3 files changed, 112 insertions, 27 deletions

diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 4cc5b0411db5..64ad9016585a 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -195,10 +195,13 @@ cmd_line_ptr:	.long	0		# (Header version 0x0202 or later)
                                         # can be located anywhere in
                                         # low memory 0x10000 or higher.
 
-ramdisk_max:    .long (-__PAGE_OFFSET-(512 << 20)-1) & 0x7fffffff
+ramdisk_max:    .long 0x7fffffff
                                         # (Header version 0x0203 or later)
                                         # The highest safe address for
                                         # the contents of an initrd
+                                        # The current kernel allows up to 4 GB,
+                                        # but leave it at 2 GB to avoid
+                                        # possible bootloader bugs.
 
 kernel_alignment:  .long CONFIG_PHYSICAL_ALIGN  #physical addr alignment
                                                 #required for protected mode
diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c
index 3bce4af60bb6..6802a383077d 100644
--- a/arch/x86/kernel/setup_32.c
+++ b/arch/x86/kernel/setup_32.c
@@ -188,9 +188,9 @@ extern int root_mountflags;
 
 unsigned long saved_videomode;
 
-#define RAMDISK_IMAGE_START_MASK        0x07FF
+#define RAMDISK_IMAGE_START_MASK        0x07FF
 #define RAMDISK_PROMPT_FLAG             0x8000
-#define RAMDISK_LOAD_FLAG               0x4000  
+#define RAMDISK_LOAD_FLAG               0x4000
 
 static char __initdata command_line[COMMAND_LINE_SIZE];
 
@@ -252,7 +252,7 @@ static int __init parse_mem(char *arg)
                  * trim the existing memory map.
                  */
                 unsigned long long mem_size;
- 
+
                 mem_size = memparse(arg, &arg);
                 limit_regions(mem_size);
                 user_defined_memmap = 1;
@@ -391,7 +391,7 @@ static void __init reserve_ebda_region(void)
         unsigned int addr;
         addr = get_bios_ebda();
         if (addr)
-                reserve_bootmem(addr, PAGE_SIZE);       
+                reserve_bootmem(addr, PAGE_SIZE);
 }
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
@@ -496,6 +496,100 @@ static inline void __init reserve_crashkernel(void)
 {}
 #endif
 
+#ifdef CONFIG_BLK_DEV_INITRD
+
+static bool do_relocate_initrd = false;
+
+static void __init reserve_initrd(void)
+{
+        unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
+        unsigned long ramdisk_size  = boot_params.hdr.ramdisk_size;
+        unsigned long ramdisk_end   = ramdisk_image + ramdisk_size;
+        unsigned long end_of_lowmem = max_low_pfn << PAGE_SHIFT;
+        unsigned long ramdisk_here;
+
+        initrd_start = 0;
+
+        if (!boot_params.hdr.type_of_loader ||
+            !ramdisk_image || !ramdisk_size)
+                return;         /* No initrd provided by bootloader */
+
+        if (ramdisk_end < ramdisk_image) {
+                printk(KERN_ERR "initrd wraps around end of memory, "
+                       "disabling initrd\n");
+                return;
+        }
+        if (ramdisk_size >= end_of_lowmem/2) {
+                printk(KERN_ERR "initrd too large to handle, "
+                       "disabling initrd\n");
+                return;
+        }
+        if (ramdisk_end <= end_of_lowmem) {
+                /* All in lowmem, easy case */
+                reserve_bootmem(ramdisk_image, ramdisk_size);
+                initrd_start = ramdisk_image + PAGE_OFFSET;
+                initrd_end = initrd_start+ramdisk_size;
+                return;
+        }
+
+        /* We need to move the initrd down into lowmem */
+        ramdisk_here = (end_of_lowmem - ramdisk_size) & PAGE_MASK;
+
+        /* Note: this includes all the lowmem currently occupied by
+           the initrd, we rely on that fact to keep the data intact. */
+        reserve_bootmem(ramdisk_here, ramdisk_size);
+        initrd_start = ramdisk_here + PAGE_OFFSET;
+        initrd_end   = initrd_start + ramdisk_size;
+
+        do_relocate_initrd = true;
+}
+
+#define MAX_MAP_CHUNK   (NR_FIX_BTMAPS << PAGE_SHIFT)
+
+static void __init relocate_initrd(void)
+{
+        unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
+        unsigned long ramdisk_size  = boot_params.hdr.ramdisk_size;
+        unsigned long end_of_lowmem = max_low_pfn << PAGE_SHIFT;
+        unsigned long ramdisk_here;
+        unsigned long slop, clen, mapaddr;
+        char *p, *q;
+
+        if (!do_relocate_initrd)
+                return;
+
+        ramdisk_here = initrd_start - PAGE_OFFSET;
+
+        q = (char *)initrd_start;
+
+        /* Copy any lowmem portion of the initrd */
+        if (ramdisk_image < end_of_lowmem) {
+                clen = end_of_lowmem - ramdisk_image;
+                p = (char *)__va(ramdisk_image);
+                memcpy(q, p, clen);
+                q += clen;
+                ramdisk_image += clen;
+                ramdisk_size  -= clen;
+        }
+
+        /* Copy the highmem portion of the initrd */
+        while (ramdisk_size) {
+                slop = ramdisk_image & ~PAGE_MASK;
+                clen = ramdisk_size;
+                if (clen > MAX_MAP_CHUNK-slop)
+                        clen = MAX_MAP_CHUNK-slop;
+                mapaddr = ramdisk_image & PAGE_MASK;
+                p = bt_ioremap(mapaddr, clen+slop);
+                memcpy(q, p+slop, clen);
+                bt_iounmap(p, clen+slop);
+                q += clen;
+                ramdisk_image += clen;
+                ramdisk_size  -= clen;
+        }
+}
+
+#endif /* CONFIG_BLK_DEV_INITRD */
+
 void __init setup_bootmem_allocator(void)
 {
         unsigned long bootmap_size;
@@ -551,26 +645,10 @@ void __init setup_bootmem_allocator(void)
          */
         find_smp_config();
 #endif
-        numa_kva_reserve();
 #ifdef CONFIG_BLK_DEV_INITRD
-        if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
-                unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
-                unsigned long ramdisk_size  = boot_params.hdr.ramdisk_size;
-                unsigned long ramdisk_end   = ramdisk_image + ramdisk_size;
-                unsigned long end_of_lowmem = max_low_pfn << PAGE_SHIFT;
-
-                if (ramdisk_end <= end_of_lowmem) {
-                        reserve_bootmem(ramdisk_image, ramdisk_size);
-                        initrd_start = ramdisk_image + PAGE_OFFSET;
-                        initrd_end = initrd_start+ramdisk_size;
-                } else {
-                        printk(KERN_ERR "initrd extends beyond end of memory "
-                               "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
-                               ramdisk_end, end_of_lowmem);
-                        initrd_start = 0;
-                }
-        }
+        reserve_initrd();
 #endif
+        numa_kva_reserve();
         reserve_crashkernel();
 }
 
@@ -713,15 +791,19 @@ void __init setup_arch(char **cmdline_p)
          * NOTE: at this point the bootmem allocator is fully available.
          */
 
+#ifdef CONFIG_BLK_DEV_INITRD
+        relocate_initrd();
+#endif
+
         paravirt_post_allocator_init();
 
         dmi_scan_machine();
 
-        io_delay_init();;
+        io_delay_init();
 
 #ifdef CONFIG_X86_GENERICARCH
         generic_apic_probe();
-#endif  
+#endif
         if (efi_enabled)
                 efi_map_memmap();
 
diff --git a/arch/x86/mm/discontig_32.c b/arch/x86/mm/discontig_32.c
index 13a474d3c6e9..88a7499e8e48 100644
--- a/arch/x86/mm/discontig_32.c
+++ b/arch/x86/mm/discontig_32.c
@@ -288,8 +288,8 @@ unsigned long __init setup_memory(void)
 
 #ifdef CONFIG_BLK_DEV_INITRD
         /* Numa kva area is below the initrd */
-        if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image)
-                kva_start_pfn = PFN_DOWN(boot_params.hdr.ramdisk_image)
+        if (initrd_start)
+                kva_start_pfn = PFN_DOWN(initrd_start - PAGE_OFFSET)
                         - kva_pages;
 #endif
         kva_start_pfn -= kva_start_pfn & (PTRS_PER_PTE-1);