octeon_switch.S

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1994, 1995, 1996, 1998, 1999, 2002, 2003 Ralf Baechle
 * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
 * Copyright (C) 1994, 1995, 1996, by Andreas Busse
 * Copyright (C) 1999 Silicon Graphics, Inc.
 * Copyright (C) 2000 MIPS Technologies, Inc.
 *    written by Carsten Langgaard, carstenl@mips.com
 */
#include <asm/asm.h>
#include <asm/cachectl.h>
#include <asm/fpregdef.h>
#include <asm/mipsregs.h>
#include <asm/asm-offsets.h>
#include <asm/pgtable-bits.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/thread_info.h>

#include <asm/asmmacro.h>

/*
 * Offset to the current process status flags, the first 32 bytes of the
 * stack are not used.
 */
#define ST_OFF (_THREAD_SIZE - 32 - PT_SIZE + PT_STATUS)

/*
 * task_struct *resume(task_struct *prev, task_struct *next,
 *                     struct thread_info *next_ti, int usedfpu)
 */
	.align	7
	LEAF(resume)
	.set arch=octeon
	mfc0	t1, CP0_STATUS
	LONG_S	t1, THREAD_STATUS(a0)
	cpu_save_nonscratch a0
	LONG_S	ra, THREAD_REG31(a0)

	/* check if we need to save COP2 registers */
	PTR_L	t2, TASK_THREAD_INFO(a0)
	LONG_L	t0, ST_OFF(t2)
	bbit0	t0, 30, 1f

	/* Disable COP2 in the stored process state */
	li	t1, ST0_CU2
	xor	t0, t1
	LONG_S	t0, ST_OFF(t2)

	/* Enable COP2 so we can save it */
	mfc0	t0, CP0_STATUS
	or	t0, t1
	mtc0	t0, CP0_STATUS

	/* Save COP2 */
	daddu	a0, THREAD_CP2
	jal octeon_cop2_save
	dsubu	a0, THREAD_CP2

	/* Disable COP2 now that we are done */
	mfc0	t0, CP0_STATUS
	li	t1, ST0_CU2
	xor	t0, t1
	mtc0	t0, CP0_STATUS

1:
#if CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE > 0
	/* Check if we need to store CVMSEG state */
	mfc0	t0, $11,7 	/* CvmMemCtl */
	bbit0	t0, 6, 3f	/* Is user access enabled? */

	/* Store the CVMSEG state */
	/* Extract the size of CVMSEG */
	andi	t0, 0x3f
	/* Multiply * (cache line size/sizeof(long)/2) */
	sll	t0, 7-LONGLOG-1
	li	t1, -32768 	/* Base address of CVMSEG */
	LONG_ADDI t2, a0, THREAD_CVMSEG	/* Where to store CVMSEG to */
	synciobdma
2:
	.set noreorder
	LONG_L	t8, 0(t1)	/* Load from CVMSEG */
	subu	t0, 1		/* Decrement loop var */
	LONG_L	t9, LONGSIZE(t1)/* Load from CVMSEG */
	LONG_ADDU t1, LONGSIZE*2 /* Increment loc in CVMSEG */
	LONG_S	t8, 0(t2)	/* Store CVMSEG to thread storage */
	LONG_ADDU t2, LONGSIZE*2 /* Increment loc in thread storage */
	bnez	t0, 2b		/* Loop until we've copied it all */
	 LONG_S	t9, -LONGSIZE(t2)/* Store CVMSEG to thread storage */
	.set reorder

	/* Disable access to CVMSEG */
	mfc0	t0, $11,7 	/* CvmMemCtl */
	xori	t0, t0, 0x40	/* Bit 6 is CVMSEG user enable */
	mtc0	t0, $11,7 	/* CvmMemCtl */
#endif
3:
	/*
	 * The order of restoring the registers takes care of the race
	 * updating $28, $29 and kernelsp without disabling ints.
	 */
	move	$28, a2
	cpu_restore_nonscratch a1

#if (_THREAD_SIZE - 32) < 0x8000
	PTR_ADDIU	t0, $28, _THREAD_SIZE - 32
#else
	PTR_LI		t0, _THREAD_SIZE - 32
	PTR_ADDU	t0, $28
#endif
	set_saved_sp	t0, t1, t2

	mfc0	t1, CP0_STATUS		/* Do we really need this? */
	li	a3, 0xff01
	and	t1, a3
	LONG_L	a2, THREAD_STATUS(a1)
	nor	a3, $0, a3
	and	a2, a3
	or	a2, t1
	mtc0	a2, CP0_STATUS
	move	v0, a0
	jr	ra
	END(resume)

/*
 * void octeon_cop2_save(struct octeon_cop2_state *a0)
 */
	.align	7
	LEAF(octeon_cop2_save)

	dmfc0	t9, $9,7	/* CvmCtl register. */

        /* Save the COP2 CRC state */
	dmfc2	t0, 0x0201
	dmfc2	t1, 0x0202
	dmfc2	t2, 0x0200
	sd	t0, OCTEON_CP2_CRC_IV(a0)
	sd	t1, OCTEON_CP2_CRC_LENGTH(a0)
	sd	t2, OCTEON_CP2_CRC_POLY(a0)
	/* Skip next instructions if CvmCtl[NODFA_CP2] set */
	bbit1	t9, 28, 1f

	/* Save the LLM state */
	dmfc2	t0, 0x0402
	dmfc2	t1, 0x040A
	sd	t0, OCTEON_CP2_LLM_DAT(a0)
	sd	t1, OCTEON_CP2_LLM_DAT+8(a0)

1:      bbit1	t9, 26, 3f	/* done if CvmCtl[NOCRYPTO] set */

	/* Save the COP2 crypto state */
        /* this part is mostly common to both pass 1 and later revisions */
	dmfc2 	t0, 0x0084
	dmfc2 	t1, 0x0080
	dmfc2 	t2, 0x0081
	dmfc2 	t3, 0x0082
	sd	t0, OCTEON_CP2_3DES_IV(a0)
	dmfc2 	t0, 0x0088
	sd	t1, OCTEON_CP2_3DES_KEY(a0)
	dmfc2 	t1, 0x0111                      /* only necessary for pass 1 */
	sd	t2, OCTEON_CP2_3DES_KEY+8(a0)
	dmfc2 	t2, 0x0102
	sd	t3, OCTEON_CP2_3DES_KEY+16(a0)
	dmfc2 	t3, 0x0103
	sd	t0, OCTEON_CP2_3DES_RESULT(a0)
	dmfc2 	t0, 0x0104
	sd	t1, OCTEON_CP2_AES_INP0(a0)     /* only necessary for pass 1 */
	dmfc2 	t1, 0x0105
	sd	t2, OCTEON_CP2_AES_IV(a0)
	dmfc2	t2, 0x0106
	sd	t3, OCTEON_CP2_AES_IV+8(a0)
	dmfc2 	t3, 0x0107
	sd	t0, OCTEON_CP2_AES_KEY(a0)
	dmfc2	t0, 0x0110
	sd	t1, OCTEON_CP2_AES_KEY+8(a0)
	dmfc2	t1, 0x0100
	sd	t2, OCTEON_CP2_AES_KEY+16(a0)
	dmfc2	t2, 0x0101
	sd	t3, OCTEON_CP2_AES_KEY+24(a0)
	mfc0	t3, $15,0 	/* Get the processor ID register */
	sd	t0, OCTEON_CP2_AES_KEYLEN(a0)
	li	t0, 0x000d0000	/* This is the processor ID of Octeon Pass1 */
	sd	t1, OCTEON_CP2_AES_RESULT(a0)
	sd	t2, OCTEON_CP2_AES_RESULT+8(a0)
	/* Skip to the Pass1 version of the remainder of the COP2 state */
	beq	t3, t0, 2f

        /* the non-pass1 state when !CvmCtl[NOCRYPTO] */
	dmfc2	t1, 0x0240
	dmfc2	t2, 0x0241
	dmfc2	t3, 0x0242
	dmfc2	t0, 0x0243
	sd	t1, OCTEON_CP2_HSH_DATW(a0)
	dmfc2	t1, 0x0244
	sd	t2, OCTEON_CP2_HSH_DATW+8(a0)
	dmfc2	t2, 0x0245
	sd	t3, OCTEON_CP2_HSH_DATW+16(a0)
	dmfc2	t3, 0x0246
	sd	t0, OCTEON_CP2_HSH_DATW+24(a0)
	dmfc2	t0, 0x0247
	sd	t1, OCTEON_CP2_HSH_DATW+32(a0)
	dmfc2	t1, 0x0248
	sd	t2, OCTEON_CP2_HSH_DATW+40(a0)
	dmfc2	t2, 0x0249
	sd	t3, OCTEON_CP2_HSH_DATW+48(a0)
	dmfc2	t3, 0x024A
	sd	t0, OCTEON_CP2_HSH_DATW+56(a0)
	dmfc2	t0, 0x024B
	sd	t1, OCTEON_CP2_HSH_DATW+64(a0)
	dmfc2	t1, 0x024C
	sd	t2, OCTEON_CP2_HSH_DATW+72(a0)
	dmfc2	t2, 0x024D
	sd	t3, OCTEON_CP2_HSH_DATW+80(a0)
	dmfc2 	t3, 0x024E
	sd	t0, OCTEON_CP2_HSH_DATW+88(a0)
	dmfc2	t0, 0x0250
	sd	t1, OCTEON_CP2_HSH_DATW+96(a0)
	dmfc2	t1, 0x0251
	sd	t2, OCTEON_CP2_HSH_DATW+104(a0)
	dmfc2	t2, 0x0252
	sd	t3, OCTEON_CP2_HSH_DATW+112(a0)
	dmfc2	t3, 0x0253
	sd	t0, OCTEON_CP2_HSH_IVW(a0)
	dmfc2	t0, 0x0254
	sd	t1, OCTEON_CP2_HSH_IVW+8(a0)
	dmfc2	t1, 0x0255
	sd	t2, OCTEON_CP2_HSH_IVW+16(a0)
	dmfc2	t2, 0x0256
	sd	t3, OCTEON_CP2_HSH_IVW+24(a0)
	dmfc2	t3, 0x0257
	sd	t0, OCTEON_CP2_HSH_IVW+32(a0)
	dmfc2 	t0, 0x0258
	sd	t1, OCTEON_CP2_HSH_IVW+40(a0)
	dmfc2 	t1, 0x0259
	sd	t2, OCTEON_CP2_HSH_IVW+48(a0)
	dmfc2	t2, 0x025E
	sd	t3, OCTEON_CP2_HSH_IVW+56(a0)
	dmfc2	t3, 0x025A
	sd	t0, OCTEON_CP2_GFM_MULT(a0)
	dmfc2	t0, 0x025B
	sd	t1, OCTEON_CP2_GFM_MULT+8(a0)
	sd	t2, OCTEON_CP2_GFM_POLY(a0)
	sd	t3, OCTEON_CP2_GFM_RESULT(a0)
	sd	t0, OCTEON_CP2_GFM_RESULT+8(a0)
	jr	ra

2:      /* pass 1 special stuff when !CvmCtl[NOCRYPTO] */
	dmfc2	t3, 0x0040
	dmfc2	t0, 0x0041
	dmfc2	t1, 0x0042
	dmfc2	t2, 0x0043
	sd	t3, OCTEON_CP2_HSH_DATW(a0)
	dmfc2	t3, 0x0044
	sd	t0, OCTEON_CP2_HSH_DATW+8(a0)
	dmfc2	t0, 0x0045
	sd	t1, OCTEON_CP2_HSH_DATW+16(a0)
	dmfc2	t1, 0x0046
	sd	t2, OCTEON_CP2_HSH_DATW+24(a0)
	dmfc2	t2, 0x0048
	sd	t3, OCTEON_CP2_HSH_DATW+32(a0)
	dmfc2	t3, 0x0049
	sd	t0, OCTEON_CP2_HSH_DATW+40(a0)
	dmfc2	t0, 0x004A
	sd	t1, OCTEON_CP2_HSH_DATW+48(a0)
	sd	t2, OCTEON_CP2_HSH_IVW(a0)
	sd	t3, OCTEON_CP2_HSH_IVW+8(a0)
	sd	t0, OCTEON_CP2_HSH_IVW+16(a0)

3:      /* pass 1 or CvmCtl[NOCRYPTO] set */
	jr	ra
	END(octeon_cop2_save)

/*
 * void octeon_cop2_restore(struct octeon_cop2_state *a0)
 */
	.align	7
	.set push
	.set noreorder
	LEAF(octeon_cop2_restore)
        /* First cache line was prefetched before the call */
        pref    4,  128(a0)
	dmfc0	t9, $9,7	/* CvmCtl register. */

        pref    4,  256(a0)
	ld	t0, OCTEON_CP2_CRC_IV(a0)
        pref    4,  384(a0)
	ld	t1, OCTEON_CP2_CRC_LENGTH(a0)
	ld	t2, OCTEON_CP2_CRC_POLY(a0)

	/* Restore the COP2 CRC state */
	dmtc2	t0, 0x0201
	dmtc2 	t1, 0x1202
	bbit1	t9, 28, 2f	/* Skip LLM if CvmCtl[NODFA_CP2] is set */
	 dmtc2	t2, 0x4200

	/* Restore the LLM state */
	ld	t0, OCTEON_CP2_LLM_DAT(a0)
	ld	t1, OCTEON_CP2_LLM_DAT+8(a0)
	dmtc2	t0, 0x0402
	dmtc2	t1, 0x040A

2:
	bbit1	t9, 26, done_restore	/* done if CvmCtl[NOCRYPTO] set */
	 nop

	/* Restore the COP2 crypto state common to pass 1 and pass 2 */
	ld	t0, OCTEON_CP2_3DES_IV(a0)
	ld	t1, OCTEON_CP2_3DES_KEY(a0)
	ld	t2, OCTEON_CP2_3DES_KEY+8(a0)
	dmtc2 	t0, 0x0084
	ld	t0, OCTEON_CP2_3DES_KEY+16(a0)
	dmtc2 	t1, 0x0080
	ld	t1, OCTEON_CP2_3DES_RESULT(a0)
	dmtc2 	t2, 0x0081
	ld	t2, OCTEON_CP2_AES_INP0(a0) /* only really needed for pass 1 */
	dmtc2	t0, 0x0082
	ld	t0, OCTEON_CP2_AES_IV(a0)
	dmtc2 	t1, 0x0098
	ld	t1, OCTEON_CP2_AES_IV+8(a0)
	dmtc2 	t2, 0x010A                  /* only really needed for pass 1 */
	ld	t2, OCTEON_CP2_AES_KEY(a0)
	dmtc2 	t0, 0x0102
	ld	t0, OCTEON_CP2_AES_KEY+8(a0)
	dmtc2	t1, 0x0103
	ld	t1, OCTEON_CP2_AES_KEY+16(a0)
	dmtc2	t2, 0x0104
	ld	t2, OCTEON_CP2_AES_KEY+24(a0)
	dmtc2	t0, 0x0105
	ld	t0, OCTEON_CP2_AES_KEYLEN(a0)
	dmtc2	t1, 0x0106
	ld	t1, OCTEON_CP2_AES_RESULT(a0)
	dmtc2	t2, 0x0107
	ld	t2, OCTEON_CP2_AES_RESULT+8(a0)
	mfc0	t3, $15,0 	/* Get the processor ID register */
	dmtc2	t0, 0x0110
	li	t0, 0x000d0000	/* This is the processor ID of Octeon Pass1 */
	dmtc2	t1, 0x0100
	bne	t0, t3, 3f	/* Skip the next stuff for non-pass1 */
	 dmtc2	t2, 0x0101

        /* this code is specific for pass 1 */
	ld	t0, OCTEON_CP2_HSH_DATW(a0)
	ld	t1, OCTEON_CP2_HSH_DATW+8(a0)
	ld	t2, OCTEON_CP2_HSH_DATW+16(a0)
	dmtc2	t0, 0x0040
	ld	t0, OCTEON_CP2_HSH_DATW+24(a0)
	dmtc2	t1, 0x0041
	ld	t1, OCTEON_CP2_HSH_DATW+32(a0)
	dmtc2	t2, 0x0042
	ld	t2, OCTEON_CP2_HSH_DATW+40(a0)
	dmtc2	t0, 0x0043
	ld	t0, OCTEON_CP2_HSH_DATW+48(a0)
	dmtc2	t1, 0x0044
	ld	t1, OCTEON_CP2_HSH_IVW(a0)
	dmtc2	t2, 0x0045
	ld	t2, OCTEON_CP2_HSH_IVW+8(a0)
	dmtc2	t0, 0x0046
	ld	t0, OCTEON_CP2_HSH_IVW+16(a0)
	dmtc2	t1, 0x0048
	dmtc2	t2, 0x0049
        b done_restore   /* unconditional branch */
	 dmtc2	t0, 0x004A

3:      /* this is post-pass1 code */
	ld	t2, OCTEON_CP2_HSH_DATW(a0)
	ld	t0, OCTEON_CP2_HSH_DATW+8(a0)
	ld	t1, OCTEON_CP2_HSH_DATW+16(a0)
	dmtc2	t2, 0x0240
	ld	t2, OCTEON_CP2_HSH_DATW+24(a0)
	dmtc2	t0, 0x0241
	ld	t0, OCTEON_CP2_HSH_DATW+32(a0)
	dmtc2	t1, 0x0242
	ld	t1, OCTEON_CP2_HSH_DATW+40(a0)
	dmtc2	t2, 0x0243
	ld	t2, OCTEON_CP2_HSH_DATW+48(a0)
	dmtc2	t0, 0x0244
	ld	t0, OCTEON_CP2_HSH_DATW+56(a0)
	dmtc2	t1, 0x0245
	ld	t1, OCTEON_CP2_HSH_DATW+64(a0)
	dmtc2	t2, 0x0246
	ld	t2, OCTEON_CP2_HSH_DATW+72(a0)
	dmtc2	t0, 0x0247
	ld	t0, OCTEON_CP2_HSH_DATW+80(a0)
	dmtc2	t1, 0x0248
	ld	t1, OCTEON_CP2_HSH_DATW+88(a0)
	dmtc2	t2, 0x0249
	ld	t2, OCTEON_CP2_HSH_DATW+96(a0)
	dmtc2	t0, 0x024A
	ld	t0, OCTEON_CP2_HSH_DATW+104(a0)
	dmtc2	t1, 0x024B
	ld	t1, OCTEON_CP2_HSH_DATW+112(a0)
	dmtc2	t2, 0x024C
	ld	t2, OCTEON_CP2_HSH_IVW(a0)
	dmtc2	t0, 0x024D
	ld	t0, OCTEON_CP2_HSH_IVW+8(a0)
	dmtc2	t1, 0x024E
	ld	t1, OCTEON_CP2_HSH_IVW+16(a0)
	dmtc2	t2, 0x0250
	ld	t2, OCTEON_CP2_HSH_IVW+24(a0)
	dmtc2	t0, 0x0251
	ld	t0, OCTEON_CP2_HSH_IVW+32(a0)
	dmtc2	t1, 0x0252
	ld	t1, OCTEON_CP2_HSH_IVW+40(a0)
	dmtc2	t2, 0x0253
	ld	t2, OCTEON_CP2_HSH_IVW+48(a0)
	dmtc2	t0, 0x0254
	ld	t0, OCTEON_CP2_HSH_IVW+56(a0)
	dmtc2	t1, 0x0255
	ld	t1, OCTEON_CP2_GFM_MULT(a0)
	dmtc2	t2, 0x0256
	ld	t2, OCTEON_CP2_GFM_MULT+8(a0)
	dmtc2	t0, 0x0257
	ld	t0, OCTEON_CP2_GFM_POLY(a0)
	dmtc2	t1, 0x0258
	ld	t1, OCTEON_CP2_GFM_RESULT(a0)
	dmtc2	t2, 0x0259
	ld	t2, OCTEON_CP2_GFM_RESULT+8(a0)
	dmtc2	t0, 0x025E
	dmtc2	t1, 0x025A
	dmtc2	t2, 0x025B

done_restore:
	jr	ra
	 nop
	END(octeon_cop2_restore)
	.set pop

/*
 * void octeon_mult_save()
 * sp is assumed to point to a struct pt_regs
 *
 * NOTE: This is called in SAVE_SOME in stackframe.h. It can only
 *       safely modify k0 and k1.
 */
	.align	7
	.set push
	.set noreorder
	LEAF(octeon_mult_save)
	dmfc0	k0, $9,7	/* CvmCtl register. */
	bbit1	k0, 27, 1f	/* Skip CvmCtl[NOMUL] */
	 nop

	/* Save the multiplier state */
	v3mulu	k0, $0, $0
	v3mulu	k1, $0, $0
	sd	k0, PT_MTP(sp)        /* PT_MTP    has P0 */
	v3mulu	k0, $0, $0
	sd	k1, PT_MTP+8(sp)      /* PT_MTP+8  has P1 */
	ori	k1, $0, 1
	v3mulu	k1, k1, $0
	sd	k0, PT_MTP+16(sp)     /* PT_MTP+16 has P2 */
	v3mulu	k0, $0, $0
	sd	k1, PT_MPL(sp)        /* PT_MPL    has MPL0 */
	v3mulu	k1, $0, $0
	sd	k0, PT_MPL+8(sp)      /* PT_MPL+8  has MPL1 */
	jr	ra
	 sd	k1, PT_MPL+16(sp)     /* PT_MPL+16 has MPL2 */

1:	/* Resume here if CvmCtl[NOMUL] */
	jr	ra
	END(octeon_mult_save)
	.set pop

/*
 * void octeon_mult_restore()
 * sp is assumed to point to a struct pt_regs
 *
 * NOTE: This is called in RESTORE_SOME in stackframe.h.
 */
	.align	7
	.set push
	.set noreorder
	LEAF(octeon_mult_restore)
	dmfc0	k1, $9,7		/* CvmCtl register. */
	ld	v0, PT_MPL(sp)        	/* MPL0 */
	ld	v1, PT_MPL+8(sp)      	/* MPL1 */
	ld	k0, PT_MPL+16(sp)     	/* MPL2 */
	bbit1	k1, 27, 1f		/* Skip CvmCtl[NOMUL] */
	/* Normally falls through, so no time wasted here */
	nop

	/* Restore the multiplier state */
	ld	k1, PT_MTP+16(sp)     	/* P2 */
	MTM0	v0			/* MPL0 */
	ld	v0, PT_MTP+8(sp)	/* P1 */
	MTM1	v1			/* MPL1 */
	ld	v1, PT_MTP(sp)   	/* P0 */
	MTM2	k0			/* MPL2 */
	MTP2	k1			/* P2 */
	MTP1	v0			/* P1 */
	jr	ra
	 MTP0	v1			/* P0 */

1:	/* Resume here if CvmCtl[NOMUL] */
	jr	ra
	 nop
	END(octeon_mult_restore)
	.set pop