--- /dev/null
+/*
+ * Moorestown 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 <asm/acpi.h>
+#include <asm/segment.h>
+#include <asm/io.h>
+#include <asm/smp.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
+
+/**
+ * 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;
+ while (pos) {
+ if (raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number,
+ devfn, pos, 4, &pcie_cap))
+ return 0;
+
+ if (pcie_cap == 0xffffffff)
+ return 0;
+
+ 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 = pcie_cap >> 20;
+ }
+
+ 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 0;
+ if (bus == 0 && (devfn == PCI_DEVFN(2, 0) || devfn == PCI_DEVFN(0, 0)))
+ return 1;
+ return 0; /* 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 mrst_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 pci_mrst_ops = {
+ .read = pci_read,
+ .write = pci_write,
+};
+
+/**
+ * pci_mrst_init - installs pci_mrst_ops
+ *
+ * Moorestown has an interesting PCI implementation (see above).
+ * Called when the early platform detection installs it.
+ */
+int __init pci_mrst_init(void)
+{
+ printk(KERN_INFO "Moorestown platform detected, using MRST PCI ops\n");
+ pci_mmcfg_late_init();
+ pcibios_enable_irq = mrst_pci_irq_enable;
+ pci_root_ops = pci_mrst_ops;
+ /* Continue with standard init */
+ return 1;
+}
+
+/*
+ * Langwell devices reside at fixed offsets, don't try to move them.
+ */
+static void __devinit pci_fixed_bar_fixup(struct pci_dev *dev)
+{
+ unsigned long offset;
+ u32 size;
+ int i;
+
+ /* 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);
projects / GitHub / exynos8895 / android_kernel_samsung_universal8895.git / commitdiff