Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upst…

…ream-linus

Pull MIPS fixes from Ralf Baechle:
 "A set of MIPS fixes for 4.9:

   - lots of fixes for printk continuations
   - six fixes for FP related code.
   - fix max_low_pfn with disabled highmem
   - fix KASLR handling of NULL FDT and KASLR for generic kernels
   - fix build of compressed image
   - provide default mips_cpc_default_phys_base to ignore CPC
   - fix reboot on Malta"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: Fix max_low_pfn with disabled highmem
  MIPS: Correct MIPS I FP sigcontext layout
  MIPS: Fix ISA I/II FP signal context offsets
  MIPS: Remove FIR from ISA I FP signal context
  MIPS: Fix ISA I FP sigcontext access violation handling
  MIPS: Fix FCSR Cause bit handling for correct SIGFPE issue
  MIPS: ptrace: Also initialize the FP context on individual FCSR writes
  MIPS: dump_tlb: Fix printk continuations
  MIPS: Fix __show_regs() output
  MIPS: traps: Fix output of show_code
  MIPS: traps: Fix output of show_stacktrace
  MIPS: traps: Fix output of show_backtrace
  MIPS: Fix build of compressed image
  MIPS: generic: Fix KASLR for generic kernel.
  MIPS: KASLR: Fix handling of NULL FDT
  MIPS: Malta: Fixup reboot
  MIPS: CPC: Provide default mips_cpc_default_phys_base to ignore CPC

arch/mips/Makefile

@@ -263,7 +263,7 @@ KBUILD_CPPFLAGS += -DDATAOFFSET=$(if $(dataoffset-y),$(dataoffset-y),0)
 
 bootvars-y	= VMLINUX_LOAD_ADDRESS=$(load-y) \
 		  VMLINUX_ENTRY_ADDRESS=$(entry-y) \
-		  PLATFORM=$(platform-y)
+		  PLATFORM="$(platform-y)"
 ifdef CONFIG_32BIT
 bootvars-y	+= ADDR_BITS=32
 endif

arch/mips/boot/dts/mti/malta.dts

@@ -84,12 +84,13 @@
 	fpga_regs: system-controller@1f000000 {
 		compatible = "mti,malta-fpga", "syscon", "simple-mfd";
 		reg = <0x1f000000 0x1000>;
+		native-endian;
 
 		reboot {
 			compatible = "syscon-reboot";
 			regmap = <&fpga_regs>;
 			offset = <0x500>;
-			mask = <0x4d>;
+			mask = <0x42>;
 		};
 	};
 

arch/mips/generic/init.c

@@ -29,10 +29,20 @@ static __initdata const struct mips_machine *mach;
 static __initdata const void *mach_match_data;
 
 void __init prom_init(void)
+{
+	plat_get_fdt();
+	BUG_ON(!fdt);
+}
+
+void __init *plat_get_fdt(void)
 {
 	const struct mips_machine *check_mach;
 	const struct of_device_id *match;
 
+	if (fdt)
+		/* Already set up */
+		return (void *)fdt;
+
 	if ((fw_arg0 == -2) && !fdt_check_header((void *)fw_arg1)) {
 		/*
 		 * We booted using the UHI boot protocol, so we have been
@@ -75,12 +85,6 @@ void __init prom_init(void)
 		/* Retrieve the machine's FDT */
 		fdt = mach->fdt;
 	}
-
-	BUG_ON(!fdt);
-}
-
-void __init *plat_get_fdt(void)
-{
 	return (void *)fdt;
 }
 

arch/mips/include/asm/fpu_emulator.h

@@ -63,6 +63,8 @@ do {									\
 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
 				    struct mips_fpu_struct *ctx, int has_fpu,
 				    void *__user *fault_addr);
+void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr,
+		     struct task_struct *tsk);
 int process_fpemu_return(int sig, void __user *fault_addr,
 			 unsigned long fcr31);
 int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
@@ -81,4 +83,15 @@ static inline void fpu_emulator_init_fpu(void)
 		set_fpr64(&t->thread.fpu.fpr[i], 0, SIGNALLING_NAN);
 }
 
+/*
+ * Mask the FCSR Cause bits according to the Enable bits, observing
+ * that Unimplemented is always enabled.
+ */
+static inline unsigned long mask_fcr31_x(unsigned long fcr31)
+{
+	return fcr31 & (FPU_CSR_UNI_X |
+			((fcr31 & FPU_CSR_ALL_E) <<
+			 (ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E))));
+}
+
 #endif /* _ASM_FPU_EMULATOR_H */

arch/mips/include/asm/switch_to.h

@@ -75,6 +75,22 @@ do {	if (cpu_has_rw_llb) {						\
 	}								\
 } while (0)
 
+/*
+ * Check FCSR for any unmasked exceptions pending set with `ptrace',
+ * clear them and send a signal.
+ */
+#define __sanitize_fcr31(next)						\
+do {									\
+	unsigned long fcr31 = mask_fcr31_x(next->thread.fpu.fcr31);	\
+	void __user *pc;						\
+									\
+	if (unlikely(fcr31)) {						\
+		pc = (void __user *)task_pt_regs(next)->cp0_epc;	\
+		next->thread.fpu.fcr31 &= ~fcr31;			\
+		force_fcr31_sig(fcr31, pc, next);			\
+	}								\
+} while (0)
+
 /*
  * For newly created kernel threads switch_to() will return to
  * ret_from_kernel_thread, newly created user threads to ret_from_fork.
@@ -85,6 +101,8 @@ do {	if (cpu_has_rw_llb) {						\
 do {									\
 	__mips_mt_fpaff_switch_to(prev);				\
 	lose_fpu_inatomic(1, prev);					\
+	if (tsk_used_math(next))					\
+		__sanitize_fcr31(next);					\
 	if (cpu_has_dsp) {						\
 		__save_dsp(prev);					\
 		__restore_dsp(next);					\

arch/mips/kernel/mips-cpc.c

@@ -21,6 +21,11 @@ static DEFINE_PER_CPU_ALIGNED(spinlock_t, cpc_core_lock);
 
 static DEFINE_PER_CPU_ALIGNED(unsigned long, cpc_core_lock_flags);
 
+phys_addr_t __weak mips_cpc_default_phys_base(void)
+{
+	return 0;
+}
+
 /**
  * mips_cpc_phys_base - retrieve the physical base address of the CPC
  *
@@ -43,8 +48,12 @@ static phys_addr_t mips_cpc_phys_base(void)
 	if (cpc_base & CM_GCR_CPC_BASE_CPCEN_MSK)
 		return cpc_base & CM_GCR_CPC_BASE_CPCBASE_MSK;
 
-	/* Otherwise, give it the default address & enable it */
+	/* Otherwise, use the default address */
 	cpc_base = mips_cpc_default_phys_base();
+	if (!cpc_base)
+		return cpc_base;
+
+	/* Enable the CPC, mapped at the default address */
 	write_gcr_cpc_base(cpc_base | CM_GCR_CPC_BASE_CPCEN_MSK);
 	return cpc_base;
 }

arch/mips/kernel/mips-r2-to-r6-emul.c

@@ -899,7 +899,7 @@ static inline int mipsr2_find_op_func(struct pt_regs *regs, u32 inst,
  * mipsr2_decoder: Decode and emulate a MIPS R2 instruction
  * @regs: Process register set
  * @inst: Instruction to decode and emulate
- * @fcr31: Floating Point Control and Status Register returned
+ * @fcr31: Floating Point Control and Status Register Cause bits returned
  */
 int mipsr2_decoder(struct pt_regs *regs, u32 inst, unsigned long *fcr31)
 {
@@ -1172,13 +1172,13 @@ int mipsr2_decoder(struct pt_regs *regs, u32 inst, unsigned long *fcr31)
 
 		err = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 0,
 					       &fault_addr);
-		*fcr31 = current->thread.fpu.fcr31;
 
 		/*
-		 * We can't allow the emulated instruction to leave any of
-		 * the cause bits set in $fcr31.
+		 * We can't allow the emulated instruction to leave any
+		 * enabled Cause bits set in $fcr31.
 		 */
-		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
+		*fcr31 = res = mask_fcr31_x(current->thread.fpu.fcr31);
+		current->thread.fpu.fcr31 &= ~res;
 
 		/*
 		 * this is a tricky issue - lose_fpu() uses LL/SC atomics

arch/mips/kernel/ptrace.c

@@ -79,16 +79,15 @@ void ptrace_disable(struct task_struct *child)
 }
 
 /*
- * Poke at FCSR according to its mask.  Don't set the cause bits as
- * this is currently not handled correctly in FP context restoration
- * and will cause an oops if a corresponding enable bit is set.
+ * Poke at FCSR according to its mask.  Set the Cause bits even
+ * if a corresponding Enable bit is set.  This will be noticed at
+ * the time the thread is switched to and SIGFPE thrown accordingly.
  */
 static void ptrace_setfcr31(struct task_struct *child, u32 value)
 {
 	u32 fcr31;
 	u32 mask;
 
-	value &= ~FPU_CSR_ALL_X;
 	fcr31 = child->thread.fpu.fcr31;
 	mask = boot_cpu_data.fpu_msk31;
 	child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);
@@ -817,6 +816,7 @@ long arch_ptrace(struct task_struct *child, long request,
 			break;
 #endif
 		case FPC_CSR:
+			init_fp_ctx(child);
 			ptrace_setfcr31(child, data);
 			break;
 		case DSP_BASE ... DSP_BASE + 5: {

arch/mips/kernel/r2300_fpu.S

@@ -19,108 +19,86 @@
 #include <asm/regdef.h>
 
 #define EX(a,b)							\
+9:	a,##b;							\
+	.section __ex_table,"a";				\
+	PTR	9b,fault;					\
+	.previous
+
+#define EX2(a,b)						\
 9:	a,##b;							\
 	.section __ex_table,"a";				\
 	PTR	9b,bad_stack;					\
+	PTR	9b+4,bad_stack;					\
 	.previous
 
 	.set	noreorder
 	.set	mips1
-	/* Save floating point context */
+
+/**
+ * _save_fp_context() - save FP context from the FPU
+ * @a0 - pointer to fpregs field of sigcontext
+ * @a1 - pointer to fpc_csr field of sigcontext
+ *
+ * Save FP context, including the 32 FP data registers and the FP
+ * control & status register, from the FPU to signal context.
+ */
 LEAF(_save_fp_context)
 	.set	push
 	SET_HARDFLOAT
 	li	v0, 0					# assume success
-	cfc1	t1,fcr31
-	EX(swc1 $f0,(SC_FPREGS+0)(a0))
-	EX(swc1 $f1,(SC_FPREGS+8)(a0))
-	EX(swc1 $f2,(SC_FPREGS+16)(a0))
-	EX(swc1 $f3,(SC_FPREGS+24)(a0))
-	EX(swc1 $f4,(SC_FPREGS+32)(a0))
-	EX(swc1 $f5,(SC_FPREGS+40)(a0))
-	EX(swc1 $f6,(SC_FPREGS+48)(a0))
-	EX(swc1 $f7,(SC_FPREGS+56)(a0))
-	EX(swc1 $f8,(SC_FPREGS+64)(a0))
-	EX(swc1 $f9,(SC_FPREGS+72)(a0))
-	EX(swc1 $f10,(SC_FPREGS+80)(a0))
-	EX(swc1 $f11,(SC_FPREGS+88)(a0))
-	EX(swc1 $f12,(SC_FPREGS+96)(a0))
-	EX(swc1 $f13,(SC_FPREGS+104)(a0))
-	EX(swc1 $f14,(SC_FPREGS+112)(a0))
-	EX(swc1 $f15,(SC_FPREGS+120)(a0))
-	EX(swc1 $f16,(SC_FPREGS+128)(a0))
-	EX(swc1 $f17,(SC_FPREGS+136)(a0))
-	EX(swc1 $f18,(SC_FPREGS+144)(a0))
-	EX(swc1 $f19,(SC_FPREGS+152)(a0))
-	EX(swc1 $f20,(SC_FPREGS+160)(a0))
-	EX(swc1 $f21,(SC_FPREGS+168)(a0))
-	EX(swc1 $f22,(SC_FPREGS+176)(a0))
-	EX(swc1 $f23,(SC_FPREGS+184)(a0))
-	EX(swc1 $f24,(SC_FPREGS+192)(a0))
-	EX(swc1 $f25,(SC_FPREGS+200)(a0))
-	EX(swc1 $f26,(SC_FPREGS+208)(a0))
-	EX(swc1 $f27,(SC_FPREGS+216)(a0))
-	EX(swc1 $f28,(SC_FPREGS+224)(a0))
-	EX(swc1 $f29,(SC_FPREGS+232)(a0))
-	EX(swc1 $f30,(SC_FPREGS+240)(a0))
-	EX(swc1 $f31,(SC_FPREGS+248)(a0))
-	EX(sw	t1,(SC_FPC_CSR)(a0))
-	cfc1	t0,$0				# implementation/version
+	cfc1	t1, fcr31
+	EX2(s.d $f0, 0(a0))
+	EX2(s.d $f2, 16(a0))
+	EX2(s.d $f4, 32(a0))
+	EX2(s.d $f6, 48(a0))
+	EX2(s.d $f8, 64(a0))
+	EX2(s.d $f10, 80(a0))
+	EX2(s.d $f12, 96(a0))
+	EX2(s.d $f14, 112(a0))
+	EX2(s.d $f16, 128(a0))
+	EX2(s.d $f18, 144(a0))
+	EX2(s.d $f20, 160(a0))
+	EX2(s.d $f22, 176(a0))
+	EX2(s.d $f24, 192(a0))
+	EX2(s.d $f26, 208(a0))
+	EX2(s.d $f28, 224(a0))
+	EX2(s.d $f30, 240(a0))
 	jr	ra
+	 EX(sw	t1, (a1))
 	.set	pop
-	.set	nomacro
-	 EX(sw	t0,(SC_FPC_EIR)(a0))
-	.set	macro
 	END(_save_fp_context)
 
-/*
- * Restore FPU state:
- *  - fp gp registers
- *  - cp1 status/control register
+/**
+ * _restore_fp_context() - restore FP context to the FPU
+ * @a0 - pointer to fpregs field of sigcontext
+ * @a1 - pointer to fpc_csr field of sigcontext
  *
- * We base the decision which registers to restore from the signal stack
- * frame on the current content of c0_status, not on the content of the
- * stack frame which might have been changed by the user.
+ * Restore FP context, including the 32 FP data registers and the FP
+ * control & status register, from signal context to the FPU.
  */
 LEAF(_restore_fp_context)
 	.set	push
 	SET_HARDFLOAT
 	li	v0, 0					# assume success
-	EX(lw t0,(SC_FPC_CSR)(a0))
-	EX(lwc1 $f0,(SC_FPREGS+0)(a0))
-	EX(lwc1 $f1,(SC_FPREGS+8)(a0))
-	EX(lwc1 $f2,(SC_FPREGS+16)(a0))
-	EX(lwc1 $f3,(SC_FPREGS+24)(a0))
-	EX(lwc1 $f4,(SC_FPREGS+32)(a0))
-	EX(lwc1 $f5,(SC_FPREGS+40)(a0))
-	EX(lwc1 $f6,(SC_FPREGS+48)(a0))
-	EX(lwc1 $f7,(SC_FPREGS+56)(a0))
-	EX(lwc1 $f8,(SC_FPREGS+64)(a0))
-	EX(lwc1 $f9,(SC_FPREGS+72)(a0))
-	EX(lwc1 $f10,(SC_FPREGS+80)(a0))
-	EX(lwc1 $f11,(SC_FPREGS+88)(a0))
-	EX(lwc1 $f12,(SC_FPREGS+96)(a0))
-	EX(lwc1 $f13,(SC_FPREGS+104)(a0))
-	EX(lwc1 $f14,(SC_FPREGS+112)(a0))
-	EX(lwc1 $f15,(SC_FPREGS+120)(a0))
-	EX(lwc1 $f16,(SC_FPREGS+128)(a0))
-	EX(lwc1 $f17,(SC_FPREGS+136)(a0))
-	EX(lwc1 $f18,(SC_FPREGS+144)(a0))
-	EX(lwc1 $f19,(SC_FPREGS+152)(a0))
-	EX(lwc1 $f20,(SC_FPREGS+160)(a0))
-	EX(lwc1 $f21,(SC_FPREGS+168)(a0))
-	EX(lwc1 $f22,(SC_FPREGS+176)(a0))
-	EX(lwc1 $f23,(SC_FPREGS+184)(a0))
-	EX(lwc1 $f24,(SC_FPREGS+192)(a0))
-	EX(lwc1 $f25,(SC_FPREGS+200)(a0))
-	EX(lwc1 $f26,(SC_FPREGS+208)(a0))
-	EX(lwc1 $f27,(SC_FPREGS+216)(a0))
-	EX(lwc1 $f28,(SC_FPREGS+224)(a0))
-	EX(lwc1 $f29,(SC_FPREGS+232)(a0))
-	EX(lwc1 $f30,(SC_FPREGS+240)(a0))
-	EX(lwc1 $f31,(SC_FPREGS+248)(a0))
+	EX(lw t0, (a1))
+	EX2(l.d $f0, 0(a0))
+	EX2(l.d $f2, 16(a0))
+	EX2(l.d $f4, 32(a0))
+	EX2(l.d $f6, 48(a0))
+	EX2(l.d $f8, 64(a0))
+	EX2(l.d $f10, 80(a0))
+	EX2(l.d $f12, 96(a0))
+	EX2(l.d $f14, 112(a0))
+	EX2(l.d $f16, 128(a0))
+	EX2(l.d $f18, 144(a0))
+	EX2(l.d $f20, 160(a0))
+	EX2(l.d $f22, 176(a0))
+	EX2(l.d $f24, 192(a0))
+	EX2(l.d $f26, 208(a0))
+	EX2(l.d $f28, 224(a0))
+	EX2(l.d $f30, 240(a0))
 	jr	ra
-	 ctc1	t0,fcr31
+	 ctc1	t0, fcr31
 	.set	pop
 	END(_restore_fp_context)
 	.set	reorder