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authorRalf Baechle <ralf@linux-mips.org>2006-04-03 17:56:36 +0100
committerRalf Baechle <ralf@linux-mips.org>2006-04-19 04:14:21 +0200
commite4ac58afdfac792c0583af30dbd9eae53e24c78b (patch)
tree7517bef2c515fc630e4d3d238867b91cde96f558 /arch/mips/mips-boards/atlas
parentd35d473c25d43d7db3e5e18b66d558d2a631cca8 (diff)
[MIPS] Rewrite all the assembler interrupt handlers to C.
Saves like 1,600 lines of code, is way easier to debug, compilers frequently do a better job than the cut and paste type of handlers many boards had. And finally having all the stuff done in a single place also means alot of bug potencial for the MT ASE is gone. The only surviving handler in assembler is the DECstation one; I hope Maciej will rewrite it. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/mips-boards/atlas')
-rw-r--r--arch/mips/mips-boards/atlas/Makefile2
-rw-r--r--arch/mips/mips-boards/atlas/atlas-irq.S120
-rw-r--r--arch/mips/mips-boards/atlas/atlas_int.c92
3 files changed, 87 insertions, 127 deletions
diff --git a/arch/mips/mips-boards/atlas/Makefile b/arch/mips/mips-boards/atlas/Makefile
index 50fec2a5aee6..d8dab75906bf 100644
--- a/arch/mips/mips-boards/atlas/Makefile
+++ b/arch/mips/mips-boards/atlas/Makefile
@@ -16,5 +16,5 @@
# 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
#
-obj-y := atlas_int.o atlas-irq.o atlas_setup.o
+obj-y := atlas_int.o atlas_setup.o
obj-$(CONFIG_KGDB) += atlas_gdb.o
diff --git a/arch/mips/mips-boards/atlas/atlas-irq.S b/arch/mips/mips-boards/atlas/atlas-irq.S
deleted file mode 100644
index 31bc99a52383..000000000000
--- a/arch/mips/mips-boards/atlas/atlas-irq.S
+++ /dev/null
@@ -1,120 +0,0 @@
-/*
- * Carsten Langgaard, carstenl@mips.com
- * Copyright (C) 1999, 2000 MIPS Technologies, Inc. All rights reserved.
- *
- * This program is free software; you can distribute it and/or modify it
- * under the terms of the GNU General Public License (Version 2) as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
- *
- * Interrupt exception dispatch code.
- */
-#include <linux/config.h>
-
-#include <asm/asm.h>
-#include <asm/mipsregs.h>
-#include <asm/regdef.h>
-#include <asm/stackframe.h>
-#include <asm/mips-boards/atlasint.h>
-
-/*
- * Furthermore, the IRQs on the MIPS board look basically (barring software
- * IRQs which we don't use at all and all external interrupt sources are
- * combined together on hardware interrupt 0 (MIPS IRQ 2)) like:
- *
- * MIPS IRQ Source
- * -------- ------
- * 0 Software (ignored)
- * 1 Software (ignored)
- * 2 Combined hardware interrupt (hw0)
- * 3 Hardware (ignored)
- * 4 Hardware (ignored)
- * 5 Hardware (ignored)
- * 6 Hardware (ignored)
- * 7 R4k timer (what we use)
- *
- * Note: On the SEAD board thing are a little bit different.
- * Here IRQ 2 (hw0) is wired to the UART0 and IRQ 3 (hw1) is wired
- * wired to UART1.
- *
- * We handle the IRQ according to _our_ priority which is:
- *
- * Highest ---- R4k Timer
- * Lowest ---- Combined hardware interrupt
- *
- * then we just return, if multiple IRQs are pending then we will just take
- * another exception, big deal.
- */
-
- .text
- .set noreorder
- .set noat
- .align 5
- NESTED(mipsIRQ, PT_SIZE, sp)
- SAVE_ALL
- CLI
- .set at
-
- mfc0 s0, CP0_CAUSE # get irq bits
- mfc0 s1, CP0_STATUS # get irq mask
- andi s0, ST0_IM # CAUSE.CE may be non-zero!
- and s0, s1
-
-#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
- .set mips32
- clz a0, s0
- .set mips0
- negu a0
- addu a0, 31-CAUSEB_IP
- bltz a0, spurious
-#else
- beqz s0, spurious
- li a0, 7
-
- and t0, s0, 0xf000
- sltiu t0, t0, 1
- sll t0, 2
- subu a0, t0
- sll s0, t0
-
- and t0, s0, 0xc000
- sltiu t0, t0, 1
- sll t0, 1
- subu a0, t0
- sll s0, t0
-
- and t0, s0, 0x8000
- sltiu t0, t0, 1
- # sll t0, 0
- subu a0, t0
- # sll s0, t0
-#endif
-
- li a1, MIPSCPU_INT_ATLAS
- bne a0, a1, 1f
- addu a0, MIPSCPU_INT_BASE
-
- jal atlas_hw0_irqdispatch
- move a0, sp
-
- j ret_from_irq
- nop
-
-1: jal do_IRQ
- move a1, sp
-
- j ret_from_irq
- nop
-
-spurious:
- j spurious_interrupt
- nop
- END(mipsIRQ)
diff --git a/arch/mips/mips-boards/atlas/atlas_int.c b/arch/mips/mips-boards/atlas/atlas_int.c
index bc0ebc69bfb3..db53950b7cfb 100644
--- a/arch/mips/mips-boards/atlas/atlas_int.c
+++ b/arch/mips/mips-boards/atlas/atlas_int.c
@@ -39,8 +39,6 @@
static struct atlas_ictrl_regs *atlas_hw0_icregs;
-extern asmlinkage void mipsIRQ(void);
-
#if 0
#define DEBUG_INT(x...) printk(x)
#else
@@ -98,7 +96,7 @@ static inline int ls1bit32(unsigned int x)
return b;
}
-void atlas_hw0_irqdispatch(struct pt_regs *regs)
+static inline void atlas_hw0_irqdispatch(struct pt_regs *regs)
{
unsigned long int_status;
int irq;
@@ -116,6 +114,91 @@ void atlas_hw0_irqdispatch(struct pt_regs *regs)
do_IRQ(irq, regs);
}
+static inline int clz(unsigned long x)
+{
+ __asm__ (
+ " .set push \n"
+ " .set mips32 \n"
+ " clz %0, %1 \n"
+ " .set pop \n"
+ : "=r" (x)
+ : "r" (x));
+
+ return x;
+}
+
+/*
+ * Version of ffs that only looks at bits 12..15.
+ */
+static inline unsigned int irq_ffs(unsigned int pending)
+{
+#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
+ return -clz(pending) + 31 - CAUSEB_IP;
+#else
+ unsigned int a0 = 7;
+ unsigned int t0;
+
+ t0 = s0 & 0xf000;
+ t0 = t0 < 1;
+ t0 = t0 << 2;
+ a0 = a0 - t0;
+ s0 = s0 << t0;
+
+ t0 = s0 & 0xc000;
+ t0 = t0 < 1;
+ t0 = t0 << 1;
+ a0 = a0 - t0;
+ s0 = s0 << t0;
+
+ t0 = s0 & 0x8000;
+ t0 = t0 < 1;
+ //t0 = t0 << 2;
+ a0 = a0 - t0;
+ //s0 = s0 << t0;
+
+ return a0;
+#endif
+}
+
+/*
+ * IRQs on the Atlas board look basically (barring software IRQs which we
+ * don't use at all and all external interrupt sources are combined together
+ * on hardware interrupt 0 (MIPS IRQ 2)) like:
+ *
+ * MIPS IRQ Source
+ * -------- ------
+ * 0 Software (ignored)
+ * 1 Software (ignored)
+ * 2 Combined hardware interrupt (hw0)
+ * 3 Hardware (ignored)
+ * 4 Hardware (ignored)
+ * 5 Hardware (ignored)
+ * 6 Hardware (ignored)
+ * 7 R4k timer (what we use)
+ *
+ * We handle the IRQ according to _our_ priority which is:
+ *
+ * Highest ---- R4k Timer
+ * Lowest ---- Combined hardware interrupt
+ *
+ * then we just return, if multiple IRQs are pending then we will just take
+ * another exception, big deal.
+ */
+asmlinkage void plat_irq_dispatch(struct pt_regs *regs)
+{
+ unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
+ int irq;
+
+ irq = irq_ffs(pending);
+
+ if (irq == MIPSCPU_INT_ATLAS)
+ atlas_hw0_irqdispatch(regs);
+ else if (irq > 0)
+ do_IRQ(MIPSCPU_INT_BASE + irq, regs);
+ else
+ spurious_interrupt(regs);
+}
+
void __init arch_init_irq(void)
{
int i;
@@ -128,9 +211,6 @@ void __init arch_init_irq(void)
*/
atlas_hw0_icregs->intrsten = 0xffffffff;
- /* Now safe to set the exception vector. */
- set_except_vector(0, mipsIRQ);
-
for (i = ATLASINT_BASE; i <= ATLASINT_END; i++) {
irq_desc[i].status = IRQ_DISABLED;
irq_desc[i].action = 0;