/*
* TLB support routines.
*
* Copyright (C) 1998-2001, 2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* 08/02/00 A. Mallick <asit.k.mallick@intel.com>
* Modified RID allocation for SMP
* Goutham Rao <goutham.rao@intel.com>
* IPI based ptc implementation and A-step IPI implementation.
* Rohit Seth <rohit.seth@intel.com>
* Ken Chen <kenneth.w.chen@intel.com>
* Christophe de Dinechin <ddd@hp.com>: Avoid ptc.e on memory allocation
* Copyright (C) 2007 Intel Corp
* Fenghua Yu <fenghua.yu@intel.com>
* Add multiple ptc.g/ptc.ga instruction support in global tlb purge.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <asm/delay.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/pal.h>
#include <asm/tlbflush.h>
#include <asm/dma.h>
#include <asm/processor.h>
#include <asm/sal.h>
#include <asm/tlb.h>
static struct {
unsigned long mask; /* mask of supported purge page-sizes */
unsigned long max_bits; /* log2 of largest supported purge page-size */
} purge;
struct ia64_ctx ia64_ctx = {
.lock = __SPIN_LOCK_UNLOCKED(ia64_ctx.lock),
.next = 1,
.max_ctx = ~0U
};
DEFINE_PER_CPU(u8, ia64_need_tlb_flush);
DEFINE_PER_CPU(u8, ia64_tr_num); /*Number of TR slots in current processor*/
DEFINE_PER_CPU(u8, ia64_tr_used); /*Max Slot number used by kernel*/
struct ia64_tr_entry __per_cpu_idtrs[NR_CPUS][2][IA64_TR_ALLOC_MAX];
/*
* Initializes the ia64_ctx.bitmap array based on max_ctx+1.
* Called after cpu_init() has setup ia64_ctx.max_ctx based on
* maximum RID that is supported by boot CPU.
*/
void __init
mmu_context_init (void)
{
ia64_ctx.bitmap = alloc_bootmem((ia64_ctx.max_ctx+1)>>3);
ia64_ctx.flushmap = alloc_bootmem((ia64_ctx.max_ctx+1)>>3);
}
/*
* Acquire the ia64_ctx.lock before calling this function!
*/
void
wrap_mmu_context (struct mm_struct *mm)
{
int i, cpu;
unsigned long flush_bit;
for (i=0; i <= ia64_ctx.max_ctx / BITS_PER_LONG; i++) {
flush_bit = xchg(&ia64_ctx.flushmap[i], 0);
ia64_ctx.bitmap[i] ^= flush_bit;
}
/* use offset at 300 to skip daemons */
ia64_ctx.next = find_next_zero_bit(ia64_ctx.bitmap,
ia64_ctx.max_ctx, 300);
ia64_ctx.limit = find_next_bit(ia64_ctx.bitmap,
ia64_ctx.max_ctx, ia64_ctx.next);
/*
* can't call flush_tlb_all() here because of race condition
* with O(1) scheduler [EF]
*/
cpu = get_cpu(); /* prevent preemption/migration */
for_each_online_cpu(i)
if (i != cpu)
per_cpu(ia64_need_tlb_flush, i) = 1;
put_cpu();
local_flush_tlb_all();
}
/*
* Implement "spinaphores" ... like counting semaphores, but they
* spin instead of sleeping. If there are ever any other users for
* this primitive it can be moved up to a spinaphore.h header.
*/
struct spinaphore {
atomic_t cur;
};
static inline void spinaphore_init(struct spinaphore *ss, int val)
{
atomic_set(&ss->cur, val);
}
static inline void down_spin(struct spinaphore *ss)
{
while (unlikely(!atomic_add_unless(&ss->cur, -1, 0)))
while (atomic_read(&ss->cur) == 0)
cpu_relax();
}
static inline void up_spin(struct spinaphore *ss)
{
atomic_add(1, &ss->cur);
}
static struct spinaphore ptcg_sem;
static u16 nptcg = 1;
static int need_ptcg_sem = 1;
static int toolatetochangeptcgsem = 0;
/*
* Kernel parameter "nptcg=" overrides max number of concurrent global TLB
* purges which is reported from either PAL or SAL PALO.
*
* We don't have sanity checking for nptcg value. It's the user's responsibility
* for valid nptcg value on the platform. Otherwise, kernel may hang in some
* cases.
*/
static int __init
set_nptcg(char *str)
{
int value = 0;
get_option(&str, &value);
setup_ptcg_sem(value, NPTCG_FROM_KERNEL_PARAMETER);
return 1;
}
__setup("nptcg=", set_nptcg);
/*
* Maximum number of simultaneous ptc.g purges in the system can
* be defined by PAL_VM_SUMMARY (in which case we should take
* the smallest value for any cpu in the system) or by the PAL
* override table (in which case we should ignore the value from
* PAL_VM_SUMMARY).
*
* Kernel parameter "nptcg=" overrides maximum number of simultanesous ptc.g
* purges defined in either PAL_VM_SUMMARY or PAL override table. In this case,
* we should ignore the value from either PAL_VM_SUMMARY or PAL override table.
*
* Complicating the logic here is the fact that num_possible_cpus()
* isn't fully setup until we start bringing cpus online.
*/
void
setup_ptcg_sem(int max_purges, int nptcg_from)
{
static int kp_override;
static int palo_override;
static int firstcpu = 1;
if (toolatetochangeptcgsem) {
if (nptcg_from == NPTCG_FROM_PAL && max_purges == 0)
BUG_ON(1 < nptcg);
else
BUG_ON(max_purges < nptcg);
return;
}
if (nptcg_from == NPTCG_FROM_KERNEL_PARAMETER) {
kp_override = 1;
nptcg = max_purges;
goto resetsema;
}
if (kp_override) {
need_ptcg_sem = num_possible_cpus() > nptcg;
return;
}
if (nptcg_from == NPTCG_FROM_PALO) {
palo_override = 1;
/* In PALO max_purges == 0 really means it! */
if (max_purges == 0)
panic("Whoa! Platform does not support global TLB purges.\n");
nptcg = max_purges;
if (nptcg == PALO_MAX_TLB_PURGES) {
need_ptcg_sem = 0;
return;
}
goto resetsema;
}
if (palo_override) {
if (nptcg != PALO_MAX_TLB_PURGES)
need_ptcg_sem = (num_possible_cpus() > nptcg);
return;
}
/* In PAL_VM_SUMMARY max_purges == 0 actually means 1 */
if (max_purges == 0) max_purges = 1;
if (firstcpu) {
nptcg = max_purges;
firstcpu = 0;
}
if (max_purges < nptcg)
nptcg = max_purges;
if (nptcg == PAL_MAX_PURGES) {
need_ptcg_sem = 0;
return;
} else
need_ptcg_sem = (num_possible_cpus() > nptcg);
resetsema:
spinaphore_init(&ptcg_sem, max_purges);
}
void
ia64_global_tlb_purge (struct mm_struct *mm, unsigned long start,
unsigned long end, unsigned long nbits)
{
struct mm_struct *active_mm = current->active_mm;
toolatetochangeptcgsem = 1;
if (mm != active_mm) {
/* Restore region IDs for mm */
if (mm && active_mm) {
activate_context(mm);
} else {
flush_tlb_all();
return;
}
}
if (need_ptcg_sem)
down_spin(&ptcg_sem);
do {
/*
* Flush ALAT entries also.
*/
ia64_ptcga(start, (nbits << 2));
ia64_srlz_i();
start += (1UL << nbits);
} while (start < end);
if (need_ptcg_sem)
up_spin(&ptcg_sem);
if (mm != active_mm) {
activate_context(active_mm);
}
}
void
local_flush_tlb_all (void)
{
unsigned long i, j, flags, count0, count1, stride0, stride1, addr;
addr = local_cpu_data->ptce_base;
count0 = local_cpu_data->ptce_count[0];
count1 = local_cpu_data->ptce_count[1];
stride0 = local_cpu_data->ptce_stride[0];
stride1 = local_cpu_data->ptce_stride[1];
local_irq_save(flags);
for (i = 0; i < count0; ++i) {
for (j = 0; j < count1; ++j) {
ia64_ptce(addr);
addr += stride1;
}
addr += stride0;
}
local_irq_restore(flags);
ia64_srlz_i(); /* srlz.i implies srlz.d */
}
void
flush_tlb_range (struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long size = end - start;
unsigned long nbits;
#ifndef CONFIG_SMP
if (mm != current->active_mm) {
mm->context = 0;
return;
}
#endif
nbits = ia64_fls(size + 0xfff);
while (unlikely (((1UL << nbits) & purge.mask) == 0) &&
(nbits < purge.max_bits))
++nbits;
if (nbits > purge.max_bits)
nbits = purge.max_bits;
start &= ~((1UL << nbits) - 1);
preempt_disable();
#ifdef CONFIG_SMP
if (mm != current->active_mm || cpus_weight(mm->cpu_vm_mask) != 1) {
platform_global_tlb_purge(mm, start, end, nbits);
preempt_enable();
return;
}
#endif
do {
ia64_ptcl(start, (nbits<<2));
start += (1UL << nbits);
} while (start < end);
preempt_enable();
ia64_srlz_i(); /* srlz.i implies srlz.d */
}
EXPORT_SYMBOL(flush_tlb_range);
void __devinit
ia64_tlb_init (void)
{
ia64_ptce_info_t uninitialized_var(ptce_info); /* GCC be quiet */
unsigned long tr_pgbits;
long status;
pal_vm_info_1_u_t vm_info_1;
pal_vm_info_2_u_t vm_info_2;
int cpu = smp_processor_id();
if ((status = ia64_pal_vm_page_size(&tr_pgbits, &purge.mask)) != 0) {
printk(KERN_ERR "PAL_VM_PAGE_SIZE failed with status=%ld; "
"defaulting to architected purge page-sizes.\n", status);
purge.mask = 0x115557000UL;
}
purge.max_bits = ia64_fls(purge.mask);
ia64_get_ptce(&ptce_info);
local_cpu_data->ptce_base = ptce_info.base;
local_cpu_data->ptce_count[0] = ptce_info.count[0];
local_cpu_data->ptce_count[1] = ptce_info.count[1];
local_cpu_data->ptce_stride[0] = ptce_info.stride[0];
local_cpu_data->ptce_stride[1] = ptce_info.stride[1];
local_flush_tlb_all(); /* nuke left overs from bootstrapping... */
status = ia64_pal_vm_summary(&vm_info_1, &vm_info_2);
if (status) {
printk(KERN_ERR "ia64_pal_vm_summary=%ld\n", status);
per_cpu(ia64_tr_num, cpu) = 8;
return;
}
per_cpu(ia64_tr_num, cpu) = vm_info_1.pal_vm_info_1_s.max_itr_entry+1;
if (per_cpu(ia64_tr_num, cpu) >
(vm_info_1.pal_vm_info_1_s.max_dtr_entry+1))
per_cpu(ia64_tr_num, cpu) =
vm_info_1.pal_vm_info_1_s.max_dtr_entry+1;
if (per_cpu(ia64_tr_num, cpu) > IA64_TR_ALLOC_MAX) {
static int justonce = 1;
per_cpu(ia64_tr_num, cpu) = IA64_TR_ALLOC_MAX;
if (justonce) {
justonce = 0;
printk(KERN_DEBUG "TR register number exceeds "
"IA64_TR_ALLOC_MAX!\n");
}
}
}
/*
* is_tr_overlap
*
* Check overlap with inserted TRs.
*/
static int is_tr_overlap(struct ia64_tr_entry *p, u64 va, u64 log_size)
{
u64 tr_log_size;
u64 tr_end;
u64 va_rr = ia64_get_rr(va);
u64 va_rid = RR_TO_RID(va_rr);
u64 va_end = va + (1<<log_size) - 1;
if (va_rid != RR_TO_RID(p->rr))
return 0;
tr_log_size = (p->itir & 0xff) >> 2;
tr_end = p->ifa + (1<<tr_log_size) - 1;
if (va > tr_end || p->ifa > va_end)
return 0;
return 1;
}
/*
* ia64_insert_tr in virtual mode. Allocate a TR slot
*
* target_mask : 0x1 : itr, 0x2 : dtr, 0x3 : idtr
*
* va : virtual address.
* pte : pte entries inserted.
* log_size: range to be covered.
*
* Return value: <0 : error No.
*
* >=0 : slot number allocated for TR.
* Must be called with preemption disabled.
*/
int ia64_itr_entry(u64 target_mask, u64 va, u64 pte, u64 log_size)
{
int i, r;
unsigned long psr;
struct ia64_tr_entry *p;
int cpu = smp_processor_id();
r = -EINVAL;
/*Check overlap with existing TR entries*/
if (target_mask & 0x1) {
p = &__per_cpu_idtrs[cpu][0][0];
for (i = IA64_TR_ALLOC_BASE; i <= per_cpu(ia64_tr_used, cpu);
i++, p++) {
if (p->pte & 0x1)
if (is_tr_overlap(p, va, log_size)) {
printk(KERN_DEBUG "Overlapped Entry"
"Inserted for TR Reigster!!\n");
goto out;
}
}
}
if (target_mask & 0x2) {
p = &__per_cpu_idtrs[cpu][1][0];
for (i = IA64_TR_ALLOC_BASE; i <= per_cpu(ia64_tr_used, cpu);
i++, p++) {
if (p->pte & 0x1)
if (is_tr_overlap(p, va, log_size)) {
printk(KERN_DEBUG "Overlapped Entry"
"Inserted for TR Reigster!!\n");
goto out;
}
}
}
for (i = IA64_TR_ALLOC_BASE; i < per_cpu(ia64_tr_num, cpu); i++) {
switch (target_mask & 0x3) {
case 1:
if (!(__per_cpu_idtrs[cpu][0][i].pte & 0x1))
goto found;
continue;
case 2:
if (!(__per_cpu_idtrs[cpu][1][i].pte & 0x1))
goto found;
continue;
case 3:
if (!(__per_cpu_idtrs[cpu][0][i].pte & 0x1) &&
!(__per_cpu_idtrs[cpu][1][i].pte & 0x1))
goto found;
continue;
default:
r = -EINVAL;
goto out;
}
}
found:
if (i >= per_cpu(ia64_tr_num, cpu))
return -EBUSY;
/*Record tr info for mca hander use!*/
if (i > per_cpu(ia64_tr_used, cpu))
per_cpu(ia64_tr_used, cpu) = i;
psr = ia64_clear_ic();
if (target_mask & 0x1) {
ia64_itr(0x1, i, va, pte, log_size);
ia64_srlz_i();
p = &__per_cpu_idtrs[cpu][0][i];
p->ifa = va;
p->pte = pte;
p->itir = log_size << 2;
p->rr = ia64_get_rr(va);
}
if (target_mask & 0x2) {
ia64_itr(0x2, i, va, pte, log_size);
ia64_srlz_i();
p = &__per_cpu_idtrs[cpu][1][i];
p->ifa = va;
p->pte = pte;
p->itir = log_size << 2;
p->rr = ia64_get_rr(va);
}
ia64_set_psr(psr);
r = i;
out:
return r;
}
EXPORT_SYMBOL_GPL(ia64_itr_entry);
/*
* ia64_purge_tr
*
* target_mask: 0x1: purge itr, 0x2 : purge dtr, 0x3 purge idtr.
* slot: slot number to be freed.
*
* Must be called with preemption disabled.
*/
void ia64_ptr_entry(u64 target_mask, int slot)
{
int cpu = smp_processor_id();
int i;
struct ia64_tr_entry *p;
if (slot < IA64_TR_ALLOC_BASE || slot >= per_cpu(ia64_tr_num, cpu))
return;
if (target_mask & 0x1) {
p = &__per_cpu_idtrs[cpu][0][slot];
if ((p->pte&0x1) && is_tr_overlap(p, p->ifa, p->itir>>2)) {
p->pte = 0;
ia64_ptr(0x1, p->ifa, p->itir>>2);
ia64_srlz_i();
}
}
if (target_mask & 0x2) {
p = &__per_cpu_idtrs[cpu][1][slot];
if ((p->pte & 0x1) && is_tr_overlap(p, p->ifa, p->itir>>2)) {
p->pte = 0;
ia64_ptr(0x2, p->ifa, p->itir>>2);
ia64_srlz_i();
}
}
for (i = per_cpu(ia64_tr_used, cpu); i >= IA64_TR_ALLOC_BASE; i--) {
if ((__per_cpu_idtrs[cpu][0][i].pte & 0x1) ||
(__per_cpu_idtrs[cpu][1][i].pte & 0x1))
break;
}
per_cpu(ia64_tr_used, cpu) = i;
}
EXPORT_SYMBOL_GPL(ia64_ptr_entry);
