From efcfdd23d72178ed873982f957cbc95b2a1de4c5 Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@felloff.net>
Date: Sat, 6 Feb 2021 13:47:45 +0100
Subject: [PATCH] bcm64: get inbound and outbound pci window base address from
 device tree

On the pi400, the xhci reset firmware mailbox request
assumes that the pci windows match the ones specified
in the device tree. The inbound window (pcidmawin)
also varies now depending on the amount of memory
installed.

It is all pretty ridiculous, as the firmware could as
well just read the pci controllers hardware register
to determine the window configuration and the os could
keep a nice simple 1:1 mapping (with pci dma addresses
== physical addresses).
---
 sys/src/9/bcm/bootargs.c | 39 ++++++++++++++++++++++++++++-----------
 sys/src/9/bcm64/dat.h    |  3 ++-
 sys/src/9/bcm64/io.h     |  2 +-
 sys/src/9/bcm64/pcibcm.c | 14 ++++++++++++--
 4 files changed, 43 insertions(+), 15 deletions(-)

diff --git a/sys/src/9/bcm/bootargs.c b/sys/src/9/bcm/bootargs.c
index aac14c501..b0feae75e 100644
--- a/sys/src/9/bcm/bootargs.c
+++ b/sys/src/9/bcm/bootargs.c
@@ -12,6 +12,7 @@ static char *confname[MAXCONF];
 static char *confval[MAXCONF];
 static int nconf;
 static char maxmem[256];
+static char pciwin[38], pcidmawin[38];
 
 static int
 findconf(char *k)
@@ -89,23 +90,23 @@ beget4(uchar *p)
 static void
 devtreeprop(char *path, char *key, void *val, int len)
 {
+	uvlong addr, size;
+	uchar *p = val;
+	char *s;
+
 	if((strcmp(path, "/memory") == 0 || strcmp(path, "/memory@0") == 0)
 	&& strcmp(key, "reg") == 0){
 		if(findconf("*maxmem") < 0 && len > 0 && (len % (3*4)) == 0){
-			uvlong top;
-			uchar *p = val;
-			char *s;
-
-			top = (uvlong)beget4(p)<<32 | beget4(p+4);
-			top += beget4(p+8);
-			s = seprint(maxmem, &maxmem[sizeof(maxmem)], "%#llux", top);
+			addr = (uvlong)beget4(p)<<32 | beget4(p+4);
+			addr += beget4(p+8);
+			s = seprint(maxmem, &maxmem[sizeof(maxmem)], "%#llux", addr);
 			p += 3*4;
 			len -= 3*4;
 			while(len > 0){
-				top = (uvlong)beget4(p)<<32 | beget4(p+4);
-				s = seprint(s, &maxmem[sizeof(maxmem)], " %#llux", top);
-				top += beget4(p+8);
-				s = seprint(s, &maxmem[sizeof(maxmem)], " %#llux", top);
+				addr = (uvlong)beget4(p)<<32 | beget4(p+4);
+				s = seprint(s, &maxmem[sizeof(maxmem)], " %#llux", addr);
+				addr += beget4(p+8);
+				s = seprint(s, &maxmem[sizeof(maxmem)], " %#llux", addr);
 				p += 3*4;
 				len -= 3*4;
 			}
@@ -113,6 +114,22 @@ devtreeprop(char *path, char *key, void *val, int len)
 		}
 		return;
 	}
+	if(strncmp(path, "/scb/pcie@", 10) == 0 && len == (3*4 + 4*4)){
+		if((beget4(p) & 0x3000000) == 0x2000000){
+			size = (uvlong)beget4(p+5*4)<<32 | beget4(p+5*4+4);
+			if(strcmp(key, "ranges") == 0 && findconf("*pciwin") < 0){
+				addr = (uvlong)beget4(p+3*4)<<32 | beget4(p+4*4);
+				snprint(pciwin, sizeof(pciwin), "%#llux %#llux", addr, addr+size);
+				addconf("*pciwin", pciwin);
+			} else if(strcmp(key, "dma-ranges") == 0 && findconf("*pcidmawin") < 0){
+				addr = (uvlong)beget4(p+1*4)<<32 | beget4(p+2*4);
+				addr -= (uvlong)beget4(p+3*4)<<32 | beget4(p+4*4);
+				snprint(pcidmawin, sizeof(pcidmawin), "%#llux %#llux", addr, addr+size);
+				addconf("*pcidmawin", pcidmawin);
+			}
+		}
+		return;
+	}
 	if(strcmp(path, "/chosen") == 0 && strcmp(key, "bootargs") == 0){
 		if(len > BOOTARGSLEN)
 			len = BOOTARGSLEN;
diff --git a/sys/src/9/bcm64/dat.h b/sys/src/9/bcm64/dat.h
index fcbd42bba..c5e19ab0d 100644
--- a/sys/src/9/bcm64/dat.h
+++ b/sys/src/9/bcm64/dat.h
@@ -249,7 +249,8 @@ struct Soc {			/* SoC dependent configuration */
 	uintptr	physio;
 	uintptr	virtio;
 	uintptr	armlocal;
-	uintptr	pciwin;
+	uintptr	pciwin;		/* PCI outbound window CPU->PCI */
+	uintptr	pcidmawin;	/* PCI inbound window PCI->DRAM */
 	int	oscfreq;
 };
 extern Soc soc;
diff --git a/sys/src/9/bcm64/io.h b/sys/src/9/bcm64/io.h
index ef6fab282..dec69a5dc 100644
--- a/sys/src/9/bcm64/io.h
+++ b/sys/src/9/bcm64/io.h
@@ -6,5 +6,5 @@ enum {
 	IRQether	= IRQgic + 29,
 };
 
-#define PCIWINDOW	0
+#define PCIWINDOW	soc.pcidmawin
 #define PCIWADDR(va)	(PADDR(va)+PCIWINDOW)
diff --git a/sys/src/9/bcm64/pcibcm.c b/sys/src/9/bcm64/pcibcm.c
index 5a6780465..0ba9b5111 100644
--- a/sys/src/9/bcm64/pcibcm.c
+++ b/sys/src/9/bcm64/pcibcm.c
@@ -244,6 +244,16 @@ void
 pcibcmlink(void)
 {
 	int log2dmasize = 30;	// 1GB
+	char *s;
+
+	if((s = getconf("*pciwin")) != nil){
+		print("*pciwin: %s\n", s);
+		soc.pciwin = (uintptr)strtoll(s, nil, 16);
+	}
+	if((s = getconf("*pcidmawin")) != nil){
+		print("*pcidmawin: %s\n", s);
+		soc.pcidmawin = (uintptr)strtoll(s, nil, 16);
+	}
 
 	regs[RGR1_SW_INIT_1] |= 3;
 	delay(200);
@@ -266,8 +276,8 @@ pcibcmlink(void)
 	// SCB_ACCESS_EN, CFG_READ_UR_MODE, MAX_BURST_SIZE_128, SCB0SIZE
 	regs[MISC_MISC_CTRL] = 1<<12 | 1<<13 | 0<<20 | (log2dmasize-15)<<27;
 
-	regs[MISC_RC_BAR2_CONFIG_LO] = (log2dmasize-15);
-	regs[MISC_RC_BAR2_CONFIG_HI] = 0;
+	regs[MISC_RC_BAR2_CONFIG_LO] = ((u32int)soc.pcidmawin & ~0x1F) | (log2dmasize-15);
+	regs[MISC_RC_BAR2_CONFIG_HI] = soc.pcidmawin >> 32;
 
 	regs[MISC_RC_BAR1_CONFIG_LO] = 0;
 	regs[MISC_RC_BAR3_CONFIG_LO] = 0;