[PATCH 13/17] RISC-V: Task implementation

[Palmer Dabbelt]

This patch contains the implementation of tasks on RISC-V, most of which
is involved in task switching.

Signed-off-by: Palmer Dabbelt 
---
 arch/riscv/include/asm/asm-offsets.h |   1 +
 arch/riscv/include/asm/current.h |  45 
 arch/riscv/include/asm/kprobes.h |  22 ++
 arch/riscv/include/asm/processor.h   |  97 
 arch/riscv/include/asm/switch_to.h   |  69 ++
 arch/riscv/include/asm/thread_info.h |  93 +++
 arch/riscv/kernel/asm-offsets.c  | 322 
 arch/riscv/kernel/entry.S| 457 +++
 arch/riscv/kernel/process.c  | 129 ++
 9 files changed, 1235 insertions(+)
 create mode 100644 arch/riscv/include/asm/asm-offsets.h
 create mode 100644 arch/riscv/include/asm/current.h
 create mode 100644 arch/riscv/include/asm/kprobes.h
 create mode 100644 arch/riscv/include/asm/processor.h
 create mode 100644 arch/riscv/include/asm/switch_to.h
 create mode 100644 arch/riscv/include/asm/thread_info.h
 create mode 100644 arch/riscv/kernel/asm-offsets.c
 create mode 100644 arch/riscv/kernel/entry.S
 create mode 100644 arch/riscv/kernel/process.c

diff --git a/arch/riscv/include/asm/asm-offsets.h 
b/arch/riscv/include/asm/asm-offsets.h
new file mode 100644
index ..d370ee36a182
--- /dev/null
+++ b/arch/riscv/include/asm/asm-offsets.h
@@ -0,0 +1 @@
+#include 
diff --git a/arch/riscv/include/asm/current.h b/arch/riscv/include/asm/current.h
new file mode 100644
index ..2cf6336ef600
--- /dev/null
+++ b/arch/riscv/include/asm/current.h
@@ -0,0 +1,45 @@
+/*
+ * Based on arm/arm64/include/asm/current.h
+ *
+ * Copyright (C) 2016 ARM
+ * Copyright (C) 2017 SiFive
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ */
+
+
+#ifndef __ASM_CURRENT_H
+#define __ASM_CURRENT_H
+
+#include 
+#include 
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+
+/*
+ * This only works because "struct thread_info" is at offset 0 from "struct
+ * task_struct".  This constraint seems to be necessary on other architectures
+ * as well, but __switch_to enforces it.  We can't check TASK_TI here because
+ *  includes this, and I can't get the definition of "struct
+ * task_struct" here due to some header ordering problems.
+ */
+static __always_inline struct task_struct *get_current(void)
+{
+   register struct task_struct *tp __asm__("tp");
+   return tp;
+}
+
+#define current get_current()
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_CURRENT_H */
diff --git a/arch/riscv/include/asm/kprobes.h b/arch/riscv/include/asm/kprobes.h
new file mode 100644
index ..c7eb010d1528
--- /dev/null
+++ b/arch/riscv/include/asm/kprobes.h
@@ -0,0 +1,22 @@
+/*
+ * Copied from arch/arm64/include/asm/kprobes.h
+ *
+ * Copyright (C) 2013 Linaro Limited
+ * Copyright (C) 2017 SiFive
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#ifndef _RISCV_KPROBES_H
+#define _RISCV_KPROBES_H
+
+#include 
+
+#endif /* _RISCV_KPROBES_H */
diff --git a/arch/riscv/include/asm/processor.h 
b/arch/riscv/include/asm/processor.h
new file mode 100644
index ..3fe4af8147d2
--- /dev/null
+++ b/arch/riscv/include/asm/processor.h
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ */
+
+#ifndef _ASM_RISCV_PROCESSOR_H
+#define _ASM_RISCV_PROCESSOR_H
+
+#include 
+
+#include 
+
+/*
+ * This decides where the kernel will search for a free chunk of vm
+ * space during mmap's.
+ */
+#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE >> 1)
+
+#define STACK_TOP  TASK_SIZE
+#define STACK_TOP_MAX  STACK_TOP
+#define STACK_ALIGN16
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+struct pt_regs;
+
+/*
+ * 

[PATCH 13/17] RISC-V: Task implementation

[Palmer Dabbelt]

This patch contains the implementation of tasks on RISC-V, most of which
is involved in task switching.

Signed-off-by: Palmer Dabbelt 
---
 arch/riscv/include/asm/asm-offsets.h |   1 +
 arch/riscv/include/asm/current.h |  45 
 arch/riscv/include/asm/kprobes.h |  22 ++
 arch/riscv/include/asm/processor.h   |  97 
 arch/riscv/include/asm/switch_to.h   |  69 ++
 arch/riscv/include/asm/thread_info.h |  93 +++
 arch/riscv/kernel/asm-offsets.c  | 322 
 arch/riscv/kernel/entry.S| 457 +++
 arch/riscv/kernel/process.c  | 129 ++
 9 files changed, 1235 insertions(+)
 create mode 100644 arch/riscv/include/asm/asm-offsets.h
 create mode 100644 arch/riscv/include/asm/current.h
 create mode 100644 arch/riscv/include/asm/kprobes.h
 create mode 100644 arch/riscv/include/asm/processor.h
 create mode 100644 arch/riscv/include/asm/switch_to.h
 create mode 100644 arch/riscv/include/asm/thread_info.h
 create mode 100644 arch/riscv/kernel/asm-offsets.c
 create mode 100644 arch/riscv/kernel/entry.S
 create mode 100644 arch/riscv/kernel/process.c

diff --git a/arch/riscv/include/asm/asm-offsets.h 
b/arch/riscv/include/asm/asm-offsets.h
new file mode 100644
index ..d370ee36a182
--- /dev/null
+++ b/arch/riscv/include/asm/asm-offsets.h
@@ -0,0 +1 @@
+#include 
diff --git a/arch/riscv/include/asm/current.h b/arch/riscv/include/asm/current.h
new file mode 100644
index ..2cf6336ef600
--- /dev/null
+++ b/arch/riscv/include/asm/current.h
@@ -0,0 +1,45 @@
+/*
+ * Based on arm/arm64/include/asm/current.h
+ *
+ * Copyright (C) 2016 ARM
+ * Copyright (C) 2017 SiFive
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ */
+
+
+#ifndef __ASM_CURRENT_H
+#define __ASM_CURRENT_H
+
+#include 
+#include 
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+
+/*
+ * This only works because "struct thread_info" is at offset 0 from "struct
+ * task_struct".  This constraint seems to be necessary on other architectures
+ * as well, but __switch_to enforces it.  We can't check TASK_TI here because
+ *  includes this, and I can't get the definition of "struct
+ * task_struct" here due to some header ordering problems.
+ */
+static __always_inline struct task_struct *get_current(void)
+{
+   register struct task_struct *tp __asm__("tp");
+   return tp;
+}
+
+#define current get_current()
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_CURRENT_H */
diff --git a/arch/riscv/include/asm/kprobes.h b/arch/riscv/include/asm/kprobes.h
new file mode 100644
index ..c7eb010d1528
--- /dev/null
+++ b/arch/riscv/include/asm/kprobes.h
@@ -0,0 +1,22 @@
+/*
+ * Copied from arch/arm64/include/asm/kprobes.h
+ *
+ * Copyright (C) 2013 Linaro Limited
+ * Copyright (C) 2017 SiFive
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#ifndef _RISCV_KPROBES_H
+#define _RISCV_KPROBES_H
+
+#include 
+
+#endif /* _RISCV_KPROBES_H */
diff --git a/arch/riscv/include/asm/processor.h 
b/arch/riscv/include/asm/processor.h
new file mode 100644
index ..3fe4af8147d2
--- /dev/null
+++ b/arch/riscv/include/asm/processor.h
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ */
+
+#ifndef _ASM_RISCV_PROCESSOR_H
+#define _ASM_RISCV_PROCESSOR_H
+
+#include 
+
+#include 
+
+/*
+ * This decides where the kernel will search for a free chunk of vm
+ * space during mmap's.
+ */
+#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE >> 1)
+
+#define STACK_TOP  TASK_SIZE
+#define STACK_TOP_MAX  STACK_TOP
+#define STACK_ALIGN16
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+struct pt_regs;
+
+/*
+ * Default implementation 

[PATCH 13/17] RISC-V: Task implementation

[Palmer Dabbelt]

This patch contains the implementation of tasks on RISC-V, most of which
is involved in task switching.

Signed-off-by: Palmer Dabbelt 
---
 arch/riscv/include/asm/asm-offsets.h |   1 +
 arch/riscv/include/asm/current.h |  45 
 arch/riscv/include/asm/kprobes.h |  22 ++
 arch/riscv/include/asm/processor.h   |  97 
 arch/riscv/include/asm/switch_to.h   |  69 ++
 arch/riscv/include/asm/thread_info.h |  93 +++
 arch/riscv/kernel/asm-offsets.c  | 322 
 arch/riscv/kernel/entry.S| 457 +++
 arch/riscv/kernel/process.c  | 129 ++
 9 files changed, 1235 insertions(+)
 create mode 100644 arch/riscv/include/asm/asm-offsets.h
 create mode 100644 arch/riscv/include/asm/current.h
 create mode 100644 arch/riscv/include/asm/kprobes.h
 create mode 100644 arch/riscv/include/asm/processor.h
 create mode 100644 arch/riscv/include/asm/switch_to.h
 create mode 100644 arch/riscv/include/asm/thread_info.h
 create mode 100644 arch/riscv/kernel/asm-offsets.c
 create mode 100644 arch/riscv/kernel/entry.S
 create mode 100644 arch/riscv/kernel/process.c

diff --git a/arch/riscv/include/asm/asm-offsets.h 
b/arch/riscv/include/asm/asm-offsets.h
new file mode 100644
index ..d370ee36a182
--- /dev/null
+++ b/arch/riscv/include/asm/asm-offsets.h
@@ -0,0 +1 @@
+#include 
diff --git a/arch/riscv/include/asm/current.h b/arch/riscv/include/asm/current.h
new file mode 100644
index ..2cf6336ef600
--- /dev/null
+++ b/arch/riscv/include/asm/current.h
@@ -0,0 +1,45 @@
+/*
+ * Based on arm/arm64/include/asm/current.h
+ *
+ * Copyright (C) 2016 ARM
+ * Copyright (C) 2017 SiFive
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ */
+
+
+#ifndef __ASM_CURRENT_H
+#define __ASM_CURRENT_H
+
+#include 
+#include 
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+
+/*
+ * This only works because "struct thread_info" is at offset 0 from "struct
+ * task_struct".  This constraint seems to be necessary on other architectures
+ * as well, but __switch_to enforces it.  We can't check TASK_TI here because
+ *  includes this, and I can't get the definition of "struct
+ * task_struct" here due to some header ordering problems.
+ */
+static __always_inline struct task_struct *get_current(void)
+{
+   register struct task_struct *tp __asm__("tp");
+   return tp;
+}
+
+#define current get_current()
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_CURRENT_H */
diff --git a/arch/riscv/include/asm/kprobes.h b/arch/riscv/include/asm/kprobes.h
new file mode 100644
index ..c7eb010d1528
--- /dev/null
+++ b/arch/riscv/include/asm/kprobes.h
@@ -0,0 +1,22 @@
+/*
+ * Copied from arch/arm64/include/asm/kprobes.h
+ *
+ * Copyright (C) 2013 Linaro Limited
+ * Copyright (C) 2017 SiFive
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#ifndef _RISCV_KPROBES_H
+#define _RISCV_KPROBES_H
+
+#include 
+
+#endif /* _RISCV_KPROBES_H */
diff --git a/arch/riscv/include/asm/processor.h 
b/arch/riscv/include/asm/processor.h
new file mode 100644
index ..3fe4af8147d2
--- /dev/null
+++ b/arch/riscv/include/asm/processor.h
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ */
+
+#ifndef _ASM_RISCV_PROCESSOR_H
+#define _ASM_RISCV_PROCESSOR_H
+
+#include 
+
+#include 
+
+/*
+ * This decides where the kernel will search for a free chunk of vm
+ * space during mmap's.
+ */
+#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE >> 1)
+
+#define STACK_TOP  TASK_SIZE
+#define STACK_TOP_MAX  STACK_TOP
+#define STACK_ALIGN16
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+struct pt_regs;
+
+/*
+ * 

[PATCH 13/17] RISC-V: Task implementation

[Palmer Dabbelt]

This patch contains the implementation of tasks on RISC-V, most of which
is involved in task switching.

Signed-off-by: Palmer Dabbelt 
---
 arch/riscv/include/asm/asm-offsets.h |   1 +
 arch/riscv/include/asm/current.h |  45 
 arch/riscv/include/asm/kprobes.h |  22 ++
 arch/riscv/include/asm/processor.h   |  97 
 arch/riscv/include/asm/switch_to.h   |  69 ++
 arch/riscv/include/asm/thread_info.h |  93 +++
 arch/riscv/kernel/asm-offsets.c  | 322 
 arch/riscv/kernel/entry.S| 457 +++
 arch/riscv/kernel/process.c  | 129 ++
 9 files changed, 1235 insertions(+)
 create mode 100644 arch/riscv/include/asm/asm-offsets.h
 create mode 100644 arch/riscv/include/asm/current.h
 create mode 100644 arch/riscv/include/asm/kprobes.h
 create mode 100644 arch/riscv/include/asm/processor.h
 create mode 100644 arch/riscv/include/asm/switch_to.h
 create mode 100644 arch/riscv/include/asm/thread_info.h
 create mode 100644 arch/riscv/kernel/asm-offsets.c
 create mode 100644 arch/riscv/kernel/entry.S
 create mode 100644 arch/riscv/kernel/process.c

diff --git a/arch/riscv/include/asm/asm-offsets.h 
b/arch/riscv/include/asm/asm-offsets.h
new file mode 100644
index ..d370ee36a182
--- /dev/null
+++ b/arch/riscv/include/asm/asm-offsets.h
@@ -0,0 +1 @@
+#include 
diff --git a/arch/riscv/include/asm/current.h b/arch/riscv/include/asm/current.h
new file mode 100644
index ..2cf6336ef600
--- /dev/null
+++ b/arch/riscv/include/asm/current.h
@@ -0,0 +1,45 @@
+/*
+ * Based on arm/arm64/include/asm/current.h
+ *
+ * Copyright (C) 2016 ARM
+ * Copyright (C) 2017 SiFive
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ */
+
+
+#ifndef __ASM_CURRENT_H
+#define __ASM_CURRENT_H
+
+#include 
+#include 
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+
+/*
+ * This only works because "struct thread_info" is at offset 0 from "struct
+ * task_struct".  This constraint seems to be necessary on other architectures
+ * as well, but __switch_to enforces it.  We can't check TASK_TI here because
+ *  includes this, and I can't get the definition of "struct
+ * task_struct" here due to some header ordering problems.
+ */
+static __always_inline struct task_struct *get_current(void)
+{
+   register struct task_struct *tp __asm__("tp");
+   return tp;
+}
+
+#define current get_current()
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_CURRENT_H */
diff --git a/arch/riscv/include/asm/kprobes.h b/arch/riscv/include/asm/kprobes.h
new file mode 100644
index ..c7eb010d1528
--- /dev/null
+++ b/arch/riscv/include/asm/kprobes.h
@@ -0,0 +1,22 @@
+/*
+ * Copied from arch/arm64/include/asm/kprobes.h
+ *
+ * Copyright (C) 2013 Linaro Limited
+ * Copyright (C) 2017 SiFive
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#ifndef _RISCV_KPROBES_H
+#define _RISCV_KPROBES_H
+
+#include 
+
+#endif /* _RISCV_KPROBES_H */
diff --git a/arch/riscv/include/asm/processor.h 
b/arch/riscv/include/asm/processor.h
new file mode 100644
index ..3fe4af8147d2
--- /dev/null
+++ b/arch/riscv/include/asm/processor.h
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ */
+
+#ifndef _ASM_RISCV_PROCESSOR_H
+#define _ASM_RISCV_PROCESSOR_H
+
+#include 
+
+#include 
+
+/*
+ * This decides where the kernel will search for a free chunk of vm
+ * space during mmap's.
+ */
+#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE >> 1)
+
+#define STACK_TOP  TASK_SIZE
+#define STACK_TOP_MAX  STACK_TOP
+#define STACK_ALIGN16
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+struct pt_regs;
+
+/*
+ * Default implementation