@@ -587,6 +587,10 @@ start_here:
lis r0, (MD_TWAM | MD_RSV4I)@h
mtspr SPRN_MD_CTR, r0
#endif
+#ifndef CONFIG_PIN_TLB_TEXT
+ li r0, 0
+ mtspr SPRN_MI_CTR, r0
+#endif
#if !defined(CONFIG_PIN_TLB_DATA) && !defined(CONFIG_PIN_TLB_IMMR)
lis r0, MD_TWAM@h
mtspr SPRN_MD_CTR, r0
@@ -683,6 +687,7 @@ SYM_FUNC_START_LOCAL(initial_mmu)
blr
SYM_FUNC_END(initial_mmu)
+#ifdef CONFIG_PIN_TLB
_GLOBAL(mmu_pin_tlb)
lis r9, (1f - PAGE_OFFSET)@h
ori r9, r9, (1f - PAGE_OFFSET)@l
@@ -704,6 +709,7 @@ _GLOBAL(mmu_pin_tlb)
mtspr SPRN_MD_CTR, r6
tlbia
+#ifdef CONFIG_PIN_TLB_TEXT
LOAD_REG_IMMEDIATE(r5, 28 << 8)
LOAD_REG_IMMEDIATE(r6, PAGE_OFFSET)
LOAD_REG_IMMEDIATE(r7, MI_SVALID | MI_PS8MEG | _PMD_ACCESSED)
@@ -724,6 +730,7 @@ _GLOBAL(mmu_pin_tlb)
bdnzt lt, 2b
lis r0, MI_RSV4I@h
mtspr SPRN_MI_CTR, r0
+#endif
LOAD_REG_IMMEDIATE(r5, 28 << 8 | MD_TWAM)
#ifdef CONFIG_PIN_TLB_DATA
@@ -783,3 +790,4 @@ _GLOBAL(mmu_pin_tlb)
mtspr SPRN_SRR1, r10
mtspr SPRN_SRR0, r11
rfi
+#endif
@@ -177,7 +177,8 @@ int mmu_mark_initmem_nx(void)
if (!debug_pagealloc_enabled_or_kfence())
err = mmu_mapin_ram_chunk(boundary, einittext8, PAGE_KERNEL, false);
- mmu_pin_tlb(block_mapped_ram, false);
+ if (IS_ENABLED(CONFIG_PIN_TLB_TEXT))
+ mmu_pin_tlb(block_mapped_ram, false);
return err;
}
@@ -203,6 +203,13 @@ config PIN_TLB_IMMR
CONFIG_PIN_TLB_DATA is also selected, it will reduce
CONFIG_PIN_TLB_DATA to 24 Mbytes.
+config PIN_TLB_TEXT
+ bool "Pinned TLB for TEXT"
+ depends on PIN_TLB
+ default y
+ help
+ This pins kernel text with 8M pages.
+
endmenu
endmenu
This reverts commit bccc58986a2f98e3af349c85c5f49aac7fb19ef2. When STRICT_KERNEL_RWX is selected, EXEC memory must stop where RW memory start. When pinning iTLBs it means an 8M alignment for RW data start. That may be acceptable on boards with a lot of memory but one of my supported boards only has 32 Mbytes and this forced alignment leads to a waste of almost 4 Mbytes with is more than 10% of the total memory. So revert commit bccc58986a2f ("powerpc/8xx: Always pin kernel text TLB") but don't restore previous behaviour in ITLB miss handler as now kernel PGD entries are copied into each process PGDIR. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> --- arch/powerpc/kernel/head_8xx.S | 8 ++++++++ arch/powerpc/mm/nohash/8xx.c | 3 ++- arch/powerpc/platforms/8xx/Kconfig | 7 +++++++ 3 files changed, 17 insertions(+), 1 deletion(-)