280 lines
7.2 KiB
C
280 lines
7.2 KiB
C
/*
|
|
* PowerPC64 Segment Translation Support.
|
|
*
|
|
* Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com
|
|
* Copyright (c) 2001 Dave Engebretsen
|
|
*
|
|
* Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/mmu.h>
|
|
#include <asm/mmu_context.h>
|
|
#include <asm/paca.h>
|
|
#include <asm/cputable.h>
|
|
#include <asm/lmb.h>
|
|
#include <asm/abs_addr.h>
|
|
|
|
struct stab_entry {
|
|
unsigned long esid_data;
|
|
unsigned long vsid_data;
|
|
};
|
|
|
|
/* Both the segment table and SLB code uses the following cache */
|
|
#define NR_STAB_CACHE_ENTRIES 8
|
|
DEFINE_PER_CPU(long, stab_cache_ptr);
|
|
DEFINE_PER_CPU(long, stab_cache[NR_STAB_CACHE_ENTRIES]);
|
|
|
|
/*
|
|
* Create a segment table entry for the given esid/vsid pair.
|
|
*/
|
|
static int make_ste(unsigned long stab, unsigned long esid, unsigned long vsid)
|
|
{
|
|
unsigned long esid_data, vsid_data;
|
|
unsigned long entry, group, old_esid, castout_entry, i;
|
|
unsigned int global_entry;
|
|
struct stab_entry *ste, *castout_ste;
|
|
unsigned long kernel_segment = (esid << SID_SHIFT) >= KERNELBASE;
|
|
|
|
vsid_data = vsid << STE_VSID_SHIFT;
|
|
esid_data = esid << SID_SHIFT | STE_ESID_KP | STE_ESID_V;
|
|
if (! kernel_segment)
|
|
esid_data |= STE_ESID_KS;
|
|
|
|
/* Search the primary group first. */
|
|
global_entry = (esid & 0x1f) << 3;
|
|
ste = (struct stab_entry *)(stab | ((esid & 0x1f) << 7));
|
|
|
|
/* Find an empty entry, if one exists. */
|
|
for (group = 0; group < 2; group++) {
|
|
for (entry = 0; entry < 8; entry++, ste++) {
|
|
if (!(ste->esid_data & STE_ESID_V)) {
|
|
ste->vsid_data = vsid_data;
|
|
asm volatile("eieio":::"memory");
|
|
ste->esid_data = esid_data;
|
|
return (global_entry | entry);
|
|
}
|
|
}
|
|
/* Now search the secondary group. */
|
|
global_entry = ((~esid) & 0x1f) << 3;
|
|
ste = (struct stab_entry *)(stab | (((~esid) & 0x1f) << 7));
|
|
}
|
|
|
|
/*
|
|
* Could not find empty entry, pick one with a round robin selection.
|
|
* Search all entries in the two groups.
|
|
*/
|
|
castout_entry = get_paca()->stab_rr;
|
|
for (i = 0; i < 16; i++) {
|
|
if (castout_entry < 8) {
|
|
global_entry = (esid & 0x1f) << 3;
|
|
ste = (struct stab_entry *)(stab | ((esid & 0x1f) << 7));
|
|
castout_ste = ste + castout_entry;
|
|
} else {
|
|
global_entry = ((~esid) & 0x1f) << 3;
|
|
ste = (struct stab_entry *)(stab | (((~esid) & 0x1f) << 7));
|
|
castout_ste = ste + (castout_entry - 8);
|
|
}
|
|
|
|
/* Dont cast out the first kernel segment */
|
|
if ((castout_ste->esid_data & ESID_MASK) != KERNELBASE)
|
|
break;
|
|
|
|
castout_entry = (castout_entry + 1) & 0xf;
|
|
}
|
|
|
|
get_paca()->stab_rr = (castout_entry + 1) & 0xf;
|
|
|
|
/* Modify the old entry to the new value. */
|
|
|
|
/* Force previous translations to complete. DRENG */
|
|
asm volatile("isync" : : : "memory");
|
|
|
|
old_esid = castout_ste->esid_data >> SID_SHIFT;
|
|
castout_ste->esid_data = 0; /* Invalidate old entry */
|
|
|
|
asm volatile("sync" : : : "memory"); /* Order update */
|
|
|
|
castout_ste->vsid_data = vsid_data;
|
|
asm volatile("eieio" : : : "memory"); /* Order update */
|
|
castout_ste->esid_data = esid_data;
|
|
|
|
asm volatile("slbie %0" : : "r" (old_esid << SID_SHIFT));
|
|
/* Ensure completion of slbie */
|
|
asm volatile("sync" : : : "memory");
|
|
|
|
return (global_entry | (castout_entry & 0x7));
|
|
}
|
|
|
|
/*
|
|
* Allocate a segment table entry for the given ea and mm
|
|
*/
|
|
static int __ste_allocate(unsigned long ea, struct mm_struct *mm)
|
|
{
|
|
unsigned long vsid;
|
|
unsigned char stab_entry;
|
|
unsigned long offset;
|
|
|
|
/* Kernel or user address? */
|
|
if (ea >= KERNELBASE) {
|
|
vsid = get_kernel_vsid(ea);
|
|
} else {
|
|
if ((ea >= TASK_SIZE_USER64) || (! mm))
|
|
return 1;
|
|
|
|
vsid = get_vsid(mm->context.id, ea);
|
|
}
|
|
|
|
stab_entry = make_ste(get_paca()->stab_addr, GET_ESID(ea), vsid);
|
|
|
|
if (ea < KERNELBASE) {
|
|
offset = __get_cpu_var(stab_cache_ptr);
|
|
if (offset < NR_STAB_CACHE_ENTRIES)
|
|
__get_cpu_var(stab_cache[offset++]) = stab_entry;
|
|
else
|
|
offset = NR_STAB_CACHE_ENTRIES+1;
|
|
__get_cpu_var(stab_cache_ptr) = offset;
|
|
|
|
/* Order update */
|
|
asm volatile("sync":::"memory");
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int ste_allocate(unsigned long ea)
|
|
{
|
|
return __ste_allocate(ea, current->mm);
|
|
}
|
|
|
|
/*
|
|
* Do the segment table work for a context switch: flush all user
|
|
* entries from the table, then preload some probably useful entries
|
|
* for the new task
|
|
*/
|
|
void switch_stab(struct task_struct *tsk, struct mm_struct *mm)
|
|
{
|
|
struct stab_entry *stab = (struct stab_entry *) get_paca()->stab_addr;
|
|
struct stab_entry *ste;
|
|
unsigned long offset = __get_cpu_var(stab_cache_ptr);
|
|
unsigned long pc = KSTK_EIP(tsk);
|
|
unsigned long stack = KSTK_ESP(tsk);
|
|
unsigned long unmapped_base;
|
|
|
|
/* Force previous translations to complete. DRENG */
|
|
asm volatile("isync" : : : "memory");
|
|
|
|
if (offset <= NR_STAB_CACHE_ENTRIES) {
|
|
int i;
|
|
|
|
for (i = 0; i < offset; i++) {
|
|
ste = stab + __get_cpu_var(stab_cache[i]);
|
|
ste->esid_data = 0; /* invalidate entry */
|
|
}
|
|
} else {
|
|
unsigned long entry;
|
|
|
|
/* Invalidate all entries. */
|
|
ste = stab;
|
|
|
|
/* Never flush the first entry. */
|
|
ste += 1;
|
|
for (entry = 1;
|
|
entry < (PAGE_SIZE / sizeof(struct stab_entry));
|
|
entry++, ste++) {
|
|
unsigned long ea;
|
|
ea = ste->esid_data & ESID_MASK;
|
|
if (ea < KERNELBASE) {
|
|
ste->esid_data = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
asm volatile("sync; slbia; sync":::"memory");
|
|
|
|
__get_cpu_var(stab_cache_ptr) = 0;
|
|
|
|
/* Now preload some entries for the new task */
|
|
if (test_tsk_thread_flag(tsk, TIF_32BIT))
|
|
unmapped_base = TASK_UNMAPPED_BASE_USER32;
|
|
else
|
|
unmapped_base = TASK_UNMAPPED_BASE_USER64;
|
|
|
|
__ste_allocate(pc, mm);
|
|
|
|
if (GET_ESID(pc) == GET_ESID(stack))
|
|
return;
|
|
|
|
__ste_allocate(stack, mm);
|
|
|
|
if ((GET_ESID(pc) == GET_ESID(unmapped_base))
|
|
|| (GET_ESID(stack) == GET_ESID(unmapped_base)))
|
|
return;
|
|
|
|
__ste_allocate(unmapped_base, mm);
|
|
|
|
/* Order update */
|
|
asm volatile("sync" : : : "memory");
|
|
}
|
|
|
|
extern void slb_initialize(void);
|
|
|
|
/*
|
|
* Allocate segment tables for secondary CPUs. These must all go in
|
|
* the first (bolted) segment, so that do_stab_bolted won't get a
|
|
* recursive segment miss on the segment table itself.
|
|
*/
|
|
void stabs_alloc(void)
|
|
{
|
|
int cpu;
|
|
|
|
if (cpu_has_feature(CPU_FTR_SLB))
|
|
return;
|
|
|
|
for_each_cpu(cpu) {
|
|
unsigned long newstab;
|
|
|
|
if (cpu == 0)
|
|
continue; /* stab for CPU 0 is statically allocated */
|
|
|
|
newstab = lmb_alloc_base(PAGE_SIZE, PAGE_SIZE, 1<<SID_SHIFT);
|
|
if (! newstab)
|
|
panic("Unable to allocate segment table for CPU %d.\n",
|
|
cpu);
|
|
|
|
newstab += KERNELBASE;
|
|
|
|
memset((void *)newstab, 0, PAGE_SIZE);
|
|
|
|
paca[cpu].stab_addr = newstab;
|
|
paca[cpu].stab_real = virt_to_abs(newstab);
|
|
printk(KERN_DEBUG "Segment table for CPU %d at 0x%lx virtual, 0x%lx absolute\n", cpu, paca[cpu].stab_addr, paca[cpu].stab_real);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Build an entry for the base kernel segment and put it into
|
|
* the segment table or SLB. All other segment table or SLB
|
|
* entries are faulted in.
|
|
*/
|
|
void stab_initialize(unsigned long stab)
|
|
{
|
|
unsigned long vsid = get_kernel_vsid(KERNELBASE);
|
|
|
|
if (cpu_has_feature(CPU_FTR_SLB)) {
|
|
slb_initialize();
|
|
} else {
|
|
asm volatile("isync; slbia; isync":::"memory");
|
|
make_ste(stab, GET_ESID(KERNELBASE), vsid);
|
|
|
|
/* Order update */
|
|
asm volatile("sync":::"memory");
|
|
}
|
|
}
|