diff options
Diffstat (limited to 'arch/powerpc/mm/slb.c')
| -rw-r--r-- | arch/powerpc/mm/slb.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c new file mode 100644 index 000000000000..0473953f6a37 --- /dev/null +++ b/arch/powerpc/mm/slb.c @@ -0,0 +1,158 @@ +/* + * PowerPC64 SLB support. + * + * Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM + * Based on earlier code writteh by: + * Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com + * Copyright (c) 2001 Dave Engebretsen + * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM + * + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/config.h> +#include <asm/pgtable.h> +#include <asm/mmu.h> +#include <asm/mmu_context.h> +#include <asm/paca.h> +#include <asm/cputable.h> + +extern void slb_allocate(unsigned long ea); + +static inline unsigned long mk_esid_data(unsigned long ea, unsigned long slot) +{ + return (ea & ESID_MASK) | SLB_ESID_V | slot; +} + +static inline unsigned long mk_vsid_data(unsigned long ea, unsigned long flags) +{ + return (get_kernel_vsid(ea) << SLB_VSID_SHIFT) | flags; +} + +static inline void create_slbe(unsigned long ea, unsigned long flags, + unsigned long entry) +{ + asm volatile("slbmte %0,%1" : + : "r" (mk_vsid_data(ea, flags)), + "r" (mk_esid_data(ea, entry)) + : "memory" ); +} + +static void slb_flush_and_rebolt(void) +{ + /* If you change this make sure you change SLB_NUM_BOLTED + * appropriately too. */ + unsigned long ksp_flags = SLB_VSID_KERNEL; + unsigned long ksp_esid_data; + + WARN_ON(!irqs_disabled()); + + if (cpu_has_feature(CPU_FTR_16M_PAGE)) + ksp_flags |= SLB_VSID_L; + + ksp_esid_data = mk_esid_data(get_paca()->kstack, 2); + if ((ksp_esid_data & ESID_MASK) == KERNELBASE) + ksp_esid_data &= ~SLB_ESID_V; + + /* We need to do this all in asm, so we're sure we don't touch + * the stack between the slbia and rebolting it. */ + asm volatile("isync\n" + "slbia\n" + /* Slot 1 - first VMALLOC segment */ + "slbmte %0,%1\n" + /* Slot 2 - kernel stack */ + "slbmte %2,%3\n" + "isync" + :: "r"(mk_vsid_data(VMALLOCBASE, SLB_VSID_KERNEL)), + "r"(mk_esid_data(VMALLOCBASE, 1)), + "r"(mk_vsid_data(ksp_esid_data, ksp_flags)), + "r"(ksp_esid_data) + : "memory"); +} + +/* Flush all user entries from the segment table of the current processor. */ +void switch_slb(struct task_struct *tsk, struct mm_struct *mm) +{ + unsigned long offset = get_paca()->slb_cache_ptr; + unsigned long esid_data = 0; + unsigned long pc = KSTK_EIP(tsk); + unsigned long stack = KSTK_ESP(tsk); + unsigned long unmapped_base; + + if (offset <= SLB_CACHE_ENTRIES) { + int i; + asm volatile("isync" : : : "memory"); + for (i = 0; i < offset; i++) { + esid_data = ((unsigned long)get_paca()->slb_cache[i] + << SID_SHIFT) | SLBIE_C; + asm volatile("slbie %0" : : "r" (esid_data)); + } + asm volatile("isync" : : : "memory"); + } else { + slb_flush_and_rebolt(); + } + + /* Workaround POWER5 < DD2.1 issue */ + if (offset == 1 || offset > SLB_CACHE_ENTRIES) + asm volatile("slbie %0" : : "r" (esid_data)); + + get_paca()->slb_cache_ptr = 0; + get_paca()->context = mm->context; + + /* + * preload some userspace segments into the SLB. + */ + if (test_tsk_thread_flag(tsk, TIF_32BIT)) + unmapped_base = TASK_UNMAPPED_BASE_USER32; + else + unmapped_base = TASK_UNMAPPED_BASE_USER64; + + if (pc >= KERNELBASE) + return; + slb_allocate(pc); + + if (GET_ESID(pc) == GET_ESID(stack)) + return; + + if (stack >= KERNELBASE) + return; + slb_allocate(stack); + + if ((GET_ESID(pc) == GET_ESID(unmapped_base)) + || (GET_ESID(stack) == GET_ESID(unmapped_base))) + return; + + if (unmapped_base >= KERNELBASE) + return; + slb_allocate(unmapped_base); +} + +void slb_initialize(void) +{ + /* On iSeries the bolted entries have already been set up by + * the hypervisor from the lparMap data in head.S */ +#ifndef CONFIG_PPC_ISERIES + unsigned long flags = SLB_VSID_KERNEL; + + /* Invalidate the entire SLB (even slot 0) & all the ERATS */ + if (cpu_has_feature(CPU_FTR_16M_PAGE)) + flags |= SLB_VSID_L; + + asm volatile("isync":::"memory"); + asm volatile("slbmte %0,%0"::"r" (0) : "memory"); + asm volatile("isync; slbia; isync":::"memory"); + create_slbe(KERNELBASE, flags, 0); + create_slbe(VMALLOCBASE, SLB_VSID_KERNEL, 1); + /* We don't bolt the stack for the time being - we're in boot, + * so the stack is in the bolted segment. By the time it goes + * elsewhere, we'll call _switch() which will bolt in the new + * one. */ + asm volatile("isync":::"memory"); +#endif + + get_paca()->stab_rr = SLB_NUM_BOLTED; +} |