microblaze_mmu_v2: Page table - ioremap - pgtable.c/h, section update

Signed-off-by: Michal Simek <monstr@monstr.eu>

1 files changed, 286 insertions, 0 deletions

diff --git a/arch/microblaze/mm/pgtable.c b/arch/microblaze/mm/pgtable.c
new file mode 100644
index 000000000000..46c4ca5d15c5
--- /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;
+}