arm64: entry.S convert el0_sync

el0_sync also unmasks exceptions on a case-by-case basis, debug exceptions
are enabled, unless this was a debug exception. Irqs are unmasked for
some exception types but not for others.

el0_dbg should run with everything masked to prevent us taking a debug
exception from do_debug_exception. For the other cases we can unmask
everything. This changes the behaviour of fpsimd_{acc,exc} and el0_inv
which previously ran with irqs masked.

This patch removed the last user of enable_dbg_and_irq, remove it.

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 1886b8b4467216009567cde9f21c09882f655b7f..90d1f01d602f653eb92ba691056e924d7acb12f8 100644 (file)
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -97,15 +97,6 @@
 9990:
        .endm
 
-/*
- * Enable both debug exceptions and interrupts. This is likely to be
- * faster than two daifclr operations, since writes to this register
- * are self-synchronising.
- */
-       .macro  enable_dbg_and_irq
-       msr     daifclr, #(8 | 2)
-       .endm
-
 /*
  * SMP data memory barrier
  */

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 72fc5969607f55a4592d985ef6c8e522c0d1e896..a3e6a3954fe0749d9379b30066415b8140bedb2a 100644 (file)
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -670,8 +670,7 @@ el0_da:
         * Data abort handling
         */
        mrs     x26, far_el1
-       // enable interrupts before calling the main handler
-       enable_dbg_and_irq
+       enable_daif
        ct_user_exit
        clear_address_tag x0, x26
        mov     x1, x25
@@ -683,8 +682,7 @@ el0_ia:
         * Instruction abort handling
         */
        mrs     x26, far_el1
-       // enable interrupts before calling the main handler
-       enable_dbg_and_irq
+       enable_daif
        ct_user_exit
        mov     x0, x26
        mov     x1, x25
@@ -695,7 +693,7 @@ el0_fpsimd_acc:
        /*
         * Floating Point or Advanced SIMD access
         */
-       enable_dbg
+       enable_daif
        ct_user_exit
        mov     x0, x25
        mov     x1, sp
@@ -705,7 +703,7 @@ el0_fpsimd_exc:
        /*
         * Floating Point or Advanced SIMD exception
         */
-       enable_dbg
+       enable_daif
        ct_user_exit
        mov     x0, x25
        mov     x1, sp
@@ -716,8 +714,7 @@ el0_sp_pc:
         * Stack or PC alignment exception handling
         */
        mrs     x26, far_el1
-       // enable interrupts before calling the main handler
-       enable_dbg_and_irq
+       enable_daif
        ct_user_exit
        mov     x0, x26
        mov     x1, x25
@@ -728,8 +725,7 @@ el0_undef:
        /*
         * Undefined instruction
         */
-       // enable interrupts before calling the main handler
-       enable_dbg_and_irq
+       enable_daif
        ct_user_exit
        mov     x0, sp
        bl      do_undefinstr
@@ -738,7 +734,7 @@ el0_sys:
        /*
         * System instructions, for trapped cache maintenance instructions
         */
-       enable_dbg_and_irq
+       enable_daif
        ct_user_exit
        mov     x0, x25
        mov     x1, sp
@@ -753,11 +749,11 @@ el0_dbg:
        mov     x1, x25
        mov     x2, sp
        bl      do_debug_exception
-       enable_dbg
+       enable_daif
        ct_user_exit
        b       ret_to_user
 el0_inv:
-       enable_dbg
+       enable_daif
        ct_user_exit
        mov     x0, sp
        mov     x1, #BAD_SYNC
@@ -836,7 +832,7 @@ el0_svc:
        mov     wsc_nr, #__NR_syscalls
 el0_svc_naked:                                 // compat entry point
        stp     x0, xscno, [sp, #S_ORIG_X0]     // save the original x0 and syscall number
-       enable_dbg_and_irq
+       enable_daif
        ct_user_exit 1
 
        ldr     x16, [tsk, #TSK_TI_FLAGS]       // check for syscall hooks