[MIPS] Make sure cpu_has_fpu is used only in atomic context

Make sure cpu_has_fpu (which uses smp_processor_id()) is used only in
atomic context.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

7 files changed, 30 insertions, 24 deletions

diff --git a/arch/mips/kernel/proc.c b/arch/mips/kernel/proc.c
index 46ee5a68ab13..4ed37ba19731 100644
--- a/arch/mips/kernel/proc.c
+++ b/arch/mips/kernel/proc.c
@@ -107,7 +107,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 
         seq_printf(m, "processor\t\t: %ld\n", n);
         sprintf(fmt, "cpu model\t\t: %%s V%%d.%%d%s\n",
-                cpu_has_fpu ? "  FPU V%d.%d" : "");
+                cpu_data[n].options & MIPS_CPU_FPU ? "  FPU V%d.%d" : "");
         seq_printf(m, fmt, cpu_name[cpu_data[n].cputype <= CPU_LAST ?
                                     cpu_data[n].cputype : CPU_UNKNOWN],
                                    (version >> 4) & 0x0f, version & 0x0f,
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index 045d987bc683..9f307eb1a31e 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -115,7 +115,7 @@ void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
         status |= KU_USER;
         regs->cp0_status = status;
         clear_used_math();
-        lose_fpu();
+        clear_fpu_owner();
         if (cpu_has_dsp)
                 __init_dsp();
         regs->cp0_epc = pc;
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 362d1728e531..258d74fd0b63 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -106,6 +106,7 @@ int ptrace_setregs (struct task_struct *child, __s64 __user *data)
 int ptrace_getfpregs (struct task_struct *child, __u32 __user *data)
 {
         int i;
+        unsigned int tmp;
 
         if (!access_ok(VERIFY_WRITE, data, 33 * 8))
                 return -EIO;
@@ -121,10 +122,10 @@ int ptrace_getfpregs (struct task_struct *child, __u32 __user *data)
 
         __put_user (child->thread.fpu.fcr31, data + 64);
 
+        preempt_disable();
         if (cpu_has_fpu) {
-                unsigned int flags, tmp;
+                unsigned int flags;
 
-                preempt_disable();
                 if (cpu_has_mipsmt) {
                         unsigned int vpflags = dvpe();
                         flags = read_c0_status();
@@ -138,11 +139,11 @@ int ptrace_getfpregs (struct task_struct *child, __u32 __user *data)
                         __asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
                         write_c0_status(flags);
                 }
-                preempt_enable();
-                __put_user (tmp, data + 65);
         } else {
-                __put_user ((__u32) 0, data + 65);
+                tmp = 0;
         }
+        preempt_enable();
+        __put_user (tmp, data + 65);
 
         return 0;
 }
@@ -245,16 +246,17 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                         unsigned int mtflags;
 #endif /* CONFIG_MIPS_MT_SMTC */
 
-                        if (!cpu_has_fpu)
+                        preempt_disable();
+                        if (!cpu_has_fpu) {
+                                preempt_enable();
                                 break;
+                        }
 
 #ifdef CONFIG_MIPS_MT_SMTC
                         /* Read-modify-write of Status must be atomic */
                         local_irq_save(irqflags);
                         mtflags = dmt();
 #endif /* CONFIG_MIPS_MT_SMTC */
-
-                        preempt_disable();
                         if (cpu_has_mipsmt) {
                                 unsigned int vpflags = dvpe();
                                 flags = read_c0_status();
diff --git a/arch/mips/kernel/ptrace32.c b/arch/mips/kernel/ptrace32.c
index f40ecd8be05f..d9a39c169450 100644
--- a/arch/mips/kernel/ptrace32.c
+++ b/arch/mips/kernel/ptrace32.c
@@ -175,7 +175,9 @@ asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
                         unsigned int mtflags;
 #endif /* CONFIG_MIPS_MT_SMTC */
 
+                        preempt_disable();
                         if (!cpu_has_fpu) {
+                                preempt_enable();
                                 tmp = 0;
                                 break;
                         }
@@ -186,7 +188,6 @@ asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
                         mtflags = dmt();
 #endif /* CONFIG_MIPS_MT_SMTC */
 
-                        preempt_disable();
                         if (cpu_has_mipsmt) {
                                 unsigned int vpflags = dvpe();
                                 flags = read_c0_status();
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index b7292a56d4cd..cce8313ec27d 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -66,7 +66,7 @@ extern asmlinkage void handle_mcheck(void);
 extern asmlinkage void handle_reserved(void);
 
 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
-        struct mips_fpu_struct *ctx);
+        struct mips_fpu_struct *ctx, int has_fpu);
 
 void (*board_be_init)(void);
 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
@@ -641,7 +641,7 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
                 preempt_enable();
 
                 /* Run the emulator */
-                sig = fpu_emulator_cop1Handler (regs, &current->thread.fpu);
+                sig = fpu_emulator_cop1Handler (regs, &current->thread.fpu, 1);
 
                 preempt_disable();
 
@@ -791,11 +791,13 @@ asmlinkage void do_cpu(struct pt_regs *regs)
                         set_used_math();
                 }
 
-                preempt_enable();
-
-                if (!cpu_has_fpu) {
-                        int sig = fpu_emulator_cop1Handler(regs,
-                                                &current->thread.fpu);
+                if (cpu_has_fpu) {
+                        preempt_enable();
+                } else {
+                        int sig;
+                        preempt_enable();
+                        sig = fpu_emulator_cop1Handler(regs,
+                                                &current->thread.fpu, 0);
                         if (sig)
                                 force_sig(sig, current);
 #ifdef CONFIG_MIPS_MT_FPAFF
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 3f0d5d26d506..80531b35cd61 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -38,8 +38,6 @@
 
 #include <asm/inst.h>
 #include <asm/bootinfo.h>
-#include <asm/cpu.h>
-#include <asm/cpu-features.h>
 #include <asm/processor.h>
 #include <asm/ptrace.h>
 #include <asm/signal.h>
@@ -1233,7 +1231,8 @@ static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
         return 0;
 }
 
-int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
+int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
+        int has_fpu)
 {
         unsigned long oldepc, prevepc;
         mips_instruction insn;
@@ -1263,7 +1262,7 @@ int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
                         ieee754_csr.rm = mips_rm[ieee754_csr.rm];
                 }
 
-                if (cpu_has_fpu)
+                if (has_fpu)
                         break;
                 if (sig)
                         break;
diff --git a/include/asm-mips/fpu.h b/include/asm-mips/fpu.h
index 58c561a9ec6b..efef843b93f0 100644
--- a/include/asm-mips/fpu.h
+++ b/include/asm-mips/fpu.h
@@ -134,9 +134,11 @@ static inline void restore_fp(struct task_struct *tsk)
 
 static inline fpureg_t *get_fpu_regs(struct task_struct *tsk)
 {
-        if (cpu_has_fpu) {
-                if ((tsk == current) && __is_fpu_owner())
+        if (tsk == current) {
+                preempt_disable();
+                if (is_fpu_owner())
                         _save_fp(current);
+                preempt_enable();
         }
 
         return tsk->thread.fpu.fpr;