From 5d8544e2d0075a5f3c9a2cf27152354d54360da1 Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Mon, 10 Jul 2017 18:03:19 -0700 Subject: RISC-V: Generic library routines and assembly This patch contains code that is more specific to the RISC-V ISA than it is to Linux. It contains string and math operations, C wrappers for various assembly instructions, stack walking code, and uaccess. Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/asm.h | 76 +++++ arch/riscv/include/asm/csr.h | 132 ++++++++ arch/riscv/include/asm/linkage.h | 20 ++ arch/riscv/include/asm/string.h | 26 ++ arch/riscv/include/asm/uaccess.h | 513 ++++++++++++++++++++++++++++++++ arch/riscv/include/asm/word-at-a-time.h | 55 ++++ 6 files changed, 822 insertions(+) create mode 100644 arch/riscv/include/asm/asm.h create mode 100644 arch/riscv/include/asm/csr.h create mode 100644 arch/riscv/include/asm/linkage.h create mode 100644 arch/riscv/include/asm/string.h create mode 100644 arch/riscv/include/asm/uaccess.h create mode 100644 arch/riscv/include/asm/word-at-a-time.h (limited to 'arch/riscv/include') diff --git a/arch/riscv/include/asm/asm.h b/arch/riscv/include/asm/asm.h new file mode 100644 index 000000000000..6cbbb6a68d76 --- /dev/null +++ b/arch/riscv/include/asm/asm.h @@ -0,0 +1,76 @@ +/* + * Copyright (C) 2015 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_ASM_H +#define _ASM_RISCV_ASM_H + +#ifdef __ASSEMBLY__ +#define __ASM_STR(x) x +#else +#define __ASM_STR(x) #x +#endif + +#if __riscv_xlen == 64 +#define __REG_SEL(a, b) __ASM_STR(a) +#elif __riscv_xlen == 32 +#define __REG_SEL(a, b) __ASM_STR(b) +#else +#error "Unexpected __riscv_xlen" +#endif + +#define REG_L __REG_SEL(ld, lw) +#define REG_S __REG_SEL(sd, sw) +#define SZREG __REG_SEL(8, 4) +#define LGREG __REG_SEL(3, 2) + +#if __SIZEOF_POINTER__ == 8 +#ifdef __ASSEMBLY__ +#define RISCV_PTR .dword +#define RISCV_SZPTR 8 +#define RISCV_LGPTR 3 +#else +#define RISCV_PTR ".dword" +#define RISCV_SZPTR "8" +#define RISCV_LGPTR "3" +#endif +#elif __SIZEOF_POINTER__ == 4 +#ifdef __ASSEMBLY__ +#define RISCV_PTR .word +#define RISCV_SZPTR 4 +#define RISCV_LGPTR 2 +#else +#define RISCV_PTR ".word" +#define RISCV_SZPTR "4" +#define RISCV_LGPTR "2" +#endif +#else +#error "Unexpected __SIZEOF_POINTER__" +#endif + +#if (__SIZEOF_INT__ == 4) +#define INT __ASM_STR(.word) +#define SZINT __ASM_STR(4) +#define LGINT __ASM_STR(2) +#else +#error "Unexpected __SIZEOF_INT__" +#endif + +#if (__SIZEOF_SHORT__ == 2) +#define SHORT __ASM_STR(.half) +#define SZSHORT __ASM_STR(2) +#define LGSHORT __ASM_STR(1) +#else +#error "Unexpected __SIZEOF_SHORT__" +#endif + +#endif /* _ASM_RISCV_ASM_H */ diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h new file mode 100644 index 000000000000..0d64bc9f4f91 --- /dev/null +++ b/arch/riscv/include/asm/csr.h @@ -0,0 +1,132 @@ +/* + * Copyright (C) 2015 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_CSR_H +#define _ASM_RISCV_CSR_H + +#include + +/* Status register flags */ +#define SR_IE _AC(0x00000002, UL) /* Interrupt Enable */ +#define SR_PIE _AC(0x00000020, UL) /* Previous IE */ +#define SR_PS _AC(0x00000100, UL) /* Previously Supervisor */ +#define SR_SUM _AC(0x00040000, UL) /* Supervisor may access User Memory */ + +#define SR_FS _AC(0x00006000, UL) /* Floating-point Status */ +#define SR_FS_OFF _AC(0x00000000, UL) +#define SR_FS_INITIAL _AC(0x00002000, UL) +#define SR_FS_CLEAN _AC(0x00004000, UL) +#define SR_FS_DIRTY _AC(0x00006000, UL) + +#define SR_XS _AC(0x00018000, UL) /* Extension Status */ +#define SR_XS_OFF _AC(0x00000000, UL) +#define SR_XS_INITIAL _AC(0x00008000, UL) +#define SR_XS_CLEAN _AC(0x00010000, UL) +#define SR_XS_DIRTY _AC(0x00018000, UL) + +#ifndef CONFIG_64BIT +#define SR_SD _AC(0x80000000, UL) /* FS/XS dirty */ +#else +#define SR_SD _AC(0x8000000000000000, UL) /* FS/XS dirty */ +#endif + +/* SPTBR flags */ +#if __riscv_xlen == 32 +#define SPTBR_PPN _AC(0x003FFFFF, UL) +#define SPTBR_MODE_32 _AC(0x80000000, UL) +#define SPTBR_MODE SPTBR_MODE_32 +#else +#define SPTBR_PPN _AC(0x00000FFFFFFFFFFF, UL) +#define SPTBR_MODE_39 _AC(0x8000000000000000, UL) +#define SPTBR_MODE SPTBR_MODE_39 +#endif + +/* Interrupt Enable and Interrupt Pending flags */ +#define SIE_SSIE _AC(0x00000002, UL) /* Software Interrupt Enable */ +#define SIE_STIE _AC(0x00000020, UL) /* Timer Interrupt Enable */ + +#define EXC_INST_MISALIGNED 0 +#define EXC_INST_ACCESS 1 +#define EXC_BREAKPOINT 3 +#define EXC_LOAD_ACCESS 5 +#define EXC_STORE_ACCESS 7 +#define EXC_SYSCALL 8 +#define EXC_INST_PAGE_FAULT 12 +#define EXC_LOAD_PAGE_FAULT 13 +#define EXC_STORE_PAGE_FAULT 15 + +#ifndef __ASSEMBLY__ + +#define csr_swap(csr, val) \ +({ \ + unsigned long __v = (unsigned long)(val); \ + __asm__ __volatile__ ("csrrw %0, " #csr ", %1" \ + : "=r" (__v) : "rK" (__v) \ + : "memory"); \ + __v; \ +}) + +#define csr_read(csr) \ +({ \ + register unsigned long __v; \ + __asm__ __volatile__ ("csrr %0, " #csr \ + : "=r" (__v) : \ + : "memory"); \ + __v; \ +}) + +#define csr_write(csr, val) \ +({ \ + unsigned long __v = (unsigned long)(val); \ + __asm__ __volatile__ ("csrw " #csr ", %0" \ + : : "rK" (__v) \ + : "memory"); \ +}) + +#define csr_read_set(csr, val) \ +({ \ + unsigned long __v = (unsigned long)(val); \ + __asm__ __volatile__ ("csrrs %0, " #csr ", %1" \ + : "=r" (__v) : "rK" (__v) \ + : "memory"); \ + __v; \ +}) + +#define csr_set(csr, val) \ +({ \ + unsigned long __v = (unsigned long)(val); \ + __asm__ __volatile__ ("csrs " #csr ", %0" \ + : : "rK" (__v) \ + : "memory"); \ +}) + +#define csr_read_clear(csr, val) \ +({ \ + unsigned long __v = (unsigned long)(val); \ + __asm__ __volatile__ ("csrrc %0, " #csr ", %1" \ + : "=r" (__v) : "rK" (__v) \ + : "memory"); \ + __v; \ +}) + +#define csr_clear(csr, val) \ +({ \ + unsigned long __v = (unsigned long)(val); \ + __asm__ __volatile__ ("csrc " #csr ", %0" \ + : : "rK" (__v) \ + : "memory"); \ +}) + +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_RISCV_CSR_H */ diff --git a/arch/riscv/include/asm/linkage.h b/arch/riscv/include/asm/linkage.h new file mode 100644 index 000000000000..b7b304ca89c4 --- /dev/null +++ b/arch/riscv/include/asm/linkage.h @@ -0,0 +1,20 @@ +/* + * Copyright (C) 2015 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_LINKAGE_H +#define _ASM_RISCV_LINKAGE_H + +#define __ALIGN .balign 4 +#define __ALIGN_STR ".balign 4" + +#endif /* _ASM_RISCV_LINKAGE_H */ diff --git a/arch/riscv/include/asm/string.h b/arch/riscv/include/asm/string.h new file mode 100644 index 000000000000..9210fcf4ff52 --- /dev/null +++ b/arch/riscv/include/asm/string.h @@ -0,0 +1,26 @@ +/* + * Copyright (C) 2013 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_STRING_H +#define _ASM_RISCV_STRING_H + +#include +#include + +#define __HAVE_ARCH_MEMSET +extern asmlinkage void *memset(void *, int, size_t); + +#define __HAVE_ARCH_MEMCPY +extern asmlinkage void *memcpy(void *, const void *, size_t); + +#endif /* _ASM_RISCV_STRING_H */ diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h new file mode 100644 index 000000000000..27b90d64814b --- /dev/null +++ b/arch/riscv/include/asm/uaccess.h @@ -0,0 +1,513 @@ +/* + * 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. + * + * This file was copied from include/asm-generic/uaccess.h + */ + +#ifndef _ASM_RISCV_UACCESS_H +#define _ASM_RISCV_UACCESS_H + +/* + * User space memory access functions + */ +#include +#include +#include +#include +#include + +#define __enable_user_access() \ + __asm__ __volatile__ ("csrs sstatus, %0" : : "r" (SR_SUM) : "memory") +#define __disable_user_access() \ + __asm__ __volatile__ ("csrc sstatus, %0" : : "r" (SR_SUM) : "memory") + +/* + * The fs value determines whether argument validity checking should be + * performed or not. If get_fs() == USER_DS, checking is performed, with + * get_fs() == KERNEL_DS, checking is bypassed. + * + * For historical reasons, these macros are grossly misnamed. + */ + +#define KERNEL_DS (~0UL) +#define USER_DS (TASK_SIZE) + +#define get_ds() (KERNEL_DS) +#define get_fs() (current_thread_info()->addr_limit) + +static inline void set_fs(mm_segment_t fs) +{ + current_thread_info()->addr_limit = fs; +} + +#define segment_eq(a, b) ((a) == (b)) + +#define user_addr_max() (get_fs()) + + +#define VERIFY_READ 0 +#define VERIFY_WRITE 1 + +/** + * access_ok: - Checks if a user space pointer is valid + * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that + * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe + * to write to a block, it is always safe to read from it. + * @addr: User space pointer to start of block to check + * @size: Size of block to check + * + * Context: User context only. This function may sleep. + * + * Checks if a pointer to a block of memory in user space is valid. + * + * Returns true (nonzero) if the memory block may be valid, false (zero) + * if it is definitely invalid. + * + * Note that, depending on architecture, this function probably just + * checks that the pointer is in the user space range - after calling + * this function, memory access functions may still return -EFAULT. + */ +#define access_ok(type, addr, size) ({ \ + __chk_user_ptr(addr); \ + likely(__access_ok((unsigned long __force)(addr), (size))); \ +}) + +/* + * Ensure that the range [addr, addr+size) is within the process's + * address space + */ +static inline int __access_ok(unsigned long addr, unsigned long size) +{ + const mm_segment_t fs = get_fs(); + + return (size <= fs) && (addr <= (fs - size)); +} + +/* + * The exception table consists of pairs of addresses: the first is the + * address of an instruction that is allowed to fault, and the second is + * the address at which the program should continue. No registers are + * modified, so it is entirely up to the continuation code to figure out + * what to do. + * + * All the routines below use bits of fixup code that are out of line + * with the main instruction path. This means when everything is well, + * we don't even have to jump over them. Further, they do not intrude + * on our cache or tlb entries. + */ + +struct exception_table_entry { + unsigned long insn, fixup; +}; + +extern int fixup_exception(struct pt_regs *state); + +#if defined(__LITTLE_ENDIAN) +#define __MSW 1 +#define __LSW 0 +#elif defined(__BIG_ENDIAN) +#define __MSW 0 +#define __LSW 1 +#else +#error "Unknown endianness" +#endif + +/* + * The "__xxx" versions of the user access functions do not verify the address + * space - it must have been done previously with a separate "access_ok()" + * call. + */ + +#ifdef CONFIG_MMU +#define __get_user_asm(insn, x, ptr, err) \ +do { \ + uintptr_t __tmp; \ + __typeof__(x) __x; \ + __enable_user_access(); \ + __asm__ __volatile__ ( \ + "1:\n" \ + " " insn " %1, %3\n" \ + "2:\n" \ + " .section .fixup,\"ax\"\n" \ + " .balign 4\n" \ + "3:\n" \ + " li %0, %4\n" \ + " li %1, 0\n" \ + " jump 2b, %2\n" \ + " .previous\n" \ + " .section __ex_table,\"a\"\n" \ + " .balign " RISCV_SZPTR "\n" \ + " " RISCV_PTR " 1b, 3b\n" \ + " .previous" \ + : "+r" (err), "=&r" (__x), "=r" (__tmp) \ + : "m" (*(ptr)), "i" (-EFAULT)); \ + __disable_user_access(); \ + (x) = __x; \ +} while (0) +#endif /* CONFIG_MMU */ + +#ifdef CONFIG_64BIT +#define __get_user_8(x, ptr, err) \ + __get_user_asm("ld", x, ptr, err) +#else /* !CONFIG_64BIT */ +#ifdef CONFIG_MMU +#define __get_user_8(x, ptr, err) \ +do { \ + u32 __user *__ptr = (u32 __user *)(ptr); \ + u32 __lo, __hi; \ + uintptr_t __tmp; \ + __enable_user_access(); \ + __asm__ __volatile__ ( \ + "1:\n" \ + " lw %1, %4\n" \ + "2:\n" \ + " lw %2, %5\n" \ + "3:\n" \ + " .section .fixup,\"ax\"\n" \ + " .balign 4\n" \ + "4:\n" \ + " li %0, %6\n" \ + " li %1, 0\n" \ + " li %2, 0\n" \ + " jump 3b, %3\n" \ + " .previous\n" \ + " .section __ex_table,\"a\"\n" \ + " .balign " RISCV_SZPTR "\n" \ + " " RISCV_PTR " 1b, 4b\n" \ + " " RISCV_PTR " 2b, 4b\n" \ + " .previous" \ + : "+r" (err), "=&r" (__lo), "=r" (__hi), \ + "=r" (__tmp) \ + : "m" (__ptr[__LSW]), "m" (__ptr[__MSW]), \ + "i" (-EFAULT)); \ + __disable_user_access(); \ + (x) = (__typeof__(x))((__typeof__((x)-(x)))( \ + (((u64)__hi << 32) | __lo))); \ +} while (0) +#endif /* CONFIG_MMU */ +#endif /* CONFIG_64BIT */ + + +/** + * __get_user: - Get a simple variable from user space, with less checking. + * @x: Variable to store result. + * @ptr: Source address, in user space. + * + * Context: User context only. This function may sleep. + * + * This macro copies a single simple variable from user space to kernel + * space. It supports simple types like char and int, but not larger + * data types like structures or arrays. + * + * @ptr must have pointer-to-simple-variable type, and the result of + * dereferencing @ptr must be assignable to @x without a cast. + * + * Caller must check the pointer with access_ok() before calling this + * function. + * + * Returns zero on success, or -EFAULT on error. + * On error, the variable @x is set to zero. + */ +#define __get_user(x, ptr) \ +({ \ + register long __gu_err = 0; \ + const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ + __chk_user_ptr(__gu_ptr); \ + switch (sizeof(*__gu_ptr)) { \ + case 1: \ + __get_user_asm("lb", (x), __gu_ptr, __gu_err); \ + break; \ + case 2: \ + __get_user_asm("lh", (x), __gu_ptr, __gu_err); \ + break; \ + case 4: \ + __get_user_asm("lw", (x), __gu_ptr, __gu_err); \ + break; \ + case 8: \ + __get_user_8((x), __gu_ptr, __gu_err); \ + break; \ + default: \ + BUILD_BUG(); \ + } \ + __gu_err; \ +}) + +/** + * get_user: - Get a simple variable from user space. + * @x: Variable to store result. + * @ptr: Source address, in user space. + * + * Context: User context only. This function may sleep. + * + * This macro copies a single simple variable from user space to kernel + * space. It supports simple types like char and int, but not larger + * data types like structures or arrays. + * + * @ptr must have pointer-to-simple-variable type, and the result of + * dereferencing @ptr must be assignable to @x without a cast. + * + * Returns zero on success, or -EFAULT on error. + * On error, the variable @x is set to zero. + */ +#define get_user(x, ptr) \ +({ \ + const __typeof__(*(ptr)) __user *__p = (ptr); \ + might_fault(); \ + access_ok(VERIFY_READ, __p, sizeof(*__p)) ? \ + __get_user((x), __p) : \ + ((x) = 0, -EFAULT); \ +}) + + +#ifdef CONFIG_MMU +#define __put_user_asm(insn, x, ptr, err) \ +do { \ + uintptr_t __tmp; \ + __typeof__(*(ptr)) __x = x; \ + __enable_user_access(); \ + __asm__ __volatile__ ( \ + "1:\n" \ + " " insn " %z3, %2\n" \ + "2:\n" \ + " .section .fixup,\"ax\"\n" \ + " .balign 4\n" \ + "3:\n" \ + " li %0, %4\n" \ + " jump 2b, %1\n" \ + " .previous\n" \ + " .section __ex_table,\"a\"\n" \ + " .balign " RISCV_SZPTR "\n" \ + " " RISCV_PTR " 1b, 3b\n" \ + " .previous" \ + : "+r" (err), "=r" (__tmp), "=m" (*(ptr)) \ + : "rJ" (__x), "i" (-EFAULT)); \ + __disable_user_access(); \ +} while (0) +#endif /* CONFIG_MMU */ + + +#ifdef CONFIG_64BIT +#define __put_user_8(x, ptr, err) \ + __put_user_asm("sd", x, ptr, err) +#else /* !CONFIG_64BIT */ +#ifdef CONFIG_MMU +#define __put_user_8(x, ptr, err) \ +do { \ + u32 __user *__ptr = (u32 __user *)(ptr); \ + u64 __x = (__typeof__((x)-(x)))(x); \ + uintptr_t __tmp; \ + __enable_user_access(); \ + __asm__ __volatile__ ( \ + "1:\n" \ + " sw %z4, %2\n" \ + "2:\n" \ + " sw %z5, %3\n" \ + "3:\n" \ + " .section .fixup,\"ax\"\n" \ + " .balign 4\n" \ + "4:\n" \ + " li %0, %6\n" \ + " jump 2b, %1\n" \ + " .previous\n" \ + " .section __ex_table,\"a\"\n" \ + " .balign " RISCV_SZPTR "\n" \ + " " RISCV_PTR " 1b, 4b\n" \ + " " RISCV_PTR " 2b, 4b\n" \ + " .previous" \ + : "+r" (err), "=r" (__tmp), \ + "=m" (__ptr[__LSW]), \ + "=m" (__ptr[__MSW]) \ + : "rJ" (__x), "rJ" (__x >> 32), "i" (-EFAULT)); \ + __disable_user_access(); \ +} while (0) +#endif /* CONFIG_MMU */ +#endif /* CONFIG_64BIT */ + + +/** + * __put_user: - Write a simple value into user space, with less checking. + * @x: Value to copy to user space. + * @ptr: Destination address, in user space. + * + * Context: User context only. This function may sleep. + * + * This macro copies a single simple value from kernel space to user + * space. It supports simple types like char and int, but not larger + * data types like structures or arrays. + * + * @ptr must have pointer-to-simple-variable type, and @x must be assignable + * to the result of dereferencing @ptr. + * + * Caller must check the pointer with access_ok() before calling this + * function. + * + * Returns zero on success, or -EFAULT on error. + */ +#define __put_user(x, ptr) \ +({ \ + register long __pu_err = 0; \ + __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ + __chk_user_ptr(__gu_ptr); \ + switch (sizeof(*__gu_ptr)) { \ + case 1: \ + __put_user_asm("sb", (x), __gu_ptr, __pu_err); \ + break; \ + case 2: \ + __put_user_asm("sh", (x), __gu_ptr, __pu_err); \ + break; \ + case 4: \ + __put_user_asm("sw", (x), __gu_ptr, __pu_err); \ + break; \ + case 8: \ + __put_user_8((x), __gu_ptr, __pu_err); \ + break; \ + default: \ + BUILD_BUG(); \ + } \ + __pu_err; \ +}) + +/** + * put_user: - Write a simple value into user space. + * @x: Value to copy to user space. + * @ptr: Destination address, in user space. + * + * Context: User context only. This function may sleep. + * + * This macro copies a single simple value from kernel space to user + * space. It supports simple types like char and int, but not larger + * data types like structures or arrays. + * + * @ptr must have pointer-to-simple-variable type, and @x must be assignable + * to the result of dereferencing @ptr. + * + * Returns zero on success, or -EFAULT on error. + */ +#define put_user(x, ptr) \ +({ \ + __typeof__(*(ptr)) __user *__p = (ptr); \ + might_fault(); \ + access_ok(VERIFY_WRITE, __p, sizeof(*__p)) ? \ + __put_user((x), __p) : \ + -EFAULT; \ +}) + + +extern unsigned long __must_check __copy_user(void __user *to, + const void __user *from, unsigned long n); + +static inline unsigned long +raw_copy_from_user(void *to, const void __user *from, unsigned long n) +{ + return __copy_user(to, from, n); +} + +static inline unsigned long +raw_copy_to_user(void __user *to, const void *from, unsigned long n) +{ + return __copy_user(to, from, n); +} + +extern long strncpy_from_user(char *dest, const char __user *src, long count); + +extern long __must_check strlen_user(const char __user *str); +extern long __must_check strnlen_user(const char __user *str, long n); + +extern +unsigned long __must_check __clear_user(void __user *addr, unsigned long n); + +static inline +unsigned long __must_check clear_user(void __user *to, unsigned long n) +{ + might_fault(); + return access_ok(VERIFY_WRITE, to, n) ? + __clear_user(to, n) : n; +} + +/* + * Atomic compare-and-exchange, but with a fixup for userspace faults. Faults + * will set "err" to -EFAULT, while successful accesses return the previous + * value. + */ +#ifdef CONFIG_MMU +#define __cmpxchg_user(ptr, old, new, err, size, lrb, scb) \ +({ \ + __typeof__(ptr) __ptr = (ptr); \ + __typeof__(*(ptr)) __old = (old); \ + __typeof__(*(ptr)) __new = (new); \ + __typeof__(*(ptr)) __ret; \ + __typeof__(err) __err = 0; \ + register unsigned int __rc; \ + __enable_user_access(); \ + switch (size) { \ + case 4: \ + __asm__ __volatile__ ( \ + "0:\n" \ + " lr.w" #scb " %[ret], %[ptr]\n" \ + " bne %[ret], %z[old], 1f\n" \ + " sc.w" #lrb " %[rc], %z[new], %[ptr]\n" \ + " bnez %[rc], 0b\n" \ + "1:\n" \ + ".section .fixup,\"ax\"\n" \ + ".balign 4\n" \ + "2:\n" \ + " li %[err], %[efault]\n" \ + " jump 1b, %[rc]\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + ".balign " RISCV_SZPTR "\n" \ + " " RISCV_PTR " 1b, 2b\n" \ + ".previous\n" \ + : [ret] "=&r" (__ret), \ + [rc] "=&r" (__rc), \ + [ptr] "+A" (*__ptr), \ + [err] "=&r" (__err) \ + : [old] "rJ" (__old), \ + [new] "rJ" (__new), \ + [efault] "i" (-EFAULT)); \ + break; \ + case 8: \ + __asm__ __volatile__ ( \ + "0:\n" \ + " lr.d" #scb " %[ret], %[ptr]\n" \ + " bne %[ret], %z[old], 1f\n" \ + " sc.d" #lrb " %[rc], %z[new], %[ptr]\n" \ + " bnez %[rc], 0b\n" \ + "1:\n" \ + ".section .fixup,\"ax\"\n" \ + ".balign 4\n" \ + "2:\n" \ + " li %[err], %[efault]\n" \ + " jump 1b, %[rc]\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + ".balign " RISCV_SZPTR "\n" \ + " " RISCV_PTR " 1b, 2b\n" \ + ".previous\n" \ + : [ret] "=&r" (__ret), \ + [rc] "=&r" (__rc), \ + [ptr] "+A" (*__ptr), \ + [err] "=&r" (__err) \ + : [old] "rJ" (__old), \ + [new] "rJ" (__new), \ + [efault] "i" (-EFAULT)); \ + break; \ + default: \ + BUILD_BUG(); \ + } \ + __disable_user_access(); \ + (err) = __err; \ + __ret; \ +}) +#endif /* CONFIG_MMU */ + +#endif /* _ASM_RISCV_UACCESS_H */ diff --git a/arch/riscv/include/asm/word-at-a-time.h b/arch/riscv/include/asm/word-at-a-time.h new file mode 100644 index 000000000000..aa6238791d3e --- /dev/null +++ b/arch/riscv/include/asm/word-at-a-time.h @@ -0,0 +1,55 @@ +/* + * 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. + * Derived from arch/x86/include/asm/word-at-a-time.h + */ + +#ifndef _ASM_RISCV_WORD_AT_A_TIME_H +#define _ASM_RISCV_WORD_AT_A_TIME_H + + +#include + +struct word_at_a_time { + const unsigned long one_bits, high_bits; +}; + +#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) } + +static inline unsigned long has_zero(unsigned long val, + unsigned long *bits, const struct word_at_a_time *c) +{ + unsigned long mask = ((val - c->one_bits) & ~val) & c->high_bits; + *bits = mask; + return mask; +} + +static inline unsigned long prep_zero_mask(unsigned long val, + unsigned long bits, const struct word_at_a_time *c) +{ + return bits; +} + +static inline unsigned long create_zero_mask(unsigned long bits) +{ + bits = (bits - 1) & ~bits; + return bits >> 7; +} + +static inline unsigned long find_zero(unsigned long mask) +{ + return fls64(mask) >> 3; +} + +/* The mask we created is directly usable as a bytemask */ +#define zero_bytemask(mask) (mask) + +#endif /* _ASM_RISCV_WORD_AT_A_TIME_H */ -- cgit v1.2.3