microblaze_mmu_v2: Page table - ioremap - pgtable.c/h, section update
Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/mm/pgtable.c b/arch/microblaze/mm/pgtable.c
new file mode 100644
index 0000000..46c4ca5
--- /dev/null
+++ b/arch/microblaze/mm/pgtable.c
@@ -0,0 +1,286 @@
+/*
+ * This file contains the routines setting up the linux page tables.
+ *
+ * Copyright (C) 2008 Michal Simek
+ * Copyright (C) 2008 PetaLogix
+ *
+ * Copyright (C) 2007 Xilinx, Inc. All rights reserved.
+ *
+ * Derived from arch/ppc/mm/pgtable.c:
+ * -- paulus
+ *
+ * Derived from arch/ppc/mm/init.c:
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
+ * and Cort Dougan (PReP) (cort@cs.nmt.edu)
+ * Copyright (C) 1996 Paul Mackerras
+ * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
+ *
+ * Derived from "arch/i386/mm/init.c"
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file COPYING in the main directory of this
+ * archive for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <linux/io.h>
+#include <asm/mmu.h>
+#include <asm/sections.h>
+
+#define flush_HPTE(X, va, pg) _tlbie(va)
+
+unsigned long ioremap_base;
+unsigned long ioremap_bot;
+
+/* The maximum lowmem defaults to 768Mb, but this can be configured to
+ * another value.
+ */
+#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
+
+#ifndef CONFIG_SMP
+struct pgtable_cache_struct quicklists;
+#endif
+
+static void __iomem *__ioremap(phys_addr_t addr, unsigned long size,
+ unsigned long flags)
+{
+ unsigned long v, i;
+ phys_addr_t p;
+ int err;
+
+ /*
+ * Choose an address to map it to.
+ * Once the vmalloc system is running, we use it.
+ * Before then, we use space going down from ioremap_base
+ * (ioremap_bot records where we're up to).
+ */
+ p = addr & PAGE_MASK;
+ size = PAGE_ALIGN(addr + size) - p;
+
+ /*
+ * Don't allow anybody to remap normal RAM that we're using.
+ * mem_init() sets high_memory so only do the check after that.
+ *
+ * However, allow remap of rootfs: TBD
+ */
+ if (mem_init_done &&
+ p >= memory_start && p < virt_to_phys(high_memory) &&
+ !(p >= virt_to_phys((unsigned long)&__bss_stop) &&
+ p < virt_to_phys((unsigned long)__bss_stop))) {
+ printk(KERN_WARNING "__ioremap(): phys addr "PTE_FMT
+ " is RAM lr %p\n", (unsigned long)p,
+ __builtin_return_address(0));
+ return NULL;
+ }
+
+ if (size == 0)
+ return NULL;
+
+ /*
+ * Is it already mapped? If the whole area is mapped then we're
+ * done, otherwise remap it since we want to keep the virt addrs for
+ * each request contiguous.
+ *
+ * We make the assumption here that if the bottom and top
+ * of the range we want are mapped then it's mapped to the
+ * same virt address (and this is contiguous).
+ * -- Cort
+ */
+
+ if (mem_init_done) {
+ struct vm_struct *area;
+ area = get_vm_area(size, VM_IOREMAP);
+ if (area == NULL)
+ return NULL;
+ v = VMALLOC_VMADDR(area->addr);
+ } else {
+ v = (ioremap_bot -= size);
+ }
+
+ if ((flags & _PAGE_PRESENT) == 0)
+ flags |= _PAGE_KERNEL;
+ if (flags & _PAGE_NO_CACHE)
+ flags |= _PAGE_GUARDED;
+
+ err = 0;
+ for (i = 0; i < size && err == 0; i += PAGE_SIZE)
+ err = map_page(v + i, p + i, flags);
+ if (err) {
+ if (mem_init_done)
+ vfree((void *)v);
+ return NULL;
+ }
+
+ return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
+}
+
+void __iomem *ioremap(phys_addr_t addr, unsigned long size)
+{
+ return __ioremap(addr, size, _PAGE_NO_CACHE);
+}
+EXPORT_SYMBOL(ioremap);
+
+void iounmap(void *addr)
+{
+ if (addr > high_memory && (unsigned long) addr < ioremap_bot)
+ vfree((void *) (PAGE_MASK & (unsigned long) addr));
+}
+EXPORT_SYMBOL(iounmap);
+
+
+int map_page(unsigned long va, phys_addr_t pa, int flags)
+{
+ pmd_t *pd;
+ pte_t *pg;
+ int err = -ENOMEM;
+ /* spin_lock(&init_mm.page_table_lock); */
+ /* Use upper 10 bits of VA to index the first level map */
+ pd = pmd_offset(pgd_offset_k(va), va);
+ /* Use middle 10 bits of VA to index the second-level map */
+ pg = pte_alloc_kernel(pd, va); /* from powerpc - pgtable.c */
+ /* pg = pte_alloc_kernel(&init_mm, pd, va); */
+
+ if (pg != NULL) {
+ err = 0;
+ set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
+ __pgprot(flags)));
+ if (mem_init_done)
+ flush_HPTE(0, va, pmd_val(*pd));
+ /* flush_HPTE(0, va, pg); */
+
+ }
+ /* spin_unlock(&init_mm.page_table_lock); */
+ return err;
+}
+
+void __init adjust_total_lowmem(void)
+{
+/* TBD */
+#if 0
+ unsigned long max_low_mem = MAX_LOW_MEM;
+
+ if (total_lowmem > max_low_mem) {
+ total_lowmem = max_low_mem;
+#ifndef CONFIG_HIGHMEM
+ printk(KERN_INFO "Warning, memory limited to %ld Mb, use "
+ "CONFIG_HIGHMEM to reach %ld Mb\n",
+ max_low_mem >> 20, total_memory >> 20);
+ total_memory = total_lowmem;
+#endif /* CONFIG_HIGHMEM */
+ }
+#endif
+}
+
+static void show_tmem(unsigned long tmem)
+{
+ volatile unsigned long a;
+ a = a + tmem;
+}
+
+/*
+ * Map in all of physical memory starting at CONFIG_KERNEL_START.
+ */
+void __init mapin_ram(void)
+{
+ unsigned long v, p, s, f;
+
+ v = CONFIG_KERNEL_START;
+ p = memory_start;
+ show_tmem(memory_size);
+ for (s = 0; s < memory_size; s += PAGE_SIZE) {
+ f = _PAGE_PRESENT | _PAGE_ACCESSED |
+ _PAGE_SHARED | _PAGE_HWEXEC;
+ if ((char *) v < _stext || (char *) v >= _etext)
+ f |= _PAGE_WRENABLE;
+ else
+ /* On the MicroBlaze, no user access
+ forces R/W kernel access */
+ f |= _PAGE_USER;
+ map_page(v, p, f);
+ v += PAGE_SIZE;
+ p += PAGE_SIZE;
+ }
+}
+
+/* is x a power of 2? */
+#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0))
+
+/*
+ * Set up a mapping for a block of I/O.
+ * virt, phys, size must all be page-aligned.
+ * This should only be called before ioremap is called.
+ */
+void __init io_block_mapping(unsigned long virt, phys_addr_t phys,
+ unsigned int size, int flags)
+{
+ int i;
+
+ if (virt > CONFIG_KERNEL_START && virt < ioremap_bot)
+ ioremap_bot = ioremap_base = virt;
+
+ /* Put it in the page tables. */
+ for (i = 0; i < size; i += PAGE_SIZE)
+ map_page(virt + i, phys + i, flags);
+}
+
+/* Scan the real Linux page tables and return a PTE pointer for
+ * a virtual address in a context.
+ * Returns true (1) if PTE was found, zero otherwise. The pointer to
+ * the PTE pointer is unmodified if PTE is not found.
+ */
+static int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep)
+{
+ pgd_t *pgd;
+ pmd_t *pmd;
+ pte_t *pte;
+ int retval = 0;
+
+ pgd = pgd_offset(mm, addr & PAGE_MASK);
+ if (pgd) {
+ pmd = pmd_offset(pgd, addr & PAGE_MASK);
+ if (pmd_present(*pmd)) {
+ pte = pte_offset_kernel(pmd, addr & PAGE_MASK);
+ if (pte) {
+ retval = 1;
+ *ptep = pte;
+ }
+ }
+ }
+ return retval;
+}
+
+/* Find physical address for this virtual address. Normally used by
+ * I/O functions, but anyone can call it.
+ */
+unsigned long iopa(unsigned long addr)
+{
+ unsigned long pa;
+
+ pte_t *pte;
+ struct mm_struct *mm;
+
+ /* Allow mapping of user addresses (within the thread)
+ * for DMA if necessary.
+ */
+ if (addr < TASK_SIZE)
+ mm = current->mm;
+ else
+ mm = &init_mm;
+
+ pa = 0;
+ if (get_pteptr(mm, addr, &pte))
+ pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);
+
+ return pa;
+}