[PATCH v2 01/10] powerpc/6xx: fix setup and use of SPRN_SPRG_PGDIR for hash32

From: Christophe Leroy
Date: Mon Mar 11 2019 - 04:30:32 EST


Not only the 603 but all 6xx need SPRN_SPRG_PGDIR to be initialised at
startup. This patch move it from __setup_cpu_603() to start_here()
and __secondary_start(), close to the initialisation of SPRN_THREAD.

Previously, virt addr of PGDIR was retrieved from thread struct.
Now that it is the phys addr which is stored in SPRN_SPRG_PGDIR,
hash_page() shall not convert it to phys anymore.
This patch removes the conversion.

Fixes: 93c4a162b014("powerpc/6xx: Store PGDIR physical address in a SPRG")
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/kernel/cpu_setup_6xx.S | 3 ---
arch/powerpc/kernel/head_32.S | 6 ++++++
arch/powerpc/mm/hash_low_32.S | 8 ++++----
3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/cpu_setup_6xx.S b/arch/powerpc/kernel/cpu_setup_6xx.S
index 6f1c11e0691f..7534ecff5e92 100644
--- a/arch/powerpc/kernel/cpu_setup_6xx.S
+++ b/arch/powerpc/kernel/cpu_setup_6xx.S
@@ -24,9 +24,6 @@ BEGIN_MMU_FTR_SECTION
li r10,0
mtspr SPRN_SPRG_603_LRU,r10 /* init SW LRU tracking */
END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
- lis r10, (swapper_pg_dir - PAGE_OFFSET)@h
- ori r10, r10, (swapper_pg_dir - PAGE_OFFSET)@l
- mtspr SPRN_SPRG_PGDIR, r10

BEGIN_FTR_SECTION
bl __init_fpu_registers
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index ce6a972f2584..48051c8977c5 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -855,6 +855,9 @@ __secondary_start:
li r3,0
stw r3, RTAS_SP(r4) /* 0 => not in RTAS */
#endif
+ lis r4, (swapper_pg_dir - PAGE_OFFSET)@h
+ ori r4, r4, (swapper_pg_dir - PAGE_OFFSET)@l
+ mtspr SPRN_SPRG_PGDIR, r4

/* enable MMU and jump to start_secondary */
li r4,MSR_KERNEL
@@ -942,6 +945,9 @@ start_here:
li r3,0
stw r3, RTAS_SP(r4) /* 0 => not in RTAS */
#endif
+ lis r4, (swapper_pg_dir - PAGE_OFFSET)@h
+ ori r4, r4, (swapper_pg_dir - PAGE_OFFSET)@l
+ mtspr SPRN_SPRG_PGDIR, r4

/* stack */
lis r1,init_thread_union@ha
diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S
index 1f13494efb2b..a6c491f18a04 100644
--- a/arch/powerpc/mm/hash_low_32.S
+++ b/arch/powerpc/mm/hash_low_32.S
@@ -70,12 +70,12 @@ _GLOBAL(hash_page)
lis r0,KERNELBASE@h /* check if kernel address */
cmplw 0,r4,r0
ori r3,r3,_PAGE_USER|_PAGE_PRESENT /* test low addresses as user */
- mfspr r5, SPRN_SPRG_PGDIR /* virt page-table root */
+ mfspr r5, SPRN_SPRG_PGDIR /* phys page-table root */
blt+ 112f /* assume user more likely */
- lis r5,swapper_pg_dir@ha /* if kernel address, use */
- addi r5,r5,swapper_pg_dir@l /* kernel page table */
+ lis r5, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */
+ addi r5 ,r5 ,(swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */
rlwimi r3,r9,32-12,29,29 /* MSR_PR -> _PAGE_USER */
-112: tophys(r5, r5)
+112:
#ifndef CONFIG_PTE_64BIT
rlwimi r5,r4,12,20,29 /* insert top 10 bits of address */
lwz r8,0(r5) /* get pmd entry */
--
2.13.3