arch/hexagon/mm/vm_tlb.c

Source file repositories/reference/linux-study-clean/arch/hexagon/mm/vm_tlb.c

File Facts

System
Linux kernel
Corpus path
arch/hexagon/mm/vm_tlb.c
Extension
.c
Size
2250 bytes
Lines
83
Domain
Architecture Layer
Bucket
arch/hexagon
Inferred role
Architecture Layer: implementation source
Status
source 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-only
/*
 * Hexagon Virtual Machine TLB functions
 *
 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
 */

/*
 * The Hexagon Virtual Machine conceals the real workings of
 * the TLB, but there are one or two functions that need to
 * be instantiated for it, differently from a native build.
 */
#include <linux/mm.h>
#include <linux/sched.h>
#include <asm/page.h>
#include <asm/hexagon_vm.h>
#include <asm/tlbflush.h>

/*
 * Initial VM implementation has only one map active at a time, with
 * TLB purgings on changes.  So either we're nuking the current map,
 * or it's a no-op.  This operation is messy on true SMPs where other
 * processors must be induced to flush the copies in their local TLBs,
 * but Hexagon thread-based virtual processors share the same MMU.
 */
void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
			unsigned long end)
{
	struct mm_struct *mm = vma->vm_mm;

	if (mm->context.ptbase == current->active_mm->context.ptbase)
		__vmclrmap((void *)start, end - start);
}

/*
 * Flush a page from the kernel virtual map - used by highmem
 */
void flush_tlb_one(unsigned long vaddr)
{
	__vmclrmap((void *)vaddr, PAGE_SIZE);
}

/*
 * Flush all TLBs across all CPUs, virtual or real.
 * A single Hexagon core has 6 thread contexts but
 * only one TLB.
 */
void tlb_flush_all(void)
{
	/*  should probably use that fixaddr end or whateve label  */
	__vmclrmap(0, 0xffff0000);
}

/*
 * Flush TLB entries associated with a given mm_struct mapping.
 */
void flush_tlb_mm(struct mm_struct *mm)
{
	/* Current Virtual Machine has only one map active at a time */
	if (current->active_mm->context.ptbase == mm->context.ptbase)
		tlb_flush_all();
}

/*
 * Flush TLB state associated with a page of a vma.
 */
void flush_tlb_page(struct vm_area_struct *vma, unsigned long vaddr)
{
	struct mm_struct *mm = vma->vm_mm;

	if (mm->context.ptbase  == current->active_mm->context.ptbase)
		__vmclrmap((void *)vaddr, PAGE_SIZE);
}

/*
 * Flush TLB entries associated with a kernel address range.
 * Like flush range, but without the check on the vma->vm_mm.
 */
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
		__vmclrmap((void *)start, end - start);
}

Annotation

Implementation Notes