i386: handle an initrd in highmem (version 2)
The boot protocol has until now required that the initrd be located in
lowmem, which makes the lowmem/highmem boundary visible to the boot
loader. This was exported to the bootloader via a compile-time
field. Unfortunately, the vmalloc= command-line option breaks this
part of the protocol; instead of adding yet another hack that affects
the bootloader, have the kernel relocate the initrd down below the
lowmem boundary inside the kernel itself.
Note that this does not rely on HIGHMEM being enabled in the kernel.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c
index 3bce4af..6802a38 100644
--- a/arch/x86/kernel/setup_32.c
+++ b/arch/x86/kernel/setup_32.c
@@ -188,9 +188,9 @@
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 @@
* 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 @@
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 @@
{}
#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 @@
*/
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 @@
* 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();