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Diffstat (limited to 'arch/powerpc/kernel/io-workarounds.c')
| -rw-r--r-- | arch/powerpc/kernel/io-workarounds.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/io-workarounds.c b/arch/powerpc/kernel/io-workarounds.c new file mode 100644 index 000000000..51bbaae94 --- /dev/null +++ b/arch/powerpc/kernel/io-workarounds.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Support PCI IO workaround + * + * Copyright (C) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org> + * IBM, Corp. + * (C) Copyright 2007-2008 TOSHIBA CORPORATION + */ +#undef DEBUG + +#include <linux/kernel.h> +#include <linux/sched/mm.h> /* for init_mm */ +#include <linux/pgtable.h> + +#include <asm/io.h> +#include <asm/machdep.h> +#include <asm/ppc-pci.h> +#include <asm/io-workarounds.h> +#include <asm/pte-walk.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_init_mm_pte(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 +void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size, + pgprot_t prot, void *caller) +{ + struct iowa_bus *bus; + void __iomem *res = __ioremap_caller(addr, size, prot, 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; +} +#endif /* !CONFIG_PPC_INDIRECT_MMIO */ + +bool io_workaround_inited; + +/* Enable IO workaround */ +static void io_workaround_init(void) +{ + if (io_workaround_inited) + return; + ppc_pci_io = iowa_pci_io; + io_workaround_inited = true; +} + +/* 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 %pOF\n", np); + 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, %pOF.\n", iowa_bus_count-1, np); +} + |