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-rw-r--r--arch/x86/pci/intel_mid_pci.c406
1 files changed, 406 insertions, 0 deletions
diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c
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index 000000000..8edd62206
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+++ b/arch/x86/pci/intel_mid_pci.c
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+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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/cpu_device_id.h>
+#include <asm/segment.h>
+#include <asm/pci_x86.h>
+#include <asm/hw_irq.h>
+#include <asm/io_apic.h>
+#include <asm/intel-family.h>
+#include <asm/intel-mid.h>
+#include <asm/acpi.h>
+
+#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
+ * @reg: configuration register offset
+ *
+ * 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 const struct x86_cpu_id intel_mid_cpu_ids[] = {
+ X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_MID, NULL),
+ {}
+};
+
+static int intel_mid_pci_irq_enable(struct pci_dev *dev)
+{
+ const struct x86_cpu_id *id;
+ struct irq_alloc_info info;
+ bool polarity_low;
+ u16 model = 0;
+ 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;
+ }
+
+ id = x86_match_cpu(intel_mid_cpu_ids);
+ if (id)
+ model = id->model;
+
+ switch (model) {
+ case INTEL_FAM6_ATOM_SILVERMONT_MID:
+ polarity_low = false;
+
+ /* 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_low = true;
+ break;
+ }
+
+ ioapic_set_alloc_attr(&info, dev_to_node(&dev->dev), 1, polarity_low);
+
+ /*
+ * 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 */
+ acpi_noirq_set();
+ 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->d3hot_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_STD_NUM_BARS; 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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-15 00:36:31 +0000