Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 109 insertions, 0 deletions

diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
new file mode 100644
index 000000000000..32c4b0e35b37
--- /dev/null
+++ b/arch/arm/mm/mmap.c
@@ -0,0 +1,109 @@
+/*
+ *  linux/arch/arm/mm/mmap.c
+ */
+#include <linux/config.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/shm.h>
+
+#include <asm/system.h>
+
+#define COLOUR_ALIGN(addr,pgoff)                \
+        ((((addr)+SHMLBA-1)&~(SHMLBA-1)) +      \
+         (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
+
+/*
+ * We need to ensure that shared mappings are correctly aligned to
+ * avoid aliasing issues with VIPT caches.  We need to ensure that
+ * a specific page of an object is always mapped at a multiple of
+ * SHMLBA bytes.
+ *
+ * We unconditionally provide this function for all cases, however
+ * in the VIVT case, we optimise out the alignment rules.
+ */
+unsigned long
+arch_get_unmapped_area(struct file *filp, unsigned long addr,
+                unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+        struct mm_struct *mm = current->mm;
+        struct vm_area_struct *vma;
+        unsigned long start_addr;
+#ifdef CONFIG_CPU_V6
+        unsigned int cache_type;
+        int do_align = 0, aliasing = 0;
+
+        /*
+         * We only need to do colour alignment if either the I or D
+         * caches alias.  This is indicated by bits 9 and 21 of the
+         * cache type register.
+         */
+        cache_type = read_cpuid(CPUID_CACHETYPE);
+        if (cache_type != read_cpuid(CPUID_ID)) {
+                aliasing = (cache_type | cache_type >> 12) & (1 << 11);
+                if (aliasing)
+                        do_align = filp || flags & MAP_SHARED;
+        }
+#else
+#define do_align 0
+#define aliasing 0
+#endif
+
+        /*
+         * We should enforce the MAP_FIXED case.  However, currently
+         * the generic kernel code doesn't allow us to handle this.
+         */
+        if (flags & MAP_FIXED) {
+                if (aliasing && flags & MAP_SHARED && addr & (SHMLBA - 1))
+                        return -EINVAL;
+                return addr;
+        }
+
+        if (len > TASK_SIZE)
+                return -ENOMEM;
+
+        if (addr) {
+                if (do_align)
+                        addr = COLOUR_ALIGN(addr, pgoff);
+                else
+                        addr = PAGE_ALIGN(addr);
+
+                vma = find_vma(mm, addr);
+                if (TASK_SIZE - len >= addr &&
+                    (!vma || addr + len <= vma->vm_start))
+                        return addr;
+        }
+        start_addr = addr = mm->free_area_cache;
+
+full_search:
+        if (do_align)
+                addr = COLOUR_ALIGN(addr, pgoff);
+        else
+                addr = PAGE_ALIGN(addr);
+
+        for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
+                /* At this point:  (!vma || addr < vma->vm_end). */
+                if (TASK_SIZE - len < addr) {
+                        /*
+                         * Start a new search - just in case we missed
+                         * some holes.
+                         */
+                        if (start_addr != TASK_UNMAPPED_BASE) {
+                                start_addr = addr = TASK_UNMAPPED_BASE;
+                                goto full_search;
+                        }
+                        return -ENOMEM;
+                }
+                if (!vma || addr + len <= vma->vm_start) {
+                        /*
+                         * Remember the place where we stopped the search:
+                         */
+                        mm->free_area_cache = addr + len;
+                        return addr;
+                }
+                addr = vma->vm_end;
+                if (do_align)
+                        addr = COLOUR_ALIGN(addr, pgoff);
+        }
+}
+