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-rw-r--r--arch/mips/loongson64/cop2-ex.c341
1 files changed, 341 insertions, 0 deletions
diff --git a/arch/mips/loongson64/cop2-ex.c b/arch/mips/loongson64/cop2-ex.c
new file mode 100644
index 000000000..00055d4b6
--- /dev/null
+++ b/arch/mips/loongson64/cop2-ex.c
@@ -0,0 +1,341 @@
+/*
+ * 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) 2014 Lemote Corporation.
+ * written by Huacai Chen <chenhc@lemote.com>
+ *
+ * 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/sched.h>
+#include <linux/notifier.h>
+#include <linux/ptrace.h>
+#include <linux/uaccess.h>
+#include <linux/sched/signal.h>
+
+#include <asm/fpu.h>
+#include <asm/cop2.h>
+#include <asm/inst.h>
+#include <asm/branch.h>
+#include <asm/current.h>
+#include <asm/mipsregs.h>
+#include <asm/unaligned-emul.h>
+
+static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action,
+ void *data)
+{
+ unsigned int res, fpu_owned;
+ unsigned long ra, value, value_next;
+ union mips_instruction insn;
+ int fr = !test_thread_flag(TIF_32BIT_FPREGS);
+ struct pt_regs *regs = (struct pt_regs *)data;
+ void __user *addr = (void __user *)regs->cp0_badvaddr;
+ unsigned int __user *pc = (unsigned int __user *)exception_epc(regs);
+
+ ra = regs->regs[31];
+ __get_user(insn.word, pc);
+
+ switch (action) {
+ case CU2_EXCEPTION:
+ preempt_disable();
+ fpu_owned = __is_fpu_owner();
+ if (!fr)
+ set_c0_status(ST0_CU1 | ST0_CU2);
+ else
+ set_c0_status(ST0_CU1 | ST0_CU2 | ST0_FR);
+ enable_fpu_hazard();
+ KSTK_STATUS(current) |= (ST0_CU1 | ST0_CU2);
+ if (fr)
+ KSTK_STATUS(current) |= ST0_FR;
+ else
+ KSTK_STATUS(current) &= ~ST0_FR;
+ /* If FPU is owned, we needn't init or restore fp */
+ if (!fpu_owned) {
+ set_thread_flag(TIF_USEDFPU);
+ init_fp_ctx(current);
+ _restore_fp(current);
+ }
+ preempt_enable();
+
+ return NOTIFY_STOP; /* Don't call default notifier */
+
+ case CU2_LWC2_OP:
+ if (insn.loongson3_lswc2_format.ls == 0)
+ goto sigbus;
+
+ if (insn.loongson3_lswc2_format.fr == 0) { /* gslq */
+ if (!access_ok(addr, 16))
+ goto sigbus;
+
+ LoadDW(addr, value, res);
+ if (res)
+ goto fault;
+
+ LoadDW(addr + 8, value_next, res);
+ if (res)
+ goto fault;
+
+ regs->regs[insn.loongson3_lswc2_format.rt] = value;
+ regs->regs[insn.loongson3_lswc2_format.rq] = value_next;
+ compute_return_epc(regs);
+ } else { /* gslqc1 */
+ if (!access_ok(addr, 16))
+ goto sigbus;
+
+ lose_fpu(1);
+ LoadDW(addr, value, res);
+ if (res)
+ goto fault;
+
+ LoadDW(addr + 8, value_next, res);
+ if (res)
+ goto fault;
+
+ set_fpr64(&current->thread.fpu.fpr[insn.loongson3_lswc2_format.rt], 0, value);
+ set_fpr64(&current->thread.fpu.fpr[insn.loongson3_lswc2_format.rq], 0, value_next);
+ compute_return_epc(regs);
+ own_fpu(1);
+ }
+ return NOTIFY_STOP; /* Don't call default notifier */
+
+ case CU2_SWC2_OP:
+ if (insn.loongson3_lswc2_format.ls == 0)
+ goto sigbus;
+
+ if (insn.loongson3_lswc2_format.fr == 0) { /* gssq */
+ if (!access_ok(addr, 16))
+ goto sigbus;
+
+ /* write upper 8 bytes first */
+ value_next = regs->regs[insn.loongson3_lswc2_format.rq];
+
+ StoreDW(addr + 8, value_next, res);
+ if (res)
+ goto fault;
+ value = regs->regs[insn.loongson3_lswc2_format.rt];
+
+ StoreDW(addr, value, res);
+ if (res)
+ goto fault;
+
+ compute_return_epc(regs);
+ } else { /* gssqc1 */
+ if (!access_ok(addr, 16))
+ goto sigbus;
+
+ lose_fpu(1);
+ value_next = get_fpr64(&current->thread.fpu.fpr[insn.loongson3_lswc2_format.rq], 0);
+
+ StoreDW(addr + 8, value_next, res);
+ if (res)
+ goto fault;
+
+ value = get_fpr64(&current->thread.fpu.fpr[insn.loongson3_lswc2_format.rt], 0);
+
+ StoreDW(addr, value, res);
+ if (res)
+ goto fault;
+
+ compute_return_epc(regs);
+ own_fpu(1);
+ }
+ return NOTIFY_STOP; /* Don't call default notifier */
+
+ case CU2_LDC2_OP:
+ switch (insn.loongson3_lsdc2_format.opcode1) {
+ /*
+ * Loongson-3 overridden ldc2 instructions.
+ * opcode1 instruction
+ * 0x1 gslhx: load 2 bytes to GPR
+ * 0x2 gslwx: load 4 bytes to GPR
+ * 0x3 gsldx: load 8 bytes to GPR
+ * 0x6 gslwxc1: load 4 bytes to FPR
+ * 0x7 gsldxc1: load 8 bytes to FPR
+ */
+ case 0x1:
+ if (!access_ok(addr, 2))
+ goto sigbus;
+
+ LoadHW(addr, value, res);
+ if (res)
+ goto fault;
+
+ compute_return_epc(regs);
+ regs->regs[insn.loongson3_lsdc2_format.rt] = value;
+ break;
+ case 0x2:
+ if (!access_ok(addr, 4))
+ goto sigbus;
+
+ LoadW(addr, value, res);
+ if (res)
+ goto fault;
+
+ compute_return_epc(regs);
+ regs->regs[insn.loongson3_lsdc2_format.rt] = value;
+ break;
+ case 0x3:
+ if (!access_ok(addr, 8))
+ goto sigbus;
+
+ LoadDW(addr, value, res);
+ if (res)
+ goto fault;
+
+ compute_return_epc(regs);
+ regs->regs[insn.loongson3_lsdc2_format.rt] = value;
+ break;
+ case 0x6:
+ die_if_kernel("Unaligned FP access in kernel code", regs);
+ BUG_ON(!used_math());
+ if (!access_ok(addr, 4))
+ goto sigbus;
+
+ lose_fpu(1);
+ LoadW(addr, value, res);
+ if (res)
+ goto fault;
+
+ set_fpr64(&current->thread.fpu.fpr[insn.loongson3_lsdc2_format.rt], 0, value);
+ compute_return_epc(regs);
+ own_fpu(1);
+
+ break;
+ case 0x7:
+ die_if_kernel("Unaligned FP access in kernel code", regs);
+ BUG_ON(!used_math());
+ if (!access_ok(addr, 8))
+ goto sigbus;
+
+ lose_fpu(1);
+ LoadDW(addr, value, res);
+ if (res)
+ goto fault;
+
+ set_fpr64(&current->thread.fpu.fpr[insn.loongson3_lsdc2_format.rt], 0, value);
+ compute_return_epc(regs);
+ own_fpu(1);
+ break;
+
+ }
+ return NOTIFY_STOP; /* Don't call default notifier */
+
+ case CU2_SDC2_OP:
+ switch (insn.loongson3_lsdc2_format.opcode1) {
+ /*
+ * Loongson-3 overridden sdc2 instructions.
+ * opcode1 instruction
+ * 0x1 gsshx: store 2 bytes from GPR
+ * 0x2 gsswx: store 4 bytes from GPR
+ * 0x3 gssdx: store 8 bytes from GPR
+ * 0x6 gsswxc1: store 4 bytes from FPR
+ * 0x7 gssdxc1: store 8 bytes from FPR
+ */
+ case 0x1:
+ if (!access_ok(addr, 2))
+ goto sigbus;
+
+ compute_return_epc(regs);
+ value = regs->regs[insn.loongson3_lsdc2_format.rt];
+
+ StoreHW(addr, value, res);
+ if (res)
+ goto fault;
+
+ break;
+ case 0x2:
+ if (!access_ok(addr, 4))
+ goto sigbus;
+
+ compute_return_epc(regs);
+ value = regs->regs[insn.loongson3_lsdc2_format.rt];
+
+ StoreW(addr, value, res);
+ if (res)
+ goto fault;
+
+ break;
+ case 0x3:
+ if (!access_ok(addr, 8))
+ goto sigbus;
+
+ compute_return_epc(regs);
+ value = regs->regs[insn.loongson3_lsdc2_format.rt];
+
+ StoreDW(addr, value, res);
+ if (res)
+ goto fault;
+
+ break;
+
+ case 0x6:
+ die_if_kernel("Unaligned FP access in kernel code", regs);
+ BUG_ON(!used_math());
+
+ if (!access_ok(addr, 4))
+ goto sigbus;
+
+ lose_fpu(1);
+ value = get_fpr64(&current->thread.fpu.fpr[insn.loongson3_lsdc2_format.rt], 0);
+
+ StoreW(addr, value, res);
+ if (res)
+ goto fault;
+
+ compute_return_epc(regs);
+ own_fpu(1);
+
+ break;
+ case 0x7:
+ die_if_kernel("Unaligned FP access in kernel code", regs);
+ BUG_ON(!used_math());
+
+ if (!access_ok(addr, 8))
+ goto sigbus;
+
+ lose_fpu(1);
+ value = get_fpr64(&current->thread.fpu.fpr[insn.loongson3_lsdc2_format.rt], 0);
+
+ StoreDW(addr, value, res);
+ if (res)
+ goto fault;
+
+ compute_return_epc(regs);
+ own_fpu(1);
+
+ break;
+ }
+ return NOTIFY_STOP; /* Don't call default notifier */
+ }
+
+ return NOTIFY_OK; /* Let default notifier send signals */
+
+fault:
+ /* roll back jump/branch */
+ regs->regs[31] = ra;
+ regs->cp0_epc = (unsigned long)pc;
+ /* Did we have an exception handler installed? */
+ if (fixup_exception(regs))
+ return NOTIFY_STOP; /* Don't call default notifier */
+
+ die_if_kernel("Unhandled kernel unaligned access", regs);
+ force_sig(SIGSEGV);
+
+ return NOTIFY_STOP; /* Don't call default notifier */
+
+sigbus:
+ die_if_kernel("Unhandled kernel unaligned access", regs);
+ force_sig(SIGBUS);
+
+ return NOTIFY_STOP; /* Don't call default notifier */
+}
+
+static int __init loongson_cu2_setup(void)
+{
+ return cu2_notifier(loongson_cu2_call, 0);
+}
+early_initcall(loongson_cu2_setup);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-16 16:43:26 +0000