arch/csky/mm/tlb.c

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

File Facts

System
Linux kernel
Corpus path
arch/csky/mm/tlb.c
Extension
.c
Size
3635 bytes
Lines
199
Domain
Architecture Layer
Bucket
arch/csky
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

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.

#include <linux/init.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/sched.h>

#include <asm/mmu_context.h>
#include <asm/setup.h>

/*
 * One C-SKY MMU TLB entry contain two PFN/page entry, ie:
 * 1VPN -> 2PFN
 */
#define TLB_ENTRY_SIZE		(PAGE_SIZE * 2)
#define TLB_ENTRY_SIZE_MASK	(PAGE_MASK << 1)

void flush_tlb_all(void)
{
	tlb_invalid_all();
}

void flush_tlb_mm(struct mm_struct *mm)
{
#ifdef CONFIG_CPU_HAS_TLBI
	sync_is();
	asm volatile(
		"tlbi.asids %0	\n"
		"sync.i		\n"
		:
		: "r" (cpu_asid(mm))
		: "memory");
#else
	tlb_invalid_all();
#endif
}

/*
 * MMU operation regs only could invalid tlb entry in jtlb and we
 * need change asid field to invalid I-utlb & D-utlb.
 */
#ifndef CONFIG_CPU_HAS_TLBI
#define restore_asid_inv_utlb(oldpid, newpid) \
do { \
	if (oldpid == newpid) \
		write_mmu_entryhi(oldpid + 1); \
	write_mmu_entryhi(oldpid); \
} while (0)
#endif

void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
			unsigned long end)
{
	unsigned long newpid = cpu_asid(vma->vm_mm);

	start &= TLB_ENTRY_SIZE_MASK;
	end   += TLB_ENTRY_SIZE - 1;
	end   &= TLB_ENTRY_SIZE_MASK;

#ifdef CONFIG_CPU_HAS_TLBI
	sync_is();
	while (start < end) {
		asm volatile(
			"tlbi.vas %0	\n"
			:
			: "r" (start | newpid)
			: "memory");

		start += 2*PAGE_SIZE;
	}
	asm volatile("sync.i\n");
#else
	{
	unsigned long flags, oldpid;

	local_irq_save(flags);
	oldpid = read_mmu_entryhi() & ASID_MASK;
	while (start < end) {
		int idx;

		write_mmu_entryhi(start | newpid);
		start += 2*PAGE_SIZE;
		tlb_probe();
		idx = read_mmu_index();
		if (idx >= 0)
			tlb_invalid_indexed();
	}
	restore_asid_inv_utlb(oldpid, newpid);
	local_irq_restore(flags);

Annotation

Implementation Notes