Initial Contribution
msm-2.6.38: tag AU_LINUX_ANDROID_GINGERBREAD.02.03.04.00.142
Signed-off-by: Bryan Huntsman <bryanh@codeaurora.org>
diff --git a/arch/arm/mach-msm/fiq_glue.S b/arch/arm/mach-msm/fiq_glue.S
new file mode 100644
index 0000000..df1c708
--- /dev/null
+++ b/arch/arm/mach-msm/fiq_glue.S
@@ -0,0 +1,112 @@
+/* arch/arm/mach-msm/fiq_glue.S
+ *
+ * Copyright (C) 2008 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+ .text
+
+ .global fiq_glue_end
+
+ /* fiq stack: r0-r15,cpsr,spsr of interrupted mode */
+
+ENTRY(fiq_glue)
+ /* store pc, cpsr from previous mode */
+ mrs r12, spsr
+ sub r11, lr, #4
+ subs r10, #1
+ bne nested_fiq
+
+ stmfd sp!, {r11-r12, lr}
+
+ /* store r8-r14 from previous mode */
+ sub sp, sp, #(7 * 4)
+ stmia sp, {r8-r14}^
+ nop
+
+ /* store r0-r7 from previous mode */
+ stmfd sp!, {r0-r7}
+
+ /* setup func(data,regs) arguments */
+ mov r0, r9
+ mov r1, sp
+ mov r3, r8
+
+ mov r7, sp
+
+ /* Get sp and lr from non-user modes */
+ and r4, r12, #MODE_MASK
+ cmp r4, #USR_MODE
+ beq fiq_from_usr_mode
+
+ mov r7, sp
+ orr r4, r4, #(PSR_I_BIT | PSR_F_BIT)
+ msr cpsr_c, r4
+ str sp, [r7, #(4 * 13)]
+ str lr, [r7, #(4 * 14)]
+ mrs r5, spsr
+ str r5, [r7, #(4 * 17)]
+
+ cmp r4, #(SVC_MODE | PSR_I_BIT | PSR_F_BIT)
+ /* use fiq stack if we reenter this mode */
+ subne sp, r7, #(4 * 3)
+
+fiq_from_usr_mode:
+ msr cpsr_c, #(SVC_MODE | PSR_I_BIT | PSR_F_BIT)
+ mov r2, sp
+ sub sp, r7, #12
+ stmfd sp!, {r2, ip, lr}
+ /* call func(data,regs) */
+ blx r3
+ ldmfd sp, {r2, ip, lr}
+ mov sp, r2
+
+ /* restore/discard saved state */
+ cmp r4, #USR_MODE
+ beq fiq_from_usr_mode_exit
+
+ msr cpsr_c, r4
+ ldr sp, [r7, #(4 * 13)]
+ ldr lr, [r7, #(4 * 14)]
+ msr spsr_cxsf, r5
+
+fiq_from_usr_mode_exit:
+ msr cpsr_c, #(FIQ_MODE | PSR_I_BIT | PSR_F_BIT)
+
+ ldmfd sp!, {r0-r7}
+ add sp, sp, #(7 * 4)
+ ldmfd sp!, {r11-r12, lr}
+exit_fiq:
+ msr spsr_cxsf, r12
+ add r10, #1
+ movs pc, r11
+
+nested_fiq:
+ orr r12, r12, #(PSR_F_BIT)
+ b exit_fiq
+
+fiq_glue_end:
+
+ENTRY(fiq_glue_setup) /* func, data, sp */
+ mrs r3, cpsr
+ msr cpsr_c, #(FIQ_MODE | PSR_I_BIT | PSR_F_BIT)
+ movs r8, r0
+ mov r9, r1
+ mov sp, r2
+ moveq r10, #0
+ movne r10, #1
+ msr cpsr_c, r3
+ bx lr
+