[RFC PATCH 1/2] powerpc/mm/hash64: Add a variable to track the end of IO mapping

["Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>]

NOT-Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/hash.h    | 1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h | 8 +++++---
 arch/powerpc/include/asm/book3s/64/radix.h   | 1 +
 arch/powerpc/mm/hash_utils_64.c              | 1 +
 arch/powerpc/mm/pgtable-radix.c              | 1 +
 arch/powerpc/mm/pgtable_64.c                 | 2 ++
 6 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index 247aff9cc6ba..94f9db7a746a 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -56,6 +56,7 @@
 #define H_VMALLOC_END	(H_VMALLOC_START + H_VMALLOC_SIZE)
 
 #define H_KERN_IO_START	H_VMALLOC_END
+#define H_KERN_IO_END	(H_KERN_VIRT_START + H_KER_VIRT_SIZE)
 
 /*
  * Region IDs
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 544e54b3046d..dc71e2b92003 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -277,9 +277,12 @@ extern unsigned long __vmalloc_end;
 extern unsigned long __kernel_virt_start;
 extern unsigned long __kernel_virt_size;
 extern unsigned long __kernel_io_start;
+extern unsigned long __kernel_io_end;
 #define KERN_VIRT_START __kernel_virt_start
 #define KERN_VIRT_SIZE  __kernel_virt_size
 #define KERN_IO_START  __kernel_io_start
+#define KERN_IO_END __kernel_io_end
+
 extern struct page *vmemmap;
 extern unsigned long ioremap_bot;
 extern unsigned long pci_io_base;
@@ -296,8 +299,7 @@ extern unsigned long pci_io_base;
 
 #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
+ * IO space itself carved into the PIO region (ISA and PHB IO space) and
  * the ioremap space
  *
  *  ISA_IO_BASE = KERN_IO_START, 64K reserved area
@@ -310,7 +312,7 @@ extern unsigned long pci_io_base;
 #define  PHB_IO_BASE	(ISA_IO_END)
 #define  PHB_IO_END	(KERN_IO_START + FULL_IO_SIZE)
 #define IOREMAP_BASE	(PHB_IO_END)
-#define IOREMAP_END	(KERN_VIRT_START + KERN_VIRT_SIZE)
+#define IOREMAP_END	(KERN_IO_END)
 
 /* 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 7d1a3d1543fc..0718c16b4e8d 100644
--- a/arch/powerpc/include/asm/book3s/64/radix.h
+++ b/arch/powerpc/include/asm/book3s/64/radix.h
@@ -111,6 +111,7 @@
 #define RADIX_VMEMMAP_BASE		(RADIX_VMALLOC_END)
 
 #define RADIX_KERN_IO_START	(RADIX_KERN_VIRT_START + (RADIX_KERN_VIRT_SIZE >> 1))
+#define RADIX_KERN_IO_END       (RADIX_KERN_VIRT_START + RADIX_KERN_VIRT_SIZE)
 
 #ifndef __ASSEMBLY__
 #define RADIX_PTE_TABLE_SIZE	(sizeof(pte_t) << RADIX_PTE_INDEX_SIZE)
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 4aa0797000f7..bbd87748f3f7 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1010,6 +1010,7 @@ void __init hash__early_init_mmu(void)
 	__vmalloc_start = H_VMALLOC_START;
 	__vmalloc_end = H_VMALLOC_END;
 	__kernel_io_start = H_KERN_IO_START;
+	__kernel_io_end = H_KERN_IO_END;
 	vmemmap = (struct page *)H_VMEMMAP_BASE;
 	ioremap_bot = IOREMAP_BASE;
 
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 931156069a81..c288abfc09e1 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -582,6 +582,7 @@ void __init radix__early_init_mmu(void)
 	__vmalloc_start = RADIX_VMALLOC_START;
 	__vmalloc_end = RADIX_VMALLOC_END;
 	__kernel_io_start = RADIX_KERN_IO_START;
+	__kernel_io_end = RADIX_KERN_IO_END;
 	vmemmap = (struct page *)RADIX_VMEMMAP_BASE;
 	ioremap_bot = IOREMAP_BASE;
 
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index fb1375c07e8c..7cea39bdf05f 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -98,6 +98,8 @@ unsigned long __vmalloc_end;
 EXPORT_SYMBOL(__vmalloc_end);
 unsigned long __kernel_io_start;
 EXPORT_SYMBOL(__kernel_io_start);
+unsigned long __kernel_io_end;
+EXPORT_SYMBOL(__kernel_io_end);
 struct page *vmemmap;
 EXPORT_SYMBOL(vmemmap);
 unsigned long __pte_frag_nr;
-- 
2.20.1