drm/amd/display: Get fb base and fb offset for DMUB from registers

[Why]
Under some hardware initialization sequences the fb base/fb offset
provided can be zero or hardwareinit can happen too late.

We want to ensure that we always have the correct fb_base/fb_offset
when performing DMCUB hardware initialization so we can do DMCUB
command table offloading during first dc hardware init.

[How]
Read from the DCN registers. VBIOS already filled these in for us.
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dmub/inc/dmub_srv.h

@@ -231,6 +231,8 @@ struct dmub_srv_base_funcs {
 struct dmub_srv_hw_funcs {
 	/* private: internal use only */
 
+	void (*init)(struct dmub_srv *dmub);
+
 	void (*reset)(struct dmub_srv *dmub);
 
 	void (*reset_release)(struct dmub_srv *dmub);

drivers/gpu/drm/amd/display/dmub/src/dmub_dcn20.c

@@ -54,6 +54,19 @@ const struct dmub_srv_common_regs dmub_srv_dcn20_regs = {
 
 /* Shared functions. */
 
+static void dmub_dcn20_get_fb_base_offset(struct dmub_srv *dmub,
+					  uint64_t *fb_base,
+					  uint64_t *fb_offset)
+{
+	uint32_t tmp;
+
+	REG_GET(DCN_VM_FB_LOCATION_BASE, FB_BASE, &tmp);
+	*fb_base = (uint64_t)tmp << 24;
+
+	REG_GET(DCN_VM_FB_OFFSET, FB_OFFSET, &tmp);
+	*fb_offset = (uint64_t)tmp << 24;
+}
+
 static inline void dmub_dcn20_translate_addr(const union dmub_addr *addr_in,
 					     uint64_t fb_base,
 					     uint64_t fb_offset,
@@ -82,7 +95,9 @@ void dmub_dcn20_backdoor_load(struct dmub_srv *dmub,
 			      const struct dmub_window *cw1)
 {
 	union dmub_addr offset;
-	uint64_t fb_base = dmub->fb_base, fb_offset = dmub->fb_offset;
+	uint64_t fb_base, fb_offset;
+
+	dmub_dcn20_get_fb_base_offset(dmub, &fb_base, &fb_offset);
 
 	REG_UPDATE(DMCUB_SEC_CNTL, DMCUB_SEC_RESET, 1);
 	REG_UPDATE_2(DMCUB_MEM_CNTL, DMCUB_MEM_READ_SPACE, 0x3,
@@ -118,7 +133,9 @@ void dmub_dcn20_setup_windows(struct dmub_srv *dmub,
 			      const struct dmub_window *cw6)
 {
 	union dmub_addr offset;
-	uint64_t fb_base = dmub->fb_base, fb_offset = dmub->fb_offset;
+	uint64_t fb_base, fb_offset;
+
+	dmub_dcn20_get_fb_base_offset(dmub, &fb_base, &fb_offset);
 
 	dmub_dcn20_translate_addr(&cw2->offset, fb_base, fb_offset, &offset);
 

drivers/gpu/drm/amd/display/dmub/src/dmub_dcn20.h

@@ -92,7 +92,9 @@ struct dmub_srv;
 	DMUB_SR(DMCUB_SCRATCH14) \
 	DMUB_SR(DMCUB_SCRATCH15) \
 	DMUB_SR(CC_DC_PIPE_DIS) \
-	DMUB_SR(MMHUBBUB_SOFT_RESET)
+	DMUB_SR(MMHUBBUB_SOFT_RESET) \
+	DMUB_SR(DCN_VM_FB_LOCATION_BASE) \
+	DMUB_SR(DCN_VM_FB_OFFSET)
 
 #define DMUB_COMMON_FIELDS() \
 	DMUB_SF(DMCUB_CNTL, DMCUB_ENABLE) \
@@ -121,7 +123,9 @@ struct dmub_srv;
 	DMUB_SF(DMCUB_REGION4_TOP_ADDRESS, DMCUB_REGION4_TOP_ADDRESS) \
 	DMUB_SF(DMCUB_REGION4_TOP_ADDRESS, DMCUB_REGION4_ENABLE) \
 	DMUB_SF(CC_DC_PIPE_DIS, DC_DMCUB_ENABLE) \
-	DMUB_SF(MMHUBBUB_SOFT_RESET, DMUIF_SOFT_RESET)
+	DMUB_SF(MMHUBBUB_SOFT_RESET, DMUIF_SOFT_RESET) \
+	DMUB_SF(DCN_VM_FB_LOCATION_BASE, FB_BASE) \
+	DMUB_SF(DCN_VM_FB_OFFSET, FB_OFFSET)
 
 struct dmub_srv_common_reg_offset {
 #define DMUB_SR(reg) uint32_t reg;