mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 16:29:59 +00:00
![Tseng-Hui (Frank) Lin](/assets/img/avatar_default.png)
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>
117 lines
3.2 KiB
C
117 lines
3.2 KiB
C
#ifndef __ASM_POWERPC_MMU_CONTEXT_H
|
|
#define __ASM_POWERPC_MMU_CONTEXT_H
|
|
#ifdef __KERNEL__
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/spinlock.h>
|
|
#include <asm/mmu.h>
|
|
#include <asm/cputable.h>
|
|
#include <asm-generic/mm_hooks.h>
|
|
#include <asm/cputhreads.h>
|
|
|
|
/*
|
|
* Most if the context management is out of line
|
|
*/
|
|
extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
|
|
extern void destroy_context(struct mm_struct *mm);
|
|
|
|
extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
|
|
extern void switch_stab(struct task_struct *tsk, struct mm_struct *mm);
|
|
extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
|
|
extern void set_context(unsigned long id, pgd_t *pgd);
|
|
|
|
#ifdef CONFIG_PPC_BOOK3S_64
|
|
extern int __init_new_context(void);
|
|
extern void __destroy_context(int context_id);
|
|
static inline void mmu_context_init(void) { }
|
|
#else
|
|
extern unsigned long __init_new_context(void);
|
|
extern void __destroy_context(unsigned long context_id);
|
|
extern void mmu_context_init(void);
|
|
#endif
|
|
|
|
extern void switch_cop(struct mm_struct *next);
|
|
extern int use_cop(unsigned long acop, struct mm_struct *mm);
|
|
extern void drop_cop(unsigned long acop, struct mm_struct *mm);
|
|
|
|
/*
|
|
* switch_mm is the entry point called from the architecture independent
|
|
* code in kernel/sched.c
|
|
*/
|
|
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
|
|
struct task_struct *tsk)
|
|
{
|
|
/* Mark this context has been used on the new CPU */
|
|
cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
|
|
|
|
/* 32-bit keeps track of the current PGDIR in the thread struct */
|
|
#ifdef CONFIG_PPC32
|
|
tsk->thread.pgdir = next->pgd;
|
|
#endif /* CONFIG_PPC32 */
|
|
|
|
/* 64-bit Book3E keeps track of current PGD in the PACA */
|
|
#ifdef CONFIG_PPC_BOOK3E_64
|
|
get_paca()->pgd = next->pgd;
|
|
#endif
|
|
/* Nothing else to do if we aren't actually switching */
|
|
if (prev == next)
|
|
return;
|
|
|
|
#ifdef CONFIG_PPC_ICSWX
|
|
/* Switch coprocessor context only if prev or next uses a coprocessor */
|
|
if (prev->context.acop || next->context.acop)
|
|
switch_cop(next);
|
|
#endif /* CONFIG_PPC_ICSWX */
|
|
|
|
/* We must stop all altivec streams before changing the HW
|
|
* context
|
|
*/
|
|
#ifdef CONFIG_ALTIVEC
|
|
if (cpu_has_feature(CPU_FTR_ALTIVEC))
|
|
asm volatile ("dssall");
|
|
#endif /* CONFIG_ALTIVEC */
|
|
|
|
/* The actual HW switching method differs between the various
|
|
* sub architectures.
|
|
*/
|
|
#ifdef CONFIG_PPC_STD_MMU_64
|
|
if (mmu_has_feature(MMU_FTR_SLB))
|
|
switch_slb(tsk, next);
|
|
else
|
|
switch_stab(tsk, next);
|
|
#else
|
|
/* Out of line for now */
|
|
switch_mmu_context(prev, next);
|
|
#endif
|
|
|
|
}
|
|
|
|
#define deactivate_mm(tsk,mm) do { } while (0)
|
|
|
|
/*
|
|
* After we have set current->mm to a new value, this activates
|
|
* the context for the new mm so we see the new mappings.
|
|
*/
|
|
static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
switch_mm(prev, next, current);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
/* We don't currently use enter_lazy_tlb() for anything */
|
|
static inline void enter_lazy_tlb(struct mm_struct *mm,
|
|
struct task_struct *tsk)
|
|
{
|
|
/* 64-bit Book3E keeps track of current PGD in the PACA */
|
|
#ifdef CONFIG_PPC_BOOK3E_64
|
|
get_paca()->pgd = NULL;
|
|
#endif
|
|
}
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* __ASM_POWERPC_MMU_CONTEXT_H */
|