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// SPDX-License-Identifier: GPL-2.0
#include <linux/cpumask.h>
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include <linux/mutex.h>
#include <linux/panic.h>
#include <linux/smp.h>
#include <linux/threads.h>
#include <as-layout.h>
#include <mem.h>
#include <os.h>
#include <skas.h>
#include <mm_id.h>
struct nommu_runner {
struct mm_id mm_id;
struct mutex turnstile;
};
static struct nommu_runner nommu_runners[NR_CPUS];
static struct nommu_runner *this_runner(void)
{
return &nommu_runners[raw_smp_processor_id()];
}
struct mutex *__get_turnstile(struct mm_id *mm_id)
{
return &container_of(mm_id, struct nommu_runner, mm_id)->turnstile;
}
void enter_turnstile(struct mm_id *mm_id)
{
mutex_lock(__get_turnstile(mm_id));
}
void exit_turnstile(struct mm_id *mm_id)
{
mutex_unlock(__get_turnstile(mm_id));
}
unsigned long current_stub_stack(void)
{
return this_runner()->mm_id.stack;
}
struct mm_id *current_mm_id(void)
{
return &this_runner()->mm_id;
}
void current_mm_sync(void)
{
}
static int __init nommu_start_runners(void)
{
unsigned long long offset;
struct nommu_runner *r;
int cpu, err, fd;
fd = phys_mapping(uml_reserved - uml_physmem, &offset);
for_each_possible_cpu(cpu) {
r = &nommu_runners[cpu];
mutex_init(&r->turnstile);
r->mm_id.stack = __get_free_pages(GFP_KERNEL | __GFP_ZERO,
ilog2(STUB_DATA_PAGES));
if (!r->mm_id.stack)
panic("OOM allocating userspace stack for CPU %d", cpu);
err = start_userspace(&r->mm_id);
if (err < 0)
panic("userspace startup for CPU %d failed: %d",
cpu, err);
map(&r->mm_id, uml_reserved, high_physmem - uml_reserved,
UM_PROT_READ | UM_PROT_WRITE | UM_PROT_EXEC, fd, offset);
err = syscall_stub_flush(&r->mm_id);
if (err < 0)
panic("physmem map/flush failed for CPU%d: %d",
cpu, err);
}
return 0;
}
arch_initcall(nommu_start_runners);
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