| /* |
| * 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> |
| #include <asm/intel-mid.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) |
| { |
| struct irq_alloc_info info; |
| int polarity; |
| |
| if (dev->irq_managed && dev->irq > 0) |
| return 0; |
| |
| if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER) |
| polarity = 0; /* active high */ |
| else |
| polarity = 1; /* active low */ |
| ioapic_set_alloc_attr(&info, dev_to_node(&dev->dev), 1, polarity); |
| |
| /* |
| * MRST only have IOAPIC, the PCI irq lines are 1:1 mapped to |
| * IOAPIC RTE entries, so we just enable RTE for the device. |
| */ |
| if (mp_set_gsi_attr(dev->irq, 1, polarity, dev_to_node(&dev->dev))) |
| return -EBUSY; |
| if (mp_map_gsi_to_irq(dev->irq, IOAPIC_MAP_ALLOC, &info) < 0) |
| return -EBUSY; |
| |
| dev->irq_managed = 1; |
| |
| return 0; |
| } |
| |
| static void intel_mid_pci_irq_disable(struct pci_dev *dev) |
| { |
| if (!mp_should_keep_irq(&dev->dev) && dev->irq_managed && |
| dev->irq > 0) { |
| mp_unmap_irq(dev->irq); |
| dev->irq_managed = 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; |
| pcibios_disable_irq = intel_mid_pci_irq_disable; |
| 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, 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); |