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csky: Remove prologue of page fault handler in entry.S

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There is a prologue on page fault handler which marking pages dirty
and/or accessed in page attributes, but all of these have been
handled in handle_pte_fault.

 - Add flush_tlb_one in vmalloc page fault instead of prologue.
 - Using cmxchg_fixup C codes in do_page_fault instead of ASM one.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
This commit is contained in:
Guo Ren
2020-12-24 02:02:55 +00:00
parent 7b513cf2bf
commit b0ae5e26b8
4 changed files with 48 additions and 131 deletions
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45
arch/csky/mm/fault.c
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@@ -39,20 +39,52 @@ int fixup_exception(struct pt_regs *regs)
return 0;
}
static inline bool is_write(struct pt_regs *regs)
{
switch (trap_no(regs)) {
case VEC_TLBINVALIDS:
return true;
case VEC_TLBMODIFIED:
return true;
}
return false;
}
#ifdef CONFIG_CPU_HAS_LDSTEX
static inline void csky_cmpxchg_fixup(struct pt_regs *regs)
{
return;
}
#else
extern unsigned long csky_cmpxchg_ldw;
extern unsigned long csky_cmpxchg_stw;
static inline void csky_cmpxchg_fixup(struct pt_regs *regs)
{
if (trap_no(regs) != VEC_TLBMODIFIED)
return;
if (instruction_pointer(regs) == csky_cmpxchg_stw)
instruction_pointer_set(regs, csky_cmpxchg_ldw);
return;
}
#endif
/*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
* routines.
*/
asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
unsigned long mmu_meh)
asmlinkage void do_page_fault(struct pt_regs *regs)
{
struct vm_area_struct *vma = NULL;
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
int si_code;
int fault;
unsigned long address = mmu_meh & PAGE_MASK;
unsigned long address = read_mmu_entryhi() & PAGE_MASK;
csky_cmpxchg_fixup(regs);
if (kprobe_page_fault(regs, tsk->thread.trap_no))
return;
@@ -104,6 +136,9 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
pte_k = pte_offset_kernel(pmd_k, address);
if (!pte_present(*pte_k))
goto no_context;
flush_tlb_one(address);
return;
}
@@ -132,7 +167,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
good_area:
si_code = SEGV_ACCERR;
if (write) {
if (is_write(regs)) {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
} else {
@@ -145,7 +180,7 @@ good_area:
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
fault = handle_mm_fault(vma, address, write ? FAULT_FLAG_WRITE : 0,
fault = handle_mm_fault(vma, address, is_write(regs) ? FAULT_FLAG_WRITE : 0,
regs);
if (unlikely(fault & VM_FAULT_ERROR)) {
if (fault & VM_FAULT_OOM)