Merge tag 'csky-for-linus-4.21' of git://github.com/c-sky/csky-linux

Pull arch/csky updates from Guo Ren:
 "Here are three main features (cpu_hotplug, basic ftrace, basic perf)
  and some bugfixes:

  Features:
   - Add CPU-hotplug support for SMP
   - Add ftrace with function trace and function graph trace
   - Add Perf support
   - Add EM_CSKY_OLD 39
   - optimize kernel panic print.
   - remove syscall_exit_work

  Bugfixes:
   - fix abiv2 mmap(... O_SYNC) failure
   - fix gdb coredump error
   - remove vdsp implement for kernel
   - fix qemu failure to bootup sometimes
   - fix ftrace call-graph panic
   - fix device tree node reference leak
   - remove meaningless header-y
   - fix save hi,lo,dspcr regs in switch_stack
   - remove unused members in processor.h"

* tag 'csky-for-linus-4.21' of git://github.com/c-sky/csky-linux:
  csky: Add perf support for C-SKY
  csky: Add EM_CSKY_OLD 39
  clocksource/drivers/c-sky: fixup ftrace call-graph panic
  csky: ftrace call graph supported.
  csky: basic ftrace supported
  csky: remove unused members in processor.h
  csky: optimize kernel panic print.
  csky: stacktrace supported.
  csky: CPU-hotplug supported for SMP
  clocksource/drivers/c-sky: fixup qemu fail to bootup sometimes.
  csky: fixup save hi,lo,dspcr regs in switch_stack.
  csky: remove syscall_exit_work
  csky: fixup remove vdsp implement for kernel.
  csky: bugfix gdb coredump error.
  csky: fixup abiv2 mmap(... O_SYNC) failed.
  csky: define syscall_get_arch()
  elf-em.h: add EM_CSKY
  csky: remove meaningless header-y
  csky: Don't leak device tree node reference

arch/csky/Kconfig

@@ -28,10 +28,13 @@ config CSKY
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
 	select HAVE_ARCH_TRACEHOOK
+	select HAVE_FUNCTION_TRACER
+	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZO
 	select HAVE_KERNEL_LZMA
+	select HAVE_PERF_EVENTS
 	select HAVE_C_RECORDMCOUNT
 	select HAVE_DMA_API_DEBUG
 	select HAVE_DMA_CONTIGUOUS
@@ -40,7 +43,7 @@ config CSKY
 	select OF
 	select OF_EARLY_FLATTREE
 	select OF_RESERVED_MEM
-	select PERF_USE_VMALLOC
+	select PERF_USE_VMALLOC if CPU_CK610
 	select RTC_LIB
 	select TIMER_OF
 	select USB_ARCH_HAS_EHCI
@@ -93,6 +96,9 @@ config MMU
 config RWSEM_GENERIC_SPINLOCK
 	def_bool y
 
+config STACKTRACE_SUPPORT
+	def_bool y
+
 config TIME_LOW_RES
 	def_bool y
 
@@ -144,6 +150,19 @@ config CPU_CK860
 	select CPU_HAS_FPUV2
 endchoice
 
+choice
+	prompt "C-SKY PMU type"
+	depends on PERF_EVENTS
+	depends on CPU_CK807 || CPU_CK810 || CPU_CK860
+
+config CPU_PMU_NONE
+	bool "None"
+
+config CSKY_PMU_V1
+	bool "Performance Monitoring Unit Ver.1"
+
+endchoice
+
 choice
 	prompt "Power Manager Instruction (wait/doze/stop)"
 	default CPU_PM_NONE
@@ -197,6 +216,15 @@ config RAM_BASE
 	hex "DRAM start addr (the same with memory-section in dts)"
 	default 0x0
 
+config HOTPLUG_CPU
+	bool "Support for hot-pluggable CPUs"
+	select GENERIC_IRQ_MIGRATION
+	depends on SMP
+	help
+	  Say Y here to allow turning CPUs off and on. CPUs can be
+	  controlled through /sys/devices/system/cpu/cpu1/hotplug/target.
+
+	  Say N if you want to disable CPU hotplug.
 endmenu
 
 source "kernel/Kconfig.hz"

arch/csky/Makefile

@@ -47,6 +47,10 @@ ifeq ($(CSKYABI),abiv2)
 KBUILD_CFLAGS += -mno-stack-size
 endif
 
+ifdef CONFIG_STACKTRACE
+KBUILD_CFLAGS += -mbacktrace
+endif
+
 abidirs := $(patsubst %,arch/csky/%/,$(CSKYABI))
 KBUILD_CFLAGS += $(patsubst %,-I$(srctree)/%inc,$(abidirs))
 

arch/csky/abiv1/inc/abi/pgtable-bits.h

@@ -26,6 +26,7 @@
 
 #define _PAGE_CACHE		(3<<9)
 #define _PAGE_UNCACHE		(2<<9)
+#define _PAGE_SO		_PAGE_UNCACHE
 
 #define _CACHE_MASK		(7<<9)
 

arch/csky/abiv1/inc/abi/switch_context.h

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ABI_CSKY_PTRACE_H
+#define __ABI_CSKY_PTRACE_H
+
+struct switch_stack {
+	unsigned long r8;
+	unsigned long r9;
+	unsigned long r10;
+	unsigned long r11;
+	unsigned long r12;
+	unsigned long r13;
+	unsigned long r14;
+	unsigned long r15;
+};
+#endif /* __ABI_CSKY_PTRACE_H */

arch/csky/abiv2/Makefile

@@ -8,3 +8,4 @@ obj-y				+= strcmp.o
 obj-y				+= strcpy.o
 obj-y				+= strlen.o
 obj-y				+= strksyms.o
+obj-$(CONFIG_FUNCTION_TRACER)	+= mcount.o

arch/csky/abiv2/inc/abi/entry.h

@@ -57,6 +57,8 @@
 	stw	lr, (sp, 60)
 	mflo	lr
 	stw	lr, (sp, 64)
+	mfcr	lr, cr14
+	stw	lr, (sp, 68)
 #endif
 	subi	sp, 80
 .endm
@@ -77,6 +79,8 @@
 	mthi	a0
 	ldw	a0, (sp, 144)
 	mtlo	a0
+	ldw	a0, (sp, 148)
+	mtcr	a0, cr14
 #endif
 
 	ldw     a0, (sp, 24)
@@ -93,21 +97,39 @@
 .endm
 
 .macro SAVE_SWITCH_STACK
-	subi	sp, 64
+	subi    sp, 64
 	stm	r4-r11, (sp)
-	stw	r15, (sp, 32)
+	stw	lr,  (sp, 32)
 	stw	r16, (sp, 36)
 	stw	r17, (sp, 40)
 	stw	r26, (sp, 44)
 	stw	r27, (sp, 48)
 	stw	r28, (sp, 52)
 	stw	r29, (sp, 56)
 	stw	r30, (sp, 60)
+#ifdef CONFIG_CPU_HAS_HILO
+	subi	sp, 16
+	mfhi	lr
+	stw	lr, (sp, 0)
+	mflo	lr
+	stw	lr, (sp, 4)
+	mfcr	lr, cr14
+	stw	lr, (sp, 8)
+#endif
 .endm
 
 .macro RESTORE_SWITCH_STACK
+#ifdef CONFIG_CPU_HAS_HILO
+	ldw	lr, (sp, 0)
+	mthi	lr
+	ldw	lr, (sp, 4)
+	mtlo	lr
+	ldw	lr, (sp, 8)
+	mtcr	lr, cr14
+	addi	sp, 16
+#endif
 	ldm	r4-r11, (sp)
-	ldw	r15, (sp, 32)
+	ldw	lr,  (sp, 32)
 	ldw	r16, (sp, 36)
 	ldw	r17, (sp, 40)
 	ldw	r26, (sp, 44)

arch/csky/abiv2/inc/abi/pgtable-bits.h

@@ -32,6 +32,6 @@
 #define _CACHE_MASK		_PAGE_CACHE
 
 #define _CACHE_CACHED		(_PAGE_VALID | _PAGE_CACHE | _PAGE_BUF)
-#define _CACHE_UNCACHED		(_PAGE_VALID | _PAGE_SO)
+#define _CACHE_UNCACHED		(_PAGE_VALID)
 
 #endif /* __ASM_CSKY_PGTABLE_BITS_H */

arch/csky/abiv2/inc/abi/switch_context.h

@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ABI_CSKY_PTRACE_H
+#define __ABI_CSKY_PTRACE_H
+
+struct switch_stack {
+#ifdef CONFIG_CPU_HAS_HILO
+	unsigned long rhi;
+	unsigned long rlo;
+	unsigned long cr14;
+	unsigned long pad;
+#endif
+	unsigned long r4;
+	unsigned long r5;
+	unsigned long r6;
+	unsigned long r7;
+	unsigned long r8;
+	unsigned long r9;
+	unsigned long r10;
+	unsigned long r11;
+
+	unsigned long r15;
+	unsigned long r16;
+	unsigned long r17;
+	unsigned long r26;
+	unsigned long r27;
+	unsigned long r28;
+	unsigned long r29;
+	unsigned long r30;
+};
+#endif /* __ABI_CSKY_PTRACE_H */

arch/csky/abiv2/mcount.S

@@ -0,0 +1,124 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+#include <asm/ftrace.h>
+
+/*
+ * csky-gcc with -pg will put the following asm after prologue:
+ *      push	r15
+ *      jsri	_mcount
+ *
+ * stack layout after mcount_enter in _mcount():
+ *
+ * current sp => 0:+-------+
+ *                 | a0-a3 | -> must save all argument regs
+ *             +16:+-------+
+ *                 | lr    | -> _mcount lr (instrumente function's pc)
+ *             +20:+-------+
+ *                 | fp=r8 | -> instrumented function fp
+ *             +24:+-------+
+ *                 | plr   | -> instrumented function lr (parent's pc)
+ *                 +-------+
+ */
+
+.macro mcount_enter
+	subi	sp, 24
+	stw	a0, (sp, 0)
+	stw	a1, (sp, 4)
+	stw	a2, (sp, 8)
+	stw	a3, (sp, 12)
+	stw	lr, (sp, 16)
+	stw	r8, (sp, 20)
+.endm
+
+.macro mcount_exit
+	ldw	a0, (sp, 0)
+	ldw	a1, (sp, 4)
+	ldw	a2, (sp, 8)
+	ldw	a3, (sp, 12)
+	ldw	t1, (sp, 16)
+	ldw	r8, (sp, 20)
+	ldw	lr, (sp, 24)
+	addi	sp, 28
+	jmp	t1
+.endm
+
+.macro save_return_regs
+	subi	sp, 16
+	stw	a0, (sp, 0)
+	stw	a1, (sp, 4)
+	stw	a2, (sp, 8)
+	stw	a3, (sp, 12)
+.endm
+
+.macro restore_return_regs
+	mov	lr, a0
+	ldw	a0, (sp, 0)
+	ldw	a1, (sp, 4)
+	ldw	a2, (sp, 8)
+	ldw	a3, (sp, 12)
+	addi	sp, 16
+.endm
+
+ENTRY(ftrace_stub)
+	jmp	lr
+END(ftrace_stub)
+
+ENTRY(_mcount)
+	mcount_enter
+
+	/* r26 is link register, only used with jsri translation */
+	lrw	r26, ftrace_trace_function
+	ldw	r26, (r26, 0)
+	lrw	a1, ftrace_stub
+	cmpne	r26, a1
+	bf	skip_ftrace
+
+	mov	a0, lr
+	subi	a0, MCOUNT_INSN_SIZE
+	ldw	a1, (sp, 24)
+
+	jsr	r26
+
+#ifndef CONFIG_FUNCTION_GRAPH_TRACER
+skip_ftrace:
+	mcount_exit
+#else
+skip_ftrace:
+	lrw	a0, ftrace_graph_return
+	ldw	a0, (a0, 0)
+	lrw	a1, ftrace_stub
+	cmpne	a0, a1
+	bt	ftrace_graph_caller
+
+	lrw	a0, ftrace_graph_entry
+	ldw	a0, (a0, 0)
+	lrw	a1, ftrace_graph_entry_stub
+	cmpne	a0, a1
+	bt	ftrace_graph_caller
+
+	mcount_exit
+#endif
+END(_mcount)
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller)
+	mov	a0, sp
+	addi	a0, 24
+	ldw	a1, (sp, 16)
+	subi	a1, MCOUNT_INSN_SIZE
+	mov	a2, r8
+	lrw	r26, prepare_ftrace_return
+	jsr	r26
+	mcount_exit
+END(ftrace_graph_caller)
+
+ENTRY(return_to_handler)
+	save_return_regs
+	mov	a0, r8
+	jsri	ftrace_return_to_handler
+	restore_return_regs
+	jmp	lr
+END(return_to_handler)
+#endif

arch/csky/abiv2/memcpy.S

@@ -27,13 +27,7 @@ ENTRY(memcpy)
 
 	LABLE_ALIGN
 .L_len_larger_16bytes:
-#if defined(__CSKY_VDSPV2__)
-	vldx.8	vr0, (r1), r19
-	PRE_BNEZAD (r18)
-	addi	r1, 16
-	vstx.8	vr0, (r0), r19
-	addi	r0, 16
-#elif defined(__CK860__)
+#if defined(__CK860__)
 	ldw	r3, (r1, 0)
 	stw	r3, (r0, 0)
 	ldw	r3, (r1, 4)

arch/csky/include/asm/elf.h

@@ -7,7 +7,8 @@
 #include <asm/ptrace.h>
 #include <abi/regdef.h>
 
-#define ELF_ARCH 252
+#define ELF_ARCH EM_CSKY
+#define EM_CSKY_OLD 39
 
 /* CSKY Relocations */
 #define R_CSKY_NONE               0
@@ -31,14 +32,20 @@ typedef unsigned long elf_greg_t;
 
 typedef struct user_fp elf_fpregset_t;
 
-#define ELF_NGREG (sizeof(struct pt_regs) / sizeof(elf_greg_t))
+/*
+ * In gdb/bfd elf32-csky.c, csky_elf_grok_prstatus() use fixed size of
+ * elf_prstatus. It's 148 for abiv1 and 220 for abiv2, the size is enough
+ * for coredump and no need full sizeof(struct pt_regs).
+ */
+#define ELF_NGREG ((sizeof(struct pt_regs) / sizeof(elf_greg_t)) - 2)
 
 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
 
 /*
  * This is used to ensure we don't load something for the wrong architecture.
  */
-#define elf_check_arch(x) ((x)->e_machine == ELF_ARCH)
+#define elf_check_arch(x) (((x)->e_machine == ELF_ARCH) || \
+			   ((x)->e_machine == EM_CSKY_OLD))
 
 /*
  * These are used to set parameters in the core dumps.

arch/csky/include/asm/ftrace.h

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_FTRACE_H
+#define __ASM_CSKY_FTRACE_H
+
+#define MCOUNT_INSN_SIZE 4
+
+#define HAVE_FUNCTION_GRAPH_FP_TEST
+
+#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+
+#endif /* __ASM_CSKY_FTRACE_H */