[PATCH v2 10/14] powerpc/8xx: reunify TLB handler routines

From: Christophe Leroy
Date: Wed May 16 2018 - 05:34:41 EST


Each handler must not exceed 64 instructions to fit into the main
exception area.
Following the significant size reduction of TLB handler routines,
the side handlers can be brought back close to the main part.

In the worst case:
Main part of ITLB handler is 45 insn, side part is 9 insn ==> total 54
Main part of DTLB handler is 37 insn, side part is 23 insn ==> total 60

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/kernel/head_8xx.S | 108 ++++++++++++++++++++---------------------
1 file changed, 52 insertions(+), 56 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 66a27044d105..0c3cfaa4e6f3 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -388,6 +388,23 @@ _ENTRY(itlb_miss_perf)
mfspr r11, SPRN_SPRG_SCRATCH1
rfi

+#ifndef CONFIG_PIN_TLB_TEXT
+ITLBMissLinear:
+ mtcr r11
+ /* Set 8M byte page and mark it valid */
+ li r11, MI_PS8MEG | MI_SVALID
+ mtspr SPRN_MI_TWC, r11
+ rlwinm r10, r10, 20, 0x0f800000 /* 8xx supports max 256Mb RAM */
+ ori r10, r10, 0xf0 | MI_SPS16K | _PAGE_PRIVILEGED | _PAGE_DIRTY | \
+ _PAGE_PRESENT
+ mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
+
+_ENTRY(itlb_miss_exit_2)
+ mfspr r10, SPRN_SPRG_SCRATCH0
+ mfspr r11, SPRN_SPRG_SCRATCH1
+ rfi
+#endif
+
. = 0x1200
DataStoreTLBMiss:
mtspr SPRN_SPRG_SCRATCH0, r10
@@ -463,6 +480,41 @@ _ENTRY(dtlb_miss_perf)
mfspr r11, SPRN_SPRG_SCRATCH1
rfi

+DTLBMissIMMR:
+ mtcr r11
+ /* Set 512k byte guarded page and mark it valid */
+ li r10, MD_PS512K | MD_GUARDED | MD_SVALID
+ mtspr SPRN_MD_TWC, r10
+ mfspr r10, SPRN_IMMR /* Get current IMMR */
+ rlwinm r10, r10, 0, 0xfff80000 /* Get 512 kbytes boundary */
+ ori r10, r10, 0xf0 | MD_SPS16K | _PAGE_PRIVILEGED | _PAGE_DIRTY | \
+ _PAGE_PRESENT | _PAGE_NO_CACHE
+ mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
+
+ li r11, RPN_PATTERN
+ mtspr SPRN_DAR, r11 /* Tag DAR */
+_ENTRY(dtlb_miss_exit_2)
+ mfspr r10, SPRN_SPRG_SCRATCH0
+ mfspr r11, SPRN_SPRG_SCRATCH1
+ rfi
+
+DTLBMissLinear:
+ mtcr r11
+ /* Set 8M byte page and mark it valid */
+ li r11, MD_PS8MEG | MD_SVALID
+ mtspr SPRN_MD_TWC, r11
+ rlwinm r10, r10, 20, 0x0f800000 /* 8xx supports max 256Mb RAM */
+ ori r10, r10, 0xf0 | MD_SPS16K | _PAGE_PRIVILEGED | _PAGE_DIRTY | \
+ _PAGE_PRESENT
+ mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
+
+ li r11, RPN_PATTERN
+ mtspr SPRN_DAR, r11 /* Tag DAR */
+_ENTRY(dtlb_miss_exit_3)
+ mfspr r10, SPRN_SPRG_SCRATCH0
+ mfspr r11, SPRN_SPRG_SCRATCH1
+ rfi
+
/* This is an instruction TLB error on the MPC8xx. This could be due
* to many reasons, such as executing guarded memory or illegal instruction
* addresses. There is nothing to do but handle a big time error fault.
@@ -565,62 +617,6 @@ InstructionBreakpoint:

. = 0x2000

-/*
- * Bottom part of DataStoreTLBMiss handlers for IMMR area and linear RAM.
- * not enough space in the DataStoreTLBMiss area.
- */
-DTLBMissIMMR:
- mtcr r11
- /* Set 512k byte guarded page and mark it valid */
- li r10, MD_PS512K | MD_GUARDED | MD_SVALID
- mtspr SPRN_MD_TWC, r10
- mfspr r10, SPRN_IMMR /* Get current IMMR */
- rlwinm r10, r10, 0, 0xfff80000 /* Get 512 kbytes boundary */
- ori r10, r10, 0xf0 | MD_SPS16K | _PAGE_PRIVILEGED | _PAGE_DIRTY | \
- _PAGE_PRESENT | _PAGE_NO_CACHE
- mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
-
- li r11, RPN_PATTERN
- mtspr SPRN_DAR, r11 /* Tag DAR */
-_ENTRY(dtlb_miss_exit_2)
- mfspr r10, SPRN_SPRG_SCRATCH0
- mfspr r11, SPRN_SPRG_SCRATCH1
- rfi
-
-DTLBMissLinear:
- mtcr r11
- /* Set 8M byte page and mark it valid */
- li r11, MD_PS8MEG | MD_SVALID
- mtspr SPRN_MD_TWC, r11
- rlwinm r10, r10, 20, 0x0f800000 /* 8xx supports max 256Mb RAM */
- ori r10, r10, 0xf0 | MD_SPS16K | _PAGE_PRIVILEGED | _PAGE_DIRTY | \
- _PAGE_PRESENT
- mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
-
- li r11, RPN_PATTERN
- mtspr SPRN_DAR, r11 /* Tag DAR */
-_ENTRY(dtlb_miss_exit_3)
- mfspr r10, SPRN_SPRG_SCRATCH0
- mfspr r11, SPRN_SPRG_SCRATCH1
- rfi
-
-#ifndef CONFIG_PIN_TLB_TEXT
-ITLBMissLinear:
- mtcr r11
- /* Set 8M byte page and mark it valid */
- li r11, MI_PS8MEG | MI_SVALID
- mtspr SPRN_MI_TWC, r11
- rlwinm r10, r10, 20, 0x0f800000 /* 8xx supports max 256Mb RAM */
- ori r10, r10, 0xf0 | MI_SPS16K | _PAGE_PRIVILEGED | _PAGE_DIRTY | \
- _PAGE_PRESENT
- mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
-
-_ENTRY(itlb_miss_exit_2)
- mfspr r10, SPRN_SPRG_SCRATCH0
- mfspr r11, SPRN_SPRG_SCRATCH1
- rfi
-#endif
-
/* This is the procedure to calculate the data EA for buggy dcbx,dcbi instructions
* by decoding the registers used by the dcbx instruction and adding them.
* DAR is set to the calculated address.
--
2.13.3