summaryrefslogtreecommitdiff
path: root/arch/x86/pci/mmconfig-shared.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/pci/mmconfig-shared.c')
-rw-r--r--arch/x86/pci/mmconfig-shared.c315
1 files changed, 315 insertions, 0 deletions
diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
new file mode 100644
index 000000000000..4df637e34f81
--- /dev/null
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -0,0 +1,315 @@
+/*
+ * 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);
+
+/* Indicate if the mmcfg resources have been placed into the resource table. */
+static int __initdata pci_mmcfg_resources_inserted;
+
+/* 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);
+
+ win = win & 0xf000;
+ if(win == 0x0000 || win == 0xf000)
+ pci_mmcfg_config_num = 0;
+ else {
+ 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 << 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;
+
+ /* Don't hit the APIC registers and their friends */
+ if ((pciexbar & mask) >= 0xf0000000U)
+ 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(unsigned long resource_flags)
+{
+#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 | resource_flags;
+ insert_resource(&iomem_resource, res);
+ names += PCI_MMCFG_RESOURCE_NAME_LEN;
+ }
+
+ /* Mark that the resources have been inserted. */
+ pci_mmcfg_resources_inserted = 1;
+}
+
+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(IORESOURCE_BUSY);
+ pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
+ } else {
+ /*
+ * Signal not to attempt to insert mmcfg resources because
+ * the architecture mmcfg setup could not initialize.
+ */
+ pci_mmcfg_resources_inserted = 1;
+ }
+}
+
+static int __init pci_mmcfg_late_insert_resources(void)
+{
+ /*
+ * If resources are already inserted or we are not using MMCONFIG,
+ * don't insert the resources.
+ */
+ if ((pci_mmcfg_resources_inserted == 1) ||
+ (pci_probe & PCI_PROBE_MMCONF) == 0 ||
+ (pci_mmcfg_config_num == 0) ||
+ (pci_mmcfg_config == NULL) ||
+ (pci_mmcfg_config[0].address == 0))
+ return 1;
+
+ /*
+ * Attempt to insert the mmcfg resources but not with the busy flag
+ * marked so it won't cause request errors when __request_region is
+ * called.
+ */
+ pci_mmcfg_insert_resources(0);
+
+ return 0;
+}
+
+/*
+ * Perform MMCONFIG resource insertion after PCI initialization to allow for
+ * misprogrammed MCFG tables that state larger sizes but actually conflict
+ * with other system resources.
+ */
+late_initcall(pci_mmcfg_late_insert_resources);