Current File : //usr/src/linux-headers-5.15.0-43/arch/sparc/include/asm/mmu_context_64.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __SPARC64_MMU_CONTEXT_H
#define __SPARC64_MMU_CONTEXT_H
/* Derived heavily from Linus's Alpha/AXP ASN code... */
#ifndef __ASSEMBLY__
#include <linux/spinlock.h>
#include <linux/mm_types.h>
#include <linux/smp.h>
#include <linux/sched.h>
#include <asm/spitfire.h>
#include <asm/adi_64.h>
#include <asm-generic/mm_hooks.h>
#include <asm/percpu.h>
extern spinlock_t ctx_alloc_lock;
extern unsigned long tlb_context_cache;
extern unsigned long mmu_context_bmap[];
DECLARE_PER_CPU(struct mm_struct *, per_cpu_secondary_mm);
void get_new_mmu_context(struct mm_struct *mm);
#define init_new_context init_new_context
int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
#define destroy_context destroy_context
void destroy_context(struct mm_struct *mm);
void __tsb_context_switch(unsigned long pgd_pa,
struct tsb_config *tsb_base,
struct tsb_config *tsb_huge,
unsigned long tsb_descr_pa,
unsigned long secondary_ctx);
static inline void tsb_context_switch_ctx(struct mm_struct *mm,
unsigned long ctx)
{
__tsb_context_switch(__pa(mm->pgd),
&mm->context.tsb_block[MM_TSB_BASE],
#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
(mm->context.tsb_block[MM_TSB_HUGE].tsb ?
&mm->context.tsb_block[MM_TSB_HUGE] :
NULL)
#else
NULL
#endif
, __pa(&mm->context.tsb_descr[MM_TSB_BASE]),
ctx);
}
#define tsb_context_switch(X) tsb_context_switch_ctx(X, 0)
void tsb_grow(struct mm_struct *mm,
unsigned long tsb_index,
unsigned long mm_rss);
#ifdef CONFIG_SMP
void smp_tsb_sync(struct mm_struct *mm);
#else
#define smp_tsb_sync(__mm) do { } while (0)
#endif
/* Set MMU context in the actual hardware. */
#define load_secondary_context(__mm) \
__asm__ __volatile__( \
"\n661: stxa %0, [%1] %2\n" \
" .section .sun4v_1insn_patch, \"ax\"\n" \
" .word 661b\n" \
" stxa %0, [%1] %3\n" \
" .previous\n" \
" flush %%g6\n" \
: /* No outputs */ \
: "r" (CTX_HWBITS((__mm)->context)), \
"r" (SECONDARY_CONTEXT), "i" (ASI_DMMU), "i" (ASI_MMU))
void __flush_tlb_mm(unsigned long, unsigned long);
/* Switch the current MM context. */
static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk)
{
unsigned long ctx_valid, flags;
int cpu = smp_processor_id();
per_cpu(per_cpu_secondary_mm, cpu) = mm;
if (unlikely(mm == &init_mm))
return;
spin_lock_irqsave(&mm->context.lock, flags);
ctx_valid = CTX_VALID(mm->context);
if (!ctx_valid)
get_new_mmu_context(mm);
/* We have to be extremely careful here or else we will miss
* a TSB grow if we switch back and forth between a kernel
* thread and an address space which has it's TSB size increased
* on another processor.
*
* It is possible to play some games in order to optimize the
* switch, but the safest thing to do is to unconditionally
* perform the secondary context load and the TSB context switch.
*
* For reference the bad case is, for address space "A":
*
* CPU 0 CPU 1
* run address space A
* set cpu0's bits in cpu_vm_mask
* switch to kernel thread, borrow
* address space A via entry_lazy_tlb
* run address space A
* set cpu1's bit in cpu_vm_mask
* flush_tlb_pending()
* reset cpu_vm_mask to just cpu1
* TSB grow
* run address space A
* context was valid, so skip
* TSB context switch
*
* At that point cpu0 continues to use a stale TSB, the one from
* before the TSB grow performed on cpu1. cpu1 did not cross-call
* cpu0 to update it's TSB because at that point the cpu_vm_mask
* only had cpu1 set in it.
*/
tsb_context_switch_ctx(mm, CTX_HWBITS(mm->context));
/* Any time a processor runs a context on an address space
* for the first time, we must flush that context out of the
* local TLB.
*/
if (!ctx_valid || !cpumask_test_cpu(cpu, mm_cpumask(mm))) {
cpumask_set_cpu(cpu, mm_cpumask(mm));
__flush_tlb_mm(CTX_HWBITS(mm->context),
SECONDARY_CONTEXT);
}
spin_unlock_irqrestore(&mm->context.lock, flags);
}
#define activate_mm(active_mm, mm) switch_mm(active_mm, mm, NULL)
#define __HAVE_ARCH_START_CONTEXT_SWITCH
static inline void arch_start_context_switch(struct task_struct *prev)
{
/* Save the current state of MCDPER register for the process
* we are switching from
*/
if (adi_capable()) {
register unsigned long tmp_mcdper;
__asm__ __volatile__(
".word 0x83438000\n\t" /* rd %mcdper, %g1 */
"mov %%g1, %0\n\t"
: "=r" (tmp_mcdper)
:
: "g1");
if (tmp_mcdper)
set_tsk_thread_flag(prev, TIF_MCDPER);
else
clear_tsk_thread_flag(prev, TIF_MCDPER);
}
}
#define finish_arch_post_lock_switch finish_arch_post_lock_switch
static inline void finish_arch_post_lock_switch(void)
{
/* Restore the state of MCDPER register for the new process
* just switched to.
*/
if (adi_capable()) {
register unsigned long tmp_mcdper;
tmp_mcdper = test_thread_flag(TIF_MCDPER);
__asm__ __volatile__(
"mov %0, %%g1\n\t"
".word 0x9d800001\n\t" /* wr %g0, %g1, %mcdper" */
".word 0xaf902001\n\t" /* wrpr %g0, 1, %pmcdper */
:
: "ir" (tmp_mcdper)
: "g1");
if (current && current->mm && current->mm->context.adi) {
struct pt_regs *regs;
regs = task_pt_regs(current);
regs->tstate |= TSTATE_MCDE;
}
}
}
#include <asm-generic/mmu_context.h>
#endif /* !(__ASSEMBLY__) */
#endif /* !(__SPARC64_MMU_CONTEXT_H) */
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