From 26025bbfbba33a9425be1b89eccb4664ea4c17b6 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Tue, 9 Oct 2012 10:54:51 +0100 Subject: [PATCH] metag: System Calls Add metag system call and gateway page interfaces. The metag architecture port uses the generic system call numbers from asm-generic/unistd.h, as well as a user gateway page mapped at 0x6ffff000 which contains fast atomic primitives (depending on SMP) and a fast method of accessing TLS data. System calls use the SWITCH instruction with the immediate 0x440001 to signal a system call. Signed-off-by: James Hogan --- arch/metag/include/asm/mman.h | 11 ++ arch/metag/include/asm/syscall.h | 104 +++++++++++++++ arch/metag/include/asm/syscalls.h | 39 ++++++ arch/metag/include/asm/unistd.h | 12 ++ arch/metag/include/asm/user_gateway.h | 44 +++++++ arch/metag/include/uapi/asm/unistd.h | 21 +++ arch/metag/kernel/sys_metag.c | 180 ++++++++++++++++++++++++++ arch/metag/kernel/user_gateway.S | 97 ++++++++++++++ 8 files changed, 508 insertions(+) create mode 100644 arch/metag/include/asm/mman.h create mode 100644 arch/metag/include/asm/syscall.h create mode 100644 arch/metag/include/asm/syscalls.h create mode 100644 arch/metag/include/asm/unistd.h create mode 100644 arch/metag/include/asm/user_gateway.h create mode 100644 arch/metag/include/uapi/asm/unistd.h create mode 100644 arch/metag/kernel/sys_metag.c create mode 100644 arch/metag/kernel/user_gateway.S diff --git a/arch/metag/include/asm/mman.h b/arch/metag/include/asm/mman.h new file mode 100644 index 000000000000..17999dba9275 --- /dev/null +++ b/arch/metag/include/asm/mman.h @@ -0,0 +1,11 @@ +#ifndef __METAG_MMAN_H__ +#define __METAG_MMAN_H__ + +#include + +#ifndef __ASSEMBLY__ +#define arch_mmap_check metag_mmap_check +int metag_mmap_check(unsigned long addr, unsigned long len, + unsigned long flags); +#endif +#endif /* __METAG_MMAN_H__ */ diff --git a/arch/metag/include/asm/syscall.h b/arch/metag/include/asm/syscall.h new file mode 100644 index 000000000000..24fc97939f77 --- /dev/null +++ b/arch/metag/include/asm/syscall.h @@ -0,0 +1,104 @@ +/* + * Access to user system call parameters and results + * + * Copyright (C) 2008 Imagination Technologies Ltd. + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU General Public License v.2. + * + * See asm-generic/syscall.h for descriptions of what we must do here. + */ + +#ifndef _ASM_METAG_SYSCALL_H +#define _ASM_METAG_SYSCALL_H + +#include +#include +#include + +#include + +static inline long syscall_get_nr(struct task_struct *task, + struct pt_regs *regs) +{ + unsigned long insn; + + /* + * FIXME there's no way to find out how we got here other than to + * examine the memory at the PC to see if it is a syscall + * SWITCH instruction. + */ + if (get_user(insn, (unsigned long *)(regs->ctx.CurrPC - 4))) + return -1; + + if (insn == __METAG_SW_ENCODING(SYS)) + return regs->ctx.DX[0].U1; + else + return -1L; +} + +static inline void syscall_rollback(struct task_struct *task, + struct pt_regs *regs) +{ + /* do nothing */ +} + +static inline long syscall_get_error(struct task_struct *task, + struct pt_regs *regs) +{ + unsigned long error = regs->ctx.DX[0].U0; + return IS_ERR_VALUE(error) ? error : 0; +} + +static inline long syscall_get_return_value(struct task_struct *task, + struct pt_regs *regs) +{ + return regs->ctx.DX[0].U0; +} + +static inline void syscall_set_return_value(struct task_struct *task, + struct pt_regs *regs, + int error, long val) +{ + regs->ctx.DX[0].U0 = (long) error ?: val; +} + +static inline void syscall_get_arguments(struct task_struct *task, + struct pt_regs *regs, + unsigned int i, unsigned int n, + unsigned long *args) +{ + unsigned int reg, j; + BUG_ON(i + n > 6); + + for (j = i, reg = 6 - i; j < (i + n); j++, reg--) { + if (reg % 2) + args[j] = regs->ctx.DX[(reg + 1) / 2].U0; + else + args[j] = regs->ctx.DX[reg / 2].U1; + } +} + +static inline void syscall_set_arguments(struct task_struct *task, + struct pt_regs *regs, + unsigned int i, unsigned int n, + const unsigned long *args) +{ + unsigned int reg; + BUG_ON(i + n > 6); + + for (reg = 6 - i; i < (i + n); i++, reg--) { + if (reg % 2) + regs->ctx.DX[(reg + 1) / 2].U0 = args[i]; + else + regs->ctx.DX[reg / 2].U1 = args[i]; + } +} + +#define NR_syscalls __NR_syscalls + +/* generic syscall table */ +extern const void *sys_call_table[]; + +#endif /* _ASM_METAG_SYSCALL_H */ diff --git a/arch/metag/include/asm/syscalls.h b/arch/metag/include/asm/syscalls.h new file mode 100644 index 000000000000..a02b95556522 --- /dev/null +++ b/arch/metag/include/asm/syscalls.h @@ -0,0 +1,39 @@ +#ifndef _ASM_METAG_SYSCALLS_H +#define _ASM_METAG_SYSCALLS_H + +#include +#include +#include +#include + +/* kernel/signal.c */ +#define sys_rt_sigreturn sys_rt_sigreturn +asmlinkage long sys_rt_sigreturn(void); + +#include + +/* kernel/sys_metag.c */ +asmlinkage int sys_metag_setglobalbit(char __user *, int); +asmlinkage void sys_metag_set_fpu_flags(unsigned int); +asmlinkage int sys_metag_set_tls(void __user *); +asmlinkage void *sys_metag_get_tls(void); + +asmlinkage long sys_truncate64_metag(const char __user *, unsigned long, + unsigned long); +asmlinkage long sys_ftruncate64_metag(unsigned int, unsigned long, + unsigned long); +asmlinkage long sys_fadvise64_64_metag(int, unsigned long, unsigned long, + unsigned long, unsigned long, int); +asmlinkage long sys_readahead_metag(int, unsigned long, unsigned long, size_t); +asmlinkage ssize_t sys_pread64_metag(unsigned long, char __user *, size_t, + unsigned long, unsigned long); +asmlinkage ssize_t sys_pwrite64_metag(unsigned long, char __user *, size_t, + unsigned long, unsigned long); +asmlinkage long sys_sync_file_range_metag(int, unsigned long, unsigned long, + unsigned long, unsigned long, + unsigned int); + +int do_work_pending(struct pt_regs *regs, unsigned int thread_flags, + int syscall); + +#endif /* _ASM_METAG_SYSCALLS_H */ diff --git a/arch/metag/include/asm/unistd.h b/arch/metag/include/asm/unistd.h new file mode 100644 index 000000000000..32955a18fb32 --- /dev/null +++ b/arch/metag/include/asm/unistd.h @@ -0,0 +1,12 @@ +/* + * Copyright (C) 2012 Imagination Technologies Ltd. + * + * 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; either version 2 of the License, or + * (at your option) any later version. + */ + +#include + +#define __ARCH_WANT_SYS_CLONE diff --git a/arch/metag/include/asm/user_gateway.h b/arch/metag/include/asm/user_gateway.h new file mode 100644 index 000000000000..e404c09e3b74 --- /dev/null +++ b/arch/metag/include/asm/user_gateway.h @@ -0,0 +1,44 @@ +/* + * Copyright (C) 2010 Imagination Technologies + */ + +#ifndef __ASM_METAG_USER_GATEWAY_H +#define __ASM_METAG_USER_GATEWAY_H + +#include + +/* Page of kernel code accessible to userspace. */ +#define USER_GATEWAY_PAGE 0x6ffff000 +/* Offset of TLS pointer array in gateway page. */ +#define USER_GATEWAY_TLS 0x100 + +#ifndef __ASSEMBLY__ + +extern char __user_gateway_start; +extern char __user_gateway_end; + +/* Kernel mapping of the gateway page. */ +extern void *gateway_page; + +static inline void set_gateway_tls(void __user *tls_ptr) +{ + void **gateway_tls = (void **)(gateway_page + USER_GATEWAY_TLS + + hard_processor_id() * 4); + + *gateway_tls = (__force void *)tls_ptr; +#ifdef CONFIG_METAG_META12 + /* Avoid cache aliases on virtually tagged cache. */ + __builtin_dcache_flush((void *)USER_GATEWAY_PAGE + USER_GATEWAY_TLS + + hard_processor_id() * sizeof(void *)); +#endif +} + +extern int __kuser_get_tls(void); +extern char *__kuser_get_tls_end[]; + +extern int __kuser_cmpxchg(int, int, unsigned long *); +extern char *__kuser_cmpxchg_end[]; + +#endif + +#endif diff --git a/arch/metag/include/uapi/asm/unistd.h b/arch/metag/include/uapi/asm/unistd.h new file mode 100644 index 000000000000..b80b8e899d22 --- /dev/null +++ b/arch/metag/include/uapi/asm/unistd.h @@ -0,0 +1,21 @@ +/* + * Copyright (C) 2012 Imagination Technologies Ltd. + * + * 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; either version 2 of the License, or + * (at your option) any later version. + */ + +/* Use the standard ABI for syscalls. */ +#include + +/* metag-specific syscalls. */ +#define __NR_metag_setglobalbit (__NR_arch_specific_syscall + 1) +__SYSCALL(__NR_metag_setglobalbit, sys_metag_setglobalbit) +#define __NR_metag_set_fpu_flags (__NR_arch_specific_syscall + 2) +__SYSCALL(__NR_metag_set_fpu_flags, sys_metag_set_fpu_flags) +#define __NR_metag_set_tls (__NR_arch_specific_syscall + 3) +__SYSCALL(__NR_metag_set_tls, sys_metag_set_tls) +#define __NR_metag_get_tls (__NR_arch_specific_syscall + 4) +__SYSCALL(__NR_metag_get_tls, sys_metag_get_tls) diff --git a/arch/metag/kernel/sys_metag.c b/arch/metag/kernel/sys_metag.c new file mode 100644 index 000000000000..efe833a452f7 --- /dev/null +++ b/arch/metag/kernel/sys_metag.c @@ -0,0 +1,180 @@ +/* + * This file contains various random system calls that + * have a non-standard calling sequence on the Linux/Meta + * platform. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define merge_64(hi, lo) ((((unsigned long long)(hi)) << 32) + \ + ((lo) & 0xffffffffUL)) + +int metag_mmap_check(unsigned long addr, unsigned long len, + unsigned long flags) +{ + /* We can't have people trying to write to the bottom of the + * memory map, there are mysterious unspecified things there that + * we don't want people trampling on. + */ + if ((flags & MAP_FIXED) && (addr < TASK_UNMAPPED_BASE)) + return -EINVAL; + + return 0; +} + +asmlinkage long sys_mmap2(unsigned long addr, unsigned long len, + unsigned long prot, unsigned long flags, + unsigned long fd, unsigned long pgoff) +{ + /* The shift for mmap2 is constant, regardless of PAGE_SIZE setting. */ + if (pgoff & ((1 << (PAGE_SHIFT - 12)) - 1)) + return -EINVAL; + + pgoff >>= PAGE_SHIFT - 12; + + return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff); +} + +asmlinkage int sys_metag_setglobalbit(char __user *addr, int mask) +{ + char tmp; + int ret = 0; + unsigned int flags; + + if (!((__force unsigned int)addr >= LINCORE_BASE)) + return -EFAULT; + + __global_lock2(flags); + + metag_data_cache_flush((__force void *)addr, sizeof(mask)); + + ret = __get_user(tmp, addr); + if (ret) + goto out; + tmp |= mask; + ret = __put_user(tmp, addr); + + metag_data_cache_flush((__force void *)addr, sizeof(mask)); + +out: + __global_unlock2(flags); + + return ret; +} + +#define TXDEFR_FPU_MASK ((0x1f << 16) | 0x1f) + +asmlinkage void sys_metag_set_fpu_flags(unsigned int flags) +{ + unsigned int temp; + + flags &= TXDEFR_FPU_MASK; + + temp = __core_reg_get(TXDEFR); + temp &= ~TXDEFR_FPU_MASK; + temp |= flags; + __core_reg_set(TXDEFR, temp); +} + +asmlinkage int sys_metag_set_tls(void __user *ptr) +{ + current->thread.tls_ptr = ptr; + set_gateway_tls(ptr); + + return 0; +} + +asmlinkage void *sys_metag_get_tls(void) +{ + return (__force void *)current->thread.tls_ptr; +} + +asmlinkage long sys_truncate64_metag(const char __user *path, unsigned long lo, + unsigned long hi) +{ + return sys_truncate64(path, merge_64(hi, lo)); +} + +asmlinkage long sys_ftruncate64_metag(unsigned int fd, unsigned long lo, + unsigned long hi) +{ + return sys_ftruncate64(fd, merge_64(hi, lo)); +} + +asmlinkage long sys_fadvise64_64_metag(int fd, unsigned long offs_lo, + unsigned long offs_hi, + unsigned long len_lo, + unsigned long len_hi, int advice) +{ + return sys_fadvise64_64(fd, merge_64(offs_hi, offs_lo), + merge_64(len_hi, len_lo), advice); +} + +asmlinkage long sys_readahead_metag(int fd, unsigned long lo, unsigned long hi, + size_t count) +{ + return sys_readahead(fd, merge_64(hi, lo), count); +} + +asmlinkage ssize_t sys_pread64_metag(unsigned long fd, char __user *buf, + size_t count, unsigned long lo, + unsigned long hi) +{ + return sys_pread64(fd, buf, count, merge_64(hi, lo)); +} + +asmlinkage ssize_t sys_pwrite64_metag(unsigned long fd, char __user *buf, + size_t count, unsigned long lo, + unsigned long hi) +{ + return sys_pwrite64(fd, buf, count, merge_64(hi, lo)); +} + +asmlinkage long sys_sync_file_range_metag(int fd, unsigned long offs_lo, + unsigned long offs_hi, + unsigned long len_lo, + unsigned long len_hi, + unsigned int flags) +{ + return sys_sync_file_range(fd, merge_64(offs_hi, offs_lo), + merge_64(len_hi, len_lo), flags); +} + +/* Provide the actual syscall number to call mapping. */ +#undef __SYSCALL +#define __SYSCALL(nr, call) [nr] = (call), + +/* + * We need wrappers for anything with unaligned 64bit arguments + */ +#define sys_truncate64 sys_truncate64_metag +#define sys_ftruncate64 sys_ftruncate64_metag +#define sys_fadvise64_64 sys_fadvise64_64_metag +#define sys_readahead sys_readahead_metag +#define sys_pread64 sys_pread64_metag +#define sys_pwrite64 sys_pwrite64_metag +#define sys_sync_file_range sys_sync_file_range_metag + +/* + * Note that we can't include here since the header + * guard will defeat us; checks for __SYSCALL as well. + */ +const void *sys_call_table[__NR_syscalls] = { + [0 ... __NR_syscalls-1] = sys_ni_syscall, +#include +}; diff --git a/arch/metag/kernel/user_gateway.S b/arch/metag/kernel/user_gateway.S new file mode 100644 index 000000000000..7167f3e8db6b --- /dev/null +++ b/arch/metag/kernel/user_gateway.S @@ -0,0 +1,97 @@ +/* + * Copyright (C) 2010 Imagination Technologies Ltd. + * + * This file contains code that can be accessed from userspace and can + * access certain kernel data structures without the overhead of a system + * call. + */ + +#include +#include + +/* + * User helpers. + * + * These are segment of kernel provided user code reachable from user space + * at a fixed address in kernel memory. This is used to provide user space + * with some operations which require kernel help because of unimplemented + * native feature and/or instructions in some Meta CPUs. The idea is for + * this code to be executed directly in user mode for best efficiency but + * which is too intimate with the kernel counter part to be left to user + * libraries. The kernel reserves the right to change this code as needed + * without warning. Only the entry points and their results are guaranteed + * to be stable. + * + * Each segment is 64-byte aligned. This mechanism should be used only for + * for things that are really small and justified, and not be abused freely. + */ + .text + .global ___user_gateway_start +___user_gateway_start: + + /* get_tls + * Offset: 0 + * Description: Get the TLS pointer for this process. + */ + .global ___kuser_get_tls + .type ___kuser_get_tls,function +___kuser_get_tls: + MOVT D1Ar1,#HI(USER_GATEWAY_PAGE + USER_GATEWAY_TLS) + ADD D1Ar1,D1Ar1,#LO(USER_GATEWAY_PAGE + USER_GATEWAY_TLS) + MOV D1Ar3,TXENABLE + AND D1Ar3,D1Ar3,#(TXENABLE_THREAD_BITS) + LSR D1Ar3,D1Ar3,#(TXENABLE_THREAD_S - 2) + GETD D0Re0,[D1Ar1+D1Ar3] +___kuser_get_tls_end: /* Beyond this point the read will complete */ + MOV PC,D1RtP + .size ___kuser_get_tls,.-___kuser_get_tls + .global ___kuser_get_tls_end + + /* cmpxchg + * Offset: 64 + * Description: Replace the value at 'ptr' with 'newval' if the current + * value is 'oldval'. Return zero if we succeeded, + * non-zero otherwise. + * + * Reference prototype: + * + * int __kuser_cmpxchg(int oldval, int newval, unsigned long *ptr) + * + */ + .balign 64 + .global ___kuser_cmpxchg + .type ___kuser_cmpxchg,function +___kuser_cmpxchg: +#ifdef CONFIG_SMP + /* + * We must use LNKGET/LNKSET with an SMP kernel because the other method + * does not provide atomicity across multiple CPUs. + */ +0: LNKGETD D0Re0,[D1Ar3] + CMP D0Re0,D1Ar1 + LNKSETDZ [D1Ar3],D0Ar2 + BNZ 1f + DEFR D0Re0,TXSTAT + ANDT D0Re0,D0Re0,#HI(0x3f000000) + CMPT D0Re0,#HI(0x02000000) + BNE 0b +#ifdef CONFIG_METAG_LNKGET_AROUND_CACHE + DCACHE [D1Ar3], D0Re0 +#endif +1: MOV D0Re0,#1 + XORZ D0Re0,D0Re0,D0Re0 + MOV PC,D1RtP +#else + GETD D0Re0,[D1Ar3] + CMP D0Re0,D1Ar1 + SETDZ [D1Ar3],D0Ar2 +___kuser_cmpxchg_end: /* Beyond this point the write will complete */ + MOV D0Re0,#1 + XORZ D0Re0,D0Re0,D0Re0 + MOV PC,D1RtP +#endif /* CONFIG_SMP */ + .size ___kuser_cmpxchg,.-___kuser_cmpxchg + .global ___kuser_cmpxchg_end + + .global ___user_gateway_end +___user_gateway_end: -- 2.20.1