--- /dev/null
+/*
+ * Copyright (C) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org>
+ * IBM, Corp.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/pci.h>
+#include <asm/io.h>
+#include <asm/machdep.h>
+#include <asm/pci-bridge.h>
+#include <asm/ppc-pci.h>
+
+
+#define SPIDER_PCI_REG_BASE 0xd000
+#define SPIDER_PCI_VCI_CNTL_STAT 0x0110
+#define SPIDER_PCI_DUMMY_READ 0x0810
+#define SPIDER_PCI_DUMMY_READ_BASE 0x0814
+
+/* Undefine that to re-enable bogus prefetch
+ *
+ * Without that workaround, the chip will do bogus prefetch past
+ * page boundary from system memory. This setting will disable that,
+ * though the documentation is unclear as to the consequences of doing
+ * so, either purely performances, or possible misbehaviour... It's not
+ * clear wether the chip can handle unaligned accesses at all without
+ * prefetching enabled.
+ *
+ * For now, things appear to be behaving properly with that prefetching
+ * disabled and IDE, possibly because IDE isn't doing any unaligned
+ * access.
+ */
+#define SPIDER_DISABLE_PREFETCH
+
+#define MAX_SPIDERS 2
+
+static struct spider_pci_bus {
+ void __iomem *regs;
+ unsigned long mmio_start;
+ unsigned long mmio_end;
+ unsigned long pio_vstart;
+ unsigned long pio_vend;
+} spider_pci_busses[MAX_SPIDERS];
+static int spider_pci_count;
+
+static struct spider_pci_bus *spider_pci_find(unsigned long vaddr,
+ unsigned long paddr)
+{
+ int i;
+
+ for (i = 0; i < spider_pci_count; i++) {
+ struct spider_pci_bus *bus = &spider_pci_busses[i];
+ if (paddr && paddr >= bus->mmio_start && paddr < bus->mmio_end)
+ return bus;
+ if (vaddr && vaddr >= bus->pio_vstart && vaddr < bus->pio_vend)
+ return bus;
+ }
+ return NULL;
+}
+
+static void spider_io_flush(const volatile void __iomem *addr)
+{
+ struct spider_pci_bus *bus;
+ int token;
+
+ /* Get platform token (set by ioremap) from address */
+ token = PCI_GET_ADDR_TOKEN(addr);
+
+ /* Fast path if we have a non-0 token, it indicates which bus we
+ * are on.
+ *
+ * If the token is 0, that means either the the ioremap was done
+ * before we initialized this layer, or it's a PIO operation. We
+ * fallback to a low path in this case. Hopefully, internal devices
+ * which are ioremap'ed early should use in_XX/out_XX functions
+ * instead of the PCI ones and thus not suffer from the slowdown.
+ *
+ * Also note that currently, the workaround will not work for areas
+ * that are not mapped with PTEs (bolted in the hash table). This
+ * is the case for ioremaps done very early at boot (before
+ * mem_init_done) and includes the mapping of the ISA IO space.
+ *
+ * Fortunately, none of the affected devices is expected to do DMA
+ * and thus there should be no problem in practice.
+ *
+ * In order to improve performances, we only do the PTE search for
+ * addresses falling in the PHB IO space area. That means it will
+ * not work for hotplug'ed PHBs but those don't exist with Spider.
+ */
+ if (token && token <= spider_pci_count)
+ bus = &spider_pci_busses[token - 1];
+ else {
+ unsigned long vaddr, paddr;
+ pte_t *ptep;
+
+ /* Fixup physical address */
+ vaddr = (unsigned long)PCI_FIX_ADDR(addr);
+
+ /* Check if it's in allowed range for PIO */
+ if (vaddr < PHBS_IO_BASE || vaddr >= IMALLOC_BASE)
+ return;
+
+ /* Try to find a PTE. If not, clear the paddr, we'll do
+ * a vaddr only lookup (PIO only)
+ */
+ ptep = find_linux_pte(init_mm.pgd, vaddr);
+ if (ptep == NULL)
+ paddr = 0;
+ else
+ paddr = pte_pfn(*ptep) << PAGE_SHIFT;
+
+ bus = spider_pci_find(vaddr, paddr);
+ if (bus == NULL)
+ return;
+ }
+
+ /* Now do the workaround
+ */
+ (void)in_be32(bus->regs + SPIDER_PCI_DUMMY_READ);
+}
+
+static u8 spider_readb(const volatile void __iomem *addr)
+{
+ u8 val = __do_readb(addr);
+ spider_io_flush(addr);
+ return val;
+}
+
+static u16 spider_readw(const volatile void __iomem *addr)
+{
+ u16 val = __do_readw(addr);
+ spider_io_flush(addr);
+ return val;
+}
+
+static u32 spider_readl(const volatile void __iomem *addr)
+{
+ u32 val = __do_readl(addr);
+ spider_io_flush(addr);
+ return val;
+}
+
+static u64 spider_readq(const volatile void __iomem *addr)
+{
+ u64 val = __do_readq(addr);
+ spider_io_flush(addr);
+ return val;
+}
+
+static u16 spider_readw_be(const volatile void __iomem *addr)
+{
+ u16 val = __do_readw_be(addr);
+ spider_io_flush(addr);
+ return val;
+}
+
+static u32 spider_readl_be(const volatile void __iomem *addr)
+{
+ u32 val = __do_readl_be(addr);
+ spider_io_flush(addr);
+ return val;
+}
+
+static u64 spider_readq_be(const volatile void __iomem *addr)
+{
+ u64 val = __do_readq_be(addr);
+ spider_io_flush(addr);
+ return val;
+}
+
+static void spider_readsb(const volatile void __iomem *addr, void *buf,
+ unsigned long count)
+{
+ __do_readsb(addr, buf, count);
+ spider_io_flush(addr);
+}
+
+static void spider_readsw(const volatile void __iomem *addr, void *buf,
+ unsigned long count)
+{
+ __do_readsw(addr, buf, count);
+ spider_io_flush(addr);
+}
+
+static void spider_readsl(const volatile void __iomem *addr, void *buf,
+ unsigned long count)
+{
+ __do_readsl(addr, buf, count);
+ spider_io_flush(addr);
+}
+
+static void spider_memcpy_fromio(void *dest, const volatile void __iomem *src,
+ unsigned long n)
+{
+ __do_memcpy_fromio(dest, src, n);
+ spider_io_flush(src);
+}
+
+
+static void __iomem * spider_ioremap(unsigned long addr, unsigned long size,
+ unsigned long flags)
+{
+ struct spider_pci_bus *bus;
+ void __iomem *res = __ioremap(addr, size, flags);
+ int busno;
+
+ pr_debug("spider_ioremap(0x%lx, 0x%lx, 0x%lx) -> 0x%p\n",
+ addr, size, flags, res);
+
+ bus = spider_pci_find(0, addr);
+ if (bus != NULL) {
+ busno = bus - spider_pci_busses;
+ pr_debug(" found bus %d, setting token\n", busno);
+ PCI_SET_ADDR_TOKEN(res, busno + 1);
+ }
+ pr_debug(" result=0x%p\n", res);
+
+ return res;
+}
+
+static void __init spider_pci_setup_chip(struct spider_pci_bus *bus)
+{
+#ifdef SPIDER_DISABLE_PREFETCH
+ u32 val = in_be32(bus->regs + SPIDER_PCI_VCI_CNTL_STAT);
+ pr_debug(" PVCI_Control_Status was 0x%08x\n", val);
+ out_be32(bus->regs + SPIDER_PCI_VCI_CNTL_STAT, val | 0x8);
+#endif
+
+ /* Configure the dummy address for the workaround */
+ out_be32(bus->regs + SPIDER_PCI_DUMMY_READ_BASE, 0x80000000);
+}
+
+static void __init spider_pci_add_one(struct pci_controller *phb)
+{
+ struct spider_pci_bus *bus = &spider_pci_busses[spider_pci_count];
+ struct device_node *np = phb->arch_data;
+ struct resource rsrc;
+ void __iomem *regs;
+
+ if (spider_pci_count >= MAX_SPIDERS) {
+ printk(KERN_ERR "Too many spider bridges, workarounds"
+ " disabled for %s\n", np->full_name);
+ return;
+ }
+
+ /* Get the registers for the beast */
+ if (of_address_to_resource(np, 0, &rsrc)) {
+ printk(KERN_ERR "Failed to get registers for spider %s"
+ " workarounds disabled\n", np->full_name);
+ return;
+ }
+
+ /* Mask out some useless bits in there to get to the base of the
+ * spider chip
+ */
+ rsrc.start &= ~0xfffffffful;
+
+ /* Map them */
+ regs = ioremap(rsrc.start + SPIDER_PCI_REG_BASE, 0x1000);
+ if (regs == NULL) {
+ printk(KERN_ERR "Failed to map registers for spider %s"
+ " workarounds disabled\n", np->full_name);
+ return;
+ }
+
+ spider_pci_count++;
+
+ /* We assume spiders only have one MMIO resource */
+ bus->mmio_start = phb->mem_resources[0].start;
+ bus->mmio_end = phb->mem_resources[0].end + 1;
+
+ bus->pio_vstart = (unsigned long)phb->io_base_virt;
+ bus->pio_vend = bus->pio_vstart + phb->pci_io_size;
+
+ bus->regs = regs;
+
+ printk(KERN_INFO "PCI: Spider MMIO workaround for %s\n",np->full_name);
+
+ pr_debug(" mmio (P) = 0x%016lx..0x%016lx\n",
+ bus->mmio_start, bus->mmio_end);
+ pr_debug(" pio (V) = 0x%016lx..0x%016lx\n",
+ bus->pio_vstart, bus->pio_vend);
+ pr_debug(" regs (P) = 0x%016lx (V) = 0x%p\n",
+ rsrc.start + SPIDER_PCI_REG_BASE, bus->regs);
+
+ spider_pci_setup_chip(bus);
+}
+
+static struct ppc_pci_io __initdata spider_pci_io = {
+ .readb = spider_readb,
+ .readw = spider_readw,
+ .readl = spider_readl,
+ .readq = spider_readq,
+ .readw_be = spider_readw_be,
+ .readl_be = spider_readl_be,
+ .readq_be = spider_readq_be,
+ .readsb = spider_readsb,
+ .readsw = spider_readsw,
+ .readsl = spider_readsl,
+ .memcpy_fromio = spider_memcpy_fromio,
+};
+
+static int __init spider_pci_workaround_init(void)
+{
+ struct pci_controller *phb;
+
+ if (!machine_is(cell))
+ return 0;
+
+ /* Find spider bridges. We assume they have been all probed
+ * in setup_arch(). If that was to change, we would need to
+ * update this code to cope with dynamically added busses
+ */
+ list_for_each_entry(phb, &hose_list, list_node) {
+ struct device_node *np = phb->arch_data;
+ const char *model = get_property(np, "model", NULL);
+
+ /* If no model property or name isn't exactly "pci", skip */
+ if (model == NULL || strcmp(np->name, "pci"))
+ continue;
+ /* If model is not "Spider", skip */
+ if (strcmp(model, "Spider"))
+ continue;
+ spider_pci_add_one(phb);
+ }
+
+ /* No Spider PCI found, exit */
+ if (spider_pci_count == 0)
+ return 0;
+
+ /* Setup IO callbacks. We only setup MMIO reads. PIO reads will
+ * fallback to MMIO reads (though without a token, thus slower)
+ */
+ ppc_pci_io = spider_pci_io;
+
+ /* Setup ioremap callback */
+ ppc_md.ioremap = spider_ioremap;
+
+ return 0;
+}
+arch_initcall(spider_pci_workaround_init);
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