x86: change early_ioremap to use slots instead of nesting

so we could remove the requirement that one needs to call
early_iounmap() in exactly reverse order of early_ioremap().

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 8876220d906b89bec29f8fff5d873a6d47550cb7..e4c43ec71b29ebeb40a40b63cd7f4394fb448b0a 100644 (file)
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -616,16 +616,22 @@ static inline void __init early_clear_fixmap(enum fixed_addresses idx)
                __early_set_fixmap(idx, 0, __pgprot(0));
 }
 
-
-static int __initdata early_ioremap_nested;
-
+static void *prev_map[FIX_BTMAPS_SLOTS] __initdata;
+static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
 static int __init check_early_ioremap_leak(void)
 {
-       if (!early_ioremap_nested)
+       int count = 0;
+       int i;
+
+       for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
+               if (prev_map[i])
+                       count++;
+
+       if (!count)
                return 0;
        WARN(1, KERN_WARNING
               "Debug warning: early ioremap leak of %d areas detected.\n",
-               early_ioremap_nested);
+               count);
        printk(KERN_WARNING
                "please boot with early_ioremap_debug and report the dmesg.\n");
 
@@ -636,15 +642,30 @@ late_initcall(check_early_ioremap_leak);
 static void __init *__early_ioremap(unsigned long phys_addr, unsigned long size, pgprot_t prot)
 {
        unsigned long offset, last_addr;
-       unsigned int nrpages, nesting;
+       unsigned int nrpages;
        enum fixed_addresses idx0, idx;
+       int i, slot;
 
        WARN_ON(system_state != SYSTEM_BOOTING);
 
-       nesting = early_ioremap_nested;
+       slot = -1;
+       for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
+               if (!prev_map[i]) {
+                       slot = i;
+                       break;
+               }
+       }
+
+       if (slot < 0) {
+               printk(KERN_INFO "early_iomap(%08lx, %08lx) not found slot\n",
+                        phys_addr, size);
+               WARN_ON(1);
+               return NULL;
+       }
+
        if (early_ioremap_debug) {
                printk(KERN_INFO "early_ioremap(%08lx, %08lx) [%d] => ",
-                      phys_addr, size, nesting);
+                      phys_addr, size, slot);
                dump_stack();
        }
 
@@ -655,11 +676,7 @@ static void __init *__early_ioremap(unsigned long phys_addr, unsigned long size,
                return NULL;
        }
 
-       if (nesting >= FIX_BTMAPS_NESTING) {
-               WARN_ON(1);
-               return NULL;
-       }
-       early_ioremap_nested++;
+       prev_size[slot] = size;
        /*
         * Mappings have to be page-aligned
         */
@@ -679,7 +696,7 @@ static void __init *__early_ioremap(unsigned long phys_addr, unsigned long size,
        /*
         * Ok, go for it..
         */
-       idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
+       idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
        idx = idx0;
        while (nrpages > 0) {
                early_set_fixmap(idx, phys_addr, prot);
@@ -690,7 +707,8 @@ static void __init *__early_ioremap(unsigned long phys_addr, unsigned long size,
        if (early_ioremap_debug)
                printk(KERN_CONT "%08lx + %08lx\n", offset, fix_to_virt(idx0));
 
-       return (void *) (offset + fix_to_virt(idx0));
+       prev_map[slot] = (void *) (offset + fix_to_virt(idx0));
+       return prev_map[slot];
 }
 
 /* Remap an IO device */
@@ -711,15 +729,33 @@ void __init early_iounmap(void *addr, unsigned long size)
        unsigned long offset;
        unsigned int nrpages;
        enum fixed_addresses idx;
-       int nesting;
+       int i, slot;
+
+       slot = -1;
+       for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
+               if (prev_map[i] == addr) {
+                       slot = i;
+                       break;
+               }
+       }
 
-       nesting = --early_ioremap_nested;
-       if (WARN_ON(nesting < 0))
+       if (slot < 0) {
+               printk(KERN_INFO "early_iounmap(%p, %08lx) not found slot\n",
+                        addr, size);
+               WARN_ON(1);
+               return;
+       }
+
+       if (prev_size[slot] != size) {
+               printk(KERN_INFO "early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n",
+                        addr, size, slot, prev_size[slot]);
+               WARN_ON(1);
                return;
+       }
 
        if (early_ioremap_debug) {
                printk(KERN_INFO "early_iounmap(%p, %08lx) [%d]\n", addr,
-                      size, nesting);
+                      size, slot);
                dump_stack();
        }
 
@@ -731,12 +767,13 @@ void __init early_iounmap(void *addr, unsigned long size)
        offset = virt_addr & ~PAGE_MASK;
        nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
 
-       idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
+       idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
        while (nrpages > 0) {
                early_clear_fixmap(idx);
                --idx;
                --nrpages;
        }
+       prev_map[slot] = 0;
 }
 
 void __this_fixmap_does_not_exist(void)

diff --git a/include/asm-x86/fixmap_32.h b/include/asm-x86/fixmap_32.h
index 784e3e759866cc0025b4dd4e9af77aeedddcdd1d..8844002da0e05df5e421846603c9b8a017bdd0a6 100644 (file)
--- a/include/asm-x86/fixmap_32.h
+++ b/include/asm-x86/fixmap_32.h
@@ -94,10 +94,10 @@ enum fixed_addresses {
         * can have a single pgd entry and a single pte table:
         */
 #define NR_FIX_BTMAPS          64
-#define FIX_BTMAPS_NESTING     4
+#define FIX_BTMAPS_SLOTS       4
        FIX_BTMAP_END = __end_of_permanent_fixed_addresses + 256 -
                        (__end_of_permanent_fixed_addresses & 255),
-       FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS*FIX_BTMAPS_NESTING - 1,
+       FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS*FIX_BTMAPS_SLOTS - 1,
        FIX_WP_TEST,
 #ifdef CONFIG_ACPI
        FIX_ACPI_BEGIN,

diff --git a/include/asm-x86/fixmap_64.h b/include/asm-x86/fixmap_64.h
index 33df64fd0e187c3e8441cf296f1548abab308955..dab4751d13070491e66038af1264db9880eda7a2 100644 (file)
--- a/include/asm-x86/fixmap_64.h
+++ b/include/asm-x86/fixmap_64.h
@@ -65,10 +65,10 @@ enum fixed_addresses {
         * can have a single pgd entry and a single pte table:
         */
 #define NR_FIX_BTMAPS          64
-#define FIX_BTMAPS_NESTING     4
+#define FIX_BTMAPS_SLOTS       4
        FIX_BTMAP_END = __end_of_permanent_fixed_addresses + 256 -
                        (__end_of_permanent_fixed_addresses & 255),
-       FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS*FIX_BTMAPS_NESTING - 1,
+       FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS*FIX_BTMAPS_SLOTS - 1,
        __end_of_fixed_addresses
 };