OpenRISC: Memory management
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/openrisc/mm/ioremap.c b/arch/openrisc/mm/ioremap.c
new file mode 100644
index 0000000..62b08ef
--- /dev/null
+++ b/arch/openrisc/mm/ioremap.c
@@ -0,0 +1,137 @@
+/*
+ * OpenRISC ioremap.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others. All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/io.h>
+#include <asm/pgalloc.h>
+#include <asm/kmap_types.h>
+#include <asm/fixmap.h>
+#include <asm/bug.h>
+#include <asm/pgtable.h>
+#include <linux/sched.h>
+#include <asm/tlbflush.h>
+
+extern int mem_init_done;
+
+static unsigned int fixmaps_used __initdata;
+
+/*
+ * Remap an arbitrary physical address space into the kernel virtual
+ * address space. Needed when the kernel wants to access high addresses
+ * directly.
+ *
+ * NOTE! We need to allow non-page-aligned mappings too: we will obviously
+ * have to convert them into an offset in a page-aligned mapping, but the
+ * caller shouldn't need to know that small detail.
+ */
+void __iomem *__init_refok
+__ioremap(phys_addr_t addr, unsigned long size, pgprot_t prot)
+{
+ phys_addr_t p;
+ unsigned long v;
+ unsigned long offset, last_addr;
+ struct vm_struct *area = NULL;
+
+ /* Don't allow wraparound or zero size */
+ last_addr = addr + size - 1;
+ if (!size || last_addr < addr)
+ return NULL;
+
+ /*
+ * Mappings have to be page-aligned
+ */
+ offset = addr & ~PAGE_MASK;
+ p = addr & PAGE_MASK;
+ size = PAGE_ALIGN(last_addr + 1) - p;
+
+ if (likely(mem_init_done)) {
+ area = get_vm_area(size, VM_IOREMAP);
+ if (!area)
+ return NULL;
+ v = (unsigned long)area->addr;
+ } else {
+ if ((fixmaps_used + (size >> PAGE_SHIFT)) > FIX_N_IOREMAPS)
+ return NULL;
+ v = fix_to_virt(FIX_IOREMAP_BEGIN + fixmaps_used);
+ fixmaps_used += (size >> PAGE_SHIFT);
+ }
+
+ if (ioremap_page_range(v, v + size, p, prot)) {
+ if (likely(mem_init_done))
+ vfree(area->addr);
+ else
+ fixmaps_used -= (size >> PAGE_SHIFT);
+ return NULL;
+ }
+
+ return (void __iomem *)(offset + (char *)v);
+}
+
+void iounmap(void *addr)
+{
+ /* If the page is from the fixmap pool then we just clear out
+ * the fixmap mapping.
+ */
+ if (unlikely((unsigned long)addr > FIXADDR_START)) {
+ /* This is a bit broken... we don't really know
+ * how big the area is so it's difficult to know
+ * how many fixed pages to invalidate...
+ * just flush tlb and hope for the best...
+ * consider this a FIXME
+ *
+ * Really we should be clearing out one or more page
+ * table entries for these virtual addresses so that
+ * future references cause a page fault... for now, we
+ * rely on two things:
+ * i) this code never gets called on known boards
+ * ii) invalid accesses to the freed areas aren't made
+ */
+ flush_tlb_all();
+ return;
+ }
+
+ return vfree((void *)(PAGE_MASK & (unsigned long)addr));
+}
+
+/**
+ * OK, this one's a bit tricky... ioremap can get called before memory is
+ * initialized (early serial console does this) and will want to alloc a page
+ * for its mapping. No userspace pages will ever get allocated before memory
+ * is initialized so this applies only to kernel pages. In the event that
+ * this is called before memory is initialized we allocate the page using
+ * the memblock infrastructure.
+ */
+
+pte_t __init_refok *pte_alloc_one_kernel(struct mm_struct *mm,
+ unsigned long address)
+{
+ pte_t *pte;
+
+ if (likely(mem_init_done)) {
+ pte = (pte_t *) __get_free_page(GFP_KERNEL | __GFP_REPEAT);
+ } else {
+ pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+#if 0
+ /* FIXME: use memblock... */
+ pte = (pte_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
+#endif
+ }
+
+ if (pte)
+ clear_page(pte);
+ return pte;
+}