^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Process creation support for Hexagon
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/sched/debug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/sched/task.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/sched/task_stack.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/tick.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/tracehook.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * Program thread launch. Often defined as a macro in processor.h,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * but we're shooting for a small footprint and it's not an inner-loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * performance-critical operation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * The Hexagon ABI specifies that R28 is zero'ed before program launch,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * so that gets automatically done here. If we ever stop doing that here,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * we'll probably want to define the ELF_PLAT_INIT macro.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) /* We want to zero all data-containing registers. Is this overkill? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) memset(regs, 0, sizeof(*regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) /* We might want to also zero all Processor registers here */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) pt_set_usermode(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) pt_set_elr(regs, pc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) pt_set_rte_sp(regs, sp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * Spin, or better still, do a hardware or VM wait instruction
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * If hardware or VM offer wait termination even though interrupts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * are disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) void arch_cpu_idle(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) __vmwait();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) /* interrupts wake us up, but irqs are still disabled */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) raw_local_irq_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) * Copy architecture-specific thread state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) struct task_struct *p, unsigned long tls)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) struct thread_info *ti = task_thread_info(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) struct hexagon_switch_stack *ss;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) struct pt_regs *childregs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) asmlinkage void ret_from_fork(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) childregs = (struct pt_regs *) (((unsigned long) ti + THREAD_SIZE) -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) sizeof(*childregs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) ti->regs = childregs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) * Establish kernel stack pointer and initial PC for new thread
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) * Note that unlike the usual situation, we do not copy the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * parent's callee-saved here; those are in pt_regs and whatever
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) * we leave here will be overridden on return to userland.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) ss = (struct hexagon_switch_stack *) ((unsigned long) childregs -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) sizeof(*ss));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) ss->lr = (unsigned long)ret_from_fork;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) p->thread.switch_sp = ss;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) if (unlikely(p->flags & PF_KTHREAD)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) memset(childregs, 0, sizeof(struct pt_regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) /* r24 <- fn, r25 <- arg */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) ss->r24 = usp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) ss->r25 = arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) pt_set_kmode(childregs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) memcpy(childregs, current_pt_regs(), sizeof(*childregs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) ss->r2524 = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) if (usp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) pt_set_rte_sp(childregs, usp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) /* Child sees zero return value */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) childregs->r00 = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) * The clone syscall has the C signature:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) * int [r0] clone(int flags [r0],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) * void *child_frame [r1],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * void *parent_tid [r2],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) * void *child_tid [r3],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * void *thread_control_block [r4]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) * ugp is used to provide TLS support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) if (clone_flags & CLONE_SETTLS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) childregs->ugp = tls;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) * Parent sees new pid -- not necessary, not even possible at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) * this point in the fork process
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) * Might also want to set things like ti->addr_limit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) * Release any architecture-specific resources locked by thread
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) void release_thread(struct task_struct *dead_task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) * Some archs flush debug and FPU info here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) void flush_thread(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) * The "wait channel" terminology is archaic, but what we want
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) * is an identification of the point at which the scheduler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) * was invoked by a blocked thread.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) unsigned long get_wchan(struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) unsigned long fp, pc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) unsigned long stack_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) int count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) if (!p || p == current || p->state == TASK_RUNNING)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) stack_page = (unsigned long)task_stack_page(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) fp = ((struct hexagon_switch_stack *)p->thread.switch_sp)->fp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) if (fp < (stack_page + sizeof(struct thread_info)) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) fp >= (THREAD_SIZE - 8 + stack_page))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) pc = ((unsigned long *)fp)[1];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) if (!in_sched_functions(pc))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) return pc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) fp = *(unsigned long *) fp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) } while (count++ < 16);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) * Called on the exit path of event entry; see vm_entry.S
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) * Interrupts will already be disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) * Returns 0 if there's no need to re-check for more work.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) int do_work_pending(struct pt_regs *regs, u32 thread_info_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) if (!(thread_info_flags & _TIF_WORK_MASK)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) } /* shortcut -- no work to be done */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) local_irq_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) if (thread_info_flags & _TIF_NEED_RESCHED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) schedule();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) if (thread_info_flags & _TIF_SIGPENDING) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) do_signal(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) if (thread_info_flags & _TIF_NOTIFY_RESUME) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) tracehook_notify_resume(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) /* Should not even reach here */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) panic("%s: bad thread_info flags 0x%08x\n", __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) thread_info_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
3 Commits
0 Branches
0 Tags
| Donate