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Commit 5649d37c authored by Jayachandran C's avatar Jayachandran C Committed by Ralf Baechle
Browse files

MIPS: Netlogic: COP2 save/restore code 



Add COP2 register state structure and functions for Netlogic XLP. The
RX and TX buffers and status registers are to be saved. Since the
registers are 64-bit, do the implementation in inline assembly which
works on both 32-bit and 64-bit kernels.

Signed-off-by: default avatarJayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Cc: ddaney.cavm@gmail.com
Patchwork: https://patchwork.linux-mips.org/patch/5413/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 64f6ebe6

arch/mips/include/asm/cop2.h

+10 −0
Original line number Diff line number Diff line
@@ -22,6 +22,16 @@ extern void octeon_cop2_restore(struct octeon_cop2_state *); 
#define cop2_present		1

#define cop2_lazy_restore	1



#elif defined(CONFIG_CPU_XLP)



extern void nlm_cop2_save(struct nlm_cop2_state *);

extern void nlm_cop2_restore(struct nlm_cop2_state *);

#define cop2_save(r)		nlm_cop2_save(r)

#define cop2_restore(r)		nlm_cop2_restore(r)



#define cop2_present		1

#define cop2_lazy_restore	0



#else



#define cop2_present		0

arch/mips/include/asm/processor.h

+13 −0
Original line number Diff line number Diff line
@@ -190,6 +190,16 @@ struct octeon_cvmseg_state { 
			    [cpu_dcache_line_size() / sizeof(unsigned long)];

};



#elif defined(CONFIG_CPU_XLP)

struct nlm_cop2_state {

	u64	rx[4];

	u64	tx[4];

	u32	tx_msg_status;

	u32	rx_msg_status;

};



#define COP2_INIT						\

	.cp2			= {{0}, {0}, 0, 0},

#else

#define COP2_INIT

#endif
@@ -236,6 +246,9 @@ struct thread_struct { 
#ifdef CONFIG_CPU_CAVIUM_OCTEON

    struct octeon_cop2_state cp2 __attribute__ ((__aligned__(128)));

    struct octeon_cvmseg_state cvmseg __attribute__ ((__aligned__(128)));

#endif

#ifdef CONFIG_CPU_XLP

	struct nlm_cop2_state cp2;

#endif

	struct mips_abi *abi;

};

arch/mips/netlogic/xlp/Makefile

+1 −1
Original line number Diff line number Diff line 
obj-y				+= setup.o nlm_hal.o

obj-y				+= setup.o nlm_hal.o cop2-ex.o

obj-$(CONFIG_SMP)		+= wakeup.o

obj-$(CONFIG_USB)		+= usb-init.o

arch/mips/netlogic/xlp/cop2-ex.c

0 → 100644
+118 −0
Original line number Diff line number Diff line 
/*

 * 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) 2013 Broadcom Corporation.

 *

 * based on arch/mips/cavium-octeon/cpu.c

 * Copyright (C) 2009 Wind River Systems,

 *   written by Ralf Baechle <ralf@linux-mips.org>

 */

#include <linux/init.h>

#include <linux/irqflags.h>

#include <linux/notifier.h>

#include <linux/prefetch.h>

#include <linux/sched.h>



#include <asm/cop2.h>

#include <asm/current.h>

#include <asm/mipsregs.h>

#include <asm/page.h>



#include <asm/netlogic/mips-extns.h>



/*

 * 64 bit ops are done in inline assembly to support 32 bit

 * compilation

 */

void nlm_cop2_save(struct nlm_cop2_state *r)

{

	asm volatile(

		".set	push\n"

		".set	noat\n"

		"dmfc2	$1, $0, 0\n"

		"sd	$1, 0(%1)\n"

		"dmfc2	$1, $0, 1\n"

		"sd	$1, 8(%1)\n"

		"dmfc2	$1, $0, 2\n"

		"sd	$1, 16(%1)\n"

		"dmfc2	$1, $0, 3\n"

		"sd	$1, 24(%1)\n"

		"dmfc2	$1, $1, 0\n"

		"sd	$1, 0(%2)\n"

		"dmfc2	$1, $1, 1\n"

		"sd	$1, 8(%2)\n"

		"dmfc2	$1, $1, 2\n"

		"sd	$1, 16(%2)\n"

		"dmfc2	$1, $1, 3\n"

		"sd	$1, 24(%2)\n"

		".set	pop\n"

		: "=m"(*r)

		: "r"(r->tx), "r"(r->rx));



	r->tx_msg_status = __read_32bit_c2_register($2, 0);

	r->rx_msg_status = __read_32bit_c2_register($3, 0) & 0x0fffffff;

}



void nlm_cop2_restore(struct nlm_cop2_state *r)

{

	u32 rstat;



	asm volatile(

		".set	push\n"

		".set	noat\n"

		"ld	$1, 0(%1)\n"

		"dmtc2	$1, $0, 0\n"

		"ld	$1, 8(%1)\n"

		"dmtc2	$1, $0, 1\n"

		"ld	$1, 16(%1)\n"

		"dmtc2	$1, $0, 2\n"

		"ld	$1, 24(%1)\n"

		"dmtc2	$1, $0, 3\n"

		"ld	$1, 0(%2)\n"

		"dmtc2	$1, $1, 0\n"

		"ld	$1, 8(%2)\n"

		"dmtc2	$1, $1, 1\n"

		"ld	$1, 16(%2)\n"

		"dmtc2	$1, $1, 2\n"

		"ld	$1, 24(%2)\n"

		"dmtc2	$1, $1, 3\n"

		".set	pop\n"

		: : "m"(*r), "r"(r->tx), "r"(r->rx));



	__write_32bit_c2_register($2, 0, r->tx_msg_status);

	rstat = __read_32bit_c2_register($3, 0) & 0xf0000000u;

	__write_32bit_c2_register($3, 0, r->rx_msg_status | rstat);

}



static int nlm_cu2_call(struct notifier_block *nfb, unsigned long action,

	void *data)

{

	unsigned long flags;

	unsigned int status;



	switch (action) {

	case CU2_EXCEPTION:

		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))

			break;

		local_irq_save(flags);

		KSTK_STATUS(current) |= ST0_CU2;

		status = read_c0_status();

		write_c0_status(status | ST0_CU2);

		nlm_cop2_restore(&(current->thread.cp2));

		write_c0_status(status & ~ST0_CU2);

		local_irq_restore(flags);

		pr_info("COP2 access enabled for pid %d (%s)\n",

					current->pid, current->comm);

		return NOTIFY_BAD;	/* Don't call default notifier */

	}



	return NOTIFY_OK;		/* Let default notifier send signals */

}



static int __init nlm_cu2_setup(void)

{

	return cu2_notifier(nlm_cu2_call, 0);

}

early_initcall(nlm_cu2_setup);