[ARM] 3370/2: ep93xx: add crunch support
Patch from Lennert Buytenhek
Add the necessary kernel bits for crunch task switching.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/crunch-bits.S b/arch/arm/kernel/crunch-bits.S
new file mode 100644
index 0000000..a268867
--- /dev/null
+++ b/arch/arm/kernel/crunch-bits.S
@@ -0,0 +1,305 @@
+/*
+ * arch/arm/kernel/crunch-bits.S
+ * Cirrus MaverickCrunch context switching and handling
+ *
+ * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ *
+ * Shamelessly stolen from the iWMMXt code by Nicolas Pitre, which is
+ * Copyright (c) 2003-2004, MontaVista Software, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+#include <asm/ptrace.h>
+#include <asm/thread_info.h>
+#include <asm/asm-offsets.h>
+#include <asm/arch/ep93xx-regs.h>
+
+/*
+ * We can't use hex constants here due to a bug in gas.
+ */
+#define CRUNCH_MVDX0 0
+#define CRUNCH_MVDX1 8
+#define CRUNCH_MVDX2 16
+#define CRUNCH_MVDX3 24
+#define CRUNCH_MVDX4 32
+#define CRUNCH_MVDX5 40
+#define CRUNCH_MVDX6 48
+#define CRUNCH_MVDX7 56
+#define CRUNCH_MVDX8 64
+#define CRUNCH_MVDX9 72
+#define CRUNCH_MVDX10 80
+#define CRUNCH_MVDX11 88
+#define CRUNCH_MVDX12 96
+#define CRUNCH_MVDX13 104
+#define CRUNCH_MVDX14 112
+#define CRUNCH_MVDX15 120
+#define CRUNCH_MVAX0L 128
+#define CRUNCH_MVAX0M 132
+#define CRUNCH_MVAX0H 136
+#define CRUNCH_MVAX1L 140
+#define CRUNCH_MVAX1M 144
+#define CRUNCH_MVAX1H 148
+#define CRUNCH_MVAX2L 152
+#define CRUNCH_MVAX2M 156
+#define CRUNCH_MVAX2H 160
+#define CRUNCH_MVAX3L 164
+#define CRUNCH_MVAX3M 168
+#define CRUNCH_MVAX3H 172
+#define CRUNCH_DSPSC 176
+
+#define CRUNCH_SIZE 184
+
+ .text
+
+/*
+ * Lazy switching of crunch coprocessor context
+ *
+ * r10 = struct thread_info pointer
+ * r9 = ret_from_exception
+ * lr = undefined instr exit
+ *
+ * called from prefetch exception handler with interrupts disabled
+ */
+ENTRY(crunch_task_enable)
+ ldr r8, =(EP93XX_APB_VIRT_BASE + 0x00130000) @ syscon addr
+
+ ldr r1, [r8, #0x80]
+ tst r1, #0x00800000 @ access to crunch enabled?
+ movne pc, lr @ if so no business here
+ mov r3, #0xaa @ unlock syscon swlock
+ str r3, [r8, #0xc0]
+ orr r1, r1, #0x00800000 @ enable access to crunch
+ str r1, [r8, #0x80]
+
+ ldr r3, =crunch_owner
+ add r0, r10, #TI_CRUNCH_STATE @ get task crunch save area
+ ldr r2, [sp, #60] @ current task pc value
+ ldr r1, [r3] @ get current crunch owner
+ str r0, [r3] @ this task now owns crunch
+ sub r2, r2, #4 @ adjust pc back
+ str r2, [sp, #60]
+
+ ldr r2, [r8, #0x80]
+ mov r2, r2 @ flush out enable (@@@)
+
+ teq r1, #0 @ test for last ownership
+ mov lr, r9 @ normal exit from exception
+ beq crunch_load @ no owner, skip save
+
+crunch_save:
+ cfstr64 mvdx0, [r1, #CRUNCH_MVDX0] @ save 64b registers
+ cfstr64 mvdx1, [r1, #CRUNCH_MVDX1]
+ cfstr64 mvdx2, [r1, #CRUNCH_MVDX2]
+ cfstr64 mvdx3, [r1, #CRUNCH_MVDX3]
+ cfstr64 mvdx4, [r1, #CRUNCH_MVDX4]
+ cfstr64 mvdx5, [r1, #CRUNCH_MVDX5]
+ cfstr64 mvdx6, [r1, #CRUNCH_MVDX6]
+ cfstr64 mvdx7, [r1, #CRUNCH_MVDX7]
+ cfstr64 mvdx8, [r1, #CRUNCH_MVDX8]
+ cfstr64 mvdx9, [r1, #CRUNCH_MVDX9]
+ cfstr64 mvdx10, [r1, #CRUNCH_MVDX10]
+ cfstr64 mvdx11, [r1, #CRUNCH_MVDX11]
+ cfstr64 mvdx12, [r1, #CRUNCH_MVDX12]
+ cfstr64 mvdx13, [r1, #CRUNCH_MVDX13]
+ cfstr64 mvdx14, [r1, #CRUNCH_MVDX14]
+ cfstr64 mvdx15, [r1, #CRUNCH_MVDX15]
+
+#ifdef __ARMEB__
+#error fix me for ARMEB
+#endif
+
+ cfmv32al mvfx0, mvax0 @ save 72b accumulators
+ cfstr32 mvfx0, [r1, #CRUNCH_MVAX0L]
+ cfmv32am mvfx0, mvax0
+ cfstr32 mvfx0, [r1, #CRUNCH_MVAX0M]
+ cfmv32ah mvfx0, mvax0
+ cfstr32 mvfx0, [r1, #CRUNCH_MVAX0H]
+ cfmv32al mvfx0, mvax1
+ cfstr32 mvfx0, [r1, #CRUNCH_MVAX1L]
+ cfmv32am mvfx0, mvax1
+ cfstr32 mvfx0, [r1, #CRUNCH_MVAX1M]
+ cfmv32ah mvfx0, mvax1
+ cfstr32 mvfx0, [r1, #CRUNCH_MVAX1H]
+ cfmv32al mvfx0, mvax2
+ cfstr32 mvfx0, [r1, #CRUNCH_MVAX2L]
+ cfmv32am mvfx0, mvax2
+ cfstr32 mvfx0, [r1, #CRUNCH_MVAX2M]
+ cfmv32ah mvfx0, mvax2
+ cfstr32 mvfx0, [r1, #CRUNCH_MVAX2H]
+ cfmv32al mvfx0, mvax3
+ cfstr32 mvfx0, [r1, #CRUNCH_MVAX3L]
+ cfmv32am mvfx0, mvax3
+ cfstr32 mvfx0, [r1, #CRUNCH_MVAX3M]
+ cfmv32ah mvfx0, mvax3
+ cfstr32 mvfx0, [r1, #CRUNCH_MVAX3H]
+
+ cfmv32sc mvdx0, dspsc @ save status word
+ cfstr64 mvdx0, [r1, #CRUNCH_DSPSC]
+
+ teq r0, #0 @ anything to load?
+ cfldr64eq mvdx0, [r1, #CRUNCH_MVDX0] @ mvdx0 was clobbered
+ moveq pc, lr
+
+crunch_load:
+ cfldr64 mvdx0, [r0, #CRUNCH_DSPSC] @ load status word
+ cfmvsc32 dspsc, mvdx0
+
+ cfldr32 mvfx0, [r0, #CRUNCH_MVAX0L] @ load 72b accumulators
+ cfmval32 mvax0, mvfx0
+ cfldr32 mvfx0, [r0, #CRUNCH_MVAX0M]
+ cfmvam32 mvax0, mvfx0
+ cfldr32 mvfx0, [r0, #CRUNCH_MVAX0H]
+ cfmvah32 mvax0, mvfx0
+ cfldr32 mvfx0, [r0, #CRUNCH_MVAX1L]
+ cfmval32 mvax1, mvfx0
+ cfldr32 mvfx0, [r0, #CRUNCH_MVAX1M]
+ cfmvam32 mvax1, mvfx0
+ cfldr32 mvfx0, [r0, #CRUNCH_MVAX1H]
+ cfmvah32 mvax1, mvfx0
+ cfldr32 mvfx0, [r0, #CRUNCH_MVAX2L]
+ cfmval32 mvax2, mvfx0
+ cfldr32 mvfx0, [r0, #CRUNCH_MVAX2M]
+ cfmvam32 mvax2, mvfx0
+ cfldr32 mvfx0, [r0, #CRUNCH_MVAX2H]
+ cfmvah32 mvax2, mvfx0
+ cfldr32 mvfx0, [r0, #CRUNCH_MVAX3L]
+ cfmval32 mvax3, mvfx0
+ cfldr32 mvfx0, [r0, #CRUNCH_MVAX3M]
+ cfmvam32 mvax3, mvfx0
+ cfldr32 mvfx0, [r0, #CRUNCH_MVAX3H]
+ cfmvah32 mvax3, mvfx0
+
+ cfldr64 mvdx0, [r0, #CRUNCH_MVDX0] @ load 64b registers
+ cfldr64 mvdx1, [r0, #CRUNCH_MVDX1]
+ cfldr64 mvdx2, [r0, #CRUNCH_MVDX2]
+ cfldr64 mvdx3, [r0, #CRUNCH_MVDX3]
+ cfldr64 mvdx4, [r0, #CRUNCH_MVDX4]
+ cfldr64 mvdx5, [r0, #CRUNCH_MVDX5]
+ cfldr64 mvdx6, [r0, #CRUNCH_MVDX6]
+ cfldr64 mvdx7, [r0, #CRUNCH_MVDX7]
+ cfldr64 mvdx8, [r0, #CRUNCH_MVDX8]
+ cfldr64 mvdx9, [r0, #CRUNCH_MVDX9]
+ cfldr64 mvdx10, [r0, #CRUNCH_MVDX10]
+ cfldr64 mvdx11, [r0, #CRUNCH_MVDX11]
+ cfldr64 mvdx12, [r0, #CRUNCH_MVDX12]
+ cfldr64 mvdx13, [r0, #CRUNCH_MVDX13]
+ cfldr64 mvdx14, [r0, #CRUNCH_MVDX14]
+ cfldr64 mvdx15, [r0, #CRUNCH_MVDX15]
+
+ mov pc, lr
+
+/*
+ * Back up crunch regs to save area and disable access to them
+ * (mainly for gdb or sleep mode usage)
+ *
+ * r0 = struct thread_info pointer of target task or NULL for any
+ */
+ENTRY(crunch_task_disable)
+ stmfd sp!, {r4, r5, lr}
+
+ mrs ip, cpsr
+ orr r2, ip, #PSR_I_BIT @ disable interrupts
+ msr cpsr_c, r2
+
+ ldr r4, =(EP93XX_APB_VIRT_BASE + 0x00130000) @ syscon addr
+
+ ldr r3, =crunch_owner
+ add r2, r0, #TI_CRUNCH_STATE @ get task crunch save area
+ ldr r1, [r3] @ get current crunch owner
+ teq r1, #0 @ any current owner?
+ beq 1f @ no: quit
+ teq r0, #0 @ any owner?
+ teqne r1, r2 @ or specified one?
+ bne 1f @ no: quit
+
+ ldr r5, [r4, #0x80] @ enable access to crunch
+ mov r2, #0xaa
+ str r2, [r4, #0xc0]
+ orr r5, r5, #0x00800000
+ str r5, [r4, #0x80]
+
+ mov r0, #0 @ nothing to load
+ str r0, [r3] @ no more current owner
+ ldr r2, [r4, #0x80] @ flush out enable (@@@)
+ mov r2, r2
+ bl crunch_save
+
+ mov r2, #0xaa @ disable access to crunch
+ str r2, [r4, #0xc0]
+ bic r5, r5, #0x00800000
+ str r5, [r4, #0x80]
+ ldr r5, [r4, #0x80] @ flush out enable (@@@)
+ mov r5, r5
+
+1: msr cpsr_c, ip @ restore interrupt mode
+ ldmfd sp!, {r4, r5, pc}
+
+/*
+ * Copy crunch state to given memory address
+ *
+ * r0 = struct thread_info pointer of target task
+ * r1 = memory address where to store crunch state
+ *
+ * this is called mainly in the creation of signal stack frames
+ */
+ENTRY(crunch_task_copy)
+ mrs ip, cpsr
+ orr r2, ip, #PSR_I_BIT @ disable interrupts
+ msr cpsr_c, r2
+
+ ldr r3, =crunch_owner
+ add r2, r0, #TI_CRUNCH_STATE @ get task crunch save area
+ ldr r3, [r3] @ get current crunch owner
+ teq r2, r3 @ does this task own it...
+ beq 1f
+
+ @ current crunch values are in the task save area
+ msr cpsr_c, ip @ restore interrupt mode
+ mov r0, r1
+ mov r1, r2
+ mov r2, #CRUNCH_SIZE
+ b memcpy
+
+1: @ this task owns crunch regs -- grab a copy from there
+ mov r0, #0 @ nothing to load
+ mov r3, lr @ preserve return address
+ bl crunch_save
+ msr cpsr_c, ip @ restore interrupt mode
+ mov pc, r3
+
+/*
+ * Restore crunch state from given memory address
+ *
+ * r0 = struct thread_info pointer of target task
+ * r1 = memory address where to get crunch state from
+ *
+ * this is used to restore crunch state when unwinding a signal stack frame
+ */
+ENTRY(crunch_task_restore)
+ mrs ip, cpsr
+ orr r2, ip, #PSR_I_BIT @ disable interrupts
+ msr cpsr_c, r2
+
+ ldr r3, =crunch_owner
+ add r2, r0, #TI_CRUNCH_STATE @ get task crunch save area
+ ldr r3, [r3] @ get current crunch owner
+ teq r2, r3 @ does this task own it...
+ beq 1f
+
+ @ this task doesn't own crunch regs -- use its save area
+ msr cpsr_c, ip @ restore interrupt mode
+ mov r0, r2
+ mov r2, #CRUNCH_SIZE
+ b memcpy
+
+1: @ this task owns crunch regs -- load them directly
+ mov r0, r1
+ mov r1, #0 @ nothing to save
+ mov r3, lr @ preserve return address
+ bl crunch_load
+ msr cpsr_c, ip @ restore interrupt mode
+ mov pc, r3