dev_priv)
+{
+ I915_WRITE(HDCP_KEY_CONF, HDCP_CLEAR_KEYS_TRIGGER);
+ I915_WRITE(HDCP_KEY_STATUS, HDCP_KEY_LOAD_DONE | HDCP_KEY_LOAD_STATUS |
+ HDCP_FUSE_IN_PROGRESS | HDCP_FUSE_ERROR | HDCP_FUSE_DONE);
+}
+
+static int intel_hdcp_load_keys(struct drm_i915_private *dev_priv)
+{
+ int ret;
+ u32 val;
+
+ /* Initiate loading the HDCP key from fuses */
+ mutex_lock(&dev_priv->pcu_lock);
+ ret = sandybridge_pcode_write(dev_priv, SKL_PCODE_LOAD_HDCP_KEYS, 1);
+ mutex_unlock(&dev_priv->pcu_lock);
+ if (ret) {
+ DRM_ERROR("Failed to initiate HDCP key load (%d)\n", ret);
+ return ret;
+ }
+
+ /* Wait for the keys to load (500us) */
+ ret = __intel_wait_for_register(dev_priv, HDCP_KEY_STATUS,
+ HDCP_KEY_LOAD_DONE, HDCP_KEY_LOAD_DONE,
+ 10, 1, &val);
+ if (ret)
+ return ret;
+ else if (!(val & HDCP_KEY_LOAD_STATUS))
+ return -ENXIO;
+
+ /* Send Aksv over to PCH display for use in authentication */
+ I915_WRITE(HDCP_KEY_CONF, HDCP_AKSV_SEND_TRIGGER);
+
+ return 0;
+}
+
+/* Returns updated SHA-1 index */
+static int intel_write_sha_text(struct drm_i915_private *dev_priv, u32 sha_text)
+{
+ I915_WRITE(HDCP_SHA_TEXT, sha_text);
+ if (intel_wait_for_register(dev_priv, HDCP_REP_CTL,
+ HDCP_SHA1_READY, HDCP_SHA1_READY, 1)) {
+ DRM_ERROR("Timed out waiting for SHA1 ready\n");
+ return -ETIMEDOUT;
+ }
+ return 0;
+}
+
+static
+u32 intel_hdcp_get_repeater_ctl(struct intel_digital_port *intel_dig_port)
+{
+ enum port port = intel_dig_port->base.port;
+ switch(port) {
+ case PORT_A:
+ return HDCP_DDIA_REP_PRESENT | HDCP_DDIA_SHA1_M0;
+ case PORT_B:
+ return HDCP_DDIB_REP_PRESENT | HDCP_DDIB_SHA1_M0;
+ case PORT_C:
+ return HDCP_DDIC_REP_PRESENT | HDCP_DDIC_SHA1_M0;
+ case PORT_D:
+ return HDCP_DDID_REP_PRESENT | HDCP_DDID_SHA1_M0;
+ case PORT_E:
+ return HDCP_DDIE_REP_PRESENT | HDCP_DDIE_SHA1_M0;
+ default:
+ break;
+ }
+ DRM_ERROR("Unknown port %d\n", port);
+ return -EINVAL;
+}
+
+static
+bool intel_hdcp_is_ksv_valid(u8 *ksv)
+{
+ int i, ones = 0;
+ /* KSV has 20 1's and 20 0's */
+ for (i = 0; i < DRM_HDCP_KSV_LEN; i++)
+ ones += hweight8(ksv[i]);
+ if (ones != 20)
+ return false;
+ return true;
+}
+
+/* Implements Part 2 of the HDCP authorization procedure */
+static
+int intel_hdcp_auth_downstream(struct intel_digital_port *intel_dig_port,
+ const struct intel_hdcp_shim *shim)
+{
+ struct drm_i915_private *dev_priv;
+ u32 vprime, sha_text, sha_leftovers, rep_ctl;
+ u8 bstatus[2], num_downstream, *ksv_fifo;
+ int ret, i, j, sha_idx;
+
+ dev_priv = intel_dig_port->base.base.dev->dev_private;
+
+ ret = shim->read_bstatus(intel_dig_port, bstatus);
+ if (ret)
+ return ret;
+
+ /* If there are no downstream devices, we're all done. */
+ num_downstream = DRM_HDCP_NUM_DOWNSTREAM(bstatus[0]);
+ if (num_downstream == 0) {
+ DRM_INFO("HDCP is enabled (no downstream devices)\n");
+ return 0;
+ }
+
+ /* Poll for ksv list ready (spec says max time allowed is 5s) */
+ ret = intel_hdcp_poll_ksv_fifo(intel_dig_port, shim);
+ if (ret) {
+ DRM_ERROR("KSV list failed to become ready (%d)\n", ret);
+ return ret;
+ }
+
+ ksv_fifo = kzalloc(num_downstream * DRM_HDCP_KSV_LEN, GFP_KERNEL);
+ if (!ksv_fifo)
+ return -ENOMEM;
+
+ ret = shim->read_ksv_fifo(intel_dig_port, num_downstream, ksv_fifo);
+ if (ret)
+ return ret;
+
+ /* Process V' values from the receiver */
+ for (i = 0; i < DRM_HDCP_V_PRIME_NUM_PARTS; i++) {
+ ret = shim->read_v_prime_part(intel_dig_port, i, &vprime);
+ if (ret)
+ return ret;
+ I915_WRITE(HDCP_SHA_V_PRIME(i), vprime);
+ }
+
+ /*
+ * We need to write the concatenation of all device KSVs, BINFO (DP) ||
+ * BSTATUS (HDMI), and M0 (which is added via HDCP_REP_CTL). This byte
+ * stream is written via the HDCP_SHA_TEXT register in 32-bit
+ * increments. Every 64 bytes, we need to write HDCP_REP_CTL again. This
+ * index will keep track of our progress through the 64 bytes as well as
+ * helping us work the 40-bit KSVs through our 32-bit register.
+ *
+ * NOTE: data passed via HDCP_SHA_TEXT should be big-endian
+ */
+ sha_idx = 0;
+ sha_text = 0;
+ sha_leftovers = 0;
+ rep_ctl = intel_hdcp_get_repeater_ctl(intel_dig_port);
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_32);
+ for (i = 0; i < num_downstream; i++) {
+ unsigned sha_empty;
+ u8 *ksv = &ksv_fifo[i * DRM_HDCP_KSV_LEN];
+
+ /* Fill up the empty slots in sha_text and write it out */
+ sha_empty = sizeof(sha_text) - sha_leftovers;
+ for (j = 0; j < sha_empty; j++)
+ sha_text |= ksv[j] << ((sizeof(sha_text) - j - 1) * 8);
+
+ ret = intel_write_sha_text(dev_priv, sha_text);
+ if (ret < 0)
+ return ret;
+
+ /* Programming guide writes this every 64 bytes */
+ sha_idx += sizeof(sha_text);
+ if (!(sha_idx % 64))
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_32);
+
+ /* Store the leftover bytes from the ksv in sha_text */
+ sha_leftovers = DRM_HDCP_KSV_LEN - sha_empty;
+ sha_text = 0;
+ for (j = 0; j < sha_leftovers; j++)
+ sha_text |= ksv[sha_empty + j] <<
+ ((sizeof(sha_text) - j - 1) * 8);
+
+ /*
+ * If we still have room in sha_text for more data, continue.
+ * Otherwise, write it out immediately.
+ */
+ if (sizeof(sha_text) > sha_leftovers)
+ continue;
+
+ ret = intel_write_sha_text(dev_priv, sha_text);
+ if (ret < 0)
+ return ret;
+ sha_leftovers = 0;
+ sha_text = 0;
+ sha_idx += sizeof(sha_text);
+ }
+
+ /*
+ * We need to write BINFO/BSTATUS, and M0 now. Depending on how many
+ * bytes are leftover from the last ksv, we might be able to fit them
+ * all in sha_text (first 2 cases), or we might need to split them up
+ * into 2 writes (last 2 cases).
+ */
+ if (sha_leftovers == 0) {
+ /* Write 16 bits of text, 16 bits of M0 */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_16);
+ ret = intel_write_sha_text(dev_priv,
+ bstatus[0] << 8 | bstatus[1]);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+
+ /* Write 32 bits of M0 */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_0);
+ ret = intel_write_sha_text(dev_priv, 0);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+
+ /* Write 16 bits of M0 */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_16);
+ ret = intel_write_sha_text(dev_priv, 0);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+
+ } else if (sha_leftovers == 1) {
+ /* Write 24 bits of text, 8 bits of M0 */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_24);
+ sha_text |= bstatus[0] << 16 | bstatus[1] << 8;
+ /* Only 24-bits of data, must be in the LSB */
+ sha_text = (sha_text & 0xffffff00) >> 8;
+ ret = intel_write_sha_text(dev_priv, sha_text);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+
+ /* Write 32 bits of M0 */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_0);
+ ret = intel_write_sha_text(dev_priv, 0);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+
+ /* Write 24 bits of M0 */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_8);
+ ret = intel_write_sha_text(dev_priv, 0);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+
+ } else if (sha_leftovers == 2) {
+ /* Write 32 bits of text */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_32);
+ sha_text |= bstatus[0] << 24 | bstatus[1] << 16;
+ ret = intel_write_sha_text(dev_priv, sha_text);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+
+ /* Write 64 bits of M0 */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_0);
+ for (i = 0; i < 2; i++) {
+ ret = intel_write_sha_text(dev_priv, 0);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+ }
+ } else if (sha_leftovers == 3) {
+ /* Write 32 bits of text */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_32);
+ sha_text |= bstatus[0] << 24;
+ ret = intel_write_sha_text(dev_priv, sha_text);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+
+ /* Write 8 bits of text, 24 bits of M0 */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_8);
+ ret = intel_write_sha_text(dev_priv, bstatus[1]);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+
+ /* Write 32 bits of M0 */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_0);
+ ret = intel_write_sha_text(dev_priv, 0);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+
+ /* Write 8 bits of M0 */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_24);
+ ret = intel_write_sha_text(dev_priv, 0);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+ } else {
+ DRM_ERROR("Invalid number of leftovers %d\n", sha_leftovers);
+ return -EINVAL;
+ }
+
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_32);
+ /* Fill up to 64-4 bytes with zeros (leave the last write for length) */
+ while ((sha_idx % 64) < (64 - sizeof(sha_text))) {
+ ret = intel_write_sha_text(dev_priv, 0);
+ if (ret < 0)
+ return ret;
+ sha_idx += sizeof(sha_text);
+ }
+
+ /*
+ * Last write gets the length of the concatenation in bits. That is:
+ * - 5 bytes per device
+ * - 10 bytes for BINFO/BSTATUS(2), M0(8)
+ */
+ sha_text = (num_downstream * 5 + 10) * 8;
+ ret = intel_write_sha_text(dev_priv, sha_text);
+ if (ret < 0)
+ return ret;
+
+ /* Tell the HW we're done with the hash and wait for it to ACK */
+ I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_COMPLETE_HASH);
+ if (intel_wait_for_register(dev_priv, HDCP_REP_CTL,
+ HDCP_SHA1_COMPLETE,
+ HDCP_SHA1_COMPLETE, 1)) {
+ DRM_ERROR("Timed out waiting for SHA1 complete\n");
+ return -ETIMEDOUT;
+ }
+ if (!(I915_READ(HDCP_REP_CTL) & HDCP_SHA1_V_MATCH)) {
+ DRM_ERROR("SHA-1 mismatch, HDCP failed\n");
+ return -ENXIO;
+ }
+
+ DRM_INFO("HDCP is enabled (%d downstream devices)\n", num_downstream);
+ return 0;
+}
+
+/* Implements Part 1 of the HDCP authorization procedure */
+static int intel_hdcp_auth(struct intel_digital_port *intel_dig_port,
+ const struct intel_hdcp_shim *shim)
+{
+ struct drm_i915_private *dev_priv;
+ enum port port;
+ unsigned long r0_prime_gen_start;
+ int ret, i;
+ union {
+ u32 reg[2];
+ u8 shim[DRM_HDCP_AN_LEN];
+ } an;
+ union {
+ u32 reg[2];
+ u8 shim[DRM_HDCP_KSV_LEN];
+ } bksv;
+ union {
+ u32 reg;
+ u8 shim[DRM_HDCP_RI_LEN];
+ } ri;
+ bool repeater_present;
+
+ dev_priv = intel_dig_port->base.base.dev->dev_private;
+
+ port = intel_dig_port->base.port;
+
+ /* Initialize An with 2 random values and acquire it */
+ for (i = 0; i < 2; i++)
+ I915_WRITE(PORT_HDCP_ANINIT(port), get_random_u32());
+ I915_WRITE(PORT_HDCP_CONF(port), HDCP_CONF_CAPTURE_AN);
+
+ /* Wait for An to be acquired */
+ if (intel_wait_for_register(dev_priv, PORT_HDCP_STATUS(port),
+ HDCP_STATUS_AN_READY,
+ HDCP_STATUS_AN_READY, 1)) {
+ DRM_ERROR("Timed out waiting for An\n");
+ return -ETIMEDOUT;
+ }
+
+ an.reg[0] = I915_READ(PORT_HDCP_ANLO(port));
+ an.reg[1] = I915_READ(PORT_HDCP_ANHI(port));
+ ret = shim->write_an_aksv(intel_dig_port, an.shim);
+ if (ret)
+ return ret;
+
+ r0_prime_gen_start = jiffies;
+
+ memset(&bksv, 0, sizeof(bksv));
+ ret = shim->read_bksv(intel_dig_port, bksv.shim);
+ if (ret)
+ return ret;
+ else if (!intel_hdcp_is_ksv_valid(bksv.shim))
+ return -ENODEV;
+
+ I915_WRITE(PORT_HDCP_BKSVLO(port), bksv.reg[0]);
+ I915_WRITE(PORT_HDCP_BKSVHI(port), bksv.reg[1]);
+
+ ret = shim->repeater_present(intel_dig_port, &repeater_present);
+ if (ret)
+ return ret;
+ if (repeater_present)
+ I915_WRITE(HDCP_REP_CTL,
+ intel_hdcp_get_repeater_ctl(intel_dig_port));
+
+ ret = shim->toggle_signalling(intel_dig_port, true);
+ if (ret)
+ return ret;
+
+ I915_WRITE(PORT_HDCP_CONF(port), HDCP_CONF_AUTH_AND_ENC);
+
+ /* Wait for R0 ready */
+ if (wait_for(I915_READ(PORT_HDCP_STATUS(port)) &
+ (HDCP_STATUS_R0_READY | HDCP_STATUS_ENC), 1)) {
+ DRM_ERROR("Timed out waiting for R0 ready\n");
+ return -ETIMEDOUT;
+ }
+
+ /*
+ * Wait for R0' to become available, the spec says 100ms from Aksv
+ * write. On DP, there's an R0_READY bit available but no such bit
+ * exists on HDMI. Since the upper-bound is the same, we'll just do
+ * the stupid thing instead of polling on one and not the other.
+ */
+ wait_remaining_ms_from_jiffies(r0_prime_gen_start, 100);
+
+ ri.reg = 0;
+ ret = shim->read_ri_prime(intel_dig_port, ri.shim);
+ if (ret)
+ return ret;
+ I915_WRITE(PORT_HDCP_RPRIME(port), ri.reg);
+
+ /* Wait for Ri prime match */
+ if (wait_for(I915_READ(PORT_HDCP_STATUS(port)) &
+ (HDCP_STATUS_RI_MATCH | HDCP_STATUS_ENC), 1)) {
+ DRM_ERROR("Timed out waiting for Ri prime match (%x)\n",
+ I915_READ(PORT_HDCP_STATUS(port)));
+ return -ETIMEDOUT;
+ }
+
+ /* Wait for encryption confirmation */
+ if (intel_wait_for_register(dev_priv, PORT_HDCP_STATUS(port),
+ HDCP_STATUS_ENC, HDCP_STATUS_ENC, 20)) {
+ DRM_ERROR("Timed out waiting for encryption\n");
+ return -ETIMEDOUT;
+ }
+
+ /*
+ * XXX: If we have MST-connected devices, we need to enable encryption
+ * on those as well.
+ */
+
+ return intel_hdcp_auth_downstream(intel_dig_port, shim);
+}
+
+static
+struct intel_digital_port *conn_to_dig_port(struct intel_connector *connector)
+{
+ return enc_to_dig_port(&intel_attached_encoder(&connector->base)->base);
+}
+
+static int _intel_hdcp_disable(struct intel_connector *connector)
+{
+ struct drm_i915_private *dev_priv = connector->base.dev->dev_private;
+ struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+ enum port port = intel_dig_port->base.port;
+ int ret;
+
+ I915_WRITE(PORT_HDCP_CONF(port), 0);
+ if (intel_wait_for_register(dev_priv, PORT_HDCP_STATUS(port), ~0, 0,
+ 20)) {
+ DRM_ERROR("Failed to disable HDCP, timeout clearing status\n");
+ return -ETIMEDOUT;
+ }
+
+ intel_hdcp_clear_keys(dev_priv);
+
+ ret = connector->hdcp_shim->toggle_signalling(intel_dig_port, false);
+ if (ret) {
+ DRM_ERROR("Failed to disable HDCP signalling\n");
+ return ret;
+ }
+
+ DRM_INFO("HDCP is disabled\n");
+ return 0;
+}
+
+static int _intel_hdcp_enable(struct intel_connector *connector)
+{
+ struct drm_i915_private *dev_priv = connector->base.dev->dev_private;
+ int i, ret;
+
+ if (!(I915_READ(SKL_FUSE_STATUS) & SKL_FUSE_PG_DIST_STATUS(1))) {
+ DRM_ERROR("PG1 is disabled, cannot load keys\n");
+ return -ENXIO;
+ }
+
+ for (i = 0; i < KEY_LOAD_TRIES; i++) {
+ ret = intel_hdcp_load_keys(dev_priv);
+ if (!ret)
+ break;
+ intel_hdcp_clear_keys(dev_priv);
+ }
+ if (ret) {
+ DRM_ERROR("Could not load HDCP keys, (%d)\n", ret);
+ return ret;
+ }
+
+ ret = intel_hdcp_auth(conn_to_dig_port(connector),
+ connector->hdcp_shim);
+ if (ret) {
+ DRM_ERROR("Failed to authenticate HDCP (%d)\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void intel_hdcp_check_work(struct work_struct *work)
+{
+ struct intel_connector *connector = container_of(to_delayed_work(work),
+ struct intel_connector,
+ hdcp_check_work);
+ if (!intel_hdcp_check_link(connector))
+ schedule_delayed_work(&connector->hdcp_check_work,
+ DRM_HDCP_CHECK_PERIOD_MS);
+}
+
+static void intel_hdcp_prop_work(struct work_struct *work)
+{
+ struct intel_connector *connector = container_of(work,
+ struct intel_connector,
+ hdcp_prop_work);
+ struct drm_device *dev = connector->base.dev;
+ struct drm_connector_state *state;
+
+ drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+ mutex_lock(&connector->hdcp_mutex);
+
+ /*
+ * This worker is only used to flip between ENABLED/DESIRED. Either of
+ * those to OFF is handled by core. If hdcp_value == OFF, we're running
+ * just after hdcp has been disabled, so just exit
+ */
+ if (connector->hdcp_value != DRM_MODE_CONTENT_PROTECTION_OFF) {
+ state = connector->base.state;
+ state->content_protection = connector->hdcp_value;
+ }
+
+ mutex_unlock(&connector->hdcp_mutex);
+ drm_modeset_unlock(&dev->mode_config.connection_mutex);
+}
+
+int intel_hdcp_init(struct intel_connector *connector,
+ const struct intel_hdcp_shim *hdcp_shim)
+{
+ int ret;
+
+ ret = drm_connector_attach_content_protection_property(
+ &connector->base);
+ if (ret)
+ return ret;
+
+ connector->hdcp_shim = hdcp_shim;
+ mutex_init(&connector->hdcp_mutex);
+ INIT_DELAYED_WORK(&connector->hdcp_check_work, intel_hdcp_check_work);
+ INIT_WORK(&connector->hdcp_prop_work, intel_hdcp_prop_work);
+ return 0;
+}
+
+int intel_hdcp_enable(struct intel_connector *connector)
+{
+ int ret;
+
+ if (!connector->hdcp_shim)
+ return -ENOENT;
+
+ mutex_lock(&connector->hdcp_mutex);
+
+ ret = _intel_hdcp_enable(connector);
+ if (ret)
+ goto out;
+
+ connector->hdcp_value = DRM_MODE_CONTENT_PROTECTION_ENABLED;
+ schedule_work(&connector->hdcp_prop_work);
+ schedule_delayed_work(&connector->hdcp_check_work,
+ DRM_HDCP_CHECK_PERIOD_MS);
+out:
+ mutex_unlock(&connector->hdcp_mutex);
+ return ret;
+}
+
+int intel_hdcp_disable(struct intel_connector *connector)
+{
+ int ret;
+
+ if (!connector->hdcp_shim)
+ return -ENOENT;
+
+ mutex_lock(&connector->hdcp_mutex);
+
+ connector->hdcp_value = DRM_MODE_CONTENT_PROTECTION_OFF;
+ ret = _intel_hdcp_disable(connector);
+
+ mutex_unlock(&connector->hdcp_mutex);
+ cancel_delayed_work_sync(&connector->hdcp_check_work);
+ return ret;
+}
+
+void intel_hdcp_atomic_check(struct drm_connector *connector,
+ struct drm_connector_state *old_state,
+ struct drm_connector_state *new_state)
+{
+ uint64_t old_cp = old_state->content_protection;
+ uint64_t new_cp = new_state->content_protection;
+ struct drm_crtc_state *crtc_state;
+
+ if (!new_state->crtc) {
+ /*
+ * If the connector is being disabled with CP enabled, mark it
+ * desired so it's re-enabled when the connector is brought back
+ */
+ if (old_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED)
+ new_state->content_protection =
+ DRM_MODE_CONTENT_PROTECTION_DESIRED;
+ return;
+ }
+
+ /*
+ * Nothing to do if the state didn't change, or HDCP was activated since
+ * the last commit
+ */
+ if (old_cp == new_cp ||
+ (old_cp == DRM_MODE_CONTENT_PROTECTION_DESIRED &&
+ new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED))
+ return;
+
+ crtc_state = drm_atomic_get_new_crtc_state(new_state->state,
+ new_state->crtc);
+ crtc_state->mode_changed = true;
+}
+
+/* Implements Part 3 of the HDCP authorization procedure */
+int intel_hdcp_check_link(struct intel_connector *connector)
+{
+ struct drm_i915_private *dev_priv = connector->base.dev->dev_private;
+ struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+ enum port port = intel_dig_port->base.port;
+ int ret = 0;
+
+ if (!connector->hdcp_shim)
+ return -ENOENT;
+
+ mutex_lock(&connector->hdcp_mutex);
+
+ if (connector->hdcp_value == DRM_MODE_CONTENT_PROTECTION_OFF)
+ goto out;
+
+ if (!(I915_READ(PORT_HDCP_STATUS(port)) & HDCP_STATUS_ENC)) {
+ DRM_ERROR("HDCP check failed: link is not encrypted, %x\n",
+ I915_READ(PORT_HDCP_STATUS(port)));
+ ret = -ENXIO;
+ connector->hdcp_value = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+ schedule_work(&connector->hdcp_prop_work);
+ goto out;
+ }
+
+ if (connector->hdcp_shim->check_link(intel_dig_port)) {
+ if (connector->hdcp_value != DRM_MODE_CONTENT_PROTECTION_OFF) {
+ connector->hdcp_value =
+ DRM_MODE_CONTENT_PROTECTION_ENABLED;
+ schedule_work(&connector->hdcp_prop_work);
+ }
+ goto out;
+ }
+
+ DRM_INFO("HDCP link failed, retrying authentication\n");
+
+ ret = _intel_hdcp_disable(connector);
+ if (ret) {
+ DRM_ERROR("Failed to disable hdcp (%d)\n", ret);
+ connector->hdcp_value = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+ schedule_work(&connector->hdcp_prop_work);
+ goto out;
+ }
+
+ ret = _intel_hdcp_enable(connector);
+ if (ret) {
+ DRM_ERROR("Failed to enable hdcp (%d)\n", ret);
+ connector->hdcp_value = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+ schedule_work(&connector->hdcp_prop_work);
+ goto out;
+ }
+
+out:
+ mutex_unlock(&connector->hdcp_mutex);
+ return ret;
+}
</pre>
</blockquote>
<br>
</body>
</html>