x86: mm: Re-use the early_ioremap fixed area
The temp fixed area is only used during boot for early_ioremap(), and
it is unused when ioremap() is functional. vmalloc/pkmap area become
available after early boot so the temp fixed area is available for
re-use.
The virtual address is more precious on i386, especially turning on
high memory. So we can re-use the virtual address space.
Remove the now unused defines FIXADDR_BOOT_START and FIXADDR_BOOT_SIZE.
Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Cc: pbonzini@redhat.com
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/1414582717-32729-1-git-send-email-mnfhuang@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/include/asm/highmem.h b/arch/x86/include/asm/highmem.h
index 302a323..04e9d02 100644
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -38,17 +38,20 @@
/*
* Ordering is:
*
- * FIXADDR_TOP
- * fixed_addresses
- * FIXADDR_START
- * temp fixed addresses
- * FIXADDR_BOOT_START
- * Persistent kmap area
- * PKMAP_BASE
- * VMALLOC_END
- * Vmalloc area
- * VMALLOC_START
- * high_memory
+ * high memory on: high_memory off:
+ * FIXADDR_TOP FIXADDR_TOP
+ * fixed addresses fixed addresses
+ * FIXADDR_START FIXADDR_START
+ * temp fixed addresses/persistent kmap area VMALLOC_END
+ * PKMAP_BASE temp fixed addresses/vmalloc area
+ * VMALLOC_END VMALLOC_START
+ * vmalloc area high_memory
+ * VMALLOC_START
+ * high_memory
+ *
+ * The temp fixed area is only used during boot for early_ioremap(), and
+ * it is unused when the ioremap() is functional. vmalloc/pkmap area become
+ * available after early boot so the temp fixed area is available for re-use.
*/
#define LAST_PKMAP_MASK (LAST_PKMAP-1)
#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)