linux-2.6.18-xen: MMCONFIG

Index: linux-2.6.18-xen.hg/arch/x86_64/pci/mmconfig.c
===================================================================
@@ -30,6 +30,36 @@ struct mmcfg_virt {
 };
 static struct mmcfg_virt *pci_mmcfg_virt;
 
+static inline int mcfg_broken(void)
+{
+       struct acpi_table_mcfg_config *cfg = &pci_mmcfg_config[0];
+
+       /* Handle more broken MCFG tables on Asus etc.
+          They only contain a single entry for bus 0-0. Assume
+          this applies to all busses. */
+       if (pci_mmcfg_config_num == 1 &&
+           cfg->pci_segment_group_number == 0 &&
+           (cfg->start_bus_number | cfg->end_bus_number) == 0)
+               return 1;
+       return 0;
+}
+
+static void __iomem * __init mcfg_ioremap(struct acpi_table_mcfg_config *cfg)
+{
+	void __iomem *addr;
+	u32 size;
+
+	size = (cfg->end_bus_number + 1) << 20;
+	printk(KERN_INFO "%s: end_bus_number=%d\n", __func__,
+	       cfg->end_bus_number);
+	addr = ioremap_nocache(cfg->base_address, size);
+	if (addr) {
+		printk(KERN_INFO "PCI: Using MMCONFIG at %Lx - %Lx\n",
+		       cfg->base_address, cfg->base_address + size - 1);
+	}
+	return addr;
+}
+
 static char __iomem *get_virt(unsigned int seg, unsigned bus)
 {
 	int cfg_num = -1;

@@ -47,13 +77,7 @@ static char __iomem *get_virt(unsigned i
 			return pci_mmcfg_virt[cfg_num].virt;
 	}
 
-	/* Handle more broken MCFG tables on Asus etc.
-	   They only contain a single entry for bus 0-0. Assume
- 	   this applies to all busses. */
-	cfg = &pci_mmcfg_config[0];
-	if (pci_mmcfg_config_num == 1 &&
-		cfg->pci_segment_group_number == 0 &&
-		(cfg->start_bus_number | cfg->end_bus_number) == 0)
+	if (mcfg_broken())
 		return pci_mmcfg_virt[0].virt;
 
 	/* Fall back to type 0 */

@@ -194,14 +218,12 @@ void __init pci_mmcfg_init(void)
 	}
 	for (i = 0; i < pci_mmcfg_config_num; ++i) {
 		pci_mmcfg_virt[i].cfg = &pci_mmcfg_config[i];
-		pci_mmcfg_virt[i].virt = ioremap_nocache(pci_mmcfg_config[i].base_address,
-							 MMCONFIG_APER_MAX);
+		pci_mmcfg_virt[i].virt = mcfg_ioremap(&pci_mmcfg_config[i]);
 		if (!pci_mmcfg_virt[i].virt) {
 			printk("PCI: Cannot map mmconfig aperture for segment %d\n",
 			       pci_mmcfg_config[i].pci_segment_group_number);
 			return;
 		}
-		printk(KERN_INFO "PCI: Using MMCONFIG at %x\n", pci_mmcfg_config[i].base_address);
 	}
 
 	unreachable_devices();

Index: linux-2.6.18-xen.hg/arch/x86_64/pci/mmconfig.c
===================================================================
@@ -17,12 +17,6 @@
 #define MMCONFIG_APER_MIN	(2 * 1024*1024)
 #define MMCONFIG_APER_MAX	(256 * 1024*1024)
 
-/* Verify the first 16 busses. We assume that systems with more busses
-   get MCFG right. */
-#define MAX_CHECK_BUS 16
-
-static DECLARE_BITMAP(fallback_slots, 32*MAX_CHECK_BUS);
-
 /* Static virtual mapping of the MMCONFIG aperture */
 struct mmcfg_virt {
 	struct acpi_table_mcfg_config *cfg;

@@ -87,9 +81,6 @@ static char __iomem *get_virt(unsigned i
 static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
 {
 	char __iomem *addr;
-	if (seg == 0 && bus < MAX_CHECK_BUS &&
-		test_bit(32*bus + PCI_SLOT(devfn), fallback_slots))
-		return NULL;
 	addr = get_virt(seg, bus);
 	if (!addr)
 		return NULL;

@@ -103,13 +94,16 @@ static int pci_mmcfg_read(unsigned int s
 
 	/* Why do we have this when nobody checks it. How about a BUG()!? -AK */
 	if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) {
-		*value = -1;
+err:		*value = -1;
 		return -EINVAL;
 	}
 
+	if (reg < 256)
+		return pci_conf1_read(seg,bus,devfn,reg,len,value);
+
 	addr = pci_dev_base(seg, bus, devfn);
 	if (!addr)
-		return pci_conf1_read(seg,bus,devfn,reg,len,value);
+		goto err;
 
 	switch (len) {
 	case 1:

@@ -135,9 +129,12 @@ static int pci_mmcfg_write(unsigned int 
 	if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
 		return -EINVAL;
 
+	if (reg < 256)
+		return pci_conf1_write(seg,bus,devfn,reg,len,value);
+
 	addr = pci_dev_base(seg, bus, devfn);
 	if (!addr)
-		return pci_conf1_write(seg,bus,devfn,reg,len,value);
+		return -EINVAL;
 
 	switch (len) {
 	case 1:

@@ -159,35 +156,6 @@ static struct pci_raw_ops pci_mmcfg = {
 	.write =	pci_mmcfg_write,
 };
 
-/* K8 systems have some devices (typically in the builtin northbridge)
-   that are only accessible using type1
-   Normally this can be expressed in the MCFG by not listing them
-   and assigning suitable _SEGs, but this isn't implemented in some BIOS.
-   Instead try to discover all devices on bus 0 that are unreachable using MM
-   and fallback for them. */
-static __init void unreachable_devices(void)
-{
-	int i, k;
-	/* Use the max bus number from ACPI here? */
-	for (k = 0; k < MAX_CHECK_BUS; k++) {
-		for (i = 0; i < 32; i++) {
-			u32 val1;
-			char __iomem *addr;
-
-			pci_conf1_read(0, k, PCI_DEVFN(i,0), 0, 4, &val1);
-			if (val1 == 0xffffffff)
-				continue;
-			addr = pci_dev_base(0, k, PCI_DEVFN(i, 0));
-			if (addr == NULL|| readl(addr) != val1) {
-				set_bit(i + 32*k, fallback_slots);
-				printk(KERN_NOTICE
-				"PCI: No mmconfig possible on device %x:%x\n",
-					k, i);
-			}
-		}
-	}
-}
-
 void __init pci_mmcfg_init(void)
 {
 	int i;

@@ -226,8 +194,6 @@ void __init pci_mmcfg_init(void)
 		}
 	}
 
-	unreachable_devices();
-
 	raw_pci_ops = &pci_mmcfg;
 	pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
 }

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