powerpc: Support for relocatable kdump kernel

[linux-2.6-omap-h63xx.git] / arch / powerpc / kernel / crash_dump.c

diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c
index e0debcca0bfadaf03dbc6f3c35a56f1ad4a3aee2..19671aca659137ca8a6f62ac80585d969203a6f9 100644 (file)
--- a/arch/powerpc/kernel/crash_dump.c
+++ b/arch/powerpc/kernel/crash_dump.c
@@ -27,6 +27,10 @@
 #define DBG(fmt...)
 #endif
 
+/* Stores the physical address of elf header of crash image. */
+unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
+
+#ifndef CONFIG_RELOCATABLE
 void __init reserve_kdump_trampoline(void)
 {
        lmb_reserve(0, KDUMP_RESERVE_LIMIT);
@@ -65,8 +69,13 @@ void __init setup_kdump_trampoline(void)
 
        DBG(" <- setup_kdump_trampoline()\n");
 }
+#endif /* CONFIG_RELOCATABLE */
 
-#ifdef CONFIG_PROC_VMCORE
+/*
+ * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
+ * is_kdump_kernel() to determine if we are booting after a panic. Hence
+ * ifdef it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE.
+ */
 static int __init parse_elfcorehdr(char *p)
 {
        if (p)
@@ -75,7 +84,6 @@ static int __init parse_elfcorehdr(char *p)
        return 1;
 }
 __setup("elfcorehdr=", parse_elfcorehdr);
-#endif
 
 static int __init parse_savemaxmem(char *p)
 {
@@ -86,6 +94,19 @@ static int __init parse_savemaxmem(char *p)
 }
 __setup("savemaxmem=", parse_savemaxmem);
 
+
+static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize,
+                               unsigned long offset, int userbuf)
+{
+       if (userbuf) {
+               if (copy_to_user((char __user *)buf, (vaddr + offset), csize))
+                       return -EFAULT;
+       } else
+               memcpy(buf, (vaddr + offset), csize);
+
+       return csize;
+}
+
 /**
  * copy_oldmem_page - copy one page from "oldmem"
  * @pfn: page frame number to be copied
@@ -107,16 +128,16 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
        if (!csize)
                return 0;
 
-       vaddr = __ioremap(pfn << PAGE_SHIFT, PAGE_SIZE, 0);
+       csize = min(csize, PAGE_SIZE);
 
-       if (userbuf) {
-               if (copy_to_user((char __user *)buf, (vaddr + offset), csize)) {
-                       iounmap(vaddr);
-                       return -EFAULT;
-               }
-       } else
-               memcpy(buf, (vaddr + offset), csize);
+       if (pfn < max_pfn) {
+               vaddr = __va(pfn << PAGE_SHIFT);
+               csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf);
+       } else {
+               vaddr = __ioremap(pfn << PAGE_SHIFT, PAGE_SIZE, 0);
+               csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf);
+               iounmap(vaddr);
+       }
 
-       iounmap(vaddr);
        return csize;
 }