Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 401 insertions, 0 deletions

diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
new file mode 100644
index 000000000..08335b229
--- /dev/null
+++ b/arch/alpha/kernel/process.c
@@ -0,0 +1,401 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/arch/alpha/kernel/process.c
+ *
+ *  Copyright (C) 1995  Linus Torvalds
+ */
+
+/*
+ * This file handles the architecture-dependent parts of process handling.
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/time.h>
+#include <linux/major.h>
+#include <linux/stat.h>
+#include <linux/vt.h>
+#include <linux/mman.h>
+#include <linux/elfcore.h>
+#include <linux/reboot.h>
+#include <linux/tty.h>
+#include <linux/console.h>
+#include <linux/slab.h>
+#include <linux/rcupdate.h>
+
+#include <asm/reg.h>
+#include <linux/uaccess.h>
+#include <asm/io.h>
+#include <asm/hwrpb.h>
+#include <asm/fpu.h>
+
+#include "proto.h"
+#include "pci_impl.h"
+
+/*
+ * Power off function, if any
+ */
+void (*pm_power_off)(void) = machine_power_off;
+EXPORT_SYMBOL(pm_power_off);
+
+#ifdef CONFIG_ALPHA_WTINT
+/*
+ * Sleep the CPU.
+ * EV6, LCA45 and QEMU know how to power down, skipping N timer interrupts.
+ */
+void arch_cpu_idle(void)
+{
+	wtint(0);
+	raw_local_irq_enable();
+}
+
+void arch_cpu_idle_dead(void)
+{
+	wtint(INT_MAX);
+}
+#endif /* ALPHA_WTINT */
+
+struct halt_info {
+	int mode;
+	char *restart_cmd;
+};
+
+static void
+common_shutdown_1(void *generic_ptr)
+{
+	struct halt_info *how = (struct halt_info *)generic_ptr;
+	struct percpu_struct *cpup;
+	unsigned long *pflags, flags;
+	int cpuid = smp_processor_id();
+
+	/* No point in taking interrupts anymore. */
+	local_irq_disable();
+
+	cpup = (struct percpu_struct *)
+			((unsigned long)hwrpb + hwrpb->processor_offset
+			 + hwrpb->processor_size * cpuid);
+	pflags = &cpup->flags;
+	flags = *pflags;
+
+	/* Clear reason to "default"; clear "bootstrap in progress". */
+	flags &= ~0x00ff0001UL;
+
+#ifdef CONFIG_SMP
+	/* Secondaries halt here. */
+	if (cpuid != boot_cpuid) {
+		flags |= 0x00040000UL; /* "remain halted" */
+		*pflags = flags;
+		set_cpu_present(cpuid, false);
+		set_cpu_possible(cpuid, false);
+		halt();
+	}
+#endif
+
+	if (how->mode == LINUX_REBOOT_CMD_RESTART) {
+		if (!how->restart_cmd) {
+			flags |= 0x00020000UL; /* "cold bootstrap" */
+		} else {
+			/* For SRM, we could probably set environment
+			   variables to get this to work.  We'd have to
+			   delay this until after srm_paging_stop unless
+			   we ever got srm_fixup working.
+
+			   At the moment, SRM will use the last boot device,
+			   but the file and flags will be the defaults, when
+			   doing a "warm" bootstrap.  */
+			flags |= 0x00030000UL; /* "warm bootstrap" */
+		}
+	} else {
+		flags |= 0x00040000UL; /* "remain halted" */
+	}
+	*pflags = flags;
+
+#ifdef CONFIG_SMP
+	/* Wait for the secondaries to halt. */
+	set_cpu_present(boot_cpuid, false);
+	set_cpu_possible(boot_cpuid, false);
+	while (cpumask_weight(cpu_present_mask))
+		barrier();
+#endif
+
+	/* If booted from SRM, reset some of the original environment. */
+	if (alpha_using_srm) {
+#ifdef CONFIG_DUMMY_CONSOLE
+		/* If we've gotten here after SysRq-b, leave interrupt
+		   context before taking over the console. */
+		if (in_interrupt())
+			irq_exit();
+		/* This has the effect of resetting the VGA video origin.  */
+		console_lock();
+		do_take_over_console(&dummy_con, 0, MAX_NR_CONSOLES-1, 1);
+		console_unlock();
+#endif
+		pci_restore_srm_config();
+		set_hae(srm_hae);
+	}
+
+	if (alpha_mv.kill_arch)
+		alpha_mv.kill_arch(how->mode);
+
+	if (! alpha_using_srm && how->mode != LINUX_REBOOT_CMD_RESTART) {
+		/* Unfortunately, since MILO doesn't currently understand
+		   the hwrpb bits above, we can't reliably halt the 
+		   processor and keep it halted.  So just loop.  */
+		return;
+	}
+
+	if (alpha_using_srm)
+		srm_paging_stop();
+
+	halt();
+}
+
+static void
+common_shutdown(int mode, char *restart_cmd)
+{
+	struct halt_info args;
+	args.mode = mode;
+	args.restart_cmd = restart_cmd;
+	on_each_cpu(common_shutdown_1, &args, 0);
+}
+
+void
+machine_restart(char *restart_cmd)
+{
+	common_shutdown(LINUX_REBOOT_CMD_RESTART, restart_cmd);
+}
+
+
+void
+machine_halt(void)
+{
+	common_shutdown(LINUX_REBOOT_CMD_HALT, NULL);
+}
+
+
+void
+machine_power_off(void)
+{
+	common_shutdown(LINUX_REBOOT_CMD_POWER_OFF, NULL);
+}
+
+
+/* Used by sysrq-p, among others.  I don't believe r9-r15 are ever
+   saved in the context it's used.  */
+
+void
+show_regs(struct pt_regs *regs)
+{
+	show_regs_print_info(KERN_DEFAULT);
+	dik_show_regs(regs, NULL);
+}
+
+/*
+ * Re-start a thread when doing execve()
+ */
+void
+start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
+{
+	regs->pc = pc;
+	regs->ps = 8;
+	wrusp(sp);
+}
+EXPORT_SYMBOL(start_thread);
+
+void
+flush_thread(void)
+{
+	/* Arrange for each exec'ed process to start off with a clean slate
+	   with respect to the FPU.  This is all exceptions disabled.  */
+	current_thread_info()->ieee_state = 0;
+	wrfpcr(FPCR_DYN_NORMAL | ieee_swcr_to_fpcr(0));
+
+	/* Clean slate for TLS.  */
+	current_thread_info()->pcb.unique = 0;
+}
+
+void
+release_thread(struct task_struct *dead_task)
+{
+}
+
+/*
+ * Copy architecture-specific thread state
+ */
+int copy_thread(unsigned long clone_flags, unsigned long usp,
+		unsigned long kthread_arg, struct task_struct *p,
+		unsigned long tls)
+{
+	extern void ret_from_fork(void);
+	extern void ret_from_kernel_thread(void);
+
+	struct thread_info *childti = task_thread_info(p);
+	struct pt_regs *childregs = task_pt_regs(p);
+	struct pt_regs *regs = current_pt_regs();
+	struct switch_stack *childstack, *stack;
+
+	childstack = ((struct switch_stack *) childregs) - 1;
+	childti->pcb.ksp = (unsigned long) childstack;
+	childti->pcb.flags = 1;	/* set FEN, clear everything else */
+
+	if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
+		/* kernel thread */
+		memset(childstack, 0,
+			sizeof(struct switch_stack) + sizeof(struct pt_regs));
+		childstack->r26 = (unsigned long) ret_from_kernel_thread;
+		childstack->r9 = usp;	/* function */
+		childstack->r10 = kthread_arg;
+		childregs->hae = alpha_mv.hae_cache,
+		childti->pcb.usp = 0;
+		return 0;
+	}
+	/* Note: if CLONE_SETTLS is not set, then we must inherit the
+	   value from the parent, which will have been set by the block
+	   copy in dup_task_struct.  This is non-intuitive, but is
+	   required for proper operation in the case of a threaded
+	   application calling fork.  */
+	if (clone_flags & CLONE_SETTLS)
+		childti->pcb.unique = tls;
+	else
+		regs->r20 = 0;	/* OSF/1 has some strange fork() semantics.  */
+	childti->pcb.usp = usp ?: rdusp();
+	*childregs = *regs;
+	childregs->r0 = 0;
+	childregs->r19 = 0;
+	childregs->r20 = 1;	/* OSF/1 has some strange fork() semantics.  */
+	stack = ((struct switch_stack *) regs) - 1;
+	*childstack = *stack;
+	childstack->r26 = (unsigned long) ret_from_fork;
+	return 0;
+}
+
+/*
+ * Fill in the user structure for a ELF core dump.
+ */
+void
+dump_elf_thread(elf_greg_t *dest, struct pt_regs *pt, struct thread_info *ti)
+{
+	/* switch stack follows right below pt_regs: */
+	struct switch_stack * sw = ((struct switch_stack *) pt) - 1;
+
+	dest[ 0] = pt->r0;
+	dest[ 1] = pt->r1;
+	dest[ 2] = pt->r2;
+	dest[ 3] = pt->r3;
+	dest[ 4] = pt->r4;
+	dest[ 5] = pt->r5;
+	dest[ 6] = pt->r6;
+	dest[ 7] = pt->r7;
+	dest[ 8] = pt->r8;
+	dest[ 9] = sw->r9;
+	dest[10] = sw->r10;
+	dest[11] = sw->r11;
+	dest[12] = sw->r12;
+	dest[13] = sw->r13;
+	dest[14] = sw->r14;
+	dest[15] = sw->r15;
+	dest[16] = pt->r16;
+	dest[17] = pt->r17;
+	dest[18] = pt->r18;
+	dest[19] = pt->r19;
+	dest[20] = pt->r20;
+	dest[21] = pt->r21;
+	dest[22] = pt->r22;
+	dest[23] = pt->r23;
+	dest[24] = pt->r24;
+	dest[25] = pt->r25;
+	dest[26] = pt->r26;
+	dest[27] = pt->r27;
+	dest[28] = pt->r28;
+	dest[29] = pt->gp;
+	dest[30] = ti == current_thread_info() ? rdusp() : ti->pcb.usp;
+	dest[31] = pt->pc;
+
+	/* Once upon a time this was the PS value.  Which is stupid
+	   since that is always 8 for usermode.  Usurped for the more
+	   useful value of the thread's UNIQUE field.  */
+	dest[32] = ti->pcb.unique;
+}
+EXPORT_SYMBOL(dump_elf_thread);
+
+int
+dump_elf_task(elf_greg_t *dest, struct task_struct *task)
+{
+	dump_elf_thread(dest, task_pt_regs(task), task_thread_info(task));
+	return 1;
+}
+EXPORT_SYMBOL(dump_elf_task);
+
+int
+dump_elf_task_fp(elf_fpreg_t *dest, struct task_struct *task)
+{
+	struct switch_stack *sw = (struct switch_stack *)task_pt_regs(task) - 1;
+	memcpy(dest, sw->fp, 32 * 8);
+	return 1;
+}
+EXPORT_SYMBOL(dump_elf_task_fp);
+
+/*
+ * Return saved PC of a blocked thread.  This assumes the frame
+ * pointer is the 6th saved long on the kernel stack and that the
+ * saved return address is the first long in the frame.  This all
+ * holds provided the thread blocked through a call to schedule() ($15
+ * is the frame pointer in schedule() and $15 is saved at offset 48 by
+ * entry.S:do_switch_stack).
+ *
+ * Under heavy swap load I've seen this lose in an ugly way.  So do
+ * some extra sanity checking on the ranges we expect these pointers
+ * to be in so that we can fail gracefully.  This is just for ps after
+ * all.  -- r~
+ */
+
+static unsigned long
+thread_saved_pc(struct task_struct *t)
+{
+	unsigned long base = (unsigned long)task_stack_page(t);
+	unsigned long fp, sp = task_thread_info(t)->pcb.ksp;
+
+	if (sp > base && sp+6*8 < base + 16*1024) {
+		fp = ((unsigned long*)sp)[6];
+		if (fp > sp && fp < base + 16*1024)
+			return *(unsigned long *)fp;
+	}
+
+	return 0;
+}
+
+unsigned long
+get_wchan(struct task_struct *p)
+{
+	unsigned long schedule_frame;
+	unsigned long pc;
+	if (!p || p == current || p->state == TASK_RUNNING)
+		return 0;
+	/*
+	 * This one depends on the frame size of schedule().  Do a
+	 * "disass schedule" in gdb to find the frame size.  Also, the
+	 * code assumes that sleep_on() follows immediately after
+	 * interruptible_sleep_on() and that add_timer() follows
+	 * immediately after interruptible_sleep().  Ugly, isn't it?
+	 * Maybe adding a wchan field to task_struct would be better,
+	 * after all...
+	 */
+
+	pc = thread_saved_pc(p);
+	if (in_sched_functions(pc)) {
+		schedule_frame = ((unsigned long *)task_thread_info(p)->pcb.ksp)[6];
+		return ((unsigned long *)schedule_frame)[12];
+	}
+	return pc;
+}