ARM: mach-shmobile: INTC interrupt priority level demux fix

[pandora-kernel.git] / arch / arm / mach-shmobile / include / mach / entry-macro.S

diff --git a/arch/arm/mach-shmobile/include/mach/entry-macro.S b/arch/arm/mach-shmobile/include/mach/entry-macro.S
index a285d13..f428c4d 100644 (file)
--- 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