2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 2013 Broadcom Corporation.
8 * based on arch/mips/cavium-octeon/cpu.c
9 * Copyright (C) 2009 Wind River Systems,
10 * written by Ralf Baechle <ralf@linux-mips.org>
12 #include <linux/capability.h>
13 #include <linux/init.h>
14 #include <linux/irqflags.h>
15 #include <linux/notifier.h>
16 #include <linux/prefetch.h>
17 #include <linux/ptrace.h>
18 #include <linux/sched.h>
19 #include <linux/sched/task_stack.h>
22 #include <asm/current.h>
23 #include <asm/mipsregs.h>
26 #include <asm/netlogic/mips-extns.h>
29 * 64 bit ops are done in inline assembly to support 32 bit
32 void nlm_cop2_save(struct nlm_cop2_state *r)
55 : "r"(r->tx), "r"(r->rx));
57 r->tx_msg_status = __read_32bit_c2_register($2, 0);
58 r->rx_msg_status = __read_32bit_c2_register($3, 0) & 0x0fffffff;
61 void nlm_cop2_restore(struct nlm_cop2_state *r)
85 : : "m"(*r), "r"(r->tx), "r"(r->rx));
87 __write_32bit_c2_register($2, 0, r->tx_msg_status);
88 rstat = __read_32bit_c2_register($3, 0) & 0xf0000000u;
89 __write_32bit_c2_register($3, 0, r->rx_msg_status | rstat);
92 static int nlm_cu2_call(struct notifier_block *nfb, unsigned long action,
100 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
102 local_irq_save(flags);
103 KSTK_STATUS(current) |= ST0_CU2;
104 status = read_c0_status();
105 write_c0_status(status | ST0_CU2);
106 nlm_cop2_restore(&(current->thread.cp2));
107 write_c0_status(status & ~ST0_CU2);
108 local_irq_restore(flags);
109 pr_info("COP2 access enabled for pid %d (%s)\n",
110 current->pid, current->comm);
111 return NOTIFY_BAD; /* Don't call default notifier */
114 return NOTIFY_OK; /* Let default notifier send signals */
117 static int __init nlm_cu2_setup(void)
119 return cu2_notifier(nlm_cu2_call, 0);
121 early_initcall(nlm_cu2_setup);