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/*
* TLB support routines.
*
* Copyright (C) 1998, 1999 Hewlett-Packard Co
* Copyright (C) 1998, 1999 David Mosberger-Tang <davidm@hpl.hp.com>
*/
#include <linux/config.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/pal.h>
#define SUPPORTED_PGBITS ( \
1 << _PAGE_SIZE_256M | \
1 << _PAGE_SIZE_64M | \
1 << _PAGE_SIZE_16M | \
1 << _PAGE_SIZE_4M | \
1 << _PAGE_SIZE_1M | \
1 << _PAGE_SIZE_256K | \
1 << _PAGE_SIZE_64K | \
1 << _PAGE_SIZE_16K | \
1 << _PAGE_SIZE_8K | \
1 << _PAGE_SIZE_4K )
static void wrap_context (struct mm_struct *mm);
unsigned long ia64_next_context = (1UL << IA64_HW_CONTEXT_BITS) + 1;
/*
* Put everything in a struct so we avoid the global offset table whenever
* possible.
*/
ia64_ptce_info_t ia64_ptce_info;
/*
* Seralize usage of ptc.g
*/
spinlock_t ptcg_lock = SPIN_LOCK_UNLOCKED; /* see <asm/pgtable.h> */
void
get_new_mmu_context (struct mm_struct *mm)
{
if ((ia64_next_context & IA64_HW_CONTEXT_MASK) == 0) {
wrap_context(mm);
}
mm->context = ia64_next_context++;
}
/*
* This is where we handle the case where (ia64_next_context &
* IA64_HW_CONTEXT_MASK) == 0. Whenever this happens, we need to
* flush the entire TLB and skip over region id number 0, which is
* used by the kernel.
*/
static void
wrap_context (struct mm_struct *mm)
{
struct task_struct *task;
/*
* We wrapped back to the first region id so we nuke the TLB
* so we can switch to the next generation of region ids.
*/
__flush_tlb_all();
if (ia64_next_context++ == 0) {
/*
* Oops, we've used up all 64 bits of the context
* space---walk through task table to ensure we don't
* get tricked into using an old context. If this
* happens, the machine has been running for a long,
* long time!
*/
ia64_next_context = (1UL << IA64_HW_CONTEXT_BITS) + 1;
read_lock(&tasklist_lock);
for_each_task (task) {
if (task->mm == mm)
continue;
flush_tlb_mm(mm);
}
read_unlock(&tasklist_lock);
}
}
void
__flush_tlb_all (void)
{
unsigned long i, j, flags, count0, count1, stride0, stride1, addr = ia64_ptce_info.base;
count0 = ia64_ptce_info.count[0];
count1 = ia64_ptce_info.count[1];
stride0 = ia64_ptce_info.stride[0];
stride1 = ia64_ptce_info.stride[1];
__save_and_cli(flags);
for (i = 0; i < count0; ++i) {
for (j = 0; j < count1; ++j) {
asm volatile ("ptc.e %0" :: "r"(addr));
addr += stride1;
}
addr += stride0;
}
__restore_flags(flags);
ia64_insn_group_barrier();
ia64_srlz_i(); /* srlz.i implies srlz.d */
ia64_insn_group_barrier();
}
void
flush_tlb_range (struct mm_struct *mm, unsigned long start, unsigned long end)
{
unsigned long size = end - start;
unsigned long nbits;
if (mm != current->active_mm) {
/* this doesn't happen often, if at all, so it's not worth optimizing for... */
mm->context = 0;
return;
}
nbits = ia64_fls(size + 0xfff);
if (((1UL << nbits) & SUPPORTED_PGBITS) == 0) {
if (nbits > _PAGE_SIZE_256M)
nbits = _PAGE_SIZE_256M;
else
/*
* Some page sizes are not implemented in the
* IA-64 arch, so if we get asked to clear an
* unsupported page size, round up to the
* nearest page size. Note that we depend on
* the fact that if page size N is not
* implemented, 2*N _is_ implemented.
*/
++nbits;
if (((1UL << nbits) & SUPPORTED_PGBITS) == 0)
panic("flush_tlb_range: BUG: nbits=%lu\n", nbits);
}
start &= ~((1UL << nbits) - 1);
spin_lock(&ptcg_lock);
do {
#ifdef CONFIG_SMP
__asm__ __volatile__ ("ptc.g %0,%1;;srlz.i;;"
:: "r"(start), "r"(nbits<<2) : "memory");
#else
__asm__ __volatile__ ("ptc.l %0,%1" :: "r"(start), "r"(nbits<<2) : "memory");
#endif
start += (1UL << nbits);
} while (start < end);
spin_unlock(&ptcg_lock);
ia64_insn_group_barrier();
ia64_srlz_i(); /* srlz.i implies srlz.d */
ia64_insn_group_barrier();
}
void
ia64_tlb_init (void)
{
ia64_get_ptce(&ia64_ptce_info);
__flush_tlb_all(); /* nuke left overs from bootstrapping... */
}
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