[PATCH] Support AGP bridge on Nvidia Nforce3 + cleanup

For some unknown reasons Nvidia NForce3 doesn't use the standard Hammer AGP architecture,
but requires set up of some shadow registers. This patch adds that to the K8 AGP driver.

Based on an old 2.4 patch from someone at Nvidia.

Also includes another bug fix for the K8 AGP handler, from Brad House.
We should not assume that there is only one northbridge in a Uniprocessor system.
Always flush all.

Also some minor cleanup.

2 files changed, 136 insertions, 44 deletions

diff --git a/drivers/char/agp/amd64-agp.c b/drivers/char/agp/amd64-agp.c
index 2d24a3cfe518..dd44599d04c7 100644
--- a/drivers/char/agp/amd64-agp.c
+++ b/drivers/char/agp/amd64-agp.c
@@ -16,11 +16,7 @@
 #include "agp.h"
 
 /* Will need to be increased if AMD64 ever goes >8-way. */
-#ifdef CONFIG_SMP
 #define MAX_HAMMER_GARTS   8
-#else
-#define MAX_HAMMER_GARTS   1
-#endif
 
 /* PTE bits. */
 #define GPTE_VALID	1
@@ -35,6 +31,14 @@
 #define INVGART		(1<<0)
 #define GARTPTEERR	(1<<1)
 
+/* NVIDIA K8 registers */
+#define NVIDIA_X86_64_0_APBASE		0x10
+#define NVIDIA_X86_64_1_APBASE1		0x50
+#define NVIDIA_X86_64_1_APLIMIT1	0x54
+#define NVIDIA_X86_64_1_APSIZE		0xa8
+#define NVIDIA_X86_64_1_APBASE2		0xd8
+#define NVIDIA_X86_64_1_APLIMIT2	0xdc
+
 static int nr_garts;
 static struct pci_dev * hammers[MAX_HAMMER_GARTS];
 
@@ -346,6 +350,10 @@ static __devinit int cache_nbs (struct pci_dev *pdev, u32 cap_ptr)
 	/* cache pci_devs of northbridges. */
 	while ((loop_dev = pci_find_device(PCI_VENDOR_ID_AMD, 0x1103, loop_dev)) 
 			!= NULL) {
+		if (i == MAX_HAMMER_GARTS) { 
+			printk(KERN_ERR PFX "Too many northbridges for AGP\n");
+			return -1;
+		}
 		if (fix_northbridge(loop_dev, pdev, cap_ptr) < 0) { 
 			printk(KERN_ERR PFX "No usable aperture found.\n");
 #ifdef __x86_64__ 
@@ -355,29 +363,111 @@ static __devinit int cache_nbs (struct pci_dev *pdev, u32 cap_ptr)
 			return -1;  
 		}
 		hammers[i++] = loop_dev;
+	}
 		nr_garts = i;
-#ifdef CONFIG_SMP
-		if (i > MAX_HAMMER_GARTS) { 
-			printk(KERN_ERR PFX "Too many northbridges for AGP\n");
-			return -1;
+	return i == 0 ? -1 : 0;
+}
+
+/* Handle AMD 8151 quirks */
+static void __devinit amd8151_init(struct pci_dev *pdev, struct agp_bridge_data *bridge)
+
+{		
+	char *revstring;
+	u8 rev_id;
+
+	pci_read_config_byte(pdev, PCI_REVISION_ID, &rev_id);
+	switch (rev_id) {
+	case 0x01: revstring="A0"; break;
+	case 0x02: revstring="A1"; break;
+	case 0x11: revstring="B0"; break;
+	case 0x12: revstring="B1"; break;
+	case 0x13: revstring="B2"; break;
+	default:   revstring="??"; break;
 		}
-#else
-		/* Uniprocessor case, return after finding first bridge.
-		   (There may be more, but in UP, we don't care). */
-		return 0;
-#endif
+
+	printk (KERN_INFO PFX "Detected AMD 8151 AGP Bridge rev %s\n", revstring);
+
+	/*
+	 * Work around errata.
+	 * Chips before B2 stepping incorrectly reporting v3.5
+	 */
+	if (rev_id < 0x13) {
+		printk (KERN_INFO PFX "Correcting AGP revision (reports 3.5, is really 3.0)\n");
+		bridge->major_version = 3;
+		bridge->minor_version = 0;
 	}
+}
 
-	return i == 0 ? -1 : 0;
+static struct aper_size_info_32 nforce3_sizes[5] =
+{
+	{512,  131072, 7, 0x00000000 },
+	{256,  65536,  6, 0x00000008 },
+	{128,  32768,  5, 0x0000000C },
+	{64,   16384,  4, 0x0000000E },
+	{32,   8192,   3, 0x0000000F }
+};
+
+/* Handle shadow device of the Nvidia NForce3 */
+/* CHECK-ME original 2.4 version set up some IORRs. Check if that is needed. */
+static int __devinit nforce3_agp_init(struct pci_dev *pdev) 
+{ 
+	u32 tmp, apbase, apbar, aplimit;
+	struct pci_dev *dev1; 
+	int i;
+	unsigned size = amd64_fetch_size(); 
+
+	printk(KERN_INFO PFX "Setting up Nforce3 AGP.\n");
+
+	dev1 = pci_find_slot((unsigned int)pdev->bus->number, PCI_DEVFN(11, 0));
+	if (dev1 == NULL) {
+		printk(KERN_INFO PFX "agpgart: Detected an NVIDIA "
+			"nForce3 chipset, but could not find "
+			"the secondary device.\n");
+		return -ENODEV;
+	}	
+
+	for (i = 0; i < ARRAY_SIZE(nforce3_sizes); i++) 
+		if (nforce3_sizes[i].size == size)
+			break; 
+
+	if (i == ARRAY_SIZE(nforce3_sizes)) {
+		printk(KERN_INFO PFX "No NForce3 size found for %d\n", size); 
+		return -ENODEV; 
+	}
+	
+	pci_read_config_dword(dev1, NVIDIA_X86_64_1_APSIZE, &tmp);
+	tmp &= ~(0xf);
+	tmp |= nforce3_sizes[i].size_value;
+	pci_write_config_dword(dev1, NVIDIA_X86_64_1_APSIZE, tmp);
+
+	/* shadow x86-64 registers into NVIDIA registers */
+	pci_read_config_dword (hammers[0], AMD64_GARTAPERTUREBASE, &apbase);
+
+	/* if x86-64 aperture base is beyond 4G, exit here */
+	if ( (apbase & 0x7fff) >> (32 - 25) )
+		 return -ENODEV;
+
+	apbase = (apbase & 0x7fff) << 25;
+
+	pci_read_config_dword(pdev, NVIDIA_X86_64_0_APBASE, &apbar);
+	apbar &= ~PCI_BASE_ADDRESS_MEM_MASK;
+	apbar |= apbase;
+	pci_write_config_dword(pdev, NVIDIA_X86_64_0_APBASE, apbar);
+
+	aplimit = apbase + (size * 1024 * 1024) - 1;
+	pci_write_config_dword(dev1, NVIDIA_X86_64_1_APBASE1, apbase);
+	pci_write_config_dword(dev1, NVIDIA_X86_64_1_APLIMIT1, aplimit);
+	pci_write_config_dword(dev1, NVIDIA_X86_64_1_APBASE2, apbase);
+	pci_write_config_dword(dev1, NVIDIA_X86_64_1_APLIMIT2, aplimit);
+
+	return 0;
 }
 
 static int __devinit agp_amd64_probe(struct pci_dev *pdev,
 				     const struct pci_device_id *ent)
 {
 	struct agp_bridge_data *bridge;
-	u8 rev_id;
 	u8 cap_ptr;
-	char *revstring=NULL;
 
 	cap_ptr = pci_find_capability(pdev, PCI_CAP_ID_AGP);
 	if (!cap_ptr)
@@ -391,32 +481,7 @@ static int __devinit agp_amd64_probe(struct pci_dev *pdev,
 
 	if (pdev->vendor == PCI_VENDOR_ID_AMD &&
 	    pdev->device == PCI_DEVICE_ID_AMD_8151_0) {
-
-		pci_read_config_byte(pdev, PCI_REVISION_ID, &rev_id);
-		switch (rev_id) {
-		case 0x01:	revstring="A0";
-				break;
-		case 0x02:	revstring="A1";
-				break;
-		case 0x11:	revstring="B0";
-				break;
-		case 0x12:	revstring="B1";
-				break;
-		case 0x13:	revstring="B2";
-				break;
-		default:	revstring="??";
-				break;
-		}
-		printk (KERN_INFO PFX "Detected AMD 8151 AGP Bridge rev %s\n", revstring);
-		/*
-		 * Work around errata.
-		 * Chips before B2 stepping incorrectly reporting v3.5
-		 */
-		if (rev_id < 0x13) {
-			printk (KERN_INFO PFX "Correcting AGP revision (reports 3.5, is really 3.0)\n");
-			bridge->major_version = 3;
-			bridge->minor_version = 0;
-		}
+		amd8151_init(pdev, bridge);
 	} else {
 		printk(KERN_INFO PFX "Detected AGP bridge %x\n",
 			pdev->devfn);
@@ -434,6 +499,14 @@ static int __devinit agp_amd64_probe(struct pci_dev *pdev,
 		return -ENODEV;
 	}
 
+	if (pdev->vendor == PCI_VENDOR_ID_NVIDIA) { 
+		int ret = nforce3_agp_init(pdev);
+		if (ret) { 
+			agp_put_bridge(bridge); 
+			return ret;
+		}
+	}
+
 	pci_set_drvdata(pdev, bridge);
 	return agp_add_bridge(bridge);
 }
@@ -478,8 +551,25 @@ static struct pci_device_id agp_amd64_pci_table[] = {
 	{
 	.class		= (PCI_CLASS_BRIDGE_HOST << 8),
 	.class_mask	= ~0,
-	.vendor		= PCI_VENDOR_ID_SI,
-	.device		= PCI_DEVICE_ID_SI_755,
+	.vendor		= PCI_VENDOR_ID_VIA,
+	.device		= PCI_DEVICE_ID_VIA_8380_0,
+	.subvendor	= PCI_ANY_ID,
+	.subdevice	= PCI_ANY_ID,
+	},
+	/* NForce3 */
+	{
+	.class		= (PCI_CLASS_BRIDGE_HOST << 8),
+	.class_mask	= ~0,
+	.vendor		= PCI_VENDOR_ID_NVIDIA,
+	.device		= PCI_DEVICE_ID_NVIDIA_NFORCE3,
+	.subvendor	= PCI_ANY_ID,
+	.subdevice	= PCI_ANY_ID,
+	},
+	{
+	.class		= (PCI_CLASS_BRIDGE_HOST << 8),
+	.class_mask	= ~0,
+	.vendor		= PCI_VENDOR_ID_NVIDIA,
+	.device		= PCI_DEVICE_ID_NVIDIA_NFORCE3S,
 	.subvendor	= PCI_ANY_ID,
 	.subdevice	= PCI_ANY_ID,
 	},
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index fdcb1287681b..424c4b2dd8fd 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -1050,6 +1050,8 @@
 #define PCI_DEVICE_ID_NVIDIA_NFORCE2S_IDE	0x0085
 #define PCI_DEVICE_ID_NVIDIA_NFORCE2S_SATA	0x008e
 #define PCI_DEVICE_ID_NVIDIA_ITNT2		0x00A0
+#define PCI_DEVICE_ID_NVIDIA_NFORCE3		0x00d1
+#define PCI_DEVICE_ID_NVIDIA_NFORCE3S  		0x00e1
 #define PCI_DEVICE_ID_NVIDIA_NFORCE3_IDE	0x00d5
 #define PCI_DEVICE_ID_NVIDIA_NFORCE3S_SATA	0x00e3
 #define PCI_DEVICE_ID_NVIDIA_NFORCE3S_IDE	0x00e5