// SPDX-License-Identifier: GPL-2.0 /* * Intel MID PCI support * Copyright (c) 2008 Intel Corporation * Jesse Barnes * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #define PCIE_CAP_OFFSET 0x100 /* Quirks for the listed devices */ #define PCI_DEVICE_ID_INTEL_MRFLD_MMC 0x1190 #define PCI_DEVICE_ID_INTEL_MRFLD_HSU 0x1191 /* 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; int ret; u8 gsi; if (dev->irq_managed && dev->irq > 0) return 0; ret = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi); if (ret < 0) { dev_warn(&dev->dev, "Failed to read interrupt line: %d\n", ret); return ret; } switch (intel_mid_identify_cpu()) { case INTEL_MID_CPU_CHIP_TANGIER: polarity = IOAPIC_POL_HIGH; /* Special treatment for IRQ0 */ if (gsi == 0) { /* * Skip HS UART common registers device since it has * IRQ0 assigned and not used by the kernel. */ if (dev->device == PCI_DEVICE_ID_INTEL_MRFLD_HSU) return -EBUSY; /* * TNG has IRQ0 assigned to eMMC controller. But there * are also other devices with bogus PCI configuration * that have IRQ0 assigned. This check ensures that * eMMC gets it. The rest of devices still could be * enabled without interrupt line being allocated. */ if (dev->device != PCI_DEVICE_ID_INTEL_MRFLD_MMC) return 0; } break; default: polarity = IOAPIC_POL_LOW; break; } 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. */ ret = mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC, &info); if (ret < 0) return ret; dev->irq = ret; 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; } } static const struct pci_ops intel_mid_pci_ops __initconst = { .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 mid_power_off_one_device(struct pci_dev *dev) { u16 pmcsr; /* * Update current state first, otherwise PCI core enforces PCI_D0 in * pci_set_power_state() for devices which status was PCI_UNKNOWN. */ pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); dev->current_state = (pci_power_t __force)(pmcsr & PCI_PM_CTRL_STATE_MASK); pci_set_power_state(dev, PCI_D3hot); } static void mid_power_off_devices(struct pci_dev *dev) { int id; if (!pci_soc_mode) return; id = intel_mid_pwr_get_lss_id(dev); if (id < 0) return; /* * This sets only PMCSR bits. The actual power off will happen in * arch/x86/platform/intel-mid/pwr.c. */ mid_power_off_one_device(dev); } DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, mid_power_off_devices); /* * 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);