powerpc/mm: vmalloc abstraction in preparation for radix

The vmalloc range differs between hash and radix config. Hence make
VMALLOC_START and related constants a variable which will be runtime
initialized depending on whether hash or radix mode is active.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Fix missing init of ioremap_bot in pgtable_64.c for ppc64e]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

3 files changed, 87 insertions, 10 deletions

diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index cd3e915..f61cad3 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -45,17 +45,17 @@
 /*
  * Define the address range of the kernel non-linear virtual area
  */
-#define KERN_VIRT_START ASM_CONST(0xD000000000000000)
-#define KERN_VIRT_SIZE	ASM_CONST(0x0000100000000000)
+#define H_KERN_VIRT_START ASM_CONST(0xD000000000000000)
+#define H_KERN_VIRT_SIZE	ASM_CONST(0x0000100000000000)
 
 /*
  * The vmalloc space starts at the beginning of that region, and
  * occupies half of it on hash CPUs and a quarter of it on Book3E
  * (we keep a quarter for the virtual memmap)
  */
-#define VMALLOC_START	KERN_VIRT_START
-#define VMALLOC_SIZE	(KERN_VIRT_SIZE >> 1)
-#define VMALLOC_END	(VMALLOC_START + VMALLOC_SIZE)
+#define H_VMALLOC_START	H_KERN_VIRT_START
+#define H_VMALLOC_SIZE	(H_KERN_VIRT_SIZE >> 1)
+#define H_VMALLOC_END	(H_VMALLOC_START + H_VMALLOC_SIZE)
 
 /*
  * Region IDs
@@ -64,7 +64,7 @@
 #define REGION_MASK		(0xfUL << REGION_SHIFT)
 #define REGION_ID(ea)		(((unsigned long)(ea)) >> REGION_SHIFT)
 
-#define VMALLOC_REGION_ID	(REGION_ID(VMALLOC_START))
+#define VMALLOC_REGION_ID	(REGION_ID(H_VMALLOC_START))
 #define KERNEL_REGION_ID	(REGION_ID(PAGE_OFFSET))
 #define VMEMMAP_REGION_ID	(0xfUL)	/* Server only */
 #define USER_REGION_ID		(0UL)
@@ -73,7 +73,7 @@
  * Defines the address of the vmemap area, in its own region on
  * hash table CPUs.
  */
-#define VMEMMAP_BASE		(VMEMMAP_REGION_ID << REGION_SHIFT)
+#define H_VMEMMAP_BASE		(VMEMMAP_REGION_ID << REGION_SHIFT)
 
 #ifdef CONFIG_PPC_MM_SLICES
 #define HAVE_ARCH_UNMAPPED_AREA
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 32a9756..f5628f9 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -208,6 +208,18 @@ extern unsigned long __pgd_val_bits;
 #define PUD_MASKED_BITS		0xc0000000000000ffUL
 /* Bits to mask out from a PGD to get to the PUD page */
 #define PGD_MASKED_BITS		0xc0000000000000ffUL
+
+extern unsigned long __vmalloc_start;
+extern unsigned long __vmalloc_end;
+#define VMALLOC_START	__vmalloc_start
+#define VMALLOC_END	__vmalloc_end
+
+extern unsigned long __kernel_virt_start;
+extern unsigned long __kernel_virt_size;
+#define KERN_VIRT_START __kernel_virt_start
+#define KERN_VIRT_SIZE  __kernel_virt_size
+extern struct page *vmemmap;
+extern unsigned long ioremap_bot;
 #endif /* __ASSEMBLY__ */
 
 #include <asm/book3s/64/hash.h>
@@ -220,7 +232,6 @@ extern unsigned long __pgd_val_bits;
 #endif
 
 #include <asm/barrier.h>
-
 /*
  * The second half of the kernel virtual space is used for IO mappings,
  * it's itself carved into the PIO region (ISA and PHB IO space) and
@@ -239,8 +250,6 @@ extern unsigned long __pgd_val_bits;
 #define IOREMAP_BASE	(PHB_IO_END)
 #define IOREMAP_END	(KERN_VIRT_START + KERN_VIRT_SIZE)
 
-#define vmemmap			((struct page *)VMEMMAP_BASE)
-
 /* Advertise special mapping type for AGP */
 #define HAVE_PAGE_AGP
 
diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h
index 63eb629..f470902 100644
--- a/arch/powerpc/include/asm/book3s/64/radix.h
+++ b/arch/powerpc/include/asm/book3s/64/radix.h
@@ -31,6 +31,74 @@
 			      RADIX_PUD_INDEX_SIZE + RADIX_PGD_INDEX_SIZE + PAGE_SHIFT)
 #define RADIX_PGTABLE_RANGE (ASM_CONST(1) << RADIX_PGTABLE_EADDR_SIZE)
 
+/*
+ * We support 52 bit address space, Use top bit for kernel
+ * virtual mapping. Also make sure kernel fit in the top
+ * quadrant.
+ *
+ *           +------------------+
+ *           +------------------+  Kernel virtual map (0xc008000000000000)
+ *           |                  |
+ *           |                  |
+ *           |                  |
+ * 0b11......+------------------+  Kernel linear map (0xc....)
+ *           |                  |
+ *           |     2 quadrant   |
+ *           |                  |
+ * 0b10......+------------------+
+ *           |                  |
+ *           |    1 quadrant    |
+ *           |                  |
+ * 0b01......+------------------+
+ *           |                  |
+ *           |    0 quadrant    |
+ *           |                  |
+ * 0b00......+------------------+
+ *
+ *
+ * 3rd quadrant expanded:
+ * +------------------------------+
+ * |                              |
+ * |                              |
+ * |                              |
+ * +------------------------------+  Kernel IO map end (0xc010000000000000)
+ * |                              |
+ * |                              |
+ * |      1/2 of virtual map      |
+ * |                              |
+ * |                              |
+ * +------------------------------+  Kernel IO map start
+ * |                              |
+ * |      1/4 of virtual map      |
+ * |                              |
+ * +------------------------------+  Kernel vmemap start
+ * |                              |
+ * |     1/4 of virtual map       |
+ * |                              |
+ * +------------------------------+  Kernel virt start (0xc008000000000000)
+ * |                              |
+ * |                              |
+ * |                              |
+ * +------------------------------+  Kernel linear (0xc.....)
+ */
+
+#define RADIX_KERN_VIRT_START ASM_CONST(0xc008000000000000)
+#define RADIX_KERN_VIRT_SIZE  ASM_CONST(0x0008000000000000)
+
+/*
+ * The vmalloc space starts at the beginning of that region, and
+ * occupies a quarter of it on radix config.
+ * (we keep a quarter for the virtual memmap)
+ */
+#define RADIX_VMALLOC_START	RADIX_KERN_VIRT_START
+#define RADIX_VMALLOC_SIZE	(RADIX_KERN_VIRT_SIZE >> 2)
+#define RADIX_VMALLOC_END	(RADIX_VMALLOC_START + RADIX_VMALLOC_SIZE)
+/*
+ * Defines the address of the vmemap area, in its own region on
+ * hash table CPUs.
+ */
+#define RADIX_VMEMMAP_BASE		(RADIX_VMALLOC_END)
+
 #ifndef __ASSEMBLY__
 #define RADIX_PTE_TABLE_SIZE	(sizeof(pte_t) << RADIX_PTE_INDEX_SIZE)
 #define RADIX_PMD_TABLE_SIZE	(sizeof(pmd_t) << RADIX_PMD_INDEX_SIZE)