Fix support for earlier i8XX chipsets (specifically the 830 and 840).

Earlier changes meant that we were reading the wrong register, on the
graphics card instead of the gmch (bus 0, device 0, function 0. it's the
memory controller on all boards with intel chipsets).  Later chipsets
have a ``mirror'' register on the graphics card device, explaining why
this didn't manifest on all chipsets. For simplicity, always find and
read the register from the GMCH. While i'm here, fixup unaligned
configuration space access (0x50 vs 0x52)

Tested by several.

2 files changed, 32 insertions, 8 deletions

diff --git a/sys/dev/pci/agp_i810.c b/sys/dev/pci/agp_i810.c
index e595cb0f59b..39c5ff52ac8 100644
--- a/sys/dev/pci/agp_i810.c
+++ b/sys/dev/pci/agp_i810.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: agp_i810.c,v 1.43 2008/12/23 22:01:38 oga Exp $	*/
+/*	$OpenBSD: agp_i810.c,v 1.44 2008/12/24 05:42:58 oga Exp $	*/
 
 /*-
  * Copyright (c) 2000 Doug Rabson
@@ -91,6 +91,7 @@ int	agp_i810_free_memory(void *, struct agp_memory *);
 int	agp_i810_bind_memory(void *, struct agp_memory *, off_t);
 int	agp_i810_unbind_memory(void *, struct agp_memory *);
 void	agp_i810_write_gatt(struct agp_i810_softc *, bus_size_t, u_int32_t);
+int	intagp_gmch_match(struct pci_attach_args *);
 
 struct cfattach intagp_ca = {
 	sizeof(struct agp_i810_softc), agp_i810_probe, agp_i810_attach
@@ -168,6 +169,21 @@ agp_i810_get_chiptype(struct pci_attach_args *pa)
 	return (CHIP_NONE);
 }
 
+/*
+ * We're intel IGD, bus 0 function 0 dev 0 should be the GMCH, so it should
+ * be Intel
+ */
+int
+intagp_gmch_match(struct pci_attach_args *pa)
+{
+	if (pa->pa_bus == 0 && pa->pa_device == 0 && pa->pa_function == 0 &&
+	    PCI_VENDOR(pa->pa_id) == PCI_VENDOR_INTEL &&
+	    PCI_CLASS(pa->pa_class) == PCI_CLASS_BRIDGE &&
+	    PCI_SUBCLASS(pa->pa_class) == PCI_SUBCLASS_BRIDGE_HOST)
+		return (1);
+	return (0);
+}
+
 int
 agp_i810_probe(struct device *parent, void *match, void *aux)
 {
@@ -185,7 +201,7 @@ agp_i810_attach(struct device *parent, struct device *self, void *aux)
 {
 	struct agp_i810_softc		*isc = (struct agp_i810_softc *)self;
 	struct agp_gatt 		*gatt;
-	struct pci_attach_args		*pa = aux;
+	struct pci_attach_args		*pa = aux, bpa;
 	struct vga_pci_softc		*vga = (struct vga_pci_softc *)parent;
 	bus_addr_t			 mmaddr, gmaddr;
 	pcireg_t			 memtype;
@@ -242,6 +258,16 @@ agp_i810_attach(struct device *parent, struct device *self, void *aux)
 
 	gatt->ag_entries = isc->aperture >> AGP_PAGE_SHIFT;
 
+	/*
+	 * Find the GMCH, some of the registers we need to read for
+	 * configuration purposes are on there. it's always at
+	 * 0/0/0 (bus/dev/func).
+	 */
+	if (pci_find_device(&bpa, intagp_gmch_match) == 0) {
+		printf("can't find GMCH\n");
+		goto out;
+	}
+
 	if (isc->chiptype == CHIP_I810) {
 		int dummyseg;
 		/* Some i810s have on-chip memory called dcache */
@@ -269,7 +295,7 @@ agp_i810_attach(struct device *parent, struct device *self, void *aux)
 		u_int32_t pgtblctl;
 		u_int16_t gcc1;
 
-		reg = pci_conf_read(pa->pa_pc, pa->pa_tag, AGP_I830_GCC1);
+		reg = pci_conf_read(bpa.pa_pc, bpa.pa_tag, AGP_I830_GCC0);
 		gcc1 = (u_int16_t)(reg >> 16);
 		switch (gcc1 & AGP_I830_GCC1_GMS) {
 		case AGP_I830_GCC1_GMS_STOLEN_512:
@@ -312,7 +338,7 @@ agp_i810_attach(struct device *parent, struct device *self, void *aux)
 		 * BIOS display.
 		 */
 
-		reg = pci_conf_read(pa->pa_pc, pa->pa_tag, AGP_I855_GCC1);
+		reg = pci_conf_read(bpa.pa_pc, bpa.pa_tag, AGP_I855_GCC1);
 		gcc1 = (u_int16_t)(reg >> 16);
                 switch (isc->chiptype) {
 		case CHIP_I855:
@@ -408,7 +434,6 @@ agp_i810_attach(struct device *parent, struct device *self, void *aux)
 			printf("unknown memory configuration, disabling\n");
 			goto out;
 		}
-
 #ifdef DEBUG
 		if (isc->stolen > 0) {
 			printf(": detected %dk stolen memory",
@@ -417,7 +442,6 @@ agp_i810_attach(struct device *parent, struct device *self, void *aux)
 			printf(": no preallocated video memory\n");
 #endif
 
-
 		/* GATT address is already in there, make sure it's enabled */
 		pgtblctl = READ4(AGP_I810_PGTBL_CTL);
 		pgtblctl |= 1;
diff --git a/sys/dev/pci/agpreg.h b/sys/dev/pci/agpreg.h
index c4ab588c19d..e8d9281855a 100644
--- a/sys/dev/pci/agpreg.h
+++ b/sys/dev/pci/agpreg.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: agpreg.h,v 1.11 2008/12/23 22:01:38 oga Exp $	*/
+/*	$OpenBSD: agpreg.h,v 1.12 2008/12/24 05:42:58 oga Exp $	*/
 /*	$NetBSD: agpreg.h,v 1.1 2001/09/10 10:01:02 fvdl Exp $	*/
 
 /*-
@@ -216,7 +216,7 @@
 /*
  * Config registers for 852GM/855GM/865G device 0
  */
-#define AGP_I855_GCC1			0x52
+#define AGP_I855_GCC1			0x50
 #define AGP_I855_GCC1_DEV2		0x08
 #define AGP_I855_GCC1_DEV2_ENABLED	0x00
 #define AGP_I855_GCC1_DEV2_DISABLED	0x08