https://github.com/torvalds/linux
Tip revision: f7644cbfcdf03528f0f450f3940c4985b2291f49 authored by Linus Torvalds on 09 August 2015, 19:54:30 UTC
Linux 4.2-rc6
Linux 4.2-rc6
Tip revision: f7644cb
io-workarounds.c
/*
* Support PCI IO workaround
*
* Copyright (C) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org>
* IBM, Corp.
* (C) Copyright 2007-2008 TOSHIBA CORPORATION
*
* 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/sched.h> /* for init_mm */
#include <asm/io.h>
#include <asm/machdep.h>
#include <asm/pgtable.h>
#include <asm/ppc-pci.h>
#include <asm/io-workarounds.h>
#define IOWA_MAX_BUS 8
static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
static unsigned int iowa_bus_count;
static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
{
int i, j;
struct resource *res;
unsigned long vstart, vend;
for (i = 0; i < iowa_bus_count; i++) {
struct iowa_bus *bus = &iowa_busses[i];
struct pci_controller *phb = bus->phb;
if (vaddr) {
vstart = (unsigned long)phb->io_base_virt;
vend = vstart + phb->pci_io_size - 1;
if ((vaddr >= vstart) && (vaddr <= vend))
return bus;
}
if (paddr)
for (j = 0; j < 3; j++) {
res = &phb->mem_resources[j];
if (paddr >= res->start && paddr <= res->end)
return bus;
}
}
return NULL;
}
#ifdef CONFIG_PPC_INDIRECT_MMIO
struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
{
unsigned hugepage_shift;
struct iowa_bus *bus;
int token;
token = PCI_GET_ADDR_TOKEN(addr);
if (token && token <= iowa_bus_count)
bus = &iowa_busses[token - 1];
else {
unsigned long vaddr, paddr;
pte_t *ptep;
vaddr = (unsigned long)PCI_FIX_ADDR(addr);
if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
return NULL;
/*
* We won't find huge pages here (iomem). Also can't hit
* a page table free due to init_mm
*/
ptep = __find_linux_pte_or_hugepte(init_mm.pgd, vaddr,
&hugepage_shift);
if (ptep == NULL)
paddr = 0;
else {
WARN_ON(hugepage_shift);
paddr = pte_pfn(*ptep) << PAGE_SHIFT;
}
bus = iowa_pci_find(vaddr, paddr);
if (bus == NULL)
return NULL;
}
return bus;
}
#else /* CONFIG_PPC_INDIRECT_MMIO */
struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
{
return NULL;
}
#endif /* !CONFIG_PPC_INDIRECT_MMIO */
#ifdef CONFIG_PPC_INDIRECT_PIO
struct iowa_bus *iowa_pio_find_bus(unsigned long port)
{
unsigned long vaddr = (unsigned long)pci_io_base + port;
return iowa_pci_find(vaddr, 0);
}
#else
struct iowa_bus *iowa_pio_find_bus(unsigned long port)
{
return NULL;
}
#endif
#define DEF_PCI_AC_RET(name, ret, at, al, space, aa) \
static ret iowa_##name at \
{ \
struct iowa_bus *bus; \
bus = iowa_##space##_find_bus(aa); \
if (bus && bus->ops && bus->ops->name) \
return bus->ops->name al; \
return __do_##name al; \
}
#define DEF_PCI_AC_NORET(name, at, al, space, aa) \
static void iowa_##name at \
{ \
struct iowa_bus *bus; \
bus = iowa_##space##_find_bus(aa); \
if (bus && bus->ops && bus->ops->name) { \
bus->ops->name al; \
return; \
} \
__do_##name al; \
}
#include <asm/io-defs.h>
#undef DEF_PCI_AC_RET
#undef DEF_PCI_AC_NORET
static const struct ppc_pci_io iowa_pci_io = {
#define DEF_PCI_AC_RET(name, ret, at, al, space, aa) .name = iowa_##name,
#define DEF_PCI_AC_NORET(name, at, al, space, aa) .name = iowa_##name,
#include <asm/io-defs.h>
#undef DEF_PCI_AC_RET
#undef DEF_PCI_AC_NORET
};
#ifdef CONFIG_PPC_INDIRECT_MMIO
static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
unsigned long flags, void *caller)
{
struct iowa_bus *bus;
void __iomem *res = __ioremap_caller(addr, size, flags, caller);
int busno;
bus = iowa_pci_find(0, (unsigned long)addr);
if (bus != NULL) {
busno = bus - iowa_busses;
PCI_SET_ADDR_TOKEN(res, busno + 1);
}
return res;
}
#else /* CONFIG_PPC_INDIRECT_MMIO */
#define iowa_ioremap NULL
#endif /* !CONFIG_PPC_INDIRECT_MMIO */
/* Enable IO workaround */
static void io_workaround_init(void)
{
static int io_workaround_inited;
if (io_workaround_inited)
return;
ppc_pci_io = iowa_pci_io;
ppc_md.ioremap = iowa_ioremap;
io_workaround_inited = 1;
}
/* Register new bus to support workaround */
void iowa_register_bus(struct pci_controller *phb, struct ppc_pci_io *ops,
int (*initfunc)(struct iowa_bus *, void *), void *data)
{
struct iowa_bus *bus;
struct device_node *np = phb->dn;
io_workaround_init();
if (iowa_bus_count >= IOWA_MAX_BUS) {
pr_err("IOWA:Too many pci bridges, "
"workarounds disabled for %s\n", np->full_name);
return;
}
bus = &iowa_busses[iowa_bus_count];
bus->phb = phb;
bus->ops = ops;
bus->private = data;
if (initfunc)
if ((*initfunc)(bus, data))
return;
iowa_bus_count++;
pr_debug("IOWA:[%d]Add bus, %s.\n", iowa_bus_count-1, np->full_name);
}