x86-64: enable MMCONFIG on AMD Fam10 systems even if the BIOS didn't

Code for this has been in Linux since 2.6.26, and since Xen itself
wants to use the MMCONFIG access method when possible, clone it
(fixing some rather obvious bugs in that code at once).

Signed-off-by: Jan Beulich <jbeulich@novell.com>

xen/arch/x86/cpu/amd.c

@@ -607,6 +607,14 @@ static void __devinit init_amd(struct cpuinfo_x86 *c)
 #ifdef __x86_64__
 	/* AMD CPUs do not support SYSENTER outside of legacy mode. */
 	clear_bit(X86_FEATURE_SEP, c->x86_capability);
+
+	if (c->x86 == 0x10) {
+		/* do this for boot cpu */
+		if (c == &boot_cpu_data)
+			check_enable_amd_mmconf_dmi();
+
+		fam10h_check_enable_mmcfg();
+	}
 #endif
 
 	/* Prevent TSC drift in non single-processor, single-core platforms. */

xen/arch/x86/x86_64/Makefile

@@ -7,6 +7,7 @@ obj-y += traps.o
 obj-y += machine_kexec.o
 obj-y += pci.o
 obj-y += acpi_mmcfg.o
+obj-y += mmconf-fam10h.o
 obj-y += mmconfig_64.o
 obj-y += mmconfig-shared.o
 obj-y += compat.o

xen/arch/x86/x86_64/mmconf-fam10h.c

@@ -0,0 +1,210 @@
+/*
+ * AMD Family 10h mmconfig enablement (taken from Linux 2.6.36)
+ */
+
+#include <xen/lib.h>
+#include <xen/acpi.h>
+#include <xen/pci.h>
+#include <xen/pci_regs.h>
+#include <xen/init.h>
+#include <xen/dmi.h>
+#include <asm/amd.h>
+#include <asm/msr.h>
+#include <asm/processor.h>
+
+#include "mmconfig.h"
+
+struct pci_hostbridge_probe {
+	u32 bus;
+	u32 slot;
+	u32 vendor;
+	u32 device;
+};
+
+static u64 __cpuinitdata fam10h_pci_mmconf_base;
+
+static struct pci_hostbridge_probe pci_probes[] __cpuinitdata = {
+	{ 0, 0x18, PCI_VENDOR_ID_AMD, 0x1200 },
+	{ 0xff, 0, PCI_VENDOR_ID_AMD, 0x1200 },
+};
+
+#define UNIT (1ULL << (5 + 3 + 12))
+#define MASK (~(UNIT - 1))
+#define SIZE (UNIT << 8)
+/* need to avoid (0xfd<<32) and (0xfe<<32), ht used space */
+#define FAM10H_PCI_MMCONF_BASE (0xfcULL<<32)
+#define BASE_VALID(b) ((b != (0xfdULL << 32)) && (b != (0xfeULL << 32)))
+static void __init get_fam10h_pci_mmconf_base(void)
+{
+	unsigned int i, j, bus, slot, hi_mmio_num;
+	u32 address;
+	u64 val, tom2, start, end;
+	struct range {
+		u64 start, end;
+	} range[8];
+
+	for (i = 0; i < ARRAY_SIZE(pci_probes); i++) {
+		u32 id;
+		u16 device;
+		u16 vendor;
+
+		bus = pci_probes[i].bus;
+		slot = pci_probes[i].slot;
+		id = pci_conf_read32(bus, slot, 0, PCI_VENDOR_ID);
+
+		vendor = id & 0xffff;
+		device = (id>>16) & 0xffff;
+		if (pci_probes[i].vendor == vendor &&
+		    pci_probes[i].device == device)
+			break;
+	}
+
+	if (i >= ARRAY_SIZE(pci_probes))
+		return;
+
+	/* SYS_CFG */
+	address = MSR_K8_SYSCFG;
+	rdmsrl(address, val);
+
+	/* TOP_MEM2 is not enabled? */
+	if (!(val & (1<<21))) {
+		tom2 = 0;
+	} else {
+		/* TOP_MEM2 */
+		address = MSR_K8_TOP_MEM2;
+		rdmsrl(address, val);
+		tom2 = val & 0xffffff800000ULL;
+	}
+
+	/*
+	 * need to check if the range is in the high mmio range that is
+	 * above 4G
+	 */
+	for (hi_mmio_num = i = 0; i < 8; i++) {
+		val = pci_conf_read32(bus, slot, 1, 0x80 + (i << 3));
+		if (!(val & 3))
+			continue;
+
+		start = (val & 0xffffff00) << 8; /* 39:16 on 31:8*/
+		val = pci_conf_read32(bus, slot, 1, 0x84 + (i << 3));
+		end = ((val & 0xffffff00) << 8) | 0xffff; /* 39:16 on 31:8*/
+
+		if (!end)
+			continue;
+
+		for (j = hi_mmio_num; j; --j) {
+			if (range[j - 1].start < start)
+				break;
+			range[j] = range[j - 1];
+		}
+		range[j].start = start;
+		range[j].end = end;
+		hi_mmio_num++;
+	}
+
+	start = FAM10H_PCI_MMCONF_BASE;
+	if (start <= tom2)
+		start = (tom2 + 2 * UNIT - 1) & MASK;
+
+	if (!hi_mmio_num)
+		goto out;
+
+	if (range[hi_mmio_num - 1].end < start)
+		goto out;
+	if (range[0].start > start + SIZE)
+		goto out;
+
+	/* need to find one window */
+	start = (range[0].start & MASK) - UNIT;
+	if (start > tom2 && BASE_VALID(start))
+		goto out;
+	start = (range[hi_mmio_num - 1].end + UNIT) & MASK;
+	if (start > tom2 && BASE_VALID(start))
+		goto out;
+	/* need to find window between ranges */
+	for (i = 1; i < hi_mmio_num; i++) {
+		start = (range[i - 1].end + UNIT) & MASK;
+		end = range[i].start & MASK;
+		if (end >= start + SIZE && start > tom2 && BASE_VALID(start))
+			goto out;
+	}
+	return;
+
+out:
+	fam10h_pci_mmconf_base = start;
+}
+
+void __cpuinit fam10h_check_enable_mmcfg(void)
+{
+	u64 val;
+	bool_t print = opt_cpu_info;
+
+	if (!(pci_probe & PCI_CHECK_ENABLE_AMD_MMCONF))
+		return;
+
+	rdmsrl(MSR_FAM10H_MMIO_CONF_BASE, val);
+
+	/* try to make sure that AP's setting is identical to BSP setting */
+	if (val & FAM10H_MMIO_CONF_ENABLE) {
+		unsigned busnbits;
+		busnbits = (val >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
+			FAM10H_MMIO_CONF_BUSRANGE_MASK;
+
+		/* only trust the one handle 256 buses, if acpi=off */
+		if (!acpi_pci_disabled || busnbits >= 8) {
+			u64 base = val & MASK;
+
+			if (!fam10h_pci_mmconf_base) {
+				fam10h_pci_mmconf_base = base;
+				return;
+			}
+			if (fam10h_pci_mmconf_base == base)
+				return;
+		}
+	}
+
+	/*
+	 * if it is not enabled, try to enable it and assume only one segment
+	 * with 256 buses
+	 */
+	/* only try to get setting from BSP */
+	if (!fam10h_pci_mmconf_base) {
+		get_fam10h_pci_mmconf_base();
+		print = 1;
+	}
+	if (!fam10h_pci_mmconf_base) {
+		pci_probe &= ~PCI_CHECK_ENABLE_AMD_MMCONF;
+		return;
+	}
+
+	if (print)
+		printk(KERN_INFO "Enable MMCONFIG on AMD Fam10h at %"PRIx64"\n",
+		       fam10h_pci_mmconf_base);
+	val &= ~((FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT) |
+	     (FAM10H_MMIO_CONF_BUSRANGE_MASK<<FAM10H_MMIO_CONF_BUSRANGE_SHIFT));
+	val |= fam10h_pci_mmconf_base | (8 << FAM10H_MMIO_CONF_BUSRANGE_SHIFT) |
+	       FAM10H_MMIO_CONF_ENABLE;
+	wrmsrl(MSR_FAM10H_MMIO_CONF_BASE, val);
+}
+
+static int __init set_check_enable_amd_mmconf(struct dmi_system_id *d)
+{
+        pci_probe |= PCI_CHECK_ENABLE_AMD_MMCONF;
+        return 0;
+}
+
+static struct dmi_system_id __initdata mmconf_dmi_table[] = {
+	{
+		.callback = set_check_enable_amd_mmconf,
+		.ident = "Sun Microsystems Machine",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Sun Microsystems"),
+		},
+	},
+	{}
+};
+
+void __init check_enable_amd_mmconf_dmi(void)
+{
+	dmi_check_system(mmconf_dmi_table);
+}

xen/arch/x86/x86_64/mmconfig-shared.c

@@ -26,7 +26,7 @@
 #include "mmconfig.h"
 
 static int __initdata known_bridge;
-static unsigned int pci_probe = PCI_PROBE_CONF1 | PCI_PROBE_MMCONF;
+unsigned int __cpuinitdata pci_probe = PCI_PROBE_CONF1 | PCI_PROBE_MMCONF;
 
 static void __init parse_mmcfg(char *s)
 {

xen/arch/x86/x86_64/mmconfig.h

@@ -34,6 +34,8 @@
 
 #define PCI_VENDOR_ID_NVIDIA       0x10de
 
+extern unsigned int pci_probe;
+
 /*
  * AMD Fam10h CPUs are buggy, and cannot access MMIO config space
  * on their northbrige except through the * %eax register. As such, you MUST

xen/include/asm-x86/amd.h

@@ -134,5 +134,12 @@
     AMD_OSVW_ERRATUM(3, AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0xff, 0xf),	\
 		        AMD_MODEL_RANGE(0x12, 0x0, 0x0, 0x1, 0x0))
 
+struct cpuinfo_x86;
 int cpu_has_amd_erratum(const struct cpuinfo_x86 *, int, ...);
+
+#ifdef __x86_64__
+void fam10h_check_enable_mmcfg(void);
+void check_enable_amd_mmconf_dmi(void);
+#endif
+
 #endif /* __AMD_H__ */