x86: early_ioremap(), debugging

add early_ioremap() debug printouts via the early_ioremap_debug
boot option.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 29 insertions, 0 deletions

diff --git a/arch/x86/mm/ioremap_32.c b/arch/x86/mm/ioremap_32.c
index 4bcd5e065df4..30855c44818d 100644
--- a/arch/x86/mm/ioremap_32.c
+++ b/arch/x86/mm/ioremap_32.c
@@ -208,6 +208,17 @@ void iounmap(volatile void __iomem *addr)
 }
 EXPORT_SYMBOL(iounmap);
 
+
+int __initdata early_ioremap_debug;
+
+static int __init early_ioremap_debug_setup(char *str)
+{
+        early_ioremap_debug = 1;
+
+        return 1;
+}
+__setup("early_ioremap_debug", early_ioremap_debug_setup);
+
 static __initdata int after_paging_init;
 static __initdata unsigned long bm_pte[1024]
                                 __attribute__((aligned(PAGE_SIZE)));
@@ -226,6 +237,9 @@ void __init early_ioremap_init(void)
 {
         unsigned long *pgd;
 
+        if (early_ioremap_debug)
+                printk("early_ioremap_init()\n");
+
         pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
         *pgd = __pa(bm_pte) | _PAGE_TABLE;
         memset(bm_pte, 0, sizeof(bm_pte));
@@ -236,6 +250,9 @@ void __init early_ioremap_clear(void)
 {
         unsigned long *pgd;
 
+        if (early_ioremap_debug)
+                printk("early_ioremap_clear()\n");
+
         pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
         *pgd = 0;
         __flush_tlb_all();
@@ -303,6 +320,11 @@ void __init *early_ioremap(unsigned long phys_addr, unsigned long size)
         WARN_ON(system_state != SYSTEM_BOOTING);
 
         nesting = early_ioremap_nested;
+        if (early_ioremap_debug) {
+                printk("early_ioremap(%08lx, %08lx) [%d] => ",
+                                phys_addr, size, nesting);
+                dump_stack();
+        }
 
         /* Don't allow wraparound or zero size */
         last_addr = phys_addr + size - 1;
@@ -343,6 +365,8 @@ void __init *early_ioremap(unsigned long phys_addr, unsigned long size)
                 --idx;
                 --nrpages;
         }
+        if (early_ioremap_debug)
+                printk(KERN_CONT "%08lx + %08lx\n", offset, fix_to_virt(idx0));
 
         return (void*) (offset + fix_to_virt(idx0));
 }
@@ -358,6 +382,11 @@ void __init early_iounmap(void *addr, unsigned long size)
         nesting = --early_ioremap_nested;
         WARN_ON(nesting < 0);
 
+        if (early_ioremap_debug) {
+                printk("early_iounmap(%p, %08lx) [%d]\n", addr, size, nesting);
+                dump_stack();
+        }
+
         virt_addr = (unsigned long)addr;
         if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) {
                 WARN_ON(1);