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-rw-r--r--arch/mips/pci/pci-xtalk-bridge.c452
1 files changed, 452 insertions, 0 deletions
diff --git a/arch/mips/pci/pci-xtalk-bridge.c b/arch/mips/pci/pci-xtalk-bridge.c
new file mode 100644
index 000000000000..8f481984ab6e
--- /dev/null
+++ b/arch/mips/pci/pci-xtalk-bridge.c
@@ -0,0 +1,452 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2003 Christoph Hellwig (hch@lst.de)
+ * Copyright (C) 1999, 2000, 04 Ralf Baechle (ralf@linux-mips.org)
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ */
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/pci.h>
+#include <linux/smp.h>
+#include <linux/dma-direct.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/xtalk-bridge.h>
+
+#include <asm/pci/bridge.h>
+#include <asm/paccess.h>
+#include <asm/sn/intr.h>
+
+/*
+ * Most of the IOC3 PCI config register aren't present
+ * we emulate what is needed for a normal PCI enumeration
+ */
+static u32 emulate_ioc3_cfg(int where, int size)
+{
+ if (size == 1 && where == 0x3d)
+ return 0x01;
+ else if (size == 2 && where == 0x3c)
+ return 0x0100;
+ else if (size == 4 && where == 0x3c)
+ return 0x00000100;
+
+ return 0;
+}
+
+static void bridge_disable_swapping(struct pci_dev *dev)
+{
+ struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
+ int slot = PCI_SLOT(dev->devfn);
+
+ /* Turn off byte swapping */
+ bridge_clr(bc, b_device[slot].reg, BRIDGE_DEV_SWAP_DIR);
+ bridge_read(bc, b_widget.w_tflush); /* Flush */
+}
+
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC3,
+ bridge_disable_swapping);
+
+
+/*
+ * The Bridge ASIC supports both type 0 and type 1 access. Type 1 is
+ * not really documented, so right now I can't write code which uses it.
+ * Therefore we use type 0 accesses for now even though they won't work
+ * correctly for PCI-to-PCI bridges.
+ *
+ * The function is complicated by the ultimate brokenness of the IOC3 chip
+ * which is used in SGI systems. The IOC3 can only handle 32-bit PCI
+ * accesses and does only decode parts of it's address space.
+ */
+static int pci_conf0_read_config(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *value)
+{
+ struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+ struct bridge_regs *bridge = bc->base;
+ int slot = PCI_SLOT(devfn);
+ int fn = PCI_FUNC(devfn);
+ void *addr;
+ u32 cf, shift, mask;
+ int res;
+
+ addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
+ if (get_dbe(cf, (u32 *)addr))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ /*
+ * IOC3 is broken beyond belief ... Don't even give the
+ * generic PCI code a chance to look at it for real ...
+ */
+ if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
+ goto is_ioc3;
+
+ addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
+
+ if (size == 1)
+ res = get_dbe(*value, (u8 *)addr);
+ else if (size == 2)
+ res = get_dbe(*value, (u16 *)addr);
+ else
+ res = get_dbe(*value, (u32 *)addr);
+
+ return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
+
+is_ioc3:
+
+ /*
+ * IOC3 special handling
+ */
+ if ((where >= 0x14 && where < 0x40) || (where >= 0x48)) {
+ *value = emulate_ioc3_cfg(where, size);
+ return PCIBIOS_SUCCESSFUL;
+ }
+
+ addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
+ if (get_dbe(cf, (u32 *)addr))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ shift = ((where & 3) << 3);
+ mask = (0xffffffffU >> ((4 - size) << 3));
+ *value = (cf >> shift) & mask;
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static int pci_conf1_read_config(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *value)
+{
+ struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+ struct bridge_regs *bridge = bc->base;
+ int busno = bus->number;
+ int slot = PCI_SLOT(devfn);
+ int fn = PCI_FUNC(devfn);
+ void *addr;
+ u32 cf, shift, mask;
+ int res;
+
+ bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
+ addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
+ if (get_dbe(cf, (u32 *)addr))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ /*
+ * IOC3 is broken beyond belief ... Don't even give the
+ * generic PCI code a chance to look at it for real ...
+ */
+ if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
+ goto is_ioc3;
+
+ addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
+
+ if (size == 1)
+ res = get_dbe(*value, (u8 *)addr);
+ else if (size == 2)
+ res = get_dbe(*value, (u16 *)addr);
+ else
+ res = get_dbe(*value, (u32 *)addr);
+
+ return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
+
+is_ioc3:
+
+ /*
+ * IOC3 special handling
+ */
+ if ((where >= 0x14 && where < 0x40) || (where >= 0x48)) {
+ *value = emulate_ioc3_cfg(where, size);
+ return PCIBIOS_SUCCESSFUL;
+ }
+
+ addr = &bridge->b_type1_cfg.c[(fn << 8) | where];
+ if (get_dbe(cf, (u32 *)addr))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ shift = ((where & 3) << 3);
+ mask = (0xffffffffU >> ((4 - size) << 3));
+ *value = (cf >> shift) & mask;
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static int pci_read_config(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *value)
+{
+ if (!pci_is_root_bus(bus))
+ return pci_conf1_read_config(bus, devfn, where, size, value);
+
+ return pci_conf0_read_config(bus, devfn, where, size, value);
+}
+
+static int pci_conf0_write_config(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 value)
+{
+ struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+ struct bridge_regs *bridge = bc->base;
+ int slot = PCI_SLOT(devfn);
+ int fn = PCI_FUNC(devfn);
+ void *addr;
+ u32 cf, shift, mask, smask;
+ int res;
+
+ addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
+ if (get_dbe(cf, (u32 *)addr))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ /*
+ * IOC3 is broken beyond belief ... Don't even give the
+ * generic PCI code a chance to look at it for real ...
+ */
+ if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
+ goto is_ioc3;
+
+ addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
+
+ if (size == 1)
+ res = put_dbe(value, (u8 *)addr);
+ else if (size == 2)
+ res = put_dbe(value, (u16 *)addr);
+ else
+ res = put_dbe(value, (u32 *)addr);
+
+ if (res)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ return PCIBIOS_SUCCESSFUL;
+
+is_ioc3:
+
+ /*
+ * IOC3 special handling
+ */
+ if ((where >= 0x14 && where < 0x40) || (where >= 0x48))
+ return PCIBIOS_SUCCESSFUL;
+
+ addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
+
+ if (get_dbe(cf, (u32 *)addr))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ shift = ((where & 3) << 3);
+ mask = (0xffffffffU >> ((4 - size) << 3));
+ smask = mask << shift;
+
+ cf = (cf & ~smask) | ((value & mask) << shift);
+ if (put_dbe(cf, (u32 *)addr))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static int pci_conf1_write_config(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 value)
+{
+ struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+ struct bridge_regs *bridge = bc->base;
+ int slot = PCI_SLOT(devfn);
+ int fn = PCI_FUNC(devfn);
+ int busno = bus->number;
+ void *addr;
+ u32 cf, shift, mask, smask;
+ int res;
+
+ bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
+ addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
+ if (get_dbe(cf, (u32 *)addr))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ /*
+ * IOC3 is broken beyond belief ... Don't even give the
+ * generic PCI code a chance to look at it for real ...
+ */
+ if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
+ goto is_ioc3;
+
+ addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
+
+ if (size == 1)
+ res = put_dbe(value, (u8 *)addr);
+ else if (size == 2)
+ res = put_dbe(value, (u16 *)addr);
+ else
+ res = put_dbe(value, (u32 *)addr);
+
+ if (res)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ return PCIBIOS_SUCCESSFUL;
+
+is_ioc3:
+
+ /*
+ * IOC3 special handling
+ */
+ if ((where >= 0x14 && where < 0x40) || (where >= 0x48))
+ return PCIBIOS_SUCCESSFUL;
+
+ addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
+ if (get_dbe(cf, (u32 *)addr))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ shift = ((where & 3) << 3);
+ mask = (0xffffffffU >> ((4 - size) << 3));
+ smask = mask << shift;
+
+ cf = (cf & ~smask) | ((value & mask) << shift);
+ if (put_dbe(cf, (u32 *)addr))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static int pci_write_config(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 value)
+{
+ if (!pci_is_root_bus(bus))
+ return pci_conf1_write_config(bus, devfn, where, size, value);
+
+ return pci_conf0_write_config(bus, devfn, where, size, value);
+}
+
+static struct pci_ops bridge_pci_ops = {
+ .read = pci_read_config,
+ .write = pci_write_config,
+};
+
+/*
+ * All observed requests have pin == 1. We could have a global here, that
+ * gets incremented and returned every time - unfortunately, pci_map_irq
+ * may be called on the same device over and over, and need to return the
+ * same value. On O2000, pin can be 0 or 1, and PCI slots can be [0..7].
+ *
+ * A given PCI device, in general, should be able to intr any of the cpus
+ * on any one of the hubs connected to its xbow.
+ */
+static int bridge_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+ struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
+ int irq;
+
+ irq = bc->pci_int[slot];
+ if (irq == -1) {
+ irq = request_bridge_irq(bc, slot);
+ if (irq < 0)
+ return irq;
+
+ bc->pci_int[slot] = irq;
+ }
+ return irq;
+}
+
+static int bridge_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct bridge_controller *bc;
+ struct pci_host_bridge *host;
+ int slot;
+ int err;
+ struct xtalk_bridge_platform_data *bd = dev_get_platdata(&pdev->dev);
+
+ pci_set_flags(PCI_PROBE_ONLY);
+
+ host = devm_pci_alloc_host_bridge(dev, sizeof(*bc));
+ if (!host)
+ return -ENOMEM;
+
+ bc = pci_host_bridge_priv(host);
+
+ bc->busn.name = "Bridge PCI busn";
+ bc->busn.start = 0;
+ bc->busn.end = 0xff;
+ bc->busn.flags = IORESOURCE_BUS;
+
+ pci_add_resource_offset(&host->windows, &bd->mem, bd->mem_offset);
+ pci_add_resource_offset(&host->windows, &bd->io, bd->io_offset);
+ pci_add_resource(&host->windows, &bc->busn);
+
+ err = devm_request_pci_bus_resources(dev, &host->windows);
+ if (err < 0) {
+ pci_free_resource_list(&host->windows);
+ return err;
+ }
+
+ bc->nasid = bd->nasid;
+
+ bc->baddr = (u64)bd->masterwid << 60 | PCI64_ATTR_BAR;
+ bc->base = (struct bridge_regs *)bd->bridge_addr;
+ bc->intr_addr = bd->intr_addr;
+
+ /*
+ * Clear all pending interrupts.
+ */
+ bridge_write(bc, b_int_rst_stat, BRIDGE_IRR_ALL_CLR);
+
+ /*
+ * Until otherwise set up, assume all interrupts are from slot 0
+ */
+ bridge_write(bc, b_int_device, 0x0);
+
+ /*
+ * disable swapping for big windows
+ */
+ bridge_clr(bc, b_wid_control,
+ BRIDGE_CTRL_IO_SWAP | BRIDGE_CTRL_MEM_SWAP);
+#ifdef CONFIG_PAGE_SIZE_4KB
+ bridge_clr(bc, b_wid_control, BRIDGE_CTRL_PAGE_SIZE);
+#else /* 16kB or larger */
+ bridge_set(bc, b_wid_control, BRIDGE_CTRL_PAGE_SIZE);
+#endif
+
+ /*
+ * Hmm... IRIX sets additional bits in the address which
+ * are documented as reserved in the bridge docs.
+ */
+ bridge_write(bc, b_wid_int_upper,
+ ((bc->intr_addr >> 32) & 0xffff) | (bd->masterwid << 16));
+ bridge_write(bc, b_wid_int_lower, bc->intr_addr & 0xffffffff);
+ bridge_write(bc, b_dir_map, (bd->masterwid << 20)); /* DMA */
+ bridge_write(bc, b_int_enable, 0);
+
+ for (slot = 0; slot < 8; slot++) {
+ bridge_set(bc, b_device[slot].reg, BRIDGE_DEV_SWAP_DIR);
+ bc->pci_int[slot] = -1;
+ }
+ bridge_read(bc, b_wid_tflush); /* wait until Bridge PIO complete */
+
+ host->dev.parent = dev;
+ host->sysdata = bc;
+ host->busnr = 0;
+ host->ops = &bridge_pci_ops;
+ host->map_irq = bridge_map_irq;
+ host->swizzle_irq = pci_common_swizzle;
+
+ err = pci_scan_root_bus_bridge(host);
+ if (err < 0)
+ return err;
+
+ pci_bus_claim_resources(host->bus);
+ pci_bus_add_devices(host->bus);
+
+ platform_set_drvdata(pdev, host->bus);
+
+ return 0;
+}
+
+static int bridge_remove(struct platform_device *pdev)
+{
+ struct pci_bus *bus = platform_get_drvdata(pdev);
+
+ pci_lock_rescan_remove();
+ pci_stop_root_bus(bus);
+ pci_remove_root_bus(bus);
+ pci_unlock_rescan_remove();
+
+ return 0;
+}
+
+static struct platform_driver bridge_driver = {
+ .probe = bridge_probe,
+ .remove = bridge_remove,
+ .driver = {
+ .name = "xtalk-bridge",
+ }
+};
+
+builtin_platform_driver(bridge_driver);
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