[SRU][Artful][PATCH 1/3] powerpc/mm/book3s64: Make KERN_IO_START a variable

Joseph Salisbury joseph.salisbury at canonical.com
Fri Feb 16 15:37:24 UTC 2018


From: Michael Ellerman <mpe at ellerman.id.au>

BugLink: http://bugs.launchpad.net/bugs/1739498

Currently KERN_IO_START is defined as:

 #define KERN_IO_START  (KERN_VIRT_START + (KERN_VIRT_SIZE >> 1))

Although it looks like a constant, both the components are actually
variables, to allow us to have a different value between Radix and
Hash with a single kernel.

However that still requires both Radix and Hash to place the kernel IO
region at the same location relative to the start and end of the
kernel virtual region (namely 1/2 way through it), and we'd like to
change that.

So split KERN_IO_START out into its own variable, and initialise it
for Radix and Hash. In the medium term we should be able to
reconsolidate this, by doing a more involved rearrangement of the
location of the regions.

Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora at gmail.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
(cherry picked from commit 63ee9b2ff9d306efaa61b04b8710fafe339ae441)
Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
---
 arch/powerpc/include/asm/book3s/64/hash.h    | 2 ++
 arch/powerpc/include/asm/book3s/64/pgtable.h | 3 ++-
 arch/powerpc/include/asm/book3s/64/radix.h   | 2 ++
 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, 10 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index 36fc7bf..d613653 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -51,6 +51,8 @@
 #define H_VMALLOC_SIZE	(H_KERN_VIRT_SIZE >> 1)
 #define H_VMALLOC_END	(H_VMALLOC_START + H_VMALLOC_SIZE)
 
+#define H_KERN_IO_START	H_VMALLOC_END
+
 /*
  * Region IDs
  */
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 818a58f..be8e404 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -272,8 +272,10 @@ extern unsigned long __vmalloc_end;
 
 extern unsigned long __kernel_virt_start;
 extern unsigned long __kernel_virt_size;
+extern unsigned long __kernel_io_start;
 #define KERN_VIRT_START __kernel_virt_start
 #define KERN_VIRT_SIZE  __kernel_virt_size
+#define KERN_IO_START  __kernel_io_start
 extern struct page *vmemmap;
 extern unsigned long ioremap_bot;
 extern unsigned long pci_io_base;
@@ -298,7 +300,6 @@ extern unsigned long pci_io_base;
  *  PHB_IO_BASE = ISA_IO_BASE + 64K to ISA_IO_BASE + 2G, PHB IO spaces
  * IOREMAP_BASE = ISA_IO_BASE + 2G to VMALLOC_START + PGTABLE_RANGE
  */
-#define KERN_IO_START	(KERN_VIRT_START + (KERN_VIRT_SIZE >> 1))
 #define FULL_IO_SIZE	0x80000000ul
 #define  ISA_IO_BASE	(KERN_IO_START)
 #define  ISA_IO_END	(KERN_IO_START + 0x10000ul)
diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h
index 544440b..1e5ba94 100644
--- a/arch/powerpc/include/asm/book3s/64/radix.h
+++ b/arch/powerpc/include/asm/book3s/64/radix.h
@@ -110,6 +110,8 @@
  */
 #define RADIX_VMEMMAP_BASE		(RADIX_VMALLOC_END)
 
+#define RADIX_KERN_IO_START	(RADIX_KERN_VIRT_START + (RADIX_KERN_VIRT_SIZE >> 1))
+
 #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)
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 7a20669..3eb7395 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1019,6 +1019,7 @@ void __init hash__early_init_mmu(void)
 	__kernel_virt_size = H_KERN_VIRT_SIZE;
 	__vmalloc_start = H_VMALLOC_START;
 	__vmalloc_end = H_VMALLOC_END;
+	__kernel_io_start = H_KERN_IO_START;
 	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 e78274a..2436d34 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -526,6 +526,7 @@ void __init radix__early_init_mmu(void)
 	__kernel_virt_size = RADIX_KERN_VIRT_SIZE;
 	__vmalloc_start = RADIX_VMALLOC_START;
 	__vmalloc_end = RADIX_VMALLOC_END;
+	__kernel_io_start = RADIX_KERN_IO_START;
 	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 0736e94..ac0717a 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -104,6 +104,8 @@ unsigned long __vmalloc_start;
 EXPORT_SYMBOL(__vmalloc_start);
 unsigned long __vmalloc_end;
 EXPORT_SYMBOL(__vmalloc_end);
+unsigned long __kernel_io_start;
+EXPORT_SYMBOL(__kernel_io_start);
 struct page *vmemmap;
 EXPORT_SYMBOL(vmemmap);
 unsigned long __pte_frag_nr;
-- 
2.7.4





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