diff options
Diffstat (limited to 'arch/x86/pci/intel_mid_pci.c')
| -rw-r--r-- | arch/x86/pci/intel_mid_pci.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c new file mode 100644 index 00000000000..51384ca727a --- /dev/null +++ b/arch/x86/pci/intel_mid_pci.c @@ -0,0 +1,310 @@ +/* + * Intel MID PCI support + * Copyright (c) 2008 Intel Corporation + * Jesse Barnes <jesse.barnes@intel.com> + * + * Moorestown has an interesting PCI implementation: + * - configuration space is memory mapped (as defined by MCFG) + * - Lincroft devices also have a real, type 1 configuration space + * - Early Lincroft silicon has a type 1 access bug that will cause + * a hang if non-existent devices are accessed + * - some devices have the "fixed BAR" capability, which means + * they can't be relocated or modified; check for that during + * BAR sizing + * + * So, we use the MCFG space for all reads and writes, but also send + * Lincroft writes to type 1 space. But only read/write if the device + * actually exists, otherwise return all 1s for reads and bit bucket + * the writes. + */ + +#include <linux/sched.h> +#include <linux/pci.h> +#include <linux/ioport.h> +#include <linux/init.h> +#include <linux/dmi.h> +#include <linux/acpi.h> +#include <linux/io.h> +#include <linux/smp.h> + +#include <asm/segment.h> +#include <asm/pci_x86.h> +#include <asm/hw_irq.h> +#include <asm/io_apic.h> + +#define PCIE_CAP_OFFSET 0x100 + +/* Fixed BAR fields */ +#define PCIE_VNDR_CAP_ID_FIXED_BAR 0x00 /* Fixed BAR (TBD) */ +#define PCI_FIXED_BAR_0_SIZE 0x04 +#define PCI_FIXED_BAR_1_SIZE 0x08 +#define PCI_FIXED_BAR_2_SIZE 0x0c +#define PCI_FIXED_BAR_3_SIZE 0x10 +#define PCI_FIXED_BAR_4_SIZE 0x14 +#define PCI_FIXED_BAR_5_SIZE 0x1c + +static int pci_soc_mode; + +/** + * fixed_bar_cap - return the offset of the fixed BAR cap if found + * @bus: PCI bus + * @devfn: device in question + * + * Look for the fixed BAR cap on @bus and @devfn, returning its offset + * if found or 0 otherwise. + */ +static int fixed_bar_cap(struct pci_bus *bus, unsigned int devfn) +{ + int pos; + u32 pcie_cap = 0, cap_data; + + pos = PCIE_CAP_OFFSET; + + if (!raw_pci_ext_ops) + return 0; + + while (pos) { + if (raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number, + devfn, pos, 4, &pcie_cap)) + return 0; + + if (PCI_EXT_CAP_ID(pcie_cap) == 0x0000 || + PCI_EXT_CAP_ID(pcie_cap) == 0xffff) + break; + + if (PCI_EXT_CAP_ID(pcie_cap) == PCI_EXT_CAP_ID_VNDR) { + raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number, + devfn, pos + 4, 4, &cap_data); + if ((cap_data & 0xffff) == PCIE_VNDR_CAP_ID_FIXED_BAR) + return pos; + } + + pos = PCI_EXT_CAP_NEXT(pcie_cap); + } + + return 0; +} + +static int pci_device_update_fixed(struct pci_bus *bus, unsigned int devfn, + int reg, int len, u32 val, int offset) +{ + u32 size; + unsigned int domain, busnum; + int bar = (reg - PCI_BASE_ADDRESS_0) >> 2; + + domain = pci_domain_nr(bus); + busnum = bus->number; + + if (val == ~0 && len == 4) { + unsigned long decode; + + raw_pci_ext_ops->read(domain, busnum, devfn, + offset + 8 + (bar * 4), 4, &size); + + /* Turn the size into a decode pattern for the sizing code */ + if (size) { + decode = size - 1; + decode |= decode >> 1; + decode |= decode >> 2; + decode |= decode >> 4; + decode |= decode >> 8; + decode |= decode >> 16; + decode++; + decode = ~(decode - 1); + } else { + decode = 0; + } + + /* + * If val is all ones, the core code is trying to size the reg, + * so update the mmconfig space with the real size. + * + * Note: this assumes the fixed size we got is a power of two. + */ + return raw_pci_ext_ops->write(domain, busnum, devfn, reg, 4, + decode); + } + + /* This is some other kind of BAR write, so just do it. */ + return raw_pci_ext_ops->write(domain, busnum, devfn, reg, len, val); +} + +/** + * type1_access_ok - check whether to use type 1 + * @bus: bus number + * @devfn: device & function in question + * + * If the bus is on a Lincroft chip and it exists, or is not on a Lincroft at + * all, the we can go ahead with any reads & writes. If it's on a Lincroft, + * but doesn't exist, avoid the access altogether to keep the chip from + * hanging. + */ +static bool type1_access_ok(unsigned int bus, unsigned int devfn, int reg) +{ + /* + * This is a workaround for A0 LNC bug where PCI status register does + * not have new CAP bit set. can not be written by SW either. + * + * PCI header type in real LNC indicates a single function device, this + * will prevent probing other devices under the same function in PCI + * shim. Therefore, use the header type in shim instead. + */ + if (reg >= 0x100 || reg == PCI_STATUS || reg == PCI_HEADER_TYPE) + return false; + if (bus == 0 && (devfn == PCI_DEVFN(2, 0) + || devfn == PCI_DEVFN(0, 0) + || devfn == PCI_DEVFN(3, 0))) + return true; + return false; /* Langwell on others */ +} + +static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, + int size, u32 *value) +{ + if (type1_access_ok(bus->number, devfn, where)) + return pci_direct_conf1.read(pci_domain_nr(bus), bus->number, + devfn, where, size, value); + return raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number, + devfn, where, size, value); +} + +static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, + int size, u32 value) +{ + int offset; + + /* + * On MRST, there is no PCI ROM BAR, this will cause a subsequent read + * to ROM BAR return 0 then being ignored. + */ + if (where == PCI_ROM_ADDRESS) + return 0; + + /* + * Devices with fixed BARs need special handling: + * - BAR sizing code will save, write ~0, read size, restore + * - so writes to fixed BARs need special handling + * - other writes to fixed BAR devices should go through mmconfig + */ + offset = fixed_bar_cap(bus, devfn); + if (offset && + (where >= PCI_BASE_ADDRESS_0 && where <= PCI_BASE_ADDRESS_5)) { + return pci_device_update_fixed(bus, devfn, where, size, value, + offset); + } + + /* + * On Moorestown update both real & mmconfig space + * Note: early Lincroft silicon can't handle type 1 accesses to + * non-existent devices, so just eat the write in that case. + */ + if (type1_access_ok(bus->number, devfn, where)) + return pci_direct_conf1.write(pci_domain_nr(bus), bus->number, + devfn, where, size, value); + return raw_pci_ext_ops->write(pci_domain_nr(bus), bus->number, devfn, + where, size, value); +} + +static int intel_mid_pci_irq_enable(struct pci_dev *dev) +{ + u8 pin; + struct io_apic_irq_attr irq_attr; + + pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); + + /* + * MRST only have IOAPIC, the PCI irq lines are 1:1 mapped to + * IOAPIC RTE entries, so we just enable RTE for the device. + */ + irq_attr.ioapic = mp_find_ioapic(dev->irq); + irq_attr.ioapic_pin = dev->irq; + irq_attr.trigger = 1; /* level */ + irq_attr.polarity = 1; /* active low */ + io_apic_set_pci_routing(&dev->dev, dev->irq, &irq_attr); + + return 0; +} + +struct pci_ops intel_mid_pci_ops = { + .read = pci_read, + .write = pci_write, +}; + +/** + * intel_mid_pci_init - installs intel_mid_pci_ops + * + * Moorestown has an interesting PCI implementation (see above). + * Called when the early platform detection installs it. + */ +int __init intel_mid_pci_init(void) +{ + pr_info("Intel MID platform detected, using MID PCI ops\n"); + pci_mmcfg_late_init(); + pcibios_enable_irq = intel_mid_pci_irq_enable; + pci_root_ops = intel_mid_pci_ops; + pci_soc_mode = 1; + /* Continue with standard init */ + return 1; +} + +/* + * Langwell devices are not true PCI devices; they are not subject to 10 ms + * d3 to d0 delay required by PCI spec. + */ +static void pci_d3delay_fixup(struct pci_dev *dev) +{ + /* + * PCI fixups are effectively decided compile time. If we have a dual + * SoC/non-SoC kernel we don't want to mangle d3 on non-SoC devices. + */ + if (!pci_soc_mode) + return; + /* + * True PCI devices in Lincroft should allow type 1 access, the rest + * are Langwell fake PCI devices. + */ + if (type1_access_ok(dev->bus->number, dev->devfn, PCI_DEVICE_ID)) + return; + dev->d3_delay = 0; +} +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_d3delay_fixup); + +static void mrst_power_off_unused_dev(struct pci_dev *dev) +{ + pci_set_power_state(dev, PCI_D3hot); +} +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0801, mrst_power_off_unused_dev); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0809, mrst_power_off_unused_dev); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x080C, mrst_power_off_unused_dev); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0812, mrst_power_off_unused_dev); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0815, mrst_power_off_unused_dev); + +/* + * Langwell devices reside at fixed offsets, don't try to move them. + */ +static void pci_fixed_bar_fixup(struct pci_dev *dev) +{ + unsigned long offset; + u32 size; + int i; + + if (!pci_soc_mode) + return; + + /* Must have extended configuration space */ + if (dev->cfg_size < PCIE_CAP_OFFSET + 4) + return; + + /* Fixup the BAR sizes for fixed BAR devices and make them unmoveable */ + offset = fixed_bar_cap(dev->bus, dev->devfn); + if (!offset || PCI_DEVFN(2, 0) == dev->devfn || + PCI_DEVFN(2, 2) == dev->devfn) + return; + + for (i = 0; i < PCI_ROM_RESOURCE; i++) { + pci_read_config_dword(dev, offset + 8 + (i * 4), &size); + dev->resource[i].end = dev->resource[i].start + size - 1; + dev->resource[i].flags |= IORESOURCE_PCI_FIXED; + } +} +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_fixed_bar_fixup); |