[PATCH V3 08/27] csky: Process management and Signal

From: Guo Ren
Date: Wed Sep 12 2018 - 09:27:13 EST

Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx>
---
arch/csky/abiv2/fpu.c | 281 +++++++++++++++++++++++++
arch/csky/abiv2/inc/abi/fpu.h | 66 ++++++
arch/csky/include/asm/mmu_context.h | 148 ++++++++++++++
arch/csky/include/asm/processor.h | 120 +++++++++++
arch/csky/include/asm/switch_to.h | 35 ++++
arch/csky/include/asm/thread_info.h | 74 +++++++
arch/csky/include/uapi/asm/sigcontext.h | 13 ++
arch/csky/kernel/process.c | 134 ++++++++++++
arch/csky/kernel/signal.c | 350 ++++++++++++++++++++++++++++++++
arch/csky/kernel/time.c | 11 +
10 files changed, 1232 insertions(+)
create mode 100644 arch/csky/abiv2/fpu.c
create mode 100644 arch/csky/abiv2/inc/abi/fpu.h
create mode 100644 arch/csky/include/asm/mmu_context.h
create mode 100644 arch/csky/include/asm/processor.h
create mode 100644 arch/csky/include/asm/switch_to.h
create mode 100644 arch/csky/include/asm/thread_info.h
create mode 100644 arch/csky/include/uapi/asm/sigcontext.h
create mode 100644 arch/csky/kernel/process.c
create mode 100644 arch/csky/kernel/signal.c
create mode 100644 arch/csky/kernel/time.c

diff --git a/arch/csky/abiv2/fpu.c b/arch/csky/abiv2/fpu.c
new file mode 100644
index 0000000..8de6b2b
--- /dev/null
+++ b/arch/csky/abiv2/fpu.c
@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/ptrace.h>
+#include <linux/uaccess.h>
+#include <abi/reg_ops.h>
+
+#define MTCR_MASK 0xFC00FFE0
+#define MFCR_MASK 0xFC00FFE0
+#define MTCR_DIST 0xC0006420
+#define MFCR_DIST 0xC0006020
+
+void __init init_fpu(void)
+{
+ mtcr("cr<1, 2>", 0);
+}
+
+/*
+ * fpu_libc_helper() is to help libc to excute:
+ * - mfcr %a, cr<1, 2>
+ * - mfcr %a, cr<2, 2>
+ * - mtcr %a, cr<1, 2>
+ * - mtcr %a, cr<2, 2>
+ */
+int fpu_libc_helper(struct pt_regs * regs)
+{
+ int fault;
+ unsigned long instrptr, regx = 0;
+ unsigned long index = 0, tmp = 0;
+ unsigned long tinstr = 0;
+ u16 instr_hi, instr_low;
+
+ instrptr = instruction_pointer(regs);
+ if (instrptr & 1) return 0;
+
+ fault = __get_user(instr_low, (u16 *)instrptr);
+ if (fault) return 0;
+
+ fault = __get_user(instr_hi, (u16 *)(instrptr + 2));
+ if (fault) return 0;
+
+ tinstr = instr_hi | ((unsigned long)instr_low << 16);
+
+ if (((tinstr >> 21) & 0x1F) != 2) return 0;
+
+ if ((tinstr & MTCR_MASK) == MTCR_DIST)
+ {
+ index = (tinstr >> 16) & 0x1F;
+ if(index > 13) return 0;
+
+ tmp = tinstr & 0x1F;
+ if (tmp > 2) return 0;
+
+ regx = *(&regs->a0 + index);
+
+ if(tmp == 1)
+ mtcr("cr<1, 2>", regx);
+ else if (tmp == 2)
+ mtcr("cr<2, 2>", regx);
+ else
+ return 0;
+
+ regs->pc +=4;
+ return 1;
+ }
+
+ if ((tinstr & MFCR_MASK) == MFCR_DIST) {
+ index = tinstr & 0x1F;
+ if(index > 13) return 0;
+
+ tmp = ((tinstr >> 16) & 0x1F);
+ if (tmp > 2) return 0;
+
+ if (tmp == 1)
+ regx = mfcr("cr<1, 2>");
+ else if (tmp == 2)
+ regx = mfcr("cr<2, 2>");
+ else
+ return 0;
+
+ *(&regs->a0 + index) = regx;
+
+ regs->pc +=4;
+ return 1;
+ }
+
+ return 0;
+}
+
+void fpu_fpe(struct pt_regs * regs)
+{
+ int sig;
+ unsigned int fesr;
+ siginfo_t info;
+
+ fesr = mfcr("cr<2, 2>");
+
+ if(fesr & FPE_ILLE){
+ info.si_code = ILL_ILLOPC;
+ sig = SIGILL;
+ }
+ else if(fesr & FPE_IDC){
+ info.si_code = ILL_ILLOPN;
+ sig = SIGILL;
+ }
+ else if(fesr & FPE_FEC){
+ sig = SIGFPE;
+ if(fesr & FPE_IOC){
+ info.si_code = FPE_FLTINV;
+ }
+ else if(fesr & FPE_DZC){
+ info.si_code = FPE_FLTDIV;
+ }
+ else if(fesr & FPE_UFC){
+ info.si_code = FPE_FLTUND;
+ }
+ else if(fesr & FPE_OFC){
+ info.si_code = FPE_FLTOVF;
+ }
+ else if(fesr & FPE_IXC){
+ info.si_code = FPE_FLTRES;
+ }
+ else {
+ info.si_code = NSIGFPE;
+ }
+ }
+ else {
+ info.si_code = NSIGFPE;
+ sig = SIGFPE;
+ }
+ info.si_signo = SIGFPE;
+ info.si_errno = 0;
+ info.si_addr = (void *)regs->pc;
+ force_sig_info(sig, &info, current);
+}
+
+#define FMFVR_FPU_REGS(vrx, vry) \
+ "fmfvrl %0, "#vrx" \n" \
+ "fmfvrh %1, "#vrx" \n" \
+ "fmfvrl %2, "#vry" \n" \
+ "fmfvrh %3, "#vry" \n"
+
+#define FMTVR_FPU_REGS(vrx, vry) \
+ "fmtvrl "#vrx", %0 \n" \
+ "fmtvrh "#vrx", %1 \n" \
+ "fmtvrl "#vry", %2 \n" \
+ "fmtvrh "#vry", %3 \n"
+
+#define STW_FPU_REGS(a, b, c, d) \
+ "stw %0, (%4, "#a") \n" \
+ "stw %1, (%4, "#b") \n" \
+ "stw %2, (%4, "#c") \n" \
+ "stw %3, (%4, "#d") \n"
+
+#define LDW_FPU_REGS(a, b, c, d) \
+ "ldw %0, (%4, "#a") \n" \
+ "ldw %1, (%4, "#b") \n" \
+ "ldw %2, (%4, "#c") \n" \
+ "ldw %3, (%4, "#d") \n"
+
+void save_to_user_fp(struct user_fp *user_fp)
+{
+ unsigned long flg;
+ unsigned long tmp1, tmp2;
+ unsigned long *fpregs;
+
+ local_irq_save(flg);
+
+ tmp1 = mfcr("cr<1, 2>");
+ tmp2 = mfcr("cr<2, 2>");
+
+ user_fp->fcr = tmp1;
+ user_fp->fesr = tmp2;
+
+ fpregs = &user_fp->vr[0];
+#ifdef CONFIG_CPU_HAS_FPUV2
+#ifdef CONFIG_CPU_HAS_VDSP
+ asm volatile(
+ "vstmu.32 vr0-vr3, (%0) \n"
+ "vstmu.32 vr4-vr7, (%0) \n"
+ "vstmu.32 vr8-vr11, (%0) \n"
+ "vstmu.32 vr12-vr15, (%0) \n"
+ "fstmu.64 vr16-vr31, (%0) \n"
+ :"+a"(fpregs)
+ ::"memory");
+#else
+ asm volatile(
+ "fstmu.64 vr0-vr31, (%0) \n"
+ :"+a"(fpregs)
+ ::"memory");
+#endif
+#else
+ {
+ unsigned long tmp3, tmp4;
+ asm volatile(
+ FMFVR_FPU_REGS(vr0, vr1)
+ STW_FPU_REGS(0, 4, 16, 20)
+ FMFVR_FPU_REGS(vr2, vr3)
+ STW_FPU_REGS(32, 36, 48, 52)
+ FMFVR_FPU_REGS(vr4, vr5)
+ STW_FPU_REGS(64, 68, 80, 84)
+ FMFVR_FPU_REGS(vr6, vr7)
+ STW_FPU_REGS(96, 100, 112, 116)
+ "addi %4, 128\n"
+ FMFVR_FPU_REGS(vr8, vr9)
+ STW_FPU_REGS(0, 4, 16, 20)
+ FMFVR_FPU_REGS(vr10, vr11)
+ STW_FPU_REGS(32, 36, 48, 52)
+ FMFVR_FPU_REGS(vr12, vr13)
+ STW_FPU_REGS(64, 68, 80, 84)
+ FMFVR_FPU_REGS(vr14, vr15)
+ STW_FPU_REGS(96, 100, 112, 116)
+ :"=a"(tmp1),"=a"(tmp2),"=a"(tmp3),
+ "=a"(tmp4),"+a"(fpregs)
+ ::"memory");
+ }
+#endif
+
+ local_irq_restore(flg);
+}
+
+void restore_from_user_fp(struct user_fp *user_fp)
+{
+ unsigned long flg;
+ unsigned long tmp1, tmp2;
+ unsigned long *fpregs;
+
+ local_irq_save(flg);
+
+ tmp1 = user_fp->fcr;
+ tmp2 = user_fp->fesr;
+
+ mtcr("cr<1, 2>", tmp1);
+ mtcr("cr<2, 2>", tmp2);
+
+ fpregs = &user_fp->vr[0];
+#ifdef CONFIG_CPU_HAS_FPUV2
+#ifdef CONFIG_CPU_HAS_VDSP
+ asm volatile(
+ "vldmu.32 vr0-vr3, (%0) \n"
+ "vldmu.32 vr4-vr7, (%0) \n"
+ "vldmu.32 vr8-vr11, (%0) \n"
+ "vldmu.32 vr12-vr15, (%0) \n"
+ "fldmu.64 vr16-vr31, (%0) \n"
+ :"+a"(fpregs)
+ ::"memory");
+#else
+ asm volatile(
+ "fldmu.64 vr0-vr31, (%0) \n"
+ :"+a"(fpregs)
+ ::"memory");
+#endif
+#else
+ {
+ unsigned long tmp3, tmp4;
+ asm volatile(
+ LDW_FPU_REGS(0, 4, 16, 20)
+ FMTVR_FPU_REGS(vr0, vr1)
+ LDW_FPU_REGS(32, 36, 48, 52)
+ FMTVR_FPU_REGS(vr2, vr3)
+ LDW_FPU_REGS(64, 68, 80, 84)
+ FMTVR_FPU_REGS(vr4, vr5)
+ LDW_FPU_REGS(96, 100, 112, 116)
+ FMTVR_FPU_REGS(vr6, vr7)
+ "addi %4, 128\n"
+ LDW_FPU_REGS(0, 4, 16, 20)
+ FMTVR_FPU_REGS(vr8, vr9)
+ LDW_FPU_REGS(32, 36, 48, 52)
+ FMTVR_FPU_REGS(vr10, vr11)
+ LDW_FPU_REGS(64, 68, 80, 84)
+ FMTVR_FPU_REGS(vr12, vr13)
+ LDW_FPU_REGS(96, 100, 112, 116)
+ FMTVR_FPU_REGS(vr14, vr15)
+ :"=a"(tmp1),"=a"(tmp2),"=a"(tmp3),
+ "=a"(tmp4),"+a"(fpregs)
+ ::"memory");
+ }
+#endif
+
+ local_irq_restore(flg);
+}
diff --git a/arch/csky/abiv2/inc/abi/fpu.h b/arch/csky/abiv2/inc/abi/fpu.h
new file mode 100644
index 0000000..a35b45a
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/fpu.h
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_FPU_H
+#define __ASM_CSKY_FPU_H
+
+#include <asm/sigcontext.h>
+#include <asm/ptrace.h>
+
+int fpu_libc_helper(struct pt_regs *regs);
+void fpu_fpe(struct pt_regs *regs);
+void __init init_fpu(void);
+
+void save_to_user_fp(struct user_fp *user_fp);
+void restore_from_user_fp(struct user_fp *user_fp);
+
+/*
+ * Define the fesr bit for fpe handle.
+ */
+#define FPE_ILLE (1 << 16) /* Illegal instruction */
+#define FPE_FEC (1 << 7) /* Input float-point arithmetic exception */
+#define FPE_IDC (1 << 5) /* Input denormalized exception */
+#define FPE_IXC (1 << 4) /* Inexact exception */
+#define FPE_UFC (1 << 3) /* Underflow exception */
+#define FPE_OFC (1 << 2) /* Overflow exception */
+#define FPE_DZC (1 << 1) /* Divide by zero exception */
+#define FPE_IOC (1 << 0) /* Invalid operation exception */
+#define FPE_REGULAR_EXCEPTION (FPE_IXC | FPE_UFC | FPE_OFC | FPE_DZC | FPE_IOC)
+
+#ifdef CONFIG_OPEN_FPU_IDE
+#define IDE_STAT (1 << 5)
+#else
+#define IDE_STAT 0
+#endif
+
+#ifdef CONFIG_OPEN_FPU_IXE
+#define IXE_STAT (1 << 4)
+#else
+#define IXE_STAT 0
+#endif
+
+#ifdef CONFIG_OPEN_FPU_UFE
+#define UFE_STAT (1 << 3)
+#else
+#define UFE_STAT 0
+#endif
+
+#ifdef CONFIG_OPEN_FPU_OFE
+#define OFE_STAT (1 << 2)
+#else
+#define OFE_STAT 0
+#endif
+
+#ifdef CONFIG_OPEN_FPU_DZE
+#define DZE_STAT (1 << 1)
+#else
+#define DZE_STAT 0
+#endif
+
+#ifdef CONFIG_OPEN_FPU_IOE
+#define IOE_STAT (1 << 0)
+#else
+#define IOE_STAT 0
+#endif
+
+#endif /* __ASM_CSKY_FPU_H */
diff --git a/arch/csky/include/asm/mmu_context.h b/arch/csky/include/asm/mmu_context.h
new file mode 100644
index 0000000..456c876
--- /dev/null
+++ b/arch/csky/include/asm/mmu_context.h
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#ifndef __ASM_CSKY_MMU_CONTEXT_H
+#define __ASM_CSKY_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>
+#include <asm/setup.h>
+#include <asm/page.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <abi/ckmmu.h>
+
+static inline void tlbmiss_handler_setup_pgd(unsigned long pgd, bool kernel)
+{
+ pgd &= ~(1<<31);
+ pgd += PHYS_OFFSET;
+ pgd |= 1;
+ setup_pgd(pgd, kernel);
+}
+
+#define TLBMISS_HANDLER_SETUP_PGD(pgd) \
+ tlbmiss_handler_setup_pgd((unsigned long)pgd, 0)
+#define TLBMISS_HANDLER_SETUP_PGD_KERNEL(pgd) \
+ tlbmiss_handler_setup_pgd((unsigned long)pgd, 1)
+
+static inline unsigned long tlb_get_pgd(void)
+{
+ return ((get_pgd()|(1<<31)) - PHYS_OFFSET) & ~1;
+}
+
+#define cpu_context(cpu, mm) ((mm)->context.asid[cpu])
+#define cpu_asid(cpu, mm) (cpu_context((cpu), (mm)) & ASID_MASK)
+#define asid_cache(cpu) (cpu_data[cpu].asid_cache)
+
+#define ASID_FIRST_VERSION (1 << CONFIG_CPU_ASID_BITS)
+#define ASID_INC 0x1
+#define ASID_MASK (ASID_FIRST_VERSION - 1)
+#define ASID_VERSION_MASK ~ASID_MASK
+
+#define destroy_context(mm) do{}while(0)
+#define enter_lazy_tlb(mm,tsk) do{}while(0)
+#define deactivate_mm(tsk,mm) do{}while(0)
+
+/*
+ * All unused by hardware upper bits will be considered
+ * as a software asid extension.
+ */
+static inline void
+get_new_mmu_context(struct mm_struct *mm, unsigned long cpu)
+{
+ unsigned long asid = asid_cache(cpu);
+
+ if (! ((asid += ASID_INC) & ASID_MASK) ) {
+ flush_tlb_all(); /* start new asid cycle */
+ if (!asid) /* fix version if needed */
+ asid = ASID_FIRST_VERSION;
+ }
+ cpu_context(cpu, mm) = asid_cache(cpu) = asid;
+}
+
+/*
+ * Initialize the context related info for a new mm_struct
+ * instance.
+ */
+static inline int
+init_new_context(struct task_struct *tsk, struct mm_struct *mm)
+{
+ int i;
+
+ for_each_online_cpu(i)
+ cpu_context(i, mm) = 0;
+ return 0;
+}
+
+static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+ struct task_struct *tsk)
+{
+ unsigned int cpu = smp_processor_id();
+ unsigned long flags;
+
+ local_irq_save(flags);
+ /* Check if our ASID is of an older version and thus invalid */
+ if ((cpu_context(cpu, next) ^ asid_cache(cpu)) & ASID_VERSION_MASK)
+ get_new_mmu_context(next, cpu);
+ write_mmu_entryhi(cpu_asid(cpu, next));
+ TLBMISS_HANDLER_SETUP_PGD(next->pgd);
+
+ /*
+ * Mark current->active_mm as not "active" anymore.
+ * We don't want to mislead possible IPI tlb flush routines.
+ */
+ cpumask_clear_cpu(cpu, mm_cpumask(prev));
+ cpumask_set_cpu(cpu, mm_cpumask(next));
+
+ local_irq_restore(flags);
+}
+
+/*
+ * After we have set current->mm to a new value, this activates
+ * the context for the new mm so we see the new mappings.
+ */
+static inline void
+activate_mm(struct mm_struct *prev, struct mm_struct *next)
+{
+ unsigned long flags;
+ int cpu = smp_processor_id();
+
+ local_irq_save(flags);
+
+ /* Unconditionally get a new ASID. */
+ get_new_mmu_context(next, cpu);
+
+ write_mmu_entryhi(cpu_asid(cpu, next));
+ TLBMISS_HANDLER_SETUP_PGD(next->pgd);
+
+ /* mark mmu ownership change */
+ cpumask_clear_cpu(cpu, mm_cpumask(prev));
+ cpumask_set_cpu(cpu, mm_cpumask(next));
+
+ local_irq_restore(flags);
+}
+
+/*
+ * If mm is currently active_mm, we can't really drop it. Instead,
+ * we will get a new one for it.
+ */
+static inline void
+drop_mmu_context(struct mm_struct *mm, unsigned cpu)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ if (cpumask_test_cpu(cpu, mm_cpumask(mm))) {
+ get_new_mmu_context(mm, cpu);
+ write_mmu_entryhi(cpu_asid(cpu, mm));
+ } else {
+ /* will get a new context next time */
+ cpu_context(cpu, mm) = 0;
+ }
+
+ local_irq_restore(flags);
+}
+
+#endif /* __ASM_CSKY_MMU_CONTEXT_H */
diff --git a/arch/csky/include/asm/processor.h b/arch/csky/include/asm/processor.h
new file mode 100644
index 0000000..7764fa5
--- /dev/null
+++ b/arch/csky/include/asm/processor.h
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#ifndef __ASM_CSKY_PROCESSOR_H
+#define __ASM_CSKY_PROCESSOR_H
+
+/*
+ * Default implementation of macro that returns current
+ * instruction pointer ("program counter").
+ */
+#define current_text_addr() ({ __label__ _l; _l: &&_l;})
+
+#include <linux/bitops.h>
+#include <asm/segment.h>
+#include <asm/ptrace.h>
+#include <asm/current.h>
+#include <asm/cache.h>
+#include <abi/reg_ops.h>
+#include <abi/regdef.h>
+#ifdef CONFIG_CPU_HAS_FPU
+#include <abi/fpu.h>
+#endif
+
+struct cpuinfo_csky {
+ unsigned long udelay_val;
+ unsigned long asid_cache;
+ /*
+ * Capability and feature descriptor structure for CSKY CPU
+ */
+ unsigned long options;
+ unsigned int processor_id[4];
+ unsigned int fpu_id;
+} __attribute__((aligned(SMP_CACHE_BYTES)));
+
+extern struct cpuinfo_csky cpu_data[];
+
+/*
+ * User space process size: 2GB. This is hardcoded into a few places,
+ * so don't change it unless you know what you are doing. TASK_SIZE
+ * for a 64 bit kernel expandable to 8192EB, of which the current CSKY
+ * implementations will "only" be able to use 1TB ...
+ */
+#define TASK_SIZE 0x7fff8000UL
+
+#ifdef __KERNEL__
+#define STACK_TOP TASK_SIZE
+#define STACK_TOP_MAX STACK_TOP
+#endif
+
+/* This decides where the kernel will search for a free chunk of vm
+ * space during mmap's.
+ */
+#define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
+
+struct thread_struct {
+ unsigned long ksp; /* kernel stack pointer */
+ unsigned long sr; /* saved status register */
+ unsigned long esp0; /* points to SR of stack frame */
+ unsigned long hi;
+ unsigned long lo;
+
+ /* Other stuff associated with the thread. */
+ unsigned long address; /* Last user fault */
+ unsigned long error_code;
+
+ /* FPU regs */
+ struct user_fp __attribute__((aligned(16))) user_fp;
+};
+
+#define INIT_THREAD { \
+ .ksp = (unsigned long) init_thread_union.stack + THREAD_SIZE, \
+ .sr = DEFAULT_PSR_VALUE, \
+}
+
+/*
+ * Do necessary setup to start up a newly executed thread.
+ *
+ * pass the data segment into user programs if it exists,
+ * it can't hurt anything as far as I can tell
+ */
+#define start_thread(_regs, _pc, _usp) \
+do { \
+ set_fs(USER_DS); /* reads from user space */ \
+ (_regs)->pc = (_pc); \
+ (_regs)->regs[1] = 0; /* ABIV1 is R7, uClibc_main rtdl arg */ \
+ (_regs)->regs[2] = 0; \
+ (_regs)->regs[3] = 0; /* ABIV2 is R7, use it? */ \
+ (_regs)->sr &= ~PS_S; \
+ (_regs)->usp = (_usp); \
+} while(0)
+
+/* Forward declaration, a strange C thing */
+struct task_struct;
+
+/* Free all resources held by a thread. */
+static inline void release_thread(struct task_struct *dead_task)
+{
+}
+
+/* Prepare to copy thread state - unlazy all lazy status */
+#define prepare_to_copy(tsk) do { } while (0)
+
+extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
+
+#define copy_segments(tsk, mm) do { } while (0)
+#define release_segments(mm) do { } while (0)
+#define forget_segments() do { } while (0)
+
+extern unsigned long thread_saved_pc(struct task_struct *tsk);
+
+unsigned long get_wchan(struct task_struct *p);
+
+#define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc)
+#define KSTK_ESP(tsk) (task_pt_regs(tsk)->usp)
+
+#define task_pt_regs(p) \
+ ((struct pt_regs *)(THREAD_SIZE + p->stack) - 1)
+
+#define cpu_relax() barrier()
+
+#endif /* __ASM_CSKY_PROCESSOR_H */
diff --git a/arch/csky/include/asm/switch_to.h b/arch/csky/include/asm/switch_to.h
new file mode 100644
index 0000000..e1cd10a
--- /dev/null
+++ b/arch/csky/include/asm/switch_to.h
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#ifndef __ASM_CSKY_SWITCH_TO_H
+#define __ASM_CSKY_SWITCH_TO_H
+
+#include <linux/thread_info.h>
+#ifdef CONFIG_CPU_HAS_FPU
+#include <abi/fpu.h>
+static inline void __switch_to_fpu(struct task_struct *prev,
+ struct task_struct *next)
+{
+ save_to_user_fp(&prev->thread.user_fp);
+ restore_from_user_fp(&next->thread.user_fp);
+}
+#else
+static inline void __switch_to_fpu(struct task_struct *prev,
+ struct task_struct *next)
+{}
+#endif
+
+/*
+ * Context switching is now performed out-of-line in switch_to.S
+ */
+extern struct task_struct *__switch_to(struct task_struct *,
+ struct task_struct *);
+
+#define switch_to(prev, next, last) \
+ do { \
+ struct task_struct *__prev = (prev); \
+ struct task_struct *__next = (next); \
+ __switch_to_fpu(__prev, __next); \
+ ((last) = __switch_to((prev), (next))); \
+ } while (0)
+
+#endif /* __ASM_CSKY_SWITCH_TO_H */
diff --git a/arch/csky/include/asm/thread_info.h b/arch/csky/include/asm/thread_info.h
new file mode 100644
index 0000000..2474da0
--- /dev/null
+++ b/arch/csky/include/asm/thread_info.h
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#ifndef _ASM_CSKY_THREAD_INFO_H
+#define _ASM_CSKY_THREAD_INFO_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/version.h>
+#include <asm/types.h>
+#include <asm/page.h>
+#include <asm/processor.h>
+
+struct thread_info {
+ struct task_struct *task;
+ void *dump_exec_domain;
+ unsigned long flags;
+ int preempt_count;
+ unsigned long tp_value;
+ mm_segment_t addr_limit;
+ struct restart_block restart_block;
+ struct pt_regs *regs;
+ unsigned int cpu;
+};
+
+#define INIT_THREAD_INFO(tsk) \
+{ \
+ .task = &tsk, \
+ .preempt_count = INIT_PREEMPT_COUNT, \
+ .addr_limit = KERNEL_DS, \
+ .cpu = 0, \
+ .restart_block = { \
+ .fn = do_no_restart_syscall, \
+ }, \
+}
+
+#define THREAD_SIZE_ORDER (THREAD_SHIFT - PAGE_SHIFT)
+
+static inline struct thread_info *current_thread_info(void)
+{
+ unsigned long sp;
+
+ asm volatile("mov %0, sp\n":"=r"(sp));
+
+ return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
+}
+
+#endif /* !__ASSEMBLY__ */
+
+/* entry.S relies on these definitions!
+ * bits 0-5 are tested at every exception exit
+ */
+#define TIF_SIGPENDING 0 /* signal pending */
+#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
+#define TIF_NEED_RESCHED 2 /* rescheduling necessary */
+#define TIF_SYSCALL_TRACE 5 /* syscall trace active */
+#define TIF_DELAYED_TRACE 14 /* single step a syscall */
+#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
+#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
+#define TIF_FREEZE 19 /* thread is freezing for suspend */
+#define TIF_RESTORE_SIGMASK 20 /* restore signal mask in do_signal() */
+#define TIF_SECCOMP 21 /* secure computing */
+
+#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
+#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
+#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
+#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
+#define _TIF_DELAYED_TRACE (1 << TIF_DELAYED_TRACE)
+#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
+#define _TIF_MEMDIE (1 << TIF_MEMDIE)
+#define _TIF_FREEZE (1 << TIF_FREEZE)
+#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
+#define _TIF_SECCOMP (1 << TIF_SECCOMP)
+
+#endif /* _ASM_CSKY_THREAD_INFO_H */
diff --git a/arch/csky/include/uapi/asm/sigcontext.h b/arch/csky/include/uapi/asm/sigcontext.h
new file mode 100644
index 0000000..633cb14
--- /dev/null
+++ b/arch/csky/include/uapi/asm/sigcontext.h
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#ifndef __ASM_CSKY_SIGCONTEXT_H
+#define __ASM_CSKY_SIGCONTEXT_H
+
+#include <asm/ptrace.h>
+
+struct sigcontext {
+ struct pt_regs sc_pt_regs;
+ struct user_fp sc_user_fp;
+};
+
+#endif /* __ASM_CSKY_SIGCONTEXT_H */
diff --git a/arch/csky/kernel/process.c b/arch/csky/kernel/process.c
new file mode 100644
index 0000000..b03b667
--- /dev/null
+++ b/arch/csky/kernel/process.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/sched/debug.h>
+#include <linux/delay.h>
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
+#include <linux/ptrace.h>
+
+#include <asm/elf.h>
+#include <abi/reg_ops.h>
+
+struct cpuinfo_csky cpu_data[NR_CPUS];
+
+asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
+
+/*
+ * Some archs flush debug and FPU info here
+ */
+void flush_thread(void){}
+
+/*
+ * Return saved PC from a blocked thread
+ */
+unsigned long thread_saved_pc(struct task_struct *tsk)
+{
+ struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
+
+ return sw->r15;
+}
+
+int copy_thread(unsigned long clone_flags,
+ unsigned long usp,
+ unsigned long kthread_arg,
+ struct task_struct *p)
+{
+ struct switch_stack *childstack;
+ struct pt_regs *childregs = task_pt_regs(p);
+
+#ifdef CONFIG_CPU_HAS_FPU
+ save_to_user_fp(&p->thread.user_fp);
+#endif
+
+ childstack = ((struct switch_stack *) childregs) - 1;
+ memset(childstack, 0, sizeof(struct switch_stack));
+
+ /* setup ksp for switch_to !!! */
+ p->thread.ksp = (unsigned long)childstack;
+
+ if (unlikely(p->flags & PF_KTHREAD)) {
+ memset(childregs, 0, sizeof(struct pt_regs));
+ childstack->r15 = (unsigned long) ret_from_kernel_thread;
+ childstack->r8 = kthread_arg;
+ childstack->r9 = usp;
+ childregs->sr = mfcr("psr");
+ } else {
+ *childregs = *(current_pt_regs());
+ if (usp)
+ childregs->usp = usp;
+ if (clone_flags & CLONE_SETTLS)
+ task_thread_info(p)->tp_value = childregs->tls
+ = childregs->regs[0];
+
+ childregs->a0 = 0;
+ childstack->r15 = (unsigned long) ret_from_fork;
+ }
+
+ return 0;
+}
+
+/* Fill in the fpu structure for a core dump. */
+int dump_fpu (struct pt_regs *regs, struct user_fp *fpu)
+{
+ memcpy(fpu, &current->thread.user_fp, sizeof(*fpu));
+ return 1;
+}
+EXPORT_SYMBOL(dump_fpu);
+
+int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs)
+{
+ struct pt_regs *regs = task_pt_regs(tsk);
+
+ /* NOTE: usp is error value. */
+ ELF_CORE_COPY_REGS ((*pr_regs), regs)
+
+ return 1;
+}
+
+unsigned long get_wchan(struct task_struct *p)
+{
+ unsigned long esp, pc;
+ unsigned long stack_page;
+ int count = 0;
+ if (!p || p == current || p->state == TASK_RUNNING)
+ return 0;
+
+ stack_page = (unsigned long)p;
+ esp = p->thread.esp0;
+ do {
+ if (esp < stack_page+sizeof(struct task_struct) ||
+ esp >= 8184+stack_page)
+ return 0;
+ /*FIXME: There's may be error here!*/
+ pc = ((unsigned long *)esp)[1];
+ /* FIXME: This depends on the order of these functions. */
+ if (!in_sched_functions(pc))
+ return pc;
+ esp = *(unsigned long *) esp;
+ } while (count++ < 16);
+ return 0;
+}
+EXPORT_SYMBOL(get_wchan);
+
+#ifndef CONFIG_CPU_PM_NONE
+void arch_cpu_idle(void)
+{
+#ifdef CONFIG_CPU_PM_WAIT
+ asm volatile("wait\n");
+#endif
+
+#ifdef CONFIG_CPU_PM_DOZE
+ asm volatile("doze\n");
+#endif
+
+#ifdef CONFIG_CPU_PM_STOP
+ asm volatile("stop\n");
+#endif
+ local_irq_enable();
+}
+#endif
diff --git a/arch/csky/kernel/signal.c b/arch/csky/kernel/signal.c
new file mode 100644
index 0000000..c40775a
--- /dev/null
+++ b/arch/csky/kernel/signal.c
@@ -0,0 +1,350 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/syscalls.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/highuid.h>
+#include <linux/personality.h>
+#include <linux/tty.h>
+#include <linux/binfmts.h>
+#include <linux/tracehook.h>
+#include <linux/freezer.h>
+#include <linux/uaccess.h>
+
+#include <asm/setup.h>
+#include <asm/pgtable.h>
+#include <asm/traps.h>
+#include <asm/ucontext.h>
+#include <asm/vdso.h>
+
+#include <abi/regdef.h>
+
+#ifdef CONFIG_CPU_HAS_FPU
+#include <abi/fpu.h>
+
+static int restore_fpu_state(struct sigcontext *sc)
+{
+ int err = 0;
+ struct user_fp user_fp;
+
+ err = copy_from_user(&user_fp, &sc->sc_user_fp, sizeof(user_fp));
+
+ restore_from_user_fp(&user_fp);
+
+ return err;
+}
+
+static int save_fpu_state(struct sigcontext *sc)
+{
+ struct user_fp user_fp;
+
+ save_to_user_fp(&user_fp);
+
+ return copy_to_user(&sc->sc_user_fp, &user_fp, sizeof(user_fp));
+}
+#else
+static inline int restore_fpu_state(struct sigcontext *sc){return 0;}
+static inline int save_fpu_state(struct sigcontext *sc){return 0;}
+#endif
+
+struct rt_sigframe
+{
+ int sig;
+ struct siginfo *pinfo;
+ void *puc;
+ struct siginfo info;
+ struct ucontext uc;
+};
+
+static int
+restore_sigframe(struct pt_regs *regs,
+ struct sigcontext *sc, int *pr2)
+{
+ int err = 0;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current_thread_info()->task->restart_block.fn = do_no_restart_syscall;
+
+ err |= copy_from_user(regs, &sc->sc_pt_regs, sizeof(struct pt_regs));
+
+ err |= restore_fpu_state(sc);
+
+ *pr2 = regs->a0;
+ return err;
+}
+
+asmlinkage int
+do_rt_sigreturn(void)
+{
+ sigset_t set;
+ int a0;
+ struct pt_regs *regs = current_pt_regs();
+ struct rt_sigframe *frame = (struct rt_sigframe *)(regs->usp);
+
+ if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+ if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+ goto badframe;
+
+ sigdelsetmask(&set, (sigmask(SIGKILL) | sigmask(SIGSTOP)));
+ spin_lock_irq(&current->sighand->siglock);
+ current->blocked = set;
+ recalc_sigpending( );
+ spin_unlock_irq(&current->sighand->siglock);
+
+ if (restore_sigframe(regs, &frame->uc.uc_mcontext, &a0))
+ goto badframe;
+
+ return a0;
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+static int setup_sigframe(struct sigcontext *sc, struct pt_regs *regs)
+{
+ int err = 0;
+
+ err |= copy_to_user(&sc->sc_pt_regs, regs, sizeof(struct pt_regs));
+ err |= save_fpu_state(sc);
+
+ return err;
+}
+
+static inline void *
+get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
+{
+ unsigned long usp;
+
+ /* Default to using normal stack. */
+ usp = regs->usp;
+
+ /* This is the X/Open sanctioned signal stack switching. */
+ if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(usp)) {
+ if (!on_sig_stack(usp))
+ usp = current->sas_ss_sp + current->sas_ss_size;
+ }
+ return (void *)((usp - frame_size) & -8UL);
+}
+
+static int setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
+ sigset_t *set, struct pt_regs *regs)
+{
+ struct rt_sigframe *frame;
+ int err = 0;
+
+ struct csky_vdso *vdso = current->mm->context.vdso;
+
+ frame = get_sigframe(ka, regs, sizeof(*frame));
+ if (!frame)
+ return 1;
+
+ err |= __put_user(sig, &frame->sig);
+ err |= __put_user(&frame->info, &frame->pinfo);
+ err |= __put_user(&frame->uc, &frame->puc);
+ err |= copy_siginfo_to_user(&frame->info, info);
+
+ /* Create the ucontext. */
+ err |= __put_user(0, &frame->uc.uc_flags);
+ err |= __put_user(0, &frame->uc.uc_link);
+ err |= __put_user((void *)current->sas_ss_sp,
+ &frame->uc.uc_stack.ss_sp);
+ err |= __put_user(sas_ss_flags(regs->usp),
+ &frame->uc.uc_stack.ss_flags);
+ err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ err |= setup_sigframe(&frame->uc.uc_mcontext, regs);
+ err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
+
+ if (err)
+ goto give_sigsegv;
+
+ /* Set up registers for signal handler */
+ regs->usp = (unsigned long) frame;
+ regs->pc = (unsigned long) ka->sa.sa_handler;
+ regs->lr = (unsigned long)vdso->rt_signal_retcode;
+
+adjust_stack:
+ regs->a0 = sig; /* first arg is signo */
+ regs->a1 = (unsigned long)(&(frame->info)); /* second arg is (siginfo_t*) */
+ regs->a2 = (unsigned long)(&(frame->uc));/* third arg pointer to ucontext */
+ return err;
+
+give_sigsegv:
+ if (sig == SIGSEGV)
+ ka->sa.sa_handler = SIG_DFL;
+ force_sig(SIGSEGV, current);
+ goto adjust_stack;
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+static int
+handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
+ sigset_t *oldset, struct pt_regs *regs)
+{
+ struct task_struct *tsk = current;
+ int ret;
+
+ /* set up the stack frame, regardless of SA_SIGINFO, and pass info anyway. */
+ ret = setup_rt_frame(sig, ka, info, oldset, regs);
+
+ if (ret != 0) {
+ force_sigsegv(sig, tsk);
+ return ret;
+ }
+
+ /* Block the signal if we were successful. */
+ spin_lock_irq(&current->sighand->siglock);
+ sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
+ if (!(ka->sa.sa_flags & SA_NODEFER))
+ sigaddset(&current->blocked, sig);
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ return 0;
+}
+
+/*
+ * Note that 'init' is a special process: it doesn't get signals it doesn't
+ * want to handle. Thus you cannot kill init even with a SIGKILL even by
+ * mistake.
+ *
+ * Note that we go through the signals twice: once to check the signals
+ * that the kernel can handle, and then we build all the user-level signal
+ * handling stack-frames in one go after that.
+ */
+static void do_signal(struct pt_regs *regs, int syscall)
+{
+ unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
+ struct ksignal ksig;
+
+ /*
+ * We want the common case to go fast, which
+ * is why we may in certain cases get here from
+ * kernel mode. Just return without doing anything
+ * if so.
+ */
+ if (!user_mode(regs))
+ return;
+
+ current->thread.esp0 = (unsigned long)regs;
+
+ /*
+ * If we were from a system call, check for system call restarting...
+ */
+ if (syscall) {
+ continue_addr = regs->pc;
+#if defined(__CSKYABIV2__)
+ restart_addr = continue_addr - 4;
+#else
+ restart_addr = continue_addr - 2;
+#endif
+ retval = regs->a0;
+
+ /*
+ * Prepare for system call restart. We do this here so that a
+ * debugger will see the already changed.
+ */
+ switch (retval) {
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ regs->a0 = regs->orig_a0;
+ regs->pc = restart_addr;
+ break;
+ case -ERESTART_RESTARTBLOCK:
+ regs->a0 = -EINTR;
+ break;
+ }
+ }
+
+ if (try_to_freeze())
+ goto no_signal;
+
+ /*
+ * Get the signal to deliver. When running under ptrace, at this
+ * point the debugger may change all our registers ...
+ */
+ if (get_signal(&ksig)) {
+ sigset_t *oldset;
+
+ /*
+ * Depending on the signal settings we may need to revert the
+ * decision to restart the system call. But skip this if a
+ * debugger has chosen to restart at a different PC.
+ */
+ if (regs->pc == restart_addr) {
+ if (retval == -ERESTARTNOHAND
+ || (retval == -ERESTARTSYS
+ && !(ksig.ka.sa.sa_flags & SA_RESTART))) {
+ regs->a0 = -EINTR;
+ regs->pc = continue_addr;
+ }
+ }
+
+ if (test_thread_flag(TIF_RESTORE_SIGMASK))
+ oldset = &current->saved_sigmask;
+ else
+ oldset = &current->blocked;
+ /* Whee! Actually deliver the signal. */
+ if (handle_signal(ksig.sig, &ksig.ka, &ksig.info, oldset, regs) == 0) {
+ /*
+ * A signal was successfully delivered; the saved
+ * sigmask will have been stored in the signal frame,
+ * and will be restored by sigreturn, so we can simply
+ * clear the TIF_RESTORE_SIGMASK flag.
+ */
+ if (test_thread_flag(TIF_RESTORE_SIGMASK))
+ clear_thread_flag(TIF_RESTORE_SIGMASK);
+ }
+ return;
+ }
+
+no_signal:
+ if (syscall) {
+ /*
+ * Handle restarting a different system call. As above,
+ * if a debugger has chosen to restart at a different PC,
+ * ignore the restart.
+ */
+ if (retval == -ERESTART_RESTARTBLOCK
+ && regs->pc == continue_addr) {
+#if defined(__CSKYABIV2__)
+ regs->regs[3] = __NR_restart_syscall;
+ regs->pc -= 4;
+#else
+ regs->regs[9] = __NR_restart_syscall;
+ regs->pc -= 2;
+#endif
+ }
+
+ /* If there's no signal to deliver, we just put the saved sigmask
+ * back.
+ */
+ if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+ clear_thread_flag(TIF_RESTORE_SIGMASK);
+ sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+ }
+ }
+}
+
+asmlinkage void
+do_notify_resume(unsigned int thread_flags, struct pt_regs *regs, int syscall)
+{
+ if (thread_flags & _TIF_SIGPENDING)
+ do_signal(regs, syscall);
+
+ if (thread_flags & _TIF_NOTIFY_RESUME) {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ }
+}
diff --git a/arch/csky/kernel/time.c b/arch/csky/kernel/time.c
new file mode 100644
index 0000000..b5fc944
--- /dev/null
+++ b/arch/csky/kernel/time.c
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/clk-provider.h>
+#include <linux/clocksource.h>
+
+void __init time_init(void)
+{
+ of_clk_init(NULL);
+ timer_probe();
+}
--
2.7.4