powerpc/64s: split do_hash_fault

This is required for subsequent interrupt wrapper implementation.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210130130852.2952424-16-npiggin@gmail.com

diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index 1a270cc37d974e8b3c57aa356e6e6b044b14ff31..d7d3a80a51d496edf75e42448f7610b2fdb7d275 100644 (file)
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -1512,7 +1512,7 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap,
 }
 EXPORT_SYMBOL_GPL(hash_page);
 
-long do_hash_fault(struct pt_regs *regs)
+static long __do_hash_fault(struct pt_regs *regs)
 {
        unsigned long ea = regs->dar;
        unsigned long dsisr = regs->dsisr;
@@ -1522,27 +1522,6 @@ long do_hash_fault(struct pt_regs *regs)
        unsigned int region_id;
        long err;
 
-       if (unlikely(dsisr & (DSISR_BAD_FAULT_64S | DSISR_KEYFAULT)))
-               goto page_fault;
-
-       /*
-        * If we are in an "NMI" (e.g., an interrupt when soft-disabled), then
-        * don't call hash_page, just fail the fault. This is required to
-        * prevent re-entrancy problems in the hash code, namely perf
-        * interrupts hitting while something holds H_PAGE_BUSY, and taking a
-        * hash fault. See the comment in hash_preload().
-        *
-        * We come here as a result of a DSI at a point where we don't want
-        * to call hash_page, such as when we are accessing memory (possibly
-        * user memory) inside a PMU interrupt that occurred while interrupts
-        * were soft-disabled.  We want to invoke the exception handler for
-        * the access, or panic if there isn't a handler.
-        */
-       if (unlikely(in_nmi())) {
-               bad_page_fault(regs, SIGSEGV);
-               return 0;
-       }
-
        region_id = get_region_id(ea);
        if ((region_id == VMALLOC_REGION_ID) || (region_id == IO_REGION_ID))
                mm = &init_mm;
@@ -1581,8 +1560,39 @@ long do_hash_fault(struct pt_regs *regs)
                        bad_page_fault(regs, SIGBUS);
                }
                err = 0;
+       }
+
+       return err;
+}
+
+long do_hash_fault(struct pt_regs *regs)
+{
+       unsigned long dsisr = regs->dsisr;
+       long err;
+
+       if (unlikely(dsisr & (DSISR_BAD_FAULT_64S | DSISR_KEYFAULT)))
+               goto page_fault;
+
+       /*
+        * If we are in an "NMI" (e.g., an interrupt when soft-disabled), then
+        * don't call hash_page, just fail the fault. This is required to
+        * prevent re-entrancy problems in the hash code, namely perf
+        * interrupts hitting while something holds H_PAGE_BUSY, and taking a
+        * hash fault. See the comment in hash_preload().
+        *
+        * We come here as a result of a DSI at a point where we don't want
+        * to call hash_page, such as when we are accessing memory (possibly
+        * user memory) inside a PMU interrupt that occurred while interrupts
+        * were soft-disabled.  We want to invoke the exception handler for
+        * the access, or panic if there isn't a handler.
+        */
+       if (unlikely(in_nmi())) {
+               bad_page_fault(regs, SIGSEGV);
+               return 0;
+       }
 
-       } else if (err) {
+       err = __do_hash_fault(regs);
+       if (err) {
 page_fault:
                err = do_page_fault(regs);
        }