1 files changed, 264 insertions, 0 deletions
diff --git a/arch/i386/pci/mmconfig-shared.c b/arch/i386/pci/mmconfig-shared.c
new file mode 100644
index 000000000000..747d8c63b0c4
--- /dev/null
+++ b/arch/i386/pci/mmconfig-shared.c
@@ -0,0 +1,264 @@
+/*
+ * mmconfig-shared.c - Low-level direct PCI config space access via
+ *                     MMCONFIG - common code between i386 and x86-64.
+ *
+ * This code does:
+ * - known chipset handling
+ * - ACPI decoding and validation
+ *
+ * Per-architecture code takes care of the mappings and accesses
+ * themselves.
+ */
+
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+#include <linux/bitmap.h>
+#include <asm/e820.h>
+
+#include "pci.h"
+
+/* aperture is up to 256MB but BIOS may reserve less */
+#define MMCONFIG_APER_MIN	(2 * 1024*1024)
+#define MMCONFIG_APER_MAX	(256 * 1024*1024)
+
+DECLARE_BITMAP(pci_mmcfg_fallback_slots, 32*PCI_MMCFG_MAX_CHECK_BUS);
+
+/* 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 void __init unreachable_devices(void)
+{
+	int i, bus;
+	/* Use the max bus number from ACPI here? */
+	for (bus = 0; bus < PCI_MMCFG_MAX_CHECK_BUS; bus++) {
+		for (i = 0; i < 32; i++) {
+			unsigned int devfn = PCI_DEVFN(i, 0);
+			u32 val1, val2;
+
+			pci_conf1_read(0, bus, devfn, 0, 4, &val1);
+			if (val1 == 0xffffffff)
+				continue;
+
+			if (pci_mmcfg_arch_reachable(0, bus, devfn)) {
+				raw_pci_ops->read(0, bus, devfn, 0, 4, &val2);
+				if (val1 == val2)
+					continue;
+			}
+			set_bit(i + 32 * bus, pci_mmcfg_fallback_slots);
+			printk(KERN_NOTICE "PCI: No mmconfig possible on device"
+			       " %02x:%02x\n", bus, i);
+		}
+	}
+}
+
+static const char __init *pci_mmcfg_e7520(void)
+{
+	u32 win;
+	pci_conf1_read(0, 0, PCI_DEVFN(0,0), 0xce, 2, &win);
+
+	pci_mmcfg_config_num = 1;
+	pci_mmcfg_config = kzalloc(sizeof(pci_mmcfg_config[0]), GFP_KERNEL);
+	if (!pci_mmcfg_config)
+		return NULL;
+	pci_mmcfg_config[0].address = (win & 0xf000) << 16;
+	pci_mmcfg_config[0].pci_segment = 0;
+	pci_mmcfg_config[0].start_bus_number = 0;
+	pci_mmcfg_config[0].end_bus_number = 255;
+
+	return "Intel Corporation E7520 Memory Controller Hub";
+}
+
+static const char __init *pci_mmcfg_intel_945(void)
+{
+	u32 pciexbar, mask = 0, len = 0;
+
+	pci_mmcfg_config_num = 1;
+
+	pci_conf1_read(0, 0, PCI_DEVFN(0,0), 0x48, 4, &pciexbar);
+
+	/* Enable bit */
+	if (!(pciexbar & 1))
+		pci_mmcfg_config_num = 0;
+
+	/* Size bits */
+	switch ((pciexbar >> 1) & 3) {
+	case 0:
+		mask = 0xf0000000U;
+		len  = 0x10000000U;
+		break;
+	case 1:
+		mask = 0xf8000000U;
+		len  = 0x08000000U;
+		break;
+	case 2:
+		mask = 0xfc000000U;
+		len  = 0x04000000U;
+		break;
+	default:
+		pci_mmcfg_config_num = 0;
+	}
+
+	/* Errata #2, things break when not aligned on a 256Mb boundary */
+	/* Can only happen in 64M/128M mode */
+
+	if ((pciexbar & mask) & 0x0fffffffU)
+		pci_mmcfg_config_num = 0;
+
+	if (pci_mmcfg_config_num) {
+		pci_mmcfg_config = kzalloc(sizeof(pci_mmcfg_config[0]), GFP_KERNEL);
+		if (!pci_mmcfg_config)
+			return NULL;
+		pci_mmcfg_config[0].address = pciexbar & mask;
+		pci_mmcfg_config[0].pci_segment = 0;
+		pci_mmcfg_config[0].start_bus_number = 0;
+		pci_mmcfg_config[0].end_bus_number = (len >> 20) - 1;
+	}
+
+	return "Intel Corporation 945G/GZ/P/PL Express Memory Controller Hub";
+}
+
+struct pci_mmcfg_hostbridge_probe {
+	u32 vendor;
+	u32 device;
+	const char *(*probe)(void);
+};
+
+static struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initdata = {
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
+};
+
+static int __init pci_mmcfg_check_hostbridge(void)
+{
+	u32 l;
+	u16 vendor, device;
+	int i;
+	const char *name;
+
+	pci_conf1_read(0, 0, PCI_DEVFN(0,0), 0, 4, &l);
+	vendor = l & 0xffff;
+	device = (l >> 16) & 0xffff;
+
+	pci_mmcfg_config_num = 0;
+	pci_mmcfg_config = NULL;
+	name = NULL;
+
+	for (i = 0; !name && i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
+		if (pci_mmcfg_probes[i].vendor == vendor &&
+		    pci_mmcfg_probes[i].device == device)
+			name = pci_mmcfg_probes[i].probe();
+	}
+
+	if (name) {
+		printk(KERN_INFO "PCI: Found %s %s MMCONFIG support.\n",
+		       name, pci_mmcfg_config_num ? "with" : "without");
+	}
+
+	return name != NULL;
+}
+
+static void __init pci_mmcfg_insert_resources(void)
+{
+#define PCI_MMCFG_RESOURCE_NAME_LEN 19
+	int i;
+	struct resource *res;
+	char *names;
+	unsigned num_buses;
+
+	res = kcalloc(PCI_MMCFG_RESOURCE_NAME_LEN + sizeof(*res),
+			pci_mmcfg_config_num, GFP_KERNEL);
+	if (!res) {
+		printk(KERN_ERR "PCI: Unable to allocate MMCONFIG resources\n");
+		return;
+	}
+
+	names = (void *)&res[pci_mmcfg_config_num];
+	for (i = 0; i < pci_mmcfg_config_num; i++, res++) {
+		struct acpi_mcfg_allocation *cfg = &pci_mmcfg_config[i];
+		num_buses = cfg->end_bus_number - cfg->start_bus_number + 1;
+		res->name = names;
+		snprintf(names, PCI_MMCFG_RESOURCE_NAME_LEN, "PCI MMCONFIG %u",
+			 cfg->pci_segment);
+		res->start = cfg->address;
+		res->end = res->start + (num_buses << 20) - 1;
+		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+		insert_resource(&iomem_resource, res);
+		names += PCI_MMCFG_RESOURCE_NAME_LEN;
+	}
+}
+
+static void __init pci_mmcfg_reject_broken(int type)
+{
+	typeof(pci_mmcfg_config[0]) *cfg;
+
+	if ((pci_mmcfg_config_num == 0) ||
+	    (pci_mmcfg_config == NULL) ||
+	    (pci_mmcfg_config[0].address == 0))
+		return;
+
+	cfg = &pci_mmcfg_config[0];
+
+	/*
+	 * Handle more broken MCFG tables on Asus etc.
+	 * They only contain a single entry for bus 0-0.
+	 */
+	if (pci_mmcfg_config_num == 1 &&
+	    cfg->pci_segment == 0 &&
+	    (cfg->start_bus_number | cfg->end_bus_number) == 0) {
+		printk(KERN_ERR "PCI: start and end of bus number is 0. "
+		       "Rejected as broken MCFG.\n");
+		goto reject;
+	}
+
+	/*
+	 * Only do this check when type 1 works. If it doesn't work
+	 * assume we run on a Mac and always use MCFG
+	 */
+	if (type == 1 && !e820_all_mapped(cfg->address,
+					  cfg->address + MMCONFIG_APER_MIN,
+					  E820_RESERVED)) {
+		printk(KERN_ERR "PCI: BIOS Bug: MCFG area at %Lx is not"
+		       " E820-reserved\n", cfg->address);
+		goto reject;
+	}
+	return;
+
+reject:
+	printk(KERN_ERR "PCI: Not using MMCONFIG.\n");
+	kfree(pci_mmcfg_config);
+	pci_mmcfg_config = NULL;
+	pci_mmcfg_config_num = 0;
+}
+
+void __init pci_mmcfg_init(int type)
+{
+	int known_bridge = 0;
+
+	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
+		return;
+
+	if (type == 1 && pci_mmcfg_check_hostbridge())
+		known_bridge = 1;
+
+	if (!known_bridge) {
+		acpi_table_parse(ACPI_SIG_MCFG, acpi_parse_mcfg);
+		pci_mmcfg_reject_broken(type);
+	}
+
+	if ((pci_mmcfg_config_num == 0) ||
+	    (pci_mmcfg_config == NULL) ||
+	    (pci_mmcfg_config[0].address == 0))
+		return;
+
+	if (pci_mmcfg_arch_init()) {
+		if (type == 1)
+			unreachable_devices();
+		if (known_bridge)
+			pci_mmcfg_insert_resources();
+		pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
+	}
+}