powerpc: Minor cleanups of kernel virt address space definitions
Make FIXADDR_TOP a compile time constant and cleanup a
couple of definitions relative to the layout of the kernel
address space on ppc32. We also print out that layout at
boot time for debugging purposes.
This is a pre-requisite for properly fixing non-coherent
DMA allocactions.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h
index d60fd18..f1f4e23 100644
--- a/arch/powerpc/include/asm/fixmap.h
+++ b/arch/powerpc/include/asm/fixmap.h
@@ -14,8 +14,6 @@
#ifndef _ASM_FIXMAP_H
#define _ASM_FIXMAP_H
-extern unsigned long FIXADDR_TOP;
-
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
#include <asm/page.h>
@@ -24,6 +22,8 @@
#include <asm/kmap_types.h>
#endif
+#define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE))
+
/*
* Here we define all the compile-time 'special' virtual
* addresses. The point is to have a constant address at
diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h
index ba45c99..28fe9d4 100644
--- a/arch/powerpc/include/asm/pgtable-ppc32.h
+++ b/arch/powerpc/include/asm/pgtable-ppc32.h
@@ -10,7 +10,7 @@
extern unsigned long va_to_phys(unsigned long address);
extern pte_t *va_to_pte(unsigned long address);
-extern unsigned long ioremap_bot, ioremap_base;
+extern unsigned long ioremap_bot;
#ifdef CONFIG_44x
extern int icache_44x_need_flush;
@@ -56,8 +56,26 @@
printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
/*
+ * This is the bottom of the PKMAP area with HIGHMEM or an arbitrary
+ * value (for now) on others, from where we can start layout kernel
+ * virtual space that goes below PKMAP and FIXMAP
+ */
+#ifdef CONFIG_HIGHMEM
+#define KVIRT_TOP PKMAP_BASE
+#else
+#define KVIRT_TOP (0xfe000000UL) /* for now, could be FIXMAP_BASE ? */
+#endif
+
+/*
+ * ioremap_bot starts at that address. Early ioremaps move down from there,
+ * until mem_init() at which point this becomes the top of the vmalloc
+ * and ioremap space
+ */
+#define IOREMAP_TOP KVIRT_TOP
+
+/*
* Just any arbitrary offset to the start of the vmalloc VM area: the
- * current 64MB value just means that there will be a 64MB "hole" after the
+ * current 16MB value just means that there will be a 64MB "hole" after the
* physical memory until the kernel virtual memory starts. That means that
* any out-of-bounds memory accesses will hopefully be caught.
* The vmalloc() routines leaves a hole of 4kB between each vmalloced
diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
index 666a5e8..3de6a0d9 100644
--- a/arch/powerpc/mm/init_32.c
+++ b/arch/powerpc/mm/init_32.c
@@ -168,12 +168,8 @@
ppc_md.progress("MMU:mapin", 0x301);
mapin_ram();
-#ifdef CONFIG_HIGHMEM
- ioremap_base = PKMAP_BASE;
-#else
- ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */
-#endif /* CONFIG_HIGHMEM */
- ioremap_bot = ioremap_base;
+ /* Initialize early top-down ioremap allocator */
+ ioremap_bot = IOREMAP_TOP;
/* Map in I/O resources */
if (ppc_md.progress)
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index d0602a7..d3a4e67 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -380,6 +380,19 @@
bsssize >> 10,
initsize >> 10);
+#ifdef CONFIG_PPC32
+ pr_info("Kernel virtual memory layout:\n");
+ pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
+#ifdef CONFIG_HIGHMEM
+ pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
+ PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
+#endif /* CONFIG_HIGHMEM */
+ pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
+ ioremap_bot, IOREMAP_TOP);
+ pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
+ VMALLOC_START, VMALLOC_END);
+#endif /* CONFIG_PPC32 */
+
mem_init_done = 1;
}
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index 430d090..5422169 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -399,8 +399,6 @@
#endif /* CONFIG_DEBUG_PAGEALLOC */
static int fixmaps;
-unsigned long FIXADDR_TOP = (-PAGE_SIZE);
-EXPORT_SYMBOL(FIXADDR_TOP);
void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
{
