cop2-ex.c
2.72 KB
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/*
* 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);