diff options
Diffstat (limited to 'drivers/misc/cxl/fault.c')
| -rw-r--r-- | drivers/misc/cxl/fault.c | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/drivers/misc/cxl/fault.c b/drivers/misc/cxl/fault.c index 6eed7d03e2b5..70dbb6de102c 100644 --- a/drivers/misc/cxl/fault.c +++ b/drivers/misc/cxl/fault.c @@ -138,6 +138,22 @@ int cxl_handle_mm_fault(struct mm_struct *mm, u64 dsisr, u64 dar) int result; unsigned long access, flags, inv_flags = 0; + /* + * Add the fault handling cpu to task mm cpumask so that we + * can do a safe lockless page table walk when inserting the + * hash page table entry. This function get called with a + * valid mm for user space addresses. Hence using the if (mm) + * check is sufficient here. + */ + if (mm && !cpumask_test_cpu(smp_processor_id(), mm_cpumask(mm))) { + cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm)); + /* + * We need to make sure we walk the table only after + * we update the cpumask. The other side of the barrier + * is explained in serialize_against_pte_lookup() + */ + smp_mb(); + } if ((result = copro_handle_mm_fault(mm, dar, dsisr, &flt))) { pr_devel("copro_handle_mm_fault failed: %#x\n", result); return result; @@ -204,22 +220,11 @@ static bool cxl_is_segment_miss(struct cxl_context *ctx, u64 dsisr) static bool cxl_is_page_fault(struct cxl_context *ctx, u64 dsisr) { - u64 crs; /* Translation Checkout Response Status */ - if ((cxl_is_power8()) && (dsisr & CXL_PSL_DSISR_An_DM)) return true; - if (cxl_is_power9()) { - crs = (dsisr & CXL_PSL9_DSISR_An_CO_MASK); - if ((crs == CXL_PSL9_DSISR_An_PF_SLR) || - (crs == CXL_PSL9_DSISR_An_PF_RGC) || - (crs == CXL_PSL9_DSISR_An_PF_RGP) || - (crs == CXL_PSL9_DSISR_An_PF_HRH) || - (crs == CXL_PSL9_DSISR_An_PF_STEG) || - (crs == CXL_PSL9_DSISR_An_URTCH)) { - return true; - } - } + if (cxl_is_power9()) + return true; return false; } |