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mop3/kernel/amd64/syscall.c
kamkow1 f103bdd739
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Redesign reschedule points, allow one operation to reschedule many cpus at once
2026-02-18 23:16:03 +01:00

87 lines
2.1 KiB
C

#include <amd64/gdt.h>
#include <amd64/intr.h>
#include <amd64/mm.h>
#include <amd64/msr-index.h>
#include <amd64/msr.h>
#include <libk/list.h>
#include <libk/string.h>
#include <m/status.h>
#include <m/syscall_defs.h>
#include <mm/liballoc.h>
#include <proc/proc.h>
#include <proc/reschedule.h>
#include <sys/debug.h>
#include <sys/smp.h>
#include <syscall/syscall.h>
extern void amd64_syscall_entry (void);
uintptr_t amd64_syscall_dispatch (void* stack_ptr) {
amd64_load_kernel_cr3 ();
struct saved_regs* regs = stack_ptr;
spin_lock (&thiscpu->lock);
struct proc* caller = thiscpu->proc_current;
int caller_pid = caller->pid;
spin_lock (&caller->lock);
memcpy (&caller->pdata.regs, regs, sizeof (struct saved_regs));
spin_unlock (&caller->lock);
spin_unlock (&thiscpu->lock);
int syscall_num = regs->rax;
syscall_handler_func_t func = syscall_find_handler (syscall_num);
if (func == NULL) {
return -ST_SYSCALL_NOT_FOUND;
}
struct reschedule_ctx rctx = {.entries = NULL, .lock = SPIN_LOCK_INIT};
uintptr_t r =
func (caller, regs, &rctx, regs->rdi, regs->rsi, regs->rdx, regs->r10, regs->r8, regs->r9);
caller = proc_find_pid (caller_pid);
if (caller != NULL) {
spin_lock (&caller->lock);
caller->pdata.regs.rax = r;
spin_unlock (&caller->lock);
}
bool reschedule_thiscpu = false;
spin_lock (&rctx.lock);
struct list_node_link *node, *tmp;
list_foreach (rctx.entries, node, tmp) {
struct reschedule_entry* entry = list_entry (node, struct reschedule_entry, link);
struct cpu* cpu = entry->cpu;
if (cpu != thiscpu) {
cpu_request_sched (cpu);
} else {
reschedule_thiscpu = true;
}
list_remove (rctx.entries, &entry->link);
free (entry);
}
spin_unlock (&rctx.lock);
if (reschedule_thiscpu) {
proc_sched ();
}
return r;
}
void syscall_init (void) {
amd64_wrmsr (MSR_STAR, ((uint64_t)GDT_KCODE << 32) | ((uint64_t)(GDT_KDATA | 0x03) << 48));
amd64_wrmsr (MSR_LSTAR, (uint64_t)&amd64_syscall_entry);
amd64_wrmsr (MSR_SYSCALL_MASK, (1ULL << 9));
amd64_wrmsr (MSR_EFER, amd64_rdmsr (MSR_EFER) | EFER_SCE);
}