From 1189be6508d45183013ddb82b18f4934193de274 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Thu, 11 Oct 2007 20:37:10 +1000 Subject: [POWERPC] Use 1TB segments This makes the kernel use 1TB segments for all kernel mappings and for user addresses of 1TB and above, on machines which support them (currently POWER5+, POWER6 and PA6T). We detect that the machine supports 1TB segments by looking at the ibm,processor-segment-sizes property in the device tree. We don't currently use 1TB segments for user addresses < 1T, since that would effectively prevent 32-bit processes from using huge pages unless we also had a way to revert to using 256MB segments. That would be possible but would involve extra complications (such as keeping track of which segment size was used when HPTEs were inserted) and is not addressed here. Parts of this patch were originally written by Ben Herrenschmidt. Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/entry_64.S | 14 +++++++++++++- arch/powerpc/kernel/head_64.S | 2 +- arch/powerpc/kernel/process.c | 9 +++++++-- 3 files changed, 21 insertions(+), 4 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index fbbd3f6f006..0ec13403489 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -372,9 +372,17 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) std r6,PACACURRENT(r13) /* Set new 'current' */ ld r8,KSP(r4) /* new stack pointer */ +BEGIN_FTR_SECTION + b 2f +END_FTR_SECTION_IFCLR(CPU_FTR_SLB) BEGIN_FTR_SECTION clrrdi r6,r8,28 /* get its ESID */ clrrdi r9,r1,28 /* get current sp ESID */ +END_FTR_SECTION_IFCLR(CPU_FTR_1T_SEGMENT) +BEGIN_FTR_SECTION + clrrdi r6,r8,40 /* get its 1T ESID */ + clrrdi r9,r1,40 /* get current sp 1T ESID */ +END_FTR_SECTION_IFSET(CPU_FTR_1T_SEGMENT) clrldi. r0,r6,2 /* is new ESID c00000000? */ cmpd cr1,r6,r9 /* or is new ESID the same as current ESID? */ cror eq,4*cr1+eq,eq @@ -384,6 +392,11 @@ BEGIN_FTR_SECTION ld r7,KSP_VSID(r4) /* Get new stack's VSID */ oris r0,r6,(SLB_ESID_V)@h ori r0,r0,(SLB_NUM_BOLTED-1)@l +BEGIN_FTR_SECTION + li r9,MMU_SEGSIZE_1T /* insert B field */ + oris r6,r6,(MMU_SEGSIZE_1T << SLBIE_SSIZE_SHIFT)@h + rldimi r7,r9,SLB_VSID_SSIZE_SHIFT,0 +END_FTR_SECTION_IFSET(CPU_FTR_1T_SEGMENT) /* Update the last bolted SLB. No write barriers are needed * here, provided we only update the current CPU's SLB shadow @@ -401,7 +414,6 @@ BEGIN_FTR_SECTION isync 2: -END_FTR_SECTION_IFSET(CPU_FTR_SLB) clrrdi r7,r8,THREAD_SHIFT /* base of new stack */ /* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE because we don't need to leave the 288-byte ABI gap at the diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index 22ac245bd59..97c5857faf0 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -935,7 +935,7 @@ _GLOBAL(do_stab_bolted) /* Calculate VSID */ /* This is a kernel address, so protovsid = ESID */ - ASM_VSID_SCRAMBLE(r11, r9) + ASM_VSID_SCRAMBLE(r11, r9, 256M) rldic r9,r11,12,16 /* r9 = vsid << 12 */ /* Search the primary group for a free entry */ diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 15998b57767..7949c203cb8 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -564,10 +564,15 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, #ifdef CONFIG_PPC64 if (cpu_has_feature(CPU_FTR_SLB)) { - unsigned long sp_vsid = get_kernel_vsid(sp); + unsigned long sp_vsid; unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp; - sp_vsid <<= SLB_VSID_SHIFT; + if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) + sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T) + << SLB_VSID_SHIFT_1T; + else + sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M) + << SLB_VSID_SHIFT; sp_vsid |= SLB_VSID_KERNEL | llp; p->thread.ksp_vsid = sp_vsid; } -- cgit v1.2.3