/*
* iSeries hashtable management.
* Derived from pSeries_htab.c
*
* SMP scalability work:
* Copyright (C) 2001 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 <asm/machdep.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/abs_addr.h>
#include <linux/spinlock.h>
#include "call_hpt.h"
static spinlock_t iSeries_hlocks[64] __cacheline_aligned_in_smp;
/*
* Very primitive algorithm for picking up a lock
*/
static inline void iSeries_hlock(unsigned long slot)
{
if (slot & 0x8)
slot = ~slot;
spin_lock(&iSeries_hlocks[(slot >> 4) & 0x3f]);
}
static inline void iSeries_hunlock(unsigned long slot)
{
if (slot & 0x8)
slot = ~slot;
spin_unlock(&iSeries_hlocks[(slot >> 4) & 0x3f]);
}
static long iSeries_hpte_insert(unsigned long hpte_group, unsigned long va,
unsigned long pa, unsigned long rflags,
unsigned long vflags, int psize, int ssize)
{
long slot;
struct hash_pte lhpte;
int secondary = 0;
BUG_ON(psize != MMU_PAGE_4K);
/*
* The hypervisor tries both primary and secondary.
* If we are being called to insert in the secondary,
* it means we have already tried both primary and secondary,
* so we return failure immediately.
*/
if (vflags & HPTE_V_SECONDARY)
return -1;
iSeries_hlock(hpte_group);
slot = HvCallHpt_findValid(&lhpte, va >> HW_PAGE_SHIFT);
if (unlikely(lhpte.v & HPTE_V_VALID)) {
if (vflags & HPTE_V_BOLTED) {
HvCallHpt_setSwBits(slot, 0x10, 0);
HvCallHpt_setPp(slot, PP_RWXX);
iSeries_hunlock(hpte_group);
if (slot < 0)
return 0x8 | (slot & 7);
else
return slot & 7;
}
BUG();
}
if (slot == -1) { /* No available entry found in either group */
iSeries_hunlock(hpte_group);
return -1;
}
if (slot < 0) { /* MSB set means secondary group */
vflags |= HPTE_V_SECONDARY;
secondary = 1;
slot &= 0x7fffffffffffffff;
}
lhpte.v = hpte_encode_v(va, MMU_PAGE_4K, MMU_SEGSIZE_256M) |
vflags | HPTE_V_VALID;
lhpte.r = hpte_encode_r(phys_to_abs(pa), MMU_PAGE_4K) | rflags;
/* Now fill in the actual HPTE */
HvCallHpt_addValidate(slot, secondary, &lhpte);
iSeries_hunlock(hpte_group);
return (secondary << 3) | (slot & 7);
}
static unsigned long iSeries_hpte_getword0(unsigned long slot)
{
struct hash_pte hpte;
HvCallHpt_get(&hpte, slot);
return hpte.v;
}
static long iSeries_hpte_remove(unsigned long hpte_group)
{
unsigned long slot_offset;
int i;
unsigned long hpte_v;
/* Pick a random slot to start at */
slot_offset = mftb() & 0x7;
iSeries_hlock(hpte_group);
for (i = 0; i < HPTES_PER_GROUP; i++) {
hpte_v = iSeries_hpte_getword0(hpte_group + slot_offset);
if (! (hpte_v & HPTE_V_BOLTED)) {
HvCallHpt_invalidateSetSwBitsGet(hpte_group +
slot_offset, 0, 0);
iSeries_hunlock(hpte_group);
return i;
}
slot_offset++;
slot_offset &= 0x7;
}
iSeries_hunlock(hpte_group);
return -1;
}
/*
* The HyperVisor expects the "flags" argument in this form:
* bits 0..59 : reserved
* bit 60 : N
* bits 61..63 : PP2,PP1,PP0
*/
static long iSeries_hpte_updatepp(unsigned long slot, unsigned long newpp,
unsigned long va, int psize, int ssize, int local)
{
struct hash_pte hpte;
unsigned long want_v;
iSeries_hlock(slot);
HvCallHpt_get(&hpte, slot);
want_v = hpte_encode_v(va, MMU_PAGE_4K, MMU_SEGSIZE_256M);
if (HPTE_V_COMPARE(hpte.v, want_v) && (hpte.v & HPTE_V_VALID)) {
/*
* Hypervisor expects bits as NPPP, which is
* different from how they are mapped in our PP.
*/
HvCallHpt_setPp(slot, (newpp & 0x3) | ((newpp & 0x4) << 1));
iSeries_hunlock(slot);
return 0;
}
iSeries_hunlock(slot);
return -1;
}
/*
* Functions used to find the PTE for a particular virtual address.
* Only used during boot when bolting pages.
*
* Input : vpn : virtual page number
* Output: PTE index within the page table of the entry
* -1 on failure
*/
static long iSeries_hpte_find(unsigned long vpn)
{
struct hash_pte hpte;
long slot;
/*
* The HvCallHpt_findValid interface is as follows:
* 0xffffffffffffffff : No entry found.
* 0x00000000xxxxxxxx : Entry found in primary group, slot x
* 0x80000000xxxxxxxx : Entry found in secondary group, slot x
*/
slot = HvCallHpt_findValid(&hpte, vpn);
if (hpte.v & HPTE_V_VALID) {
if (slot < 0) {
slot &= 0x7fffffffffffffff;
slot = -slot;
}
} else
slot = -1;
return slot;
}
/*
* Update the page protection bits. Intended to be used to create
* guard pages for kernel data structures on pages which are bolted
* in the HPT. Assumes pages being operated on will not be stolen.
* Does not work on large pages.
*
* No need to lock here because we should be the only user.
*/
static void iSeries_hpte_updateboltedpp(unsigned long newpp, unsigned long ea,
int psize, int ssize)
{
unsigned long vsid,va,vpn;
long slot;
BUG_ON(psize != MMU_PAGE_4K);
vsid = get_kernel_vsid(ea, MMU_SEGSIZE_256M);
va = (vsid << 28) | (ea & 0x0fffffff);
vpn = va >> HW_PAGE_SHIFT;
slot = iSeries_hpte_find(vpn);
if (slot == -1)
panic("updateboltedpp: Could not find page to bolt\n");
HvCallHpt_setPp(slot, newpp);
}
static void iSeries_hpte_invalidate(unsigned long slot, unsigned long va,
int psize, int ssize, int local)
{
unsigned long hpte_v;
unsigned long avpn = va >> 23;
unsigned long flags;
local_irq_save(flags);
iSeries_hlock(slot);
hpte_v = iSeries_hpte_getword0(slot);
if ((HPTE_V_AVPN_VAL(hpte_v) == avpn) && (hpte_v & HPTE_V_VALID))
HvCallHpt_invalidateSetSwBitsGet(slot, 0, 0);
iSeries_hunlock(slot);
local_irq_restore(flags);
}
void __init hpte_init_iSeries(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(iSeries_hlocks); i++)
spin_lock_init(&iSeries_hlocks[i]);
ppc_md.hpte_invalidate = iSeries_hpte_invalidate;
ppc_md.hpte_updatepp = iSeries_hpte_updatepp;
ppc_md.hpte_updateboltedpp = iSeries_hpte_updateboltedpp;
ppc_md.hpte_insert = iSeries_hpte_insert;
ppc_md.hpte_remove = iSeries_hpte_remove;
}
