diff options
| -rw-r--r-- | arch/c6x/include/asm/processor.h | 132 | ||||
| -rw-r--r-- | arch/c6x/include/asm/thread_info.h | 121 | ||||
| -rw-r--r-- | arch/c6x/kernel/process.c | 263 | ||||
| -rw-r--r-- | arch/c6x/kernel/switch_to.S | 74 |
4 files changed, 590 insertions, 0 deletions
diff --git a/arch/c6x/include/asm/processor.h b/arch/c6x/include/asm/processor.h new file mode 100644 index 0000000..8154c4e --- /dev/null +++ b/arch/c6x/include/asm/processor.h @@ -0,0 +1,132 @@ +/* + * Port on Texas Instruments TMS320C6x architecture + * + * Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated + * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com) + * + * Updated for 2.6.34: Mark Salter <msalter@redhat.com> + * + * 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. + */ +#ifndef _ASM_C6X_PROCESSOR_H +#define _ASM_C6X_PROCESSOR_H + +#include <asm/ptrace.h> +#include <asm/page.h> +#include <asm/current.h> + +/* + * Default implementation of macro that returns current + * instruction pointer ("program counter"). + */ +#define current_text_addr() \ +({ \ + void *__pc; \ + asm("mvc .S2 pce1,%0\n" : "=b"(__pc)); \ + __pc; \ +}) + +/* + * User space process size. This is mostly meaningless for NOMMU + * but some C6X processors may have RAM addresses up to 0xFFFFFFFF. + * Since calls like mmap() can return an address or an error, we + * have to allow room for error returns when code does something + * like: + * + * addr = do_mmap(...) + * if ((unsigned long)addr >= TASK_SIZE) + * ... its an error code, not an address ... + * + * Here, we allow for 4096 error codes which means we really can't + * use the last 4K page on systems with RAM extending all the way + * to the end of the 32-bit address space. + */ +#define TASK_SIZE 0xFFFFF000 + +/* + * This decides where the kernel will search for a free chunk of vm + * space during mmap's. We won't be using it + */ +#define TASK_UNMAPPED_BASE 0 + +struct thread_struct { + unsigned long long b15_14; + unsigned long long a15_14; + unsigned long long b13_12; + unsigned long long a13_12; + unsigned long long b11_10; + unsigned long long a11_10; + unsigned long long ricl_icl; + unsigned long usp; /* user stack pointer */ + unsigned long pc; /* kernel pc */ + unsigned long wchan; +}; + +#define INIT_THREAD \ +{ \ + .usp = 0, \ + .wchan = 0, \ +} + +#define INIT_MMAP { \ + &init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, \ + NULL, NULL } + +#define task_pt_regs(task) \ + ((struct pt_regs *)(THREAD_START_SP + task_stack_page(task)) - 1) + +#define alloc_kernel_stack() __get_free_page(GFP_KERNEL) +#define free_kernel_stack(page) free_page((page)) + + +/* Forward declaration, a strange C thing */ +struct task_struct; + +extern void start_thread(struct pt_regs *regs, unsigned int pc, + unsigned long usp); + +/* 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) + +/* + * saved PC of a blocked thread. + */ +#define thread_saved_pc(tsk) (task_pt_regs(tsk)->pc) + +/* + * saved kernel SP and DP of a blocked thread. + */ +#ifdef _BIG_ENDIAN +#define thread_saved_ksp(tsk) \ + (*(unsigned long *)&(tsk)->thread.b15_14) +#define thread_saved_dp(tsk) \ + (*(((unsigned long *)&(tsk)->thread.b15_14) + 1)) +#else +#define thread_saved_ksp(tsk) \ + (*(((unsigned long *)&(tsk)->thread.b15_14) + 1)) +#define thread_saved_dp(tsk) \ + (*(unsigned long *)&(tsk)->thread.b15_14) +#endif + +extern unsigned long get_wchan(struct task_struct *p); + +#define KSTK_EIP(tsk) (task_pt_regs(task)->pc) +#define KSTK_ESP(tsk) (task_pt_regs(task)->sp) + +#define cpu_relax() do { } while (0) + +extern const struct seq_operations cpuinfo_op; + +#endif /* ASM_C6X_PROCESSOR_H */ diff --git a/arch/c6x/include/asm/thread_info.h b/arch/c6x/include/asm/thread_info.h new file mode 100644 index 0000000..fd99148 --- /dev/null +++ b/arch/c6x/include/asm/thread_info.h @@ -0,0 +1,121 @@ +/* + * Port on Texas Instruments TMS320C6x architecture + * + * Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated + * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com) + * + * Updated for 2.6.3x: Mark Salter <msalter@redhat.com> + * + * 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. + */ +#ifndef _ASM_C6X_THREAD_INFO_H +#define _ASM_C6X_THREAD_INFO_H + +#ifdef __KERNEL__ + +#include <asm/page.h> + +#ifdef CONFIG_4KSTACKS +#define THREAD_SIZE 4096 +#define THREAD_SHIFT 12 +#define THREAD_ORDER 0 +#else +#define THREAD_SIZE 8192 +#define THREAD_SHIFT 13 +#define THREAD_ORDER 1 +#endif + +#define THREAD_START_SP (THREAD_SIZE - 8) + +#ifndef __ASSEMBLY__ + +typedef struct { + unsigned long seg; +} mm_segment_t; + +/* + * low level task data. + */ +struct thread_info { + struct task_struct *task; /* main task structure */ + struct exec_domain *exec_domain; /* execution domain */ + unsigned long flags; /* low level flags */ + int cpu; /* cpu we're on */ + int preempt_count; /* 0 = preemptable, <0 = BUG */ + mm_segment_t addr_limit; /* thread address space */ + struct restart_block restart_block; +}; + +/* + * macros/functions for gaining access to the thread information structure + * + * preempt_count needs to be 1 initially, until the scheduler is functional. + */ +#define INIT_THREAD_INFO(tsk) \ +{ \ + .task = &tsk, \ + .exec_domain = &default_exec_domain, \ + .flags = 0, \ + .cpu = 0, \ + .preempt_count = INIT_PREEMPT_COUNT, \ + .addr_limit = KERNEL_DS, \ + .restart_block = { \ + .fn = do_no_restart_syscall, \ + }, \ +} + +#define init_thread_info (init_thread_union.thread_info) +#define init_stack (init_thread_union.stack) + +/* get the thread information struct of current task */ +static inline __attribute__((const)) +struct thread_info *current_thread_info(void) +{ + struct thread_info *ti; + asm volatile (" clr .s2 B15,0,%1,%0\n" + : "=b" (ti) + : "Iu5" (THREAD_SHIFT - 1)); + return ti; +} + +#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR + +/* thread information allocation */ +#ifdef CONFIG_DEBUG_STACK_USAGE +#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO) +#else +#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK) +#endif + +#define alloc_thread_info_node(tsk, node) \ + ((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER)) + +#define free_thread_info(ti) free_pages((unsigned long) (ti), THREAD_ORDER) +#define get_thread_info(ti) get_task_struct((ti)->task) +#define put_thread_info(ti) put_task_struct((ti)->task) +#endif /* __ASSEMBLY__ */ + +#define PREEMPT_ACTIVE 0x10000000 + +/* + * thread information flag bit numbers + * - pending work-to-be-done flags are in LSW + * - other flags in MSW + */ +#define TIF_SYSCALL_TRACE 0 /* syscall trace active */ +#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */ +#define TIF_SIGPENDING 2 /* signal pending */ +#define TIF_NEED_RESCHED 3 /* rescheduling necessary */ +#define TIF_RESTORE_SIGMASK 4 /* restore signal mask in do_signal() */ + +#define TIF_POLLING_NRFLAG 16 /* true if polling TIF_NEED_RESCHED */ +#define TIF_MEMDIE 17 /* OOM killer killed process */ + +#define TIF_WORK_MASK 0x00007FFE /* work on irq/exception return */ +#define TIF_ALLWORK_MASK 0x00007FFF /* work on any return to u-space */ + +#endif /* __KERNEL__ */ + +#endif /* _ASM_C6X_THREAD_INFO_H */ diff --git a/arch/c6x/kernel/process.c b/arch/c6x/kernel/process.c new file mode 100644 index 0000000..aa65c87 --- /dev/null +++ b/arch/c6x/kernel/process.c @@ -0,0 +1,263 @@ +/* + * Port on Texas Instruments TMS320C6x architecture + * + * Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated + * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com) + * + * 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. + * + */ +#include <linux/module.h> +#include <linux/unistd.h> +#include <linux/ptrace.h> +#include <linux/init_task.h> +#include <linux/tick.h> +#include <linux/mqueue.h> +#include <linux/syscalls.h> +#include <linux/reboot.h> + +#include <asm/syscalls.h> + +/* hooks for board specific support */ +void (*c6x_restart)(void); +void (*c6x_halt)(void); + +extern asmlinkage void ret_from_fork(void); + +static struct signal_struct init_signals = INIT_SIGNALS(init_signals); +static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand); + +/* + * Initial thread structure. + */ +union thread_union init_thread_union __init_task_data = { + INIT_THREAD_INFO(init_task) +}; + +/* + * Initial task structure. + */ +struct task_struct init_task = INIT_TASK(init_task); +EXPORT_SYMBOL(init_task); + +/* + * power off function, if any + */ +void (*pm_power_off)(void); +EXPORT_SYMBOL(pm_power_off); + +static void c6x_idle(void) +{ + unsigned long tmp; + + /* + * Put local_irq_enable and idle in same execute packet + * to make them atomic and avoid race to idle with + * interrupts enabled. + */ + asm volatile (" mvc .s2 CSR,%0\n" + " or .d2 1,%0,%0\n" + " mvc .s2 %0,CSR\n" + "|| idle\n" + : "=b"(tmp)); +} + +/* + * The idle loop for C64x + */ +void cpu_idle(void) +{ + /* endless idle loop with no priority at all */ + while (1) { + tick_nohz_stop_sched_tick(1); + while (1) { + local_irq_disable(); + if (need_resched()) { + local_irq_enable(); + break; + } + c6x_idle(); /* enables local irqs */ + } + tick_nohz_restart_sched_tick(); + + preempt_enable_no_resched(); + schedule(); + preempt_disable(); + } +} + +static void halt_loop(void) +{ + printk(KERN_EMERG "System Halted, OK to turn off power\n"); + local_irq_disable(); + while (1) + asm volatile("idle\n"); +} + +void machine_restart(char *__unused) +{ + if (c6x_restart) + c6x_restart(); + halt_loop(); +} + +void machine_halt(void) +{ + if (c6x_halt) + c6x_halt(); + halt_loop(); +} + +void machine_power_off(void) +{ + if (pm_power_off) + pm_power_off(); + halt_loop(); +} + +static void kernel_thread_helper(int dummy, void *arg, int (*fn)(void *)) +{ + do_exit(fn(arg)); +} + +/* + * Create a kernel thread + */ +int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) +{ + struct pt_regs regs; + + /* + * copy_thread sets a4 to zero (child return from fork) + * so we can't just set things up to directly return to + * fn. + */ + memset(®s, 0, sizeof(regs)); + regs.b4 = (unsigned long) arg; + regs.a6 = (unsigned long) fn; + regs.pc = (unsigned long) kernel_thread_helper; + local_save_flags(regs.csr); + regs.csr |= 1; + regs.tsr = 5; /* Set GEE and GIE in TSR */ + + /* Ok, create the new process.. */ + return do_fork(flags | CLONE_VM | CLONE_UNTRACED, -1, ®s, + 0, NULL, NULL); +} +EXPORT_SYMBOL(kernel_thread); + +void flush_thread(void) +{ +} + +void exit_thread(void) +{ +} + +SYSCALL_DEFINE1(c6x_clone, struct pt_regs *, regs) +{ + unsigned long clone_flags; + unsigned long newsp; + + /* syscall puts clone_flags in A4 and usp in B4 */ + clone_flags = regs->orig_a4; + if (regs->b4) + newsp = regs->b4; + else + newsp = regs->sp; + + return do_fork(clone_flags, newsp, regs, 0, (int __user *)regs->a6, + (int __user *)regs->b6); +} + +/* + * Do necessary setup to start up a newly executed thread. + */ +void start_thread(struct pt_regs *regs, unsigned int pc, unsigned long usp) +{ + /* + * The binfmt loader will setup a "full" stack, but the C6X + * operates an "empty" stack. So we adjust the usp so that + * argc doesn't get destroyed if an interrupt is taken before + * it is read from the stack. + * + * NB: Library startup code needs to match this. + */ + usp -= 8; + + set_fs(USER_DS); + regs->pc = pc; + regs->sp = usp; + regs->tsr |= 0x40; /* set user mode */ + current->thread.usp = usp; +} + +/* + * Copy a new thread context in its stack. + */ +int copy_thread(unsigned long clone_flags, unsigned long usp, + unsigned long ustk_size, + struct task_struct *p, struct pt_regs *regs) +{ + struct pt_regs *childregs; + + childregs = task_pt_regs(p); + + *childregs = *regs; + childregs->a4 = 0; + + if (usp == -1) + /* case of __kernel_thread: we return to supervisor space */ + childregs->sp = (unsigned long)(childregs + 1); + else + /* Otherwise use the given stack */ + childregs->sp = usp; + + /* Set usp/ksp */ + p->thread.usp = childregs->sp; + /* switch_to uses stack to save/restore 14 callee-saved regs */ + thread_saved_ksp(p) = (unsigned long)childregs - 8; + p->thread.pc = (unsigned int) ret_from_fork; + p->thread.wchan = (unsigned long) ret_from_fork; +#ifdef __DSBT__ + { + unsigned long dp; + + asm volatile ("mv .S2 b14,%0\n" : "=b"(dp)); + + thread_saved_dp(p) = dp; + if (usp == -1) + childregs->dp = dp; + } +#endif + return 0; +} + +/* + * c6x_execve() executes a new program. + */ +SYSCALL_DEFINE4(c6x_execve, const char __user *, name, + const char __user *const __user *, argv, + const char __user *const __user *, envp, + struct pt_regs *, regs) +{ + int error; + char *filename; + + filename = getname(name); + error = PTR_ERR(filename); + if (IS_ERR(filename)) + goto out; + + error = do_execve(filename, argv, envp, regs); + putname(filename); +out: + return error; +} + +unsigned long get_wchan(struct task_struct *p) +{ + return p->thread.wchan; +} diff --git a/arch/c6x/kernel/switch_to.S b/arch/c6x/kernel/switch_to.S new file mode 100644 index 0000000..09177ed --- /dev/null +++ b/arch/c6x/kernel/switch_to.S @@ -0,0 +1,74 @@ +/* + * Copyright (C) 2011 Texas Instruments Incorporated + * Author: Mark Salter (msalter@redhat.com) + * + * 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. + */ + +#include <linux/linkage.h> +#include <asm/asm-offsets.h> + +#define SP B15 + + /* + * void __switch_to(struct thread_info *prev, + * struct thread_info *next, + * struct task_struct *tsk) ; + */ +ENTRY(__switch_to) + LDDW .D2T2 *+B4(THREAD_B15_14),B7:B6 + || MV .L2X A4,B5 ; prev + || MV .L1X B4,A5 ; next + || MVC .S2 RILC,B1 + + STW .D2T2 B3,*+B5(THREAD_PC) + || STDW .D1T1 A13:A12,*+A4(THREAD_A13_12) + || MVC .S2 ILC,B0 + + LDW .D2T2 *+B4(THREAD_PC),B3 + || LDDW .D1T1 *+A5(THREAD_A13_12),A13:A12 + + STDW .D1T1 A11:A10,*+A4(THREAD_A11_10) + || STDW .D2T2 B1:B0,*+B5(THREAD_RICL_ICL) +#ifndef __DSBT__ + || MVKL .S2 current_ksp,B1 +#endif + + STDW .D2T2 B15:B14,*+B5(THREAD_B15_14) + || STDW .D1T1 A15:A14,*+A4(THREAD_A15_14) +#ifndef __DSBT__ + || MVKH .S2 current_ksp,B1 +#endif + + ;; Switch to next SP + MV .S2 B7,SP +#ifdef __DSBT__ + || STW .D2T2 B7,*+B14(current_ksp) +#else + || STW .D2T2 B7,*B1 + || MV .L2 B6,B14 +#endif + || LDDW .D1T1 *+A5(THREAD_RICL_ICL),A1:A0 + + STDW .D2T2 B11:B10,*+B5(THREAD_B11_10) + || LDDW .D1T1 *+A5(THREAD_A15_14),A15:A14 + + STDW .D2T2 B13:B12,*+B5(THREAD_B13_12) + || LDDW .D1T1 *+A5(THREAD_A11_10),A11:A10 + + B .S2 B3 ; return in next E1 + || LDDW .D2T2 *+B4(THREAD_B13_12),B13:B12 + + LDDW .D2T2 *+B4(THREAD_B11_10),B11:B10 + NOP + + MV .L2X A0,B0 + || MV .S1 A6,A4 + + MVC .S2 B0,ILC + || MV .L2X A1,B1 + + MVC .S2 B1,RILC +ENDPROC(__switch_to) |
