drm/amd/display: Support for DMUB AUX

[WHY]
To process AUX transactions with DMUB using inbox1 and outbox1 mail boxes.

[HOW]
1) Added inbox1 command DMUB_CMD__DP_AUX_ACCESS to issue AUX commands
   to DMUB in dc_process_dmub_aux_transfer_async(). DMUB processes AUX cmd
   with DCN and sends reply back in an outbox1 message triggering an
   outbox1 interrupt to driver.
2) In existing driver implementation, AUX commands are processed
   synchronously by configuring DCN reg. But in DMUB AUX, driver sends an
   inbox1 message and waits for a conditional variable (CV) which will be
   signaled by outbox1 ISR.
3) As the driver holds dal and dc locks while waiting for CV, the outbox1
   ISR is registered with noMutexWait set to true, which allows ISR to run
   and signal CV. This sets a constraint on ISR to not modify variables
   such as dc, dmub, etc.
4) Created dmub_outbox.c with dmub_enable_outbox_notification() to enable
   outbox1 mailbox.
5) New mailbox address ranges allocated for outbox1 of size DMUB_RB_SIZE.
   Created dmub functions for Outbox1: dmub_dcn20_setup_out_mailbox(),
   dmub_dcn20_get_outbox1_wptr() and dmub_dcn20_set_outbox1_rptr().
6) Added functions dc_stat_get_dmub_notification() and
   dmub_srv_stat_get_notification() to retrieve Outbox1 message.
7) Currently, DMUB doesn't opens DDC in AUX mode before issuing AUX
   transaction. A workaround is added in dce_aux_transfer_dmub_raw() to
   open in DDC in AUX mode for every AUX transaction.
8) Added dc debug option enable_dmub_aux_for_legacy_ddc enable/disable
   DMUB AUX. This debug option is checked dce_aux_transfer_with_retries()
   to select the method to process AUX transactions.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

7 files changed, 258 insertions, 5 deletions

diff --git a/drivers/gpu/drm/amd/display/dmub/dmub_srv.h b/drivers/gpu/drm/amd/display/dmub/dmub_srv.h
index 863cd9cc93ff..6e4f558fe97e 100644
--- a/drivers/gpu/drm/amd/display/dmub/dmub_srv.h
+++ b/drivers/gpu/drm/amd/display/dmub/dmub_srv.h
@@ -107,6 +107,15 @@ enum dmub_window_id {
 	DMUB_WINDOW_TOTAL,
 };
 
+/* enum dmub_notification_type - dmub outbox notification identifier */
+enum dmub_notification_type {
+	DMUB_NOTIFICATION_NO_DATA = 0,
+	DMUB_NOTIFICATION_AUX_REPLY,
+	DMUB_NOTIFICATION_HPD,
+	DMUB_NOTIFICATION_HPD_IRQ,
+	DMUB_NOTIFICATION_MAX
+};
+
 /**
  * struct dmub_region - dmub hw memory region
  * @base: base address for region, must be 256 byte aligned
@@ -256,6 +265,13 @@ struct dmub_srv_hw_funcs {
 
 	void (*set_inbox1_wptr)(struct dmub_srv *dmub, uint32_t wptr_offset);
 
+	void (*setup_out_mailbox)(struct dmub_srv *dmub,
+			      const struct dmub_region *outbox1);
+
+	uint32_t (*get_outbox1_wptr)(struct dmub_srv *dmub);
+
+	void (*set_outbox1_rptr)(struct dmub_srv *dmub, uint32_t rptr_offset);
+
 	uint32_t (*emul_get_inbox1_rptr)(struct dmub_srv *dmub);
 
 	void (*emul_set_inbox1_wptr)(struct dmub_srv *dmub, uint32_t wptr_offset);
@@ -338,6 +354,11 @@ struct dmub_srv {
 	struct dmub_srv_base_funcs funcs;
 	struct dmub_srv_hw_funcs hw_funcs;
 	struct dmub_rb inbox1_rb;
+	/**
+	 * outbox1_rb is accessed without locks (dal & dc)
+	 * and to be used only in dmub_srv_stat_get_notification()
+	 */
+	struct dmub_rb outbox1_rb;
 
 	bool sw_init;
 	bool hw_init;
@@ -351,6 +372,26 @@ struct dmub_srv {
 };
 
 /**
+ * struct dmub_notification - dmub notification data
+ * @type: dmub notification type
+ * @link_index: link index to identify aux connection
+ * @result: USB4 status returned from dmub
+ * @pending_notification: Indicates there are other pending notifications
+ * @aux_reply: aux reply
+ * @hpd_status: hpd status
+ */
+struct dmub_notification {
+	enum dmub_notification_type type;
+	uint8_t link_index;
+	uint8_t result;
+	bool pending_notification;
+	union {
+		struct aux_reply_data aux_reply;
+		enum dp_hpd_status hpd_status;
+	};
+};
+
+/**
  * DMUB firmware version helper macro - useful for checking if the version
  * of a firmware to know if feature or functionality is supported or present.
  */
diff --git a/drivers/gpu/drm/amd/display/dmub/dmub_srv_stat.h b/drivers/gpu/drm/amd/display/dmub/dmub_srv_stat.h
new file mode 100644
index 000000000000..6c78aa406e90
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/dmub/dmub_srv_stat.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2020 Advanced Micro Devices, 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: AMD
+ *
+ */
+
+#ifndef _DMUB_SRV_STAT_H_
+#define _DMUB_SRV_STAT_H_
+
+/**
+ * DOC: DMUB_SRV STAT Interface
+ *
+ * These interfaces are called without acquiring DAL and DC locks.
+ * Hence, there is limitations on whese interfaces can access. Only
+ * variables exclusively defined for these interfaces can be modified.
+ */
+#include "dmub_srv.h"
+
+enum dmub_status dmub_srv_stat_get_notification(struct dmub_srv *dmub,
+						struct dmub_notification *notify);
+
+#endif /* _DMUB_SRV_STAT_H_ */
diff --git a/drivers/gpu/drm/amd/display/dmub/src/Makefile b/drivers/gpu/drm/amd/display/dmub/src/Makefile
index 945287164cf2..7495c23c73a9 100644
--- a/drivers/gpu/drm/amd/display/dmub/src/Makefile
+++ b/drivers/gpu/drm/amd/display/dmub/src/Makefile
@@ -20,7 +20,7 @@
 # OTHER DEALINGS IN THE SOFTWARE.
 #
 
-DMUB = dmub_srv.o dmub_reg.o dmub_dcn20.o dmub_dcn21.o
+DMUB = dmub_srv.o dmub_srv_stat.o dmub_reg.o dmub_dcn20.o dmub_dcn21.o
 DMUB += dmub_dcn30.o dmub_dcn301.o
 DMUB += dmub_dcn302.o
 
diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn20.c b/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn20.c
index ea30da4f794f..071331bcc427 100644
--- a/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn20.c
+++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn20.c
@@ -135,6 +135,8 @@ void dmub_dcn20_reset(struct dmub_srv *dmub)
 	REG_UPDATE(MMHUBBUB_SOFT_RESET, DMUIF_SOFT_RESET, 1);
 	REG_WRITE(DMCUB_INBOX1_RPTR, 0);
 	REG_WRITE(DMCUB_INBOX1_WPTR, 0);
+	REG_WRITE(DMCUB_OUTBOX1_RPTR, 0);
+	REG_WRITE(DMCUB_OUTBOX1_WPTR, 0);
 	REG_WRITE(DMCUB_SCRATCH0, 0);
 }
 
@@ -287,6 +289,36 @@ void dmub_dcn20_set_inbox1_wptr(struct dmub_srv *dmub, uint32_t wptr_offset)
 	REG_WRITE(DMCUB_INBOX1_WPTR, wptr_offset);
 }
 
+void dmub_dcn20_setup_out_mailbox(struct dmub_srv *dmub,
+			      const struct dmub_region *outbox1)
+{
+	/* New firmware can support CW4 for the outbox. */
+	if (dmub_dcn20_use_cached_inbox(dmub))
+		REG_WRITE(DMCUB_OUTBOX1_BASE_ADDRESS, outbox1->base);
+	else
+		REG_WRITE(DMCUB_OUTBOX1_BASE_ADDRESS, 0x80002000);
+
+	REG_WRITE(DMCUB_OUTBOX1_SIZE, outbox1->top - outbox1->base);
+}
+
+uint32_t dmub_dcn20_get_outbox1_wptr(struct dmub_srv *dmub)
+{
+	/**
+	 * outbox1 wptr register is accessed without locks (dal & dc)
+	 * and to be called only by dmub_srv_stat_get_notification()
+	 */
+	return REG_READ(DMCUB_OUTBOX1_WPTR);
+}
+
+void dmub_dcn20_set_outbox1_rptr(struct dmub_srv *dmub, uint32_t rptr_offset)
+{
+	/**
+	 * outbox1 rptr register is accessed without locks (dal & dc)
+	 * and to be called only by dmub_srv_stat_get_notification()
+	 */
+	REG_WRITE(DMCUB_OUTBOX1_RPTR, rptr_offset);
+}
+
 bool dmub_dcn20_is_hw_init(struct dmub_srv *dmub)
 {
 	uint32_t is_hw_init;
diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn20.h b/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn20.h
index 30c6d631a431..df85c3b86607 100644
--- a/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn20.h
+++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn20.h
@@ -40,6 +40,10 @@ struct dmub_srv;
 	DMUB_SR(DMCUB_INBOX1_SIZE) \
 	DMUB_SR(DMCUB_INBOX1_RPTR) \
 	DMUB_SR(DMCUB_INBOX1_WPTR) \
+	DMUB_SR(DMCUB_OUTBOX1_BASE_ADDRESS) \
+	DMUB_SR(DMCUB_OUTBOX1_SIZE) \
+	DMUB_SR(DMCUB_OUTBOX1_RPTR) \
+	DMUB_SR(DMCUB_OUTBOX1_WPTR) \
 	DMUB_SR(DMCUB_REGION3_CW0_OFFSET) \
 	DMUB_SR(DMCUB_REGION3_CW1_OFFSET) \
 	DMUB_SR(DMCUB_REGION3_CW2_OFFSET) \
@@ -185,6 +189,13 @@ uint32_t dmub_dcn20_get_inbox1_rptr(struct dmub_srv *dmub);
 
 void dmub_dcn20_set_inbox1_wptr(struct dmub_srv *dmub, uint32_t wptr_offset);
 
+void dmub_dcn20_setup_out_mailbox(struct dmub_srv *dmub,
+			      const struct dmub_region *outbox1);
+
+uint32_t dmub_dcn20_get_outbox1_wptr(struct dmub_srv *dmub);
+
+void dmub_dcn20_set_outbox1_rptr(struct dmub_srv *dmub, uint32_t rptr_offset);
+
 bool dmub_dcn20_is_hw_init(struct dmub_srv *dmub);
 
 bool dmub_dcn20_is_supported(struct dmub_srv *dmub);
diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
index 61f64a295f06..6943bf679b42 100644
--- a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
+++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
@@ -46,8 +46,8 @@
 /* Context size. */
 #define DMUB_CONTEXT_SIZE (512 * 1024)
 
-/* Mailbox size */
-#define DMUB_MAILBOX_SIZE (DMUB_RB_SIZE)
+/* Mailbox size : Ring buffers are required for both inbox and outbox */
+#define DMUB_MAILBOX_SIZE ((2 * DMUB_RB_SIZE))
 
 /* Default state size if meta is absent. */
 #define DMUB_FW_STATE_SIZE (64 * 1024)
@@ -157,6 +157,11 @@ static bool dmub_srv_hw_setup(struct dmub_srv *dmub, enum dmub_asic asic)
 		funcs->enable_dmub_boot_options = dmub_dcn20_enable_dmub_boot_options;
 		funcs->skip_dmub_panel_power_sequence = dmub_dcn20_skip_dmub_panel_power_sequence;
 
+		// Out mailbox register access functions for RN and above
+		funcs->setup_out_mailbox = dmub_dcn20_setup_out_mailbox;
+		funcs->get_outbox1_wptr = dmub_dcn20_get_outbox1_wptr;
+		funcs->set_outbox1_rptr = dmub_dcn20_set_outbox1_rptr;
+
 		if (asic == DMUB_ASIC_DCN21) {
 			dmub->regs = &dmub_srv_dcn21_regs;
 
@@ -397,7 +402,7 @@ enum dmub_status dmub_srv_hw_init(struct dmub_srv *dmub,
 
 	struct dmub_rb_init_params rb_params;
 	struct dmub_window cw0, cw1, cw2, cw3, cw4, cw5, cw6;
-	struct dmub_region inbox1;
+	struct dmub_region inbox1, outbox1;
 
 	if (!dmub->sw_init)
 		return DMUB_STATUS_INVALID;
@@ -444,8 +449,17 @@ enum dmub_status dmub_srv_hw_init(struct dmub_srv *dmub,
 		cw4.region.base = DMUB_CW4_BASE;
 		cw4.region.top = cw4.region.base + mail_fb->size;
 
+		/**
+		 * Doubled the mailbox region to accomodate inbox and outbox.
+		 * Note: Currently, currently total mailbox size is 16KB. It is split
+		 * equally into 8KB between inbox and outbox. If this config is
+		 * changed, then uncached base address configuration of outbox1
+		 * has to be updated in funcs->setup_out_mailbox.
+		 */
 		inbox1.base = cw4.region.base;
-		inbox1.top = cw4.region.top;
+		inbox1.top = cw4.region.base + DMUB_RB_SIZE;
+		outbox1.base = inbox1.top;
+		outbox1.top = cw4.region.top;
 
 		cw5.offset.quad_part = tracebuff_fb->gpu_addr;
 		cw5.region.base = DMUB_CW5_BASE;
@@ -465,6 +479,8 @@ enum dmub_status dmub_srv_hw_init(struct dmub_srv *dmub,
 
 		if (dmub->hw_funcs.setup_mailbox)
 			dmub->hw_funcs.setup_mailbox(dmub, &inbox1);
+		if (dmub->hw_funcs.setup_out_mailbox)
+			dmub->hw_funcs.setup_out_mailbox(dmub, &outbox1);
 	}
 
 	if (mail_fb) {
@@ -474,6 +490,13 @@ enum dmub_status dmub_srv_hw_init(struct dmub_srv *dmub,
 		rb_params.capacity = DMUB_RB_SIZE;
 
 		dmub_rb_init(&dmub->inbox1_rb, &rb_params);
+
+		// Initialize outbox1 ring buffer
+		rb_params.ctx = dmub;
+		rb_params.base_address = (void *) ((uint64_t) (mail_fb->cpu_addr) + DMUB_RB_SIZE);
+		rb_params.capacity = DMUB_RB_SIZE;
+		dmub_rb_init(&dmub->outbox1_rb, &rb_params);
+
 	}
 
 	if (dmub->hw_funcs.reset_release)
diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv_stat.c b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv_stat.c
new file mode 100644
index 000000000000..e6f3bfab33d3
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv_stat.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2019 Advanced Micro Devices, 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: AMD
+ *
+ */
+
+#include "dmub/dmub_srv_stat.h"
+#include "dmub/inc/dmub_cmd.h"
+
+/**
+ * DOC: DMUB_SRV STAT Interface
+ *
+ * These interfaces are called without acquiring DAL and DC locks.
+ * Hence, there is limitations on whese interfaces can access. Only
+ * variables exclusively defined for these interfaces can be modified.
+ */
+
+/**
+ *****************************************************************************
+ *  Function: dmub_srv_stat_get_notification
+ *
+ *  @brief
+ *		Retrieves a dmub outbox notification, set up dmub notification
+ *		structure with message information. Also a pending bit if queue
+ *		is having more notifications
+ *
+ *  @param [in] dmub: dmub srv structure
+ *  @param [out] pnotify: dmub notification structure to be filled up
+ *
+ *  @return
+ *     dmub_status
+ *****************************************************************************
+ */
+enum dmub_status dmub_srv_stat_get_notification(struct dmub_srv *dmub,
+						struct dmub_notification *notify)
+{
+	/**
+	 * This function is called without dal and dc locks, so
+	 * we shall not modify any dmub variables, only dmub->outbox1_rb
+	 * is exempted as it is exclusively accessed by this function
+	 */
+	union dmub_rb_out_cmd cmd = {0};
+
+	if (!dmub->hw_init) {
+		notify->type = DMUB_NOTIFICATION_NO_DATA;
+		notify->pending_notification = false;
+		return DMUB_STATUS_INVALID;
+	}
+
+	/* Get write pointer which is updated by dmub */
+	dmub->outbox1_rb.wrpt = dmub->hw_funcs.get_outbox1_wptr(dmub);
+
+	if (!dmub_rb_out_front(&dmub->outbox1_rb, &cmd)) {
+		notify->type = DMUB_NOTIFICATION_NO_DATA;
+		notify->pending_notification = false;
+		return DMUB_STATUS_OK;
+	}
+
+	switch (cmd.cmd_common.header.type) {
+	case DMUB_OUT_CMD__DP_AUX_REPLY:
+		notify->type = DMUB_NOTIFICATION_AUX_REPLY;
+		notify->link_index = cmd.dp_aux_reply.control.instance;
+		notify->result = cmd.dp_aux_reply.control.result;
+		dmub_memcpy((void *)&notify->aux_reply,
+			(void *)&cmd.dp_aux_reply.reply_data, sizeof(struct aux_reply_data));
+		break;
+	default:
+		notify->type = DMUB_NOTIFICATION_NO_DATA;
+		break;
+	}
+
+	/* Pop outbox1 ringbuffer and update read pointer */
+	dmub_rb_pop_front(&dmub->outbox1_rb);
+	dmub->hw_funcs.set_outbox1_rptr(dmub, dmub->outbox1_rb.rptr);
+
+	/**
+	 * Notify dc whether dmub has a pending outbox message,
+	 * this is to avoid one more call to dmub_srv_stat_get_notification
+	 */
+	if (dmub_rb_empty(&dmub->outbox1_rb))
+		notify->pending_notification = false;
+	else
+		notify->pending_notification = true;
+
+	return DMUB_STATUS_OK;
+}