arch/powerpc/mm/nohash/tlb.c

Source file repositories/reference/linux-study-clean/arch/powerpc/mm/nohash/tlb.c

File Facts

System
Linux kernel
Corpus path
arch/powerpc/mm/nohash/tlb.c
Extension
.c
Size
8073 bytes
Lines
342
Domain
Architecture Layer
Bucket
arch/powerpc
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct tlb_flush_param {
	unsigned long addr;
	unsigned int pid;
	unsigned int tsize;
	unsigned int ind;
};

static void do_flush_tlb_mm_ipi(void *param)
{
	struct tlb_flush_param *p = param;

	_tlbil_pid(p ? p->pid : 0);
}

static void do_flush_tlb_page_ipi(void *param)
{
	struct tlb_flush_param *p = param;

	_tlbil_va(p->addr, p->pid, p->tsize, p->ind);
}


/* Note on invalidations and PID:
 *
 * We snapshot the PID with preempt disabled. At this point, it can still
 * change either because:
 * - our context is being stolen (PID -> NO_CONTEXT) on another CPU
 * - we are invaliating some target that isn't currently running here
 *   and is concurrently acquiring a new PID on another CPU
 * - some other CPU is re-acquiring a lost PID for this mm
 * etc...
 *
 * However, this shouldn't be a problem as we only guarantee
 * invalidation of TLB entries present prior to this call, so we
 * don't care about the PID changing, and invalidating a stale PID
 * is generally harmless.
 */

void flush_tlb_mm(struct mm_struct *mm)
{
	unsigned int pid;

	preempt_disable();
	pid = mm->context.id;
	if (unlikely(pid == MMU_NO_CONTEXT))
		goto no_context;
	if (!mm_is_core_local(mm)) {
		struct tlb_flush_param p = { .pid = pid };
		/* Ignores smp_processor_id() even if set. */
		smp_call_function_many(mm_cpumask(mm),
				       do_flush_tlb_mm_ipi, &p, 1);
	}
	_tlbil_pid(pid);
 no_context:
	preempt_enable();
}
EXPORT_SYMBOL(flush_tlb_mm);

void __flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
		      int tsize, int ind)
{
	struct cpumask *cpu_mask;
	unsigned int pid;

	/*
	 * This function as well as __local_flush_tlb_page() must only be called
	 * for user contexts.
	 */
	if (WARN_ON(!mm))
		return;

	preempt_disable();
	pid = mm->context.id;
	if (unlikely(pid == MMU_NO_CONTEXT))
		goto bail;
	cpu_mask = mm_cpumask(mm);
	if (!mm_is_core_local(mm)) {
		/* If broadcast tlbivax is supported, use it */
		if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) {
			int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL);
			if (lock)
				raw_spin_lock(&tlbivax_lock);
			_tlbivax_bcast(vmaddr, pid, tsize, ind);
			if (lock)
				raw_spin_unlock(&tlbivax_lock);
			goto bail;
		} else {
			struct tlb_flush_param p = {
				.pid = pid,
				.addr = vmaddr,

Annotation

Implementation Notes