https://github.com/torvalds/linux
Tip revision: 418baf2c28f3473039f2f7377760bd8f6897ae18 authored by Linus Torvalds on 22 November 2020, 23:36:08 UTC
Linux 5.10-rc5
Linux 5.10-rc5
Tip revision: 418baf2
tlb-r3k.c
// SPDX-License-Identifier: GPL-2.0
/*
* r2300.c: R2000 and R3000 specific mmu/cache code.
*
* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
*
* with a lot of changes to make this thing work for R3000s
* Tx39XX R4k style caches added. HK
* Copyright (C) 1998, 1999, 2000 Harald Koerfgen
* Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
* Copyright (C) 2002 Ralf Baechle
* Copyright (C) 2002 Maciej W. Rozycki
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <asm/page.h>
#include <asm/mmu_context.h>
#include <asm/tlbmisc.h>
#include <asm/isadep.h>
#include <asm/io.h>
#include <asm/bootinfo.h>
#include <asm/cpu.h>
#undef DEBUG_TLB
extern void build_tlb_refill_handler(void);
/* CP0 hazard avoidance. */
#define BARRIER \
__asm__ __volatile__( \
".set push\n\t" \
".set noreorder\n\t" \
"nop\n\t" \
".set pop\n\t")
int r3k_have_wired_reg; /* Should be in cpu_data? */
/* TLB operations. */
static void local_flush_tlb_from(int entry)
{
unsigned long old_ctx;
old_ctx = read_c0_entryhi() & cpu_asid_mask(¤t_cpu_data);
write_c0_entrylo0(0);
while (entry < current_cpu_data.tlbsize) {
write_c0_index(entry << 8);
write_c0_entryhi((entry | 0x80000) << 12);
entry++; /* BARRIER */
tlb_write_indexed();
}
write_c0_entryhi(old_ctx);
}
void local_flush_tlb_all(void)
{
unsigned long flags;
#ifdef DEBUG_TLB
printk("[tlball]");
#endif
local_irq_save(flags);
local_flush_tlb_from(r3k_have_wired_reg ? read_c0_wired() : 8);
local_irq_restore(flags);
}
void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
unsigned long asid_mask = cpu_asid_mask(¤t_cpu_data);
struct mm_struct *mm = vma->vm_mm;
int cpu = smp_processor_id();
if (cpu_context(cpu, mm) != 0) {
unsigned long size, flags;
#ifdef DEBUG_TLB
printk("[tlbrange<%lu,0x%08lx,0x%08lx>]",
cpu_context(cpu, mm) & asid_mask, start, end);
#endif
local_irq_save(flags);
size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
if (size <= current_cpu_data.tlbsize) {
int oldpid = read_c0_entryhi() & asid_mask;
int newpid = cpu_context(cpu, mm) & asid_mask;
start &= PAGE_MASK;
end += PAGE_SIZE - 1;
end &= PAGE_MASK;
while (start < end) {
int idx;
write_c0_entryhi(start | newpid);
start += PAGE_SIZE; /* BARRIER */
tlb_probe();
idx = read_c0_index();
write_c0_entrylo0(0);
write_c0_entryhi(KSEG0);
if (idx < 0) /* BARRIER */
continue;
tlb_write_indexed();
}
write_c0_entryhi(oldpid);
} else {
drop_mmu_context(mm);
}
local_irq_restore(flags);
}
}
void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
unsigned long size, flags;
#ifdef DEBUG_TLB
printk("[tlbrange<%lu,0x%08lx,0x%08lx>]", start, end);
#endif
local_irq_save(flags);
size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
if (size <= current_cpu_data.tlbsize) {
int pid = read_c0_entryhi();
start &= PAGE_MASK;
end += PAGE_SIZE - 1;
end &= PAGE_MASK;
while (start < end) {
int idx;
write_c0_entryhi(start);
start += PAGE_SIZE; /* BARRIER */
tlb_probe();
idx = read_c0_index();
write_c0_entrylo0(0);
write_c0_entryhi(KSEG0);
if (idx < 0) /* BARRIER */
continue;
tlb_write_indexed();
}
write_c0_entryhi(pid);
} else {
local_flush_tlb_all();
}
local_irq_restore(flags);
}
void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
unsigned long asid_mask = cpu_asid_mask(¤t_cpu_data);
int cpu = smp_processor_id();
if (cpu_context(cpu, vma->vm_mm) != 0) {
unsigned long flags;
int oldpid, newpid, idx;
#ifdef DEBUG_TLB
printk("[tlbpage<%lu,0x%08lx>]", cpu_context(cpu, vma->vm_mm), page);
#endif
newpid = cpu_context(cpu, vma->vm_mm) & asid_mask;
page &= PAGE_MASK;
local_irq_save(flags);
oldpid = read_c0_entryhi() & asid_mask;
write_c0_entryhi(page | newpid);
BARRIER;
tlb_probe();
idx = read_c0_index();
write_c0_entrylo0(0);
write_c0_entryhi(KSEG0);
if (idx < 0) /* BARRIER */
goto finish;
tlb_write_indexed();
finish:
write_c0_entryhi(oldpid);
local_irq_restore(flags);
}
}
void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
{
unsigned long asid_mask = cpu_asid_mask(¤t_cpu_data);
unsigned long flags;
int idx, pid;
/*
* Handle debugger faulting in for debugee.
*/
if (current->active_mm != vma->vm_mm)
return;
pid = read_c0_entryhi() & asid_mask;
#ifdef DEBUG_TLB
if ((pid != (cpu_context(cpu, vma->vm_mm) & asid_mask)) || (cpu_context(cpu, vma->vm_mm) == 0)) {
printk("update_mmu_cache: Wheee, bogus tlbpid mmpid=%lu tlbpid=%d\n",
(cpu_context(cpu, vma->vm_mm)), pid);
}
#endif
local_irq_save(flags);
address &= PAGE_MASK;
write_c0_entryhi(address | pid);
BARRIER;
tlb_probe();
idx = read_c0_index();
write_c0_entrylo0(pte_val(pte));
write_c0_entryhi(address | pid);
if (idx < 0) { /* BARRIER */
tlb_write_random();
} else {
tlb_write_indexed();
}
write_c0_entryhi(pid);
local_irq_restore(flags);
}
void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
unsigned long entryhi, unsigned long pagemask)
{
unsigned long asid_mask = cpu_asid_mask(¤t_cpu_data);
unsigned long flags;
unsigned long old_ctx;
static unsigned long wired = 0;
if (r3k_have_wired_reg) { /* TX39XX */
unsigned long old_pagemask;
unsigned long w;
#ifdef DEBUG_TLB
printk("[tlbwired<entry lo0 %8x, hi %8x\n, pagemask %8x>]\n",
entrylo0, entryhi, pagemask);
#endif
local_irq_save(flags);
/* Save old context and create impossible VPN2 value */
old_ctx = read_c0_entryhi() & asid_mask;
old_pagemask = read_c0_pagemask();
w = read_c0_wired();
write_c0_wired(w + 1);
write_c0_index(w << 8);
write_c0_pagemask(pagemask);
write_c0_entryhi(entryhi);
write_c0_entrylo0(entrylo0);
BARRIER;
tlb_write_indexed();
write_c0_entryhi(old_ctx);
write_c0_pagemask(old_pagemask);
local_flush_tlb_all();
local_irq_restore(flags);
} else if (wired < 8) {
#ifdef DEBUG_TLB
printk("[tlbwired<entry lo0 %8x, hi %8x\n>]\n",
entrylo0, entryhi);
#endif
local_irq_save(flags);
old_ctx = read_c0_entryhi() & asid_mask;
write_c0_entrylo0(entrylo0);
write_c0_entryhi(entryhi);
write_c0_index(wired);
wired++; /* BARRIER */
tlb_write_indexed();
write_c0_entryhi(old_ctx);
local_flush_tlb_all();
local_irq_restore(flags);
}
}
void tlb_init(void)
{
switch (current_cpu_type()) {
case CPU_TX3922:
case CPU_TX3927:
r3k_have_wired_reg = 1;
write_c0_wired(0); /* Set to 8 on reset... */
break;
}
local_flush_tlb_from(0);
build_tlb_refill_handler();
}