3c726f8dee
Adds a new CONFIG_PPC_64K_PAGES which, when enabled, changes the kernel base page size to 64K. The resulting kernel still boots on any hardware. On current machines with 4K pages support only, the kernel will maintain 16 "subpages" for each 64K page transparently. Note that while real 64K capable HW has been tested, the current patch will not enable it yet as such hardware is not released yet, and I'm still verifying with the firmware architects the proper to get the information from the newer hypervisors. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
86 lines
2.3 KiB
C
86 lines
2.3 KiB
C
#ifndef __PPC64_MMU_CONTEXT_H
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#define __PPC64_MMU_CONTEXT_H
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#include <linux/config.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <asm/mmu.h>
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#include <asm/cputable.h>
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/*
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* Copyright (C) 2001 PPC 64 Team, IBM Corp
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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/*
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* Getting into a kernel thread, there is no valid user segment, mark
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* paca->pgdir NULL so that SLB miss on user addresses will fault
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*/
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static inline void enter_lazy_tlb(struct mm_struct *mm,
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struct task_struct *tsk)
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{
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#ifdef CONFIG_PPC_64K_PAGES
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get_paca()->pgdir = NULL;
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#endif /* CONFIG_PPC_64K_PAGES */
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}
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#define NO_CONTEXT 0
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#define MAX_CONTEXT (0x100000-1)
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extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
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extern void destroy_context(struct mm_struct *mm);
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extern void switch_stab(struct task_struct *tsk, struct mm_struct *mm);
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extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
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/*
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* switch_mm is the entry point called from the architecture independent
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* code in kernel/sched.c
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*/
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static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
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struct task_struct *tsk)
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{
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if (!cpu_isset(smp_processor_id(), next->cpu_vm_mask))
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cpu_set(smp_processor_id(), next->cpu_vm_mask);
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/* No need to flush userspace segments if the mm doesnt change */
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#ifdef CONFIG_PPC_64K_PAGES
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if (prev == next && get_paca()->pgdir == next->pgd)
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return;
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#else
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if (prev == next)
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return;
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#endif /* CONFIG_PPC_64K_PAGES */
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#ifdef CONFIG_ALTIVEC
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if (cpu_has_feature(CPU_FTR_ALTIVEC))
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asm volatile ("dssall");
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#endif /* CONFIG_ALTIVEC */
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if (cpu_has_feature(CPU_FTR_SLB))
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switch_slb(tsk, next);
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else
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switch_stab(tsk, next);
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}
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#define deactivate_mm(tsk,mm) do { } while (0)
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/*
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* After we have set current->mm to a new value, this activates
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* the context for the new mm so we see the new mappings.
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*/
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static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
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{
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unsigned long flags;
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local_irq_save(flags);
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switch_mm(prev, next, current);
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local_irq_restore(flags);
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}
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#endif /* __PPC64_MMU_CONTEXT_H */
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