From 77bf4400319db9d2a8af6b00c2be6faa0f3d07cb Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Tue, 16 Oct 2007 01:26:58 -0700 Subject: uml: remove code made redundant by CHOOSE_MODE removal This patch makes a number of simplifications enabled by the removal of CHOOSE_MODE. There were lots of functions that looked like int foo(args){ foo_skas(args); } The bodies of foo_skas are now folded into foo, and their declarations (and sometimes entire header files) are deleted. In addition, the union uml_pt_regs, which was a union between the tt and skas register formats, is now a struct, with the tt-mode arm of the union being removed. It turns out that usr2_handler was unused, so it is gone. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/kernel/process.c | 120 ++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 99 insertions(+), 21 deletions(-) (limited to 'arch/um/kernel/process.c') diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 22ad46fd2c0..d3b9c62e73c 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -43,8 +43,7 @@ #include "frame_kern.h" #include "sigcontext.h" #include "os.h" -#include "mode.h" -#include "mode_kern.h" +#include "skas.h" /* This is a per-cpu array. A processor only modifies its entry and it only * cares about its entry, so it's OK if another processor is modifying its @@ -54,7 +53,8 @@ struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } }; static inline int external_pid(struct task_struct *task) { - return external_pid_skas(task); + /* FIXME: Need to look up userspace_pid by cpu */ + return(userspace_pid[0]); } int pid_to_processor_id(int pid) @@ -104,6 +104,8 @@ static inline void set_current(struct task_struct *task) { external_pid(task), task }); } +extern void arch_switch_to(struct task_struct *from, struct task_struct *to); + void *_switch_to(void *prev, void *next, void *last) { struct task_struct *from = prev; @@ -114,7 +116,19 @@ void *_switch_to(void *prev, void *next, void *last) do { current->thread.saved_task = NULL; - switch_to_skas(prev, next); + + /* XXX need to check runqueues[cpu].idle */ + if(current->pid == 0) + switch_timers(0); + + switch_threads(&from->thread.switch_buf, + &to->thread.switch_buf); + + arch_switch_to(current->thread.prev_sched, current); + + if(current->pid == 0) + switch_timers(1); + if(current->thread.saved_task) show_regs(&(current->thread.regs)); next= current->thread.saved_task; @@ -133,11 +147,6 @@ void interrupt_end(void) do_signal(); } -void release_thread(struct task_struct *task) -{ - release_thread_skas(task); -} - void exit_thread(void) { } @@ -147,27 +156,95 @@ void *get_current(void) return current; } +extern void schedule_tail(struct task_struct *prev); + +/* This is called magically, by its address being stuffed in a jmp_buf + * and being longjmp-d to. + */ +void new_thread_handler(void) +{ + int (*fn)(void *), n; + void *arg; + + if(current->thread.prev_sched != NULL) + schedule_tail(current->thread.prev_sched); + current->thread.prev_sched = NULL; + + fn = current->thread.request.u.thread.proc; + arg = current->thread.request.u.thread.arg; + + /* The return value is 1 if the kernel thread execs a process, + * 0 if it just exits + */ + n = run_kernel_thread(fn, arg, ¤t->thread.exec_buf); + if(n == 1){ + /* Handle any immediate reschedules or signals */ + interrupt_end(); + userspace(¤t->thread.regs.regs); + } + else do_exit(0); +} + +/* Called magically, see new_thread_handler above */ +void fork_handler(void) +{ + force_flush_all(); + if(current->thread.prev_sched == NULL) + panic("blech"); + + schedule_tail(current->thread.prev_sched); + + /* XXX: if interrupt_end() calls schedule, this call to + * arch_switch_to isn't needed. We could want to apply this to + * improve performance. -bb */ + arch_switch_to(current->thread.prev_sched, current); + + current->thread.prev_sched = NULL; + + /* Handle any immediate reschedules or signals */ + interrupt_end(); + + userspace(¤t->thread.regs.regs); +} + int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, unsigned long stack_top, struct task_struct * p, struct pt_regs *regs) { - int ret; + void (*handler)(void); + int ret = 0; p->thread = (struct thread_struct) INIT_THREAD; - ret = copy_thread_skas(nr, clone_flags, sp, stack_top, p, regs); - if (ret || !current->thread.forking) - goto out; + if(current->thread.forking){ + memcpy(&p->thread.regs.regs, ®s->regs, + sizeof(p->thread.regs.regs)); + REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.regs, 0); + if(sp != 0) + REGS_SP(p->thread.regs.regs.regs) = sp; - clear_flushed_tls(p); + handler = fork_handler; - /* - * Set a new TLS for the child thread? - */ - if (clone_flags & CLONE_SETTLS) - ret = arch_copy_tls(p); + arch_copy_thread(¤t->thread.arch, &p->thread.arch); + } + else { + init_thread_registers(&p->thread.regs.regs); + p->thread.request.u.thread = current->thread.request.u.thread; + handler = new_thread_handler; + } + + new_thread(task_stack_page(p), &p->thread.switch_buf, handler); + + if (current->thread.forking) { + clear_flushed_tls(p); + + /* + * Set a new TLS for the child thread? + */ + if (clone_flags & CLONE_SETTLS) + ret = arch_copy_tls(p); + } -out: return ret; } @@ -198,7 +275,8 @@ void default_idle(void) void cpu_idle(void) { - init_idle_skas(); + cpu_tasks[current_thread->cpu].pid = os_getpid(); + default_idle(); } void *um_virt_to_phys(struct task_struct *task, unsigned long addr, -- cgit v1.2.3