[PATCH 6/7] setup.c: clean up initrd related code

[Franck Bui-Huu <vagabon.xyz@gmail.com>]

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
---
 arch/mips/kernel/setup.c |   75 +++++++++++++++++++++++++++++-----------------
 arch/mips/mm/init.c      |    5 ---
 2 files changed, 48 insertions(+), 32 deletions(-)

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index b52cc97..89440a0 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -145,13 +145,12 @@ static int __init rd_start_early(char *p
        unsigned long start = memparse(p, &p);
 
 #ifdef CONFIG_64BIT
-       /* HACK: Guess if the sign extension was forgotten */
-       if (start > 0x0000000080000000 && start < 0x00000000ffffffff)
-               start |= 0xffffffff00000000UL;
+       /* Guess if the sign extension was forgotten by bootloader */
+       if (start < XKPHYS)
+               start = (int)start;
 #endif
        initrd_start = start;
        initrd_end += start;
-
        return 0;
 }
 early_param("rd_start", rd_start_early);
@@ -159,41 +158,64 @@ early_param("rd_start", rd_start_early);
 static int __init rd_size_early(char *p)
 {
        initrd_end += memparse(p, &p);
-
        return 0;
 }
 early_param("rd_size", rd_size_early);
 
+/* it returns the next free pfn after initrd */
 static unsigned long __init init_initrd(void)
 {
-       unsigned long tmp, end, size;
+       unsigned long end;
        u32 *initrd_header;
 
-       ROOT_DEV = Root_RAM0;
-
        /*
         * Board specific code or command line parser should have
         * already set up initrd_start and initrd_end. In these cases
         * perfom sanity checks and use them if all looks good.
         */
-       size = initrd_end - initrd_start;
-       if (initrd_end == 0 || size == 0) {
-               initrd_start = 0;
-               initrd_end = 0;
-       } else
-               return initrd_end;
-
-       end = (unsigned long)&_end;
-       tmp = PAGE_ALIGN(end) - sizeof(u32) * 2;
-       if (tmp < end)
-               tmp += PAGE_SIZE;
-
-       initrd_header = (u32 *)tmp;
-       if (initrd_header[0] == 0x494E5244) {
-               initrd_start = (unsigned long)&initrd_header[2];
-               initrd_end = initrd_start + initrd_header[1];
+       if (initrd_start && initrd_end > initrd_start)
+               goto sanitize;
+
+       /*
+        * See if initrd has been added to the kernel image by
+        * arch/mips/boot/addinitrd.c. In that case a header is
+        * prepended to initrd and is made up by 8 bytes. The fisrt
+        * word is a magic number and the second one is the size of
+        * initrd.  Initrd start must be page aligned in any cases.
+        */
+       initrd_header = __va(PAGE_ALIGN(__pa_symbol(&_end) + 8)) - 8;
+       if (initrd_header[0] != 0x494E5244)
+               goto disable;
+       initrd_start = (unsigned long)(initrd_header + 2);
+       initrd_end = initrd_start + initrd_header[1];
+
+sanitize:
+       if (initrd_start & ~PAGE_MASK) {
+               printk(KERN_ERR "initrd start must be page aligned\n");
+               goto disable;
        }
-       return initrd_end;
+       if (initrd_start < PAGE_OFFSET) {
+               printk(KERN_ERR "initrd start < PAGE_OFFSET\n");
+               goto disable;
+       }
+
+       /*
+        * Sanitize initrd addresses. For example firmware
+        * can't guess if they need to pass them through
+        * 64-bits values if the kernel has been built in pure
+        * 32-bit. We need also to switch from KSEG0 to XKPHYS
+        * addresses now, so the code can now safely use __pa().
+        */
+       end = __pa(initrd_end);
+       initrd_end = (unsigned long)__va(end);
+       initrd_start = (unsigned long)__va(__pa(initrd_start));
+
+       ROOT_DEV = Root_RAM0;
+       return PFN_UP(end);
+disable:
+       initrd_start = 0;
+       initrd_end = 0;
+       return 0;
 }
 
 static void __init finalize_initrd(void)
@@ -259,8 +281,7 @@ static void __init bootmem_init(void)
         * not selected. Once that done we can determine the low bound
         * of usable memory.
         */
-       reserved_end = init_initrd();
-       reserved_end = PFN_UP(max(__pa(reserved_end), __pa_symbol(&_end)));
+       reserved_end = max(init_initrd(), PFN_UP(__pa_symbol(&_end)));
 
        /*
         * Find the highest page frame number we have available.
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 4431ea0..072b3b0 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -502,11 +502,6 @@ void free_init_pages(char *what, unsigne
 #ifdef CONFIG_BLK_DEV_INITRD
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
-#ifdef CONFIG_64BIT
-       /* Switch from KSEG0 to XKPHYS addresses */
-       start = (unsigned long)phys_to_virt(CPHYSADDR(start));
-       end = (unsigned long)phys_to_virt(CPHYSADDR(end));
-#endif
        free_init_pages("initrd memory", start, end);
 }
 #endif
-- 
1.4.2.3