[PATCH] [POWERPC] Use PAGE_OFFSET to tell if an address is user/kernel in SW TLB handlers

[Kumar Gala]

Move to using PAGE_OFFSET instead of TASK_SIZE or KERNELBASE value on
6xx/40x/44x/fsl-booke to determine if the faulting address is a kernel or
user space address.  This mimics how the macro is_kernel_addr() works.

---

I've tested this on fsl_booke & 603 systems.

 arch/powerpc/kernel/head_32.S        |   18 +++++++++---------
 arch/powerpc/kernel/head_40x.S       |    6 +++---
 arch/powerpc/kernel/head_44x.S       |    6 +++---
 arch/powerpc/kernel/head_fsl_booke.S |   11 ++++-------
 4 files changed, 19 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index d83f04e..a5b13ae 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -469,12 +469,12 @@ InstructionTLBMiss:
 	mfctr	r0
 	/* Get PTE (linux-style) and check access */
 	mfspr	r3,SPRN_IMISS
-	lis	r1,KERNELBASE at h		/* check if kernel address */
-	cmplw	0,r3,r1
+	lis	r1,PAGE_OFFSET at h		/* check if kernel address */
+	cmplw	0,r1,r3
 	mfspr	r2,SPRN_SPRG3
 	li	r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
 	lwz	r2,PGDIR(r2)
-	blt+	112f
+	bge-	112f
 	mfspr	r2,SPRN_SRR1		/* and MSR_PR bit from SRR1 */
 	rlwimi	r1,r2,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */
 	lis	r2,swapper_pg_dir at ha	/* if kernel address, use */
@@ -543,12 +543,12 @@ DataLoadTLBMiss:
 	mfctr	r0
 	/* Get PTE (linux-style) and check access */
 	mfspr	r3,SPRN_DMISS
-	lis	r1,KERNELBASE at h		/* check if kernel address */
-	cmplw	0,r3,r1
+	lis	r1,PAGE_OFFSET at h		/* check if kernel address */
+	cmplw	0,r1,r3
 	mfspr	r2,SPRN_SPRG3
 	li	r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
 	lwz	r2,PGDIR(r2)
-	blt+	112f
+	bge-	112f
 	mfspr	r2,SPRN_SRR1		/* and MSR_PR bit from SRR1 */
 	rlwimi	r1,r2,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */
 	lis	r2,swapper_pg_dir at ha	/* if kernel address, use */
@@ -615,12 +615,12 @@ DataStoreTLBMiss:
 	mfctr	r0
 	/* Get PTE (linux-style) and check access */
 	mfspr	r3,SPRN_DMISS
-	lis	r1,KERNELBASE at h		/* check if kernel address */
-	cmplw	0,r3,r1
+	lis	r1,PAGE_OFFSET at h		/* check if kernel address */
+	cmplw	0,r1,r3
 	mfspr	r2,SPRN_SPRG3
 	li	r1,_PAGE_RW|_PAGE_USER|_PAGE_PRESENT /* access flags */
 	lwz	r2,PGDIR(r2)
-	blt+	112f
+	bge-	112f
 	mfspr	r2,SPRN_SRR1		/* and MSR_PR bit from SRR1 */
 	rlwimi	r1,r2,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */
 	lis	r2,swapper_pg_dir at ha	/* if kernel address, use */
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index e312824..cfefc2d 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -289,7 +289,7 @@ label:
 	/* If we are faulting a kernel address, we have to use the
 	 * kernel page tables.
 	 */
-	lis	r11, TASK_SIZE at h
+	lis	r11, PAGE_OFFSET at h
 	cmplw	r10, r11
 	blt+	3f
 	lis	r11, swapper_pg_dir at h
@@ -481,7 +481,7 @@ label:
 	/* If we are faulting a kernel address, we have to use the
 	 * kernel page tables.
 	 */
-	lis	r11, TASK_SIZE at h
+	lis	r11, PAGE_OFFSET at h
 	cmplw	r10, r11
 	blt+	3f
 	lis	r11, swapper_pg_dir at h
@@ -581,7 +581,7 @@ label:
 	/* If we are faulting a kernel address, we have to use the
 	 * kernel page tables.
 	 */
-	lis	r11, TASK_SIZE at h
+	lis	r11, PAGE_OFFSET at h
 	cmplw	r10, r11
 	blt+	3f
 	lis	r11, swapper_pg_dir at h
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 864d63f..409db61 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -319,7 +319,7 @@ interrupt_base:
 	/* If we are faulting a kernel address, we have to use the
 	 * kernel page tables.
 	 */
-	lis	r11, TASK_SIZE at h
+	lis	r11, PAGE_OFFSET at h
 	cmplw	r10, r11
 	blt+	3f
 	lis	r11, swapper_pg_dir at h
@@ -458,7 +458,7 @@ interrupt_base:
 	/* If we are faulting a kernel address, we have to use the
 	 * kernel page tables.
 	 */
-	lis	r11, TASK_SIZE at h
+	lis	r11, PAGE_OFFSET at h
 	cmplw	r10, r11
 	blt+	3f
 	lis	r11, swapper_pg_dir at h
@@ -528,7 +528,7 @@ interrupt_base:
 	/* If we are faulting a kernel address, we have to use the
 	 * kernel page tables.
 	 */
-	lis	r11, TASK_SIZE at h
+	lis	r11, PAGE_OFFSET at h
 	cmplw	r10, r11
 	blt+	3f
 	lis	r11, swapper_pg_dir at h
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index ee33ddd..4b98227 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -461,8 +461,7 @@ interrupt_base:
 	/* If we are faulting a kernel address, we have to use the
 	 * kernel page tables.
 	 */
-	lis	r11, TASK_SIZE at h
-	ori	r11, r11, TASK_SIZE at l
+	lis	r11, PAGE_OFFSET at h
 	cmplw	0, r10, r11
 	bge	2f

@@ -584,8 +583,7 @@ interrupt_base:
 	/* If we are faulting a kernel address, we have to use the
 	 * kernel page tables.
 	 */
-	lis	r11, TASK_SIZE at h
-	ori	r11, r11, TASK_SIZE at l
+	lis	r11, PAGE_OFFSET at h
 	cmplw	5, r10, r11
 	blt	5, 3f
 	lis	r11, swapper_pg_dir at h
@@ -645,8 +643,7 @@ interrupt_base:
 	/* If we are faulting a kernel address, we have to use the
 	 * kernel page tables.
 	 */
-	lis	r11, TASK_SIZE at h
-	ori	r11, r11, TASK_SIZE at l
+	lis	r11, PAGE_OFFSET at h
 	cmplw	5, r10, r11
 	blt	5, 3f
 	lis	r11, swapper_pg_dir at h
@@ -744,7 +741,7 @@ data_access:
  *	r10 - EA of fault
  *	r11 - TLB (info from Linux PTE)
  *	r12, r13 - available to use
- *	CR5 - results of addr < TASK_SIZE
+ *	CR5 - results of addr >= PAGE_OFFSET
  *	MAS0, MAS1 - loaded with proper value when we get here
  *	MAS2, MAS3 - will need additional info from Linux PTE
  *	Upon exit, we reload everything and RFI.
-- 
1.5.2.4