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-rw-r--r--arch/powerpc/kernel/io-workarounds.c207
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);
+}
+