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-rw-r--r--arch/loongarch/include/asm/atomic.h2
-rw-r--r--arch/loongarch/include/asm/mmu_context.h35
-rw-r--r--arch/loongarch/include/asm/pgtable.h32
-rw-r--r--arch/loongarch/mm/fault.c41
4 files changed, 83 insertions, 27 deletions
diff --git a/arch/loongarch/include/asm/atomic.h b/arch/loongarch/include/asm/atomic.h
index 99af8b3160a8..c86f0ab922ec 100644
--- a/arch/loongarch/include/asm/atomic.h
+++ b/arch/loongarch/include/asm/atomic.h
@@ -15,6 +15,7 @@
#define __LL "ll.w "
#define __SC "sc.w "
#define __AMADD "amadd.w "
+#define __AMOR "amor.w "
#define __AMAND_DB "amand_db.w "
#define __AMOR_DB "amor_db.w "
#define __AMXOR_DB "amxor_db.w "
@@ -22,6 +23,7 @@
#define __LL "ll.d "
#define __SC "sc.d "
#define __AMADD "amadd.d "
+#define __AMOR "amor.d "
#define __AMAND_DB "amand_db.d "
#define __AMOR_DB "amor_db.d "
#define __AMXOR_DB "amxor_db.d "
diff --git a/arch/loongarch/include/asm/mmu_context.h b/arch/loongarch/include/asm/mmu_context.h
index 9f97c3453b9c..304363bd3935 100644
--- a/arch/loongarch/include/asm/mmu_context.h
+++ b/arch/loongarch/include/asm/mmu_context.h
@@ -49,12 +49,12 @@ static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
/* Normal, classic get_new_mmu_context */
static inline void
-get_new_mmu_context(struct mm_struct *mm, unsigned long cpu)
+get_new_mmu_context(struct mm_struct *mm, unsigned long cpu, bool *need_flush)
{
u64 asid = asid_cache(cpu);
if (!((++asid) & cpu_asid_mask(&cpu_data[cpu])))
- local_flush_tlb_user(); /* start new asid cycle */
+ *need_flush = true; /* start new asid cycle */
cpu_context(cpu, mm) = asid_cache(cpu) = asid;
}
@@ -74,21 +74,34 @@ init_new_context(struct task_struct *tsk, struct mm_struct *mm)
return 0;
}
+static inline void atomic_update_pgd_asid(unsigned long asid, unsigned long pgdl)
+{
+ __asm__ __volatile__(
+ "csrwr %[pgdl_val], %[pgdl_reg] \n\t"
+ "csrwr %[asid_val], %[asid_reg] \n\t"
+ : [asid_val] "+r" (asid), [pgdl_val] "+r" (pgdl)
+ : [asid_reg] "i" (LOONGARCH_CSR_ASID), [pgdl_reg] "i" (LOONGARCH_CSR_PGDL)
+ : "memory"
+ );
+}
+
static inline void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
+ bool need_flush = false;
unsigned int cpu = smp_processor_id();
/* Check if our ASID is of an older version and thus invalid */
if (!asid_valid(next, cpu))
- get_new_mmu_context(next, cpu);
-
- write_csr_asid(cpu_asid(cpu, next));
+ get_new_mmu_context(next, cpu, &need_flush);
if (next != &init_mm)
- csr_write64((unsigned long)next->pgd, LOONGARCH_CSR_PGDL);
+ atomic_update_pgd_asid(cpu_asid(cpu, next), (unsigned long)next->pgd);
else
- csr_write64((unsigned long)invalid_pg_dir, LOONGARCH_CSR_PGDL);
+ atomic_update_pgd_asid(cpu_asid(cpu, next), (unsigned long)invalid_pg_dir);
+
+ if (need_flush)
+ local_flush_tlb_user(); /* Flush tlb after update ASID */
/*
* Mark current->active_mm as not "active" anymore.
@@ -135,9 +148,15 @@ drop_mmu_context(struct mm_struct *mm, unsigned int cpu)
asid = read_csr_asid() & cpu_asid_mask(&current_cpu_data);
if (asid == cpu_asid(cpu, mm)) {
+ bool need_flush = false;
+
if (!current->mm || (current->mm == mm)) {
- get_new_mmu_context(mm, cpu);
+ get_new_mmu_context(mm, cpu, &need_flush);
+
write_csr_asid(cpu_asid(cpu, mm));
+ if (need_flush)
+ local_flush_tlb_user(); /* Flush tlb after update ASID */
+
goto out;
}
}
diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
index 85431f20a14d..9965f52ef65b 100644
--- a/arch/loongarch/include/asm/pgtable.h
+++ b/arch/loongarch/include/asm/pgtable.h
@@ -331,29 +331,23 @@ static inline void set_pte(pte_t *ptep, pte_t pteval)
* Make sure the buddy is global too (if it's !none,
* it better already be global)
*/
+ if (pte_none(ptep_get(buddy))) {
#ifdef CONFIG_SMP
- /*
- * For SMP, multiple CPUs can race, so we need to do
- * this atomically.
- */
- unsigned long page_global = _PAGE_GLOBAL;
- unsigned long tmp;
-
- __asm__ __volatile__ (
- "1:" __LL "%[tmp], %[buddy] \n"
- " bnez %[tmp], 2f \n"
- " or %[tmp], %[tmp], %[global] \n"
- __SC "%[tmp], %[buddy] \n"
- " beqz %[tmp], 1b \n"
- " nop \n"
- "2: \n"
- __WEAK_LLSC_MB
- : [buddy] "+m" (buddy->pte), [tmp] "=&r" (tmp)
- : [global] "r" (page_global));
+ /*
+ * For SMP, multiple CPUs can race, so we need
+ * to do this atomically.
+ */
+ __asm__ __volatile__(
+ __AMOR "$zero, %[global], %[buddy] \n"
+ : [buddy] "+ZB" (buddy->pte)
+ : [global] "r" (_PAGE_GLOBAL)
+ : "memory");
+
+ DBAR(0b11000); /* o_wrw = 0b11000 */
#else /* !CONFIG_SMP */
- if (pte_none(ptep_get(buddy)))
WRITE_ONCE(*buddy, __pte(pte_val(ptep_get(buddy)) | _PAGE_GLOBAL));
#endif /* CONFIG_SMP */
+ }
}
}
diff --git a/arch/loongarch/mm/fault.c b/arch/loongarch/mm/fault.c
index 97b40defde06..deefd9617d00 100644
--- a/arch/loongarch/mm/fault.c
+++ b/arch/loongarch/mm/fault.c
@@ -31,11 +31,52 @@
int show_unhandled_signals = 1;
+static int __kprobes spurious_fault(unsigned long write, unsigned long address)
+{
+ pgd_t *pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ if (!(address & __UA_LIMIT))
+ return 0;
+
+ pgd = pgd_offset_k(address);
+ if (!pgd_present(pgdp_get(pgd)))
+ return 0;
+
+ p4d = p4d_offset(pgd, address);
+ if (!p4d_present(p4dp_get(p4d)))
+ return 0;
+
+ pud = pud_offset(p4d, address);
+ if (!pud_present(pudp_get(pud)))
+ return 0;
+
+ pmd = pmd_offset(pud, address);
+ if (!pmd_present(pmdp_get(pmd)))
+ return 0;
+
+ if (pmd_leaf(*pmd)) {
+ return write ? pmd_write(pmdp_get(pmd)) : 1;
+ } else {
+ pte = pte_offset_kernel(pmd, address);
+ if (!pte_present(ptep_get(pte)))
+ return 0;
+
+ return write ? pte_write(ptep_get(pte)) : 1;
+ }
+}
+
static void __kprobes no_context(struct pt_regs *regs,
unsigned long write, unsigned long address)
{
const int field = sizeof(unsigned long) * 2;
+ if (spurious_fault(write, address))
+ return;
+
/* Are we prepared to handle this kernel fault? */
if (fixup_exception(regs))
return;