/*
* PowerPC64 SLB support.
*
* Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM
* Based on earlier code writteh by:
* 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>
extern void slb_allocate(unsigned long ea);
static inline unsigned long mk_esid_data(unsigned long ea, unsigned long slot)
{
return (ea & ESID_MASK) | SLB_ESID_V | slot;
}
static inline unsigned long mk_vsid_data(unsigned long ea, unsigned long flags)
{
return (get_kernel_vsid(ea) << SLB_VSID_SHIFT) | flags;
}
static inline void create_slbe(unsigned long ea, unsigned long vsid,
unsigned long flags, unsigned long entry)
{
asm volatile("slbmte %0,%1" :
: "r" (mk_vsid_data(ea, flags)),
"r" (mk_esid_data(ea, entry))
: "memory" );
}
static void slb_flush_and_rebolt(void)
{
/* If you change this make sure you change SLB_NUM_BOLTED
* appropriately too. */
unsigned long ksp_flags = SLB_VSID_KERNEL;
unsigned long ksp_esid_data;
WARN_ON(!irqs_disabled());
if (cpu_has_feature(CPU_FTR_16M_PAGE))
ksp_flags |= SLB_VSID_L;
ksp_esid_data = mk_esid_data(get_paca()->kstack, 2);
if ((ksp_esid_data & ESID_MASK) == KERNELBASE)
ksp_esid_data &= ~SLB_ESID_V;
/* We need to do this all in asm, so we're sure we don't touch
* the stack between the slbia and rebolting it. */
asm volatile("isync\n"
"slbia\n"
/* Slot 1 - first VMALLOC segment */
"slbmte %0,%1\n"
/* Slot 2 - kernel stack */
"slbmte %2,%3\n"
"isync"
:: "r"(mk_vsid_data(VMALLOCBASE, SLB_VSID_KERNEL)),
"r"(mk_esid_data(VMALLOCBASE, 1)),
"r"(mk_vsid_data(ksp_esid_data, ksp_flags)),
"r"(ksp_esid_data)
: "memory");
}
/* Flush all user entries from the segment table of the current processor. */
void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
{
unsigned long offset = get_paca()->slb_cache_ptr;
unsigned long esid_data = 0;
unsigned long pc = KSTK_EIP(tsk);
unsigned long stack = KSTK_ESP(tsk);
unsigned long unmapped_base;
if (offset <= SLB_CACHE_ENTRIES) {
int i;
asm volatile("isync" : : : "memory");
for (i = 0; i < offset; i++) {
esid_data = (unsigned long)get_paca()->slb_cache[i]
<< SID_SHIFT;
asm volatile("slbie %0" : : "r" (esid_data));
}
asm volatile("isync" : : : "memory");
} else {
slb_flush_and_rebolt();
}
/* Workaround POWER5 < DD2.1 issue */
if (offset == 1 || offset > SLB_CACHE_ENTRIES)
asm volatile("slbie %0" : : "r" (esid_data));
get_paca()->slb_cache_ptr = 0;
get_paca()->context = mm->context;
/*
* preload some userspace segments into the SLB.
*/
if (test_tsk_thread_flag(tsk, TIF_32BIT))
unmapped_base = TASK_UNMAPPED_BASE_USER32;
else
unmapped_base = TASK_UNMAPPED_BASE_USER64;
if (pc >= KERNELBASE)
return;
slb_allocate(pc);
if (GET_ESID(pc) == GET_ESID(stack))
return;
if (stack >= KERNELBASE)
return;
slb_allocate(stack);
if ((GET_ESID(pc) == GET_ESID(unmapped_base))
|| (GET_ESID(stack) == GET_ESID(unmapped_base)))
return;
if (unmapped_base >= KERNELBASE)
return;
slb_allocate(unmapped_base);
}
void slb_initialize(void)
{
/* On iSeries the bolted entries have already been set up by
* the hypervisor from the lparMap data in head.S */
#ifndef CONFIG_PPC_ISERIES
unsigned long flags = SLB_VSID_KERNEL;
/* Invalidate the entire SLB (even slot 0) & all the ERATS */
if (cpu_has_feature(CPU_FTR_16M_PAGE))
flags |= SLB_VSID_L;
asm volatile("isync":::"memory");
asm volatile("slbmte %0,%0"::"r" (0) : "memory");
asm volatile("isync; slbia; isync":::"memory");
create_slbe(KERNELBASE, get_kernel_vsid(KERNELBASE), flags, 0);
create_slbe(VMALLOCBASE, get_kernel_vsid(KERNELBASE),
SLB_VSID_KERNEL, 1);
/* We don't bolt the stack for the time being - we're in boot,
* so the stack is in the bolted segment. By the time it goes
* elsewhere, we'll call _switch() which will bolt in the new
* one. */
asm volatile("isync":::"memory");
#endif
get_paca()->stab_rr = SLB_NUM_BOLTED;
}
