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arch/x86_64:g_current_regs is only used to determine if we are in irq,

Browse source 
with other functionalities removed.

Signed-off-by: liwenxiang1 <liwenxiang1@xiaomi.com>
This commit is contained in:
liwenxiang1 2024-12-06 16:25:39 +08:00 committed by Xiang Xiao
parent ce920f9e93
commit 4612185cd6
5 changed files with 44 additions and 204 deletions
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7
arch/x86_64/src/common/x86_64_internal.h
View file

@ -122,13 +122,6 @@
#define getreg32(p) inl(p)
#define putreg32(v,p) outl(v,p)
/* Macros to handle saving and restore interrupt state. In the current
* model, the state is copied from the stack to the TCB, but only a
* referenced is passed to get the state from the TCB.
*/
#define x86_64_restorestate(regs) (up_set_current_regs(regs))
/* ISR/IRQ stack size */
#if CONFIG_ARCH_INTERRUPTSTACK == 0

4
arch/x86_64/src/common/x86_64_switchcontext.c
View file

@ -74,10 +74,6 @@ void up_switch_context(struct tcb_s *tcb, struct tcb_s *rtcb)
/* Restore addition x86_64 state */
x86_64_restore_auxstate(tcb);
/* Update current regs to signal that we need context switch */
x86_64_restorestate(tcb->xcp.regs);
}
/* We are not in an interrupt handler. Copy the user C context

53
arch/x86_64/src/intel64/intel64_handlers.c
View file

@ -81,6 +81,7 @@ static uint64_t *common_handler(int irq, uint64_t *regs)
/* Deliver the IRQ */
irq_dispatch(irq, regs);
tcb = this_task();
/* Check for a context switch. If a context switch occurred, then
* g_current_regs will have a different value than it did on entry. If an
@ -88,7 +89,7 @@ static uint64_t *common_handler(int irq, uint64_t *regs)
* correct address environment before returning from the interrupt.
*/
if (regs != up_current_regs())
if (*running_task != tcb)
{
tcb = this_task();
@ -119,20 +120,12 @@ static uint64_t *common_handler(int irq, uint64_t *regs)
restore_critical_section(tcb, this_cpu());
}
/* If a context switch occurred while processing the interrupt then
* g_current_regs may have change value. If we return any value different
* from the input regs, then the lower level will know that a context
* switch occurred during interrupt processing.
*/
regs = (uint64_t *)up_current_regs();
/* Set g_current_regs to NULL to indicate that we are no longer in an
* interrupt handler.
*/
up_set_current_regs(NULL);
return regs;
return tcb->xcp.regs;
}
#endif
@ -151,6 +144,7 @@ static uint64_t *common_handler(int irq, uint64_t *regs)
uint64_t *isr_handler(uint64_t *regs, uint64_t irq)
{
struct tcb_s **running_task = &g_running_tasks[this_cpu()];
struct tcb_s *tcb;
if (*running_task != NULL)
{
@ -196,16 +190,49 @@ uint64_t *isr_handler(uint64_t *regs, uint64_t irq)
break;
}
/* Maybe we need a context switch */
tcb = this_task();
regs = (uint64_t *)up_current_regs();
/* Check for a context switch. If a context switch occurred, then
* g_current_regs will have a different value than it did on entry. If an
* interrupt level context switch has occurred, then the establish the
* correct address environment before returning from the interrupt.
*/
if (*running_task != tcb)
{
#ifdef CONFIG_ARCH_ADDRENV
/* Make sure that the address environment for the previously
* running task is closed down gracefully (data caches dump,
* MMU flushed) and set up the address environment for the new
* thread at the head of the ready-to-run list.
*/
addrenv_switch(NULL);
#endif
/* Update scheduler parameters */
nxsched_suspend_scheduler(*running_task);
nxsched_resume_scheduler(tcb);
/* Record the new "running" task when context switch occurred.
* g_running_tasks[] is only used by assertion logic for reporting
* crashes.
*/
*running_task = tcb;
/* Restore the cpu lock */
restore_critical_section(tcb, this_cpu());
}
/* Set g_current_regs to NULL to indicate that we are no longer in an
* interrupt handler.
*/
up_set_current_regs(NULL);
return regs;
return tcb->xcp.regs;
#endif
}

171
arch/x86_64/src/intel64/intel64_schedulesigaction.c
View file

@ -72,187 +72,21 @@
*
****************************************************************************/
#ifndef CONFIG_SMP
void up_schedule_sigaction(struct tcb_s *tcb)
{
sinfo("tcb=%p, rtcb=%p current_regs=%p\n", tcb,
this_task(), up_current_regs());
/* First, handle some special cases when the signal is being delivered
* to the currently executing task.
*/
if (tcb == this_task())
{
/* CASE 1: We are not in an interrupt handler and a task is
* signalling itself for some reason.
*/
if (!up_current_regs())
{
/* In this case just deliver the signal with a function call
* now.
*/
(tcb->sigdeliver)(tcb);
tcb->sigdeliver = NULL;
}
/* CASE 2: We are in an interrupt handler AND the interrupted task
* is the same as the one that must receive the signal, then we
* will have to modify the return state as well as the state in the
* TCB.
*
* Hmmm... there looks like a latent bug here: The following logic
* would fail in the strange case where we are in an interrupt
* handler, the thread is signalling itself, but a context switch
* to another task has occurred so that current_regs does not
* refer to the thread of this_task()!
*/
else
{
/* Save the return lr and cpsr and one scratch register. These
* will be restored by the signal trampoline after the signals
* have been delivered.
*/
tcb->xcp.saved_rip = up_current_regs()[REG_RIP];
tcb->xcp.saved_rsp = up_current_regs()[REG_RSP];
tcb->xcp.saved_rflags = up_current_regs()[REG_RFLAGS];
/* Then set up to vector to the trampoline with interrupts
* disabled
*/
up_current_regs()[REG_RIP] = (uint64_t)x86_64_sigdeliver;
up_current_regs()[REG_RSP] = up_current_regs()[REG_RSP] - 8;
up_current_regs()[REG_RFLAGS] = 0;
#ifdef CONFIG_ARCH_KERNEL_STACK
/* Update segments to kernel segments */
up_current_regs()[REG_SS] = tcb->xcp.regs[REG_SS];
up_current_regs()[REG_CS] = tcb->xcp.regs[REG_CS];
up_current_regs()[REG_DS] = tcb->xcp.regs[REG_DS];
/* Update RSP to kernel stack */
up_current_regs()[REG_RSP] = (uint64_t)x86_64_get_ktopstk();
#endif
}
}
/* Otherwise, we are (1) signaling a task is not running
* from an interrupt handler or (2) we are not in an
* interrupt handler and the running task is signalling
* some non-running task.
*/
else
{
/* Save the return lr and cpsr and one scratch register
* These will be restored by the signal trampoline after
* the signals have been delivered.
*/
tcb->xcp.saved_rip = tcb->xcp.regs[REG_RIP];
tcb->xcp.saved_rsp = tcb->xcp.regs[REG_RSP];
tcb->xcp.saved_rflags = tcb->xcp.regs[REG_RFLAGS];
/* Then set up to vector to the trampoline with interrupts
* disabled
*/
tcb->xcp.regs[REG_RIP] = (uint64_t)x86_64_sigdeliver;
tcb->xcp.regs[REG_RSP] = tcb->xcp.regs[REG_RSP] - 8;
tcb->xcp.regs[REG_RFLAGS] = 0;
}
}
#else /* !CONFIG_SMP */
void up_schedule_sigaction(struct tcb_s *tcb)
{
int cpu;
int me;
sinfo("tcb=%p, rtcb=%p current_regs=%p\n", tcb,
this_task(), up_current_regs());
this_task(), this_task()->xcp.regs);
/* First, handle some special cases when the signal is being delivered
* to task that is currently executing on any CPU.
*/
if (tcb->task_state == TSTATE_TASK_RUNNING)
if (tcb == this_task() && !up_interrupt_context())
{
me = this_cpu();
cpu = tcb->cpu;
/* CASE 1: We are not in an interrupt handler and a task is
* signaling itself for some reason.
*/
if (cpu == me && !up_current_regs())
{
/* In this case just deliver the signal now.
* REVISIT: Signal handler will run in a critical section!
*/
(tcb->sigdeliver)(tcb);
tcb->sigdeliver = NULL;
}
/* CASE 2: The task that needs to receive the signal is running.
* This could happen if the task is running on another CPU OR if
* we are in an interrupt handler and the task is running on this
* CPU. In the former case, we will have to PAUSE the other CPU
* first. But in either case, we will have to modify the return
* state as well as the state in the TCB.
*/
else
{
/* tcb is running on the same CPU */
/* Save the return lr and cpsr and one scratch register.
* These will be restored by the signal trampoline after
* the signals have been delivered.
*/
tcb->xcp.saved_rip = up_current_regs()[REG_RIP];
tcb->xcp.saved_rsp = up_current_regs()[REG_RSP];
tcb->xcp.saved_rflags = up_current_regs()[REG_RFLAGS];
/* Then set up to vector to the trampoline with interrupts
* disabled
*/
up_current_regs()[REG_RIP] = (uint64_t)x86_64_sigdeliver;
up_current_regs()[REG_RSP] = up_current_regs()[REG_RSP] - 8;
up_current_regs()[REG_RFLAGS] = 0;
#ifdef CONFIG_ARCH_KERNEL_STACK
/* Update segments to kernel segments */
up_current_regs()[REG_SS] = tcb->xcp.regs[REG_SS];
up_current_regs()[REG_CS] = tcb->xcp.regs[REG_CS];
up_current_regs()[REG_DS] = tcb->xcp.regs[REG_DS];
/* Update RSP to kernel stack */
up_current_regs()[REG_RSP] =
(uint64_t)x86_64_get_ktopstk();
#endif
/* Mark that full context switch is necessary when we
* return from interrupt handler.
* In that case RIP, RSP and RFLAGS are changed, but
* register area pointer remains the same, so we need an
* additional variable to signal the need for full context switch
*/
tcb->xcp.regs[REG_AUX] = REG_AUX_FULLCONTEXT;
}
}
/* Otherwise, we are (1) signaling a task is not running from an
* interrupt handler or (2) we are not in an interrupt handler and the
* running task is signaling some other non-running task.
@ -278,4 +112,3 @@ void up_schedule_sigaction(struct tcb_s *tcb)
tcb->xcp.regs[REG_RFLAGS] = 0;
}
}
#endif /* CONFIG_SMP */

9
arch/x86_64/src/intel64/intel64_smpcall.c
View file

@ -60,13 +60,7 @@
int x86_64_smp_call_handler(int irq, void *c, void *arg)
{
struct tcb_s *tcb;
int cpu = this_cpu();
tcb = current_task(cpu);
nxsched_smp_call_handler(irq, c, arg);
tcb = current_task(cpu);
x86_64_restorestate(tcb->xcp.regs);
return OK;
}
@ -93,12 +87,9 @@ int x86_64_smp_call_handler(int irq, void *c, void *arg)
int x86_64_smp_sched_handler(int irq, void *c, void *arg)
{
struct tcb_s *tcb;
int cpu = this_cpu();
nxsched_process_delivered(cpu);
tcb = current_task(cpu);
x86_64_restorestate(tcb->xcp.regs);
return OK;
}