851d2e2fe8
Icswx is a PowerPC instruction to send data to a co-processor. On Book-S processors the LPAR_ID and process ID (PID) of the owning process are registered in the window context of the co-processor at initialization time. When the icswx instruction is executed the L2 generates a cop-reg transaction on PowerBus. The transaction has no address and the processor does not perform an MMU access to authenticate the transaction. The co-processor compares the LPAR_ID and the PID included in the transaction and the LPAR_ID and PID held in the window context to determine if the process is authorized to generate the transaction. The OS needs to assign a 16-bit PID for the process. This cop-PID needs to be updated during context switch. The cop-PID needs to be destroyed when the context is destroyed. Signed-off-by: Sonny Rao <sonnyrao@linux.vnet.ibm.com> Signed-off-by: Tseng-Hui (Frank) Lin <thlin@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
118 lines
3.2 KiB
C
118 lines
3.2 KiB
C
#ifndef __ASM_POWERPC_MMU_CONTEXT_H
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#define __ASM_POWERPC_MMU_CONTEXT_H
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#ifdef __KERNEL__
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/sched.h>
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#include <linux/spinlock.h>
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#include <asm/mmu.h>
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#include <asm/cputable.h>
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#include <asm-generic/mm_hooks.h>
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#include <asm/cputhreads.h>
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/*
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* Most if the context management is out of line
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*/
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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_mmu_context(struct mm_struct *prev, struct mm_struct *next);
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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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extern void set_context(unsigned long id, pgd_t *pgd);
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#ifdef CONFIG_PPC_BOOK3S_64
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extern int __init_new_context(void);
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extern void __destroy_context(int context_id);
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static inline void mmu_context_init(void) { }
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#else
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extern unsigned long __init_new_context(void);
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extern void __destroy_context(unsigned long context_id);
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extern void mmu_context_init(void);
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#endif
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extern void switch_cop(struct mm_struct *next);
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extern int use_cop(unsigned long acop, struct mm_struct *mm);
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extern void drop_cop(unsigned long acop, 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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/* Mark this context has been used on the new CPU */
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cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
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/* 32-bit keeps track of the current PGDIR in the thread struct */
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#ifdef CONFIG_PPC32
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tsk->thread.pgdir = next->pgd;
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#endif /* CONFIG_PPC32 */
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/* 64-bit Book3E keeps track of current PGD in the PACA */
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#ifdef CONFIG_PPC_BOOK3E_64
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get_paca()->pgd = next->pgd;
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#endif
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/* Nothing else to do if we aren't actually switching */
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if (prev == next)
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return;
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#ifdef CONFIG_PPC_ICSWX
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/* Switch coprocessor context only if prev or next uses a coprocessor */
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if (prev->context.acop || next->context.acop)
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switch_cop(next);
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#endif /* CONFIG_PPC_ICSWX */
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/* We must stop all altivec streams before changing the HW
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* context
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*/
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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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/* The actual HW switching method differs between the various
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* sub architectures.
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*/
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#ifdef CONFIG_PPC_STD_MMU_64
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if (mmu_has_feature(MMU_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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#else
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/* Out of line for now */
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switch_mmu_context(prev, next);
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#endif
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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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/* We don't currently use enter_lazy_tlb() for anything */
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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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/* 64-bit Book3E keeps track of current PGD in the PACA */
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#ifdef CONFIG_PPC_BOOK3E_64
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get_paca()->pgd = NULL;
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#endif
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}
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#endif /* __KERNEL__ */
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#endif /* __ASM_POWERPC_MMU_CONTEXT_H */
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