arm64: entry.S: convert el1_sync

el1_sync unmasks exceptions on a case-by-case basis, debug exceptions
are unmasked, unless this was a debug exception. IRQs are unmasked
for instruction and data aborts only if the interupted context had
irqs unmasked.

Following our 'dai' order, el1_dbg should run with everything masked.
For the other cases we can inherit whatever we interrupted.

Add a macro inherit_daif to set daif based on the interrupted pstate.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 8bc63fc98752992a9571b14dbe1116241ebc3726..1886b8b4467216009567cde9f21c09882f655b7f 100644 (file)
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -49,6 +49,12 @@
        msr     daif, \flags
        .endm
 
+       /* Only on aarch64 pstate, PSR_D_BIT is different for aarch32 */
+       .macro  inherit_daif, pstate:req, tmp:req
+       and     \tmp, \pstate, #(PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
+       msr     daif, \tmp
+       .endm
+
 /*
  * Enable and disable interrupts.
  */

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index eff4a07c7ad76952fd6792f823bd883ed6416242..72fc5969607f55a4592d985ef6c8e522c0d1e896 100644 (file)
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -510,11 +510,7 @@ el1_da:
         * Data abort handling
         */
        mrs     x3, far_el1
-       enable_dbg
-       // re-enable interrupts if they were enabled in the aborted context
-       tbnz    x23, #7, 1f                     // PSR_I_BIT
-       enable_irq
-1:
+       inherit_daif    pstate=x23, tmp=x2
        clear_address_tag x0, x3
        mov     x2, sp                          // struct pt_regs
        bl      do_mem_abort
@@ -525,7 +521,7 @@ el1_sp_pc:
         * Stack or PC alignment exception handling
         */
        mrs     x0, far_el1
-       enable_dbg
+       inherit_daif    pstate=x23, tmp=x2
        mov     x2, sp
        bl      do_sp_pc_abort
        ASM_BUG()
@@ -533,7 +529,7 @@ el1_undef:
        /*
         * Undefined instruction
         */
-       enable_dbg
+       inherit_daif    pstate=x23, tmp=x2
        mov     x0, sp
        bl      do_undefinstr
        ASM_BUG()
@@ -550,7 +546,7 @@ el1_dbg:
        kernel_exit 1
 el1_inv:
        // TODO: add support for undefined instructions in kernel mode
-       enable_dbg
+       inherit_daif    pstate=x23, tmp=x2
        mov     x0, sp
        mov     x2, x1
        mov     x1, #BAD_SYNC