1 files changed, 26 insertions, 4 deletions

diff --git a/arch/arm/mach-shmobile/include/mach/entry-macro.S b/arch/arm/mach-shmobile/include/mach/entry-macro.S
index a285d13c7416..f428c4db2b60 100644
--- a/arch/arm/mach-shmobile/include/mach/entry-macro.S
+++ b/arch/arm/mach-shmobile/include/mach/entry-macro.S
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2010 Magnus Damm
  * Copyright (C) 2008 Renesas Solutions Corp.
  *
  * This program is free software; you can redistribute it and/or modify
@@ -14,24 +15,45 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
-#include <mach/hardware.h>
 #include <mach/irqs.h>
 
+#define INTCA_BASE      0xe6980000
+#define INTFLGA_OFFS    0x00000018 /* accept pending interrupt */
+#define INTEVTA_OFFS    0x00000020 /* vector number of accepted interrupt */
+#define INTLVLA_OFFS    0x00000030 /* priority level of accepted interrupt */
+#define INTLVLB_OFFS    0x00000034 /* previous priority level */
+
         .macro  disable_fiq
         .endm
 
         .macro  get_irqnr_preamble, base, tmp
-        ldr     \base, =INTFLGA
+        ldr     \base, =INTCA_BASE
         .endm
 
         .macro  arch_ret_to_user, tmp1, tmp2
         .endm
 
         .macro  get_irqnr_and_base, irqnr, irqstat, base, tmp
-        ldr     \irqnr, [\base]
+        /* The single INTFLGA read access below results in the following:
+         *
+         * 1. INTLVLB is updated with old priority value from INTLVLA
+         * 2. Highest priority interrupt is accepted
+         * 3. INTLVLA is updated to contain priority of accepted interrupt
+         * 4. Accepted interrupt vector is stored in INTFLGA and INTEVTA
+         */
+        ldr     \irqnr, [\base, #INTFLGA_OFFS]
+
+        /* Restore INTLVLA with the value saved in INTLVLB.
+         * This is required to support interrupt priorities properly.
+         */
+        ldrb    \tmp, [\base, #INTLVLB_OFFS]
+        strb    \tmp, [\base, #INTLVLA_OFFS]
+
+        /* Handle invalid vector number case */
         cmp     \irqnr, #0
         beq     1000f
-        /* intevt to irq number */
+
+        /* Convert vector to irq number, same as the evt2irq() macro */
         lsr     \irqnr, \irqnr, #0x5
         subs    \irqnr, \irqnr, #16