minix/kernel/arch/arm/arch_system.c
Ben Gras 604046faf3 kernel: trap-dependent state restore, trace fixes
. restore state depends on how saving of state was done;
	  also remember trap style in sig context
	. actually set and restore TRACEBIT with new trap styles;
	  have to remove it once process enters kernel though, done
	  in debug trap exception handler
	. introduce MF_STEP that makes arch-specific code
	  turn on trace bit instead of setting TRACEBIT directly,
	  a bit more arch-friendly and avoids keeping precious
	  state in per-process PSW arch-dependently
2013-01-08 15:47:37 +00:00

183 lines
3.8 KiB
C

/* system dependent functions for use inside the whole kernel. */
#include "kernel/kernel.h"
#include <unistd.h>
#include <ctype.h>
#include <string.h>
#include <minix/cpufeature.h>
#include <assert.h>
#include <signal.h>
#include <machine/vm.h>
#include <minix/u64.h>
#include "archconst.h"
#include "arch_proto.h"
#include "serial.h"
#include "kernel/proc.h"
#include "kernel/debug.h"
#include "glo.h"
void * k_stacks;
static void ser_init(void);
void fpu_init(void)
{
}
void save_local_fpu(struct proc *pr, int retain)
{
}
void save_fpu(struct proc *pr)
{
}
void arch_proc_reset(struct proc *pr)
{
assert(pr->p_nr < NR_PROCS);
/* Clear process state. */
memset(&pr->p_reg, 0, sizeof(pr->p_reg));
if(iskerneln(pr->p_nr))
pr->p_reg.psr = INIT_TASK_PSR;
else
pr->p_reg.psr = INIT_PSR;
}
void arch_proc_setcontext(struct proc *p, struct stackframe_s *state,
int isuser, int trapstyle)
{
}
void arch_set_secondary_ipc_return(struct proc *p, u32_t val)
{
p->p_reg.r1 = val;
}
int restore_fpu(struct proc *pr)
{
return 0;
}
void cpu_identify(void)
{
u32_t midr;
unsigned cpu = cpuid;
asm volatile("mrc p15, 0, %[midr], c0, c0, 0 @ read MIDR\n\t"
: [midr] "=r" (midr));
cpu_info[cpu].implementer = midr >> 24;
cpu_info[cpu].variant = (midr >> 20) & 0xF;
cpu_info[cpu].arch = (midr >> 16) & 0xF;
cpu_info[cpu].part = (midr >> 4) & 0xFFF;
cpu_info[cpu].revision = midr & 0xF;
}
void arch_init(void)
{
k_stacks = (void*) &k_stacks_start;
assert(!((vir_bytes) k_stacks % K_STACK_SIZE));
#ifndef CONFIG_SMP
/*
* use stack 0 and cpu id 0 on a single processor machine, SMP
* configuration does this in smp_init() for all cpus at once
*/
tss_init(0, get_k_stack_top(0));
#endif
ser_init();
}
/*===========================================================================*
* do_ser_debug *
*===========================================================================*/
void do_ser_debug()
{
}
void arch_do_syscall(struct proc *proc)
{
/* do_ipc assumes that it's running because of the current process */
assert(proc == get_cpulocal_var(proc_ptr));
/* Make the system call, for real this time. */
proc->p_reg.retreg =
do_ipc(proc->p_reg.retreg, proc->p_reg.r1, proc->p_reg.r2);
}
reg_t svc_stack;
struct proc * arch_finish_switch_to_user(void)
{
char * stk;
struct proc * p;
#ifdef CONFIG_SMP
stk = (char *)tss[cpuid].sp0;
#else
stk = (char *)tss[0].sp0;
#endif
svc_stack = (reg_t)stk;
/* set pointer to the process to run on the stack */
p = get_cpulocal_var(proc_ptr);
*((reg_t *)stk) = (reg_t) p;
/* make sure I bit is clear in PSR so that interrupts won't be disabled
* once p's context is restored. this should not be possible.
*/
assert(!(p->p_reg.psr & PSR_I));
return p;
}
void fpu_sigcontext(struct proc *pr, struct sigframe *fr, struct sigcontext *sc)
{
}
reg_t arch_get_sp(struct proc *p) { return p->p_reg.sp; }
void get_randomness(struct k_randomness *rand, int source)
{
}
static void ser_init(void)
{
}
/*===========================================================================*/
/* __switch_address_space */
/*===========================================================================*/
/*
* sets the ttbr register to the supplied value if it is not already set to the
* same value in which case it would only result in an extra TLB flush which is
* not desirable
*/
void __switch_address_space(struct proc *p, struct proc **__ptproc)
{
reg_t orig_ttbr, new_ttbr;
new_ttbr = p->p_seg.p_ttbr;
if (new_ttbr == 0)
return;
orig_ttbr = read_ttbr0();
/*
* test if ttbr is loaded with the current value to avoid unnecessary
* TLB flushes
*/
if (new_ttbr == orig_ttbr)
return;
refresh_tlb();
write_ttbr0(new_ttbr);
*__ptproc = p;
return;
}