diff options
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/Kconfig | 18 | ||||
| -rw-r--r-- | arch/powerpc/kernel/head_8xx.S | 4 |
2 files changed, 17 insertions, 5 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 43fa82e409bf..ad8e22827de0 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -722,7 +722,8 @@ config THREAD_SHIFT want. Only change this if you know what you are doing. config ETEXT_SHIFT_BOOL - bool "Set custom etext alignment" if STRICT_KERNEL_RWX && PPC_BOOK3S_32 + bool "Set custom etext alignment" if STRICT_KERNEL_RWX && \ + (PPC_BOOK3S_32 || PPC_8xx) depends on ADVANCED_OPTIONS help This option allows you to set the kernel end of text alignment. When @@ -734,6 +735,7 @@ config ETEXT_SHIFT_BOOL config ETEXT_SHIFT int "_etext shift" if ETEXT_SHIFT_BOOL range 17 28 if STRICT_KERNEL_RWX && PPC_BOOK3S_32 + range 19 23 if STRICT_KERNEL_RWX && PPC_8xx default 17 if STRICT_KERNEL_RWX && PPC_BOOK3S_32 default 19 if STRICT_KERNEL_RWX && PPC_8xx default PPC_PAGE_SHIFT @@ -741,8 +743,13 @@ config ETEXT_SHIFT On Book3S 32 (603+), IBATs are used to map kernel text. Smaller is the alignment, greater is the number of necessary IBATs. + On 8xx, large pages (512kb or 8M) are used to map kernel linear + memory. Aligning to 8M reduces TLB misses as only 8M pages are used + in that case. + config DATA_SHIFT_BOOL - bool "Set custom data alignment" if STRICT_KERNEL_RWX && PPC_BOOK3S_32 + bool "Set custom data alignment" if STRICT_KERNEL_RWX && \ + (PPC_BOOK3S_32 || PPC_8xx) depends on ADVANCED_OPTIONS help This option allows you to set the kernel data alignment. When @@ -755,13 +762,18 @@ config DATA_SHIFT int "Data shift" if DATA_SHIFT_BOOL default 24 if STRICT_KERNEL_RWX && PPC64 range 17 28 if STRICT_KERNEL_RWX && PPC_BOOK3S_32 + range 19 23 if STRICT_KERNEL_RWX && PPC_8xx default 22 if STRICT_KERNEL_RWX && PPC_BOOK3S_32 - default 19 if STRICT_KERNEL_RWX && PPC_8xx + default 23 if STRICT_KERNEL_RWX && PPC_8xx default PPC_PAGE_SHIFT help On Book3S 32 (603+), DBATs are used to map kernel text and rodata RO. Smaller is the alignment, greater is the number of necessary DBATs. + On 8xx, large pages (512kb or 8M) are used to map kernel linear + memory. Aligning to 8M reduces TLB misses as only 8M pages are used + in that case. + config FORCE_MAX_ZONEORDER int "Maximum zone order" range 8 9 if PPC64 && PPC_64K_PAGES diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 3f2d1afba2d1..50303d25cbc1 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -416,7 +416,7 @@ InstructionTLBMiss: #ifndef CONFIG_PIN_TLB_TEXT ITLBMissLinear: mtcr r11 -#ifdef CONFIG_STRICT_KERNEL_RWX +#if defined(CONFIG_STRICT_KERNEL_RWX) && CONFIG_ETEXT_SHIFT < 23 patch_site 0f, patch__itlbmiss_linmem_top8 mfspr r10, SPRN_SRR0 @@ -537,7 +537,7 @@ DTLBMissIMMR: DTLBMissLinear: mtcr r11 rlwinm r10, r10, 20, 0x0f800000 /* 8xx supports max 256Mb RAM */ -#ifdef CONFIG_STRICT_KERNEL_RWX +#if defined(CONFIG_STRICT_KERNEL_RWX) && CONFIG_DATA_SHIFT < 23 patch_site 0f, patch__dtlbmiss_romem_top8 0: subis r11, r10, (PAGE_OFFSET - 0x80000000)@ha |