mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 17:59:32 +00:00
![Olof Johansson](/assets/img/avatar_default.png)
The patch "KVM: fix !SMP build error" change the way smp_call_function() actually uses the passed in function names on non-SMP builds. So previously it was never caught that the function passed in was never actually defined. This causes a build error on ppc64_defconfig + CONFIG_SMP=n: arch/powerpc/mm/tlb_64.c: In function 'pgtable_free_now': arch/powerpc/mm/tlb_64.c:71: error: 'pte_free_smp_sync' undeclared (first use in this function) arch/powerpc/mm/tlb_64.c:71: error: (Each undeclared identifier is reported only once arch/powerpc/mm/tlb_64.c:71: error: for each function it appears in.) So we need to define it even if CONFIG_SMP is off. Either that or ifdef out the smp_call_function() call, but that's ugly. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
300 lines
8.3 KiB
C
300 lines
8.3 KiB
C
/*
|
|
* This file contains the routines for flushing entries from the
|
|
* TLB and MMU hash table.
|
|
*
|
|
* Derived from arch/ppc64/mm/init.c:
|
|
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
|
|
*
|
|
* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
|
|
* and Cort Dougan (PReP) (cort@cs.nmt.edu)
|
|
* Copyright (C) 1996 Paul Mackerras
|
|
*
|
|
* Derived from "arch/i386/mm/init.c"
|
|
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
|
|
*
|
|
* Dave Engebretsen <engebret@us.ibm.com>
|
|
* Rework for PPC64 port.
|
|
*
|
|
* 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/kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/init.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/hardirq.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/tlb.h>
|
|
#include <asm/bug.h>
|
|
|
|
DEFINE_PER_CPU(struct ppc64_tlb_batch, ppc64_tlb_batch);
|
|
|
|
/* This is declared as we are using the more or less generic
|
|
* include/asm-powerpc/tlb.h file -- tgall
|
|
*/
|
|
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
|
|
DEFINE_PER_CPU(struct pte_freelist_batch *, pte_freelist_cur);
|
|
unsigned long pte_freelist_forced_free;
|
|
|
|
struct pte_freelist_batch
|
|
{
|
|
struct rcu_head rcu;
|
|
unsigned int index;
|
|
pgtable_free_t tables[0];
|
|
};
|
|
|
|
DEFINE_PER_CPU(struct pte_freelist_batch *, pte_freelist_cur);
|
|
unsigned long pte_freelist_forced_free;
|
|
|
|
#define PTE_FREELIST_SIZE \
|
|
((PAGE_SIZE - sizeof(struct pte_freelist_batch)) \
|
|
/ sizeof(pgtable_free_t))
|
|
|
|
static void pte_free_smp_sync(void *arg)
|
|
{
|
|
/* Do nothing, just ensure we sync with all CPUs */
|
|
}
|
|
|
|
/* This is only called when we are critically out of memory
|
|
* (and fail to get a page in pte_free_tlb).
|
|
*/
|
|
static void pgtable_free_now(pgtable_free_t pgf)
|
|
{
|
|
pte_freelist_forced_free++;
|
|
|
|
smp_call_function(pte_free_smp_sync, NULL, 0, 1);
|
|
|
|
pgtable_free(pgf);
|
|
}
|
|
|
|
static void pte_free_rcu_callback(struct rcu_head *head)
|
|
{
|
|
struct pte_freelist_batch *batch =
|
|
container_of(head, struct pte_freelist_batch, rcu);
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < batch->index; i++)
|
|
pgtable_free(batch->tables[i]);
|
|
|
|
free_page((unsigned long)batch);
|
|
}
|
|
|
|
static void pte_free_submit(struct pte_freelist_batch *batch)
|
|
{
|
|
INIT_RCU_HEAD(&batch->rcu);
|
|
call_rcu(&batch->rcu, pte_free_rcu_callback);
|
|
}
|
|
|
|
void pgtable_free_tlb(struct mmu_gather *tlb, pgtable_free_t pgf)
|
|
{
|
|
/* This is safe since tlb_gather_mmu has disabled preemption */
|
|
cpumask_t local_cpumask = cpumask_of_cpu(smp_processor_id());
|
|
struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur);
|
|
|
|
if (atomic_read(&tlb->mm->mm_users) < 2 ||
|
|
cpus_equal(tlb->mm->cpu_vm_mask, local_cpumask)) {
|
|
pgtable_free(pgf);
|
|
return;
|
|
}
|
|
|
|
if (*batchp == NULL) {
|
|
*batchp = (struct pte_freelist_batch *)__get_free_page(GFP_ATOMIC);
|
|
if (*batchp == NULL) {
|
|
pgtable_free_now(pgf);
|
|
return;
|
|
}
|
|
(*batchp)->index = 0;
|
|
}
|
|
(*batchp)->tables[(*batchp)->index++] = pgf;
|
|
if ((*batchp)->index == PTE_FREELIST_SIZE) {
|
|
pte_free_submit(*batchp);
|
|
*batchp = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* A linux PTE was changed and the corresponding hash table entry
|
|
* neesd to be flushed. This function will either perform the flush
|
|
* immediately or will batch it up if the current CPU has an active
|
|
* batch on it.
|
|
*
|
|
* Must be called from within some kind of spinlock/non-preempt region...
|
|
*/
|
|
void hpte_need_flush(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep, unsigned long pte, int huge)
|
|
{
|
|
struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
|
|
unsigned long vsid, vaddr;
|
|
unsigned int psize;
|
|
int ssize;
|
|
real_pte_t rpte;
|
|
int i;
|
|
|
|
i = batch->index;
|
|
|
|
/* We mask the address for the base page size. Huge pages will
|
|
* have applied their own masking already
|
|
*/
|
|
addr &= PAGE_MASK;
|
|
|
|
/* Get page size (maybe move back to caller).
|
|
*
|
|
* NOTE: when using special 64K mappings in 4K environment like
|
|
* for SPEs, we obtain the page size from the slice, which thus
|
|
* must still exist (and thus the VMA not reused) at the time
|
|
* of this call
|
|
*/
|
|
if (huge) {
|
|
#ifdef CONFIG_HUGETLB_PAGE
|
|
psize = mmu_huge_psize;
|
|
#else
|
|
BUG();
|
|
psize = pte_pagesize_index(mm, addr, pte); /* shutup gcc */
|
|
#endif
|
|
} else
|
|
psize = pte_pagesize_index(mm, addr, pte);
|
|
|
|
/* Build full vaddr */
|
|
if (!is_kernel_addr(addr)) {
|
|
ssize = user_segment_size(addr);
|
|
vsid = get_vsid(mm->context.id, addr, ssize);
|
|
WARN_ON(vsid == 0);
|
|
} else {
|
|
vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
|
|
ssize = mmu_kernel_ssize;
|
|
}
|
|
vaddr = hpt_va(addr, vsid, ssize);
|
|
rpte = __real_pte(__pte(pte), ptep);
|
|
|
|
/*
|
|
* Check if we have an active batch on this CPU. If not, just
|
|
* flush now and return. For now, we don global invalidates
|
|
* in that case, might be worth testing the mm cpu mask though
|
|
* and decide to use local invalidates instead...
|
|
*/
|
|
if (!batch->active) {
|
|
flush_hash_page(vaddr, rpte, psize, ssize, 0);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* This can happen when we are in the middle of a TLB batch and
|
|
* we encounter memory pressure (eg copy_page_range when it tries
|
|
* to allocate a new pte). If we have to reclaim memory and end
|
|
* up scanning and resetting referenced bits then our batch context
|
|
* will change mid stream.
|
|
*
|
|
* We also need to ensure only one page size is present in a given
|
|
* batch
|
|
*/
|
|
if (i != 0 && (mm != batch->mm || batch->psize != psize ||
|
|
batch->ssize != ssize)) {
|
|
__flush_tlb_pending(batch);
|
|
i = 0;
|
|
}
|
|
if (i == 0) {
|
|
batch->mm = mm;
|
|
batch->psize = psize;
|
|
batch->ssize = ssize;
|
|
}
|
|
batch->pte[i] = rpte;
|
|
batch->vaddr[i] = vaddr;
|
|
batch->index = ++i;
|
|
if (i >= PPC64_TLB_BATCH_NR)
|
|
__flush_tlb_pending(batch);
|
|
}
|
|
|
|
/*
|
|
* This function is called when terminating an mmu batch or when a batch
|
|
* is full. It will perform the flush of all the entries currently stored
|
|
* in a batch.
|
|
*
|
|
* Must be called from within some kind of spinlock/non-preempt region...
|
|
*/
|
|
void __flush_tlb_pending(struct ppc64_tlb_batch *batch)
|
|
{
|
|
cpumask_t tmp;
|
|
int i, local = 0;
|
|
|
|
i = batch->index;
|
|
tmp = cpumask_of_cpu(smp_processor_id());
|
|
if (cpus_equal(batch->mm->cpu_vm_mask, tmp))
|
|
local = 1;
|
|
if (i == 1)
|
|
flush_hash_page(batch->vaddr[0], batch->pte[0],
|
|
batch->psize, batch->ssize, local);
|
|
else
|
|
flush_hash_range(i, local);
|
|
batch->index = 0;
|
|
}
|
|
|
|
void pte_free_finish(void)
|
|
{
|
|
/* This is safe since tlb_gather_mmu has disabled preemption */
|
|
struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur);
|
|
|
|
if (*batchp == NULL)
|
|
return;
|
|
pte_free_submit(*batchp);
|
|
*batchp = NULL;
|
|
}
|
|
|
|
/**
|
|
* __flush_hash_table_range - Flush all HPTEs for a given address range
|
|
* from the hash table (and the TLB). But keeps
|
|
* the linux PTEs intact.
|
|
*
|
|
* @mm : mm_struct of the target address space (generally init_mm)
|
|
* @start : starting address
|
|
* @end : ending address (not included in the flush)
|
|
*
|
|
* This function is mostly to be used by some IO hotplug code in order
|
|
* to remove all hash entries from a given address range used to map IO
|
|
* space on a removed PCI-PCI bidge without tearing down the full mapping
|
|
* since 64K pages may overlap with other bridges when using 64K pages
|
|
* with 4K HW pages on IO space.
|
|
*
|
|
* Because of that usage pattern, it's only available with CONFIG_HOTPLUG
|
|
* and is implemented for small size rather than speed.
|
|
*/
|
|
#ifdef CONFIG_HOTPLUG
|
|
|
|
void __flush_hash_table_range(struct mm_struct *mm, unsigned long start,
|
|
unsigned long end)
|
|
{
|
|
unsigned long flags;
|
|
|
|
start = _ALIGN_DOWN(start, PAGE_SIZE);
|
|
end = _ALIGN_UP(end, PAGE_SIZE);
|
|
|
|
BUG_ON(!mm->pgd);
|
|
|
|
/* Note: Normally, we should only ever use a batch within a
|
|
* PTE locked section. This violates the rule, but will work
|
|
* since we don't actually modify the PTEs, we just flush the
|
|
* hash while leaving the PTEs intact (including their reference
|
|
* to being hashed). This is not the most performance oriented
|
|
* way to do things but is fine for our needs here.
|
|
*/
|
|
local_irq_save(flags);
|
|
arch_enter_lazy_mmu_mode();
|
|
for (; start < end; start += PAGE_SIZE) {
|
|
pte_t *ptep = find_linux_pte(mm->pgd, start);
|
|
unsigned long pte;
|
|
|
|
if (ptep == NULL)
|
|
continue;
|
|
pte = pte_val(*ptep);
|
|
if (!(pte & _PAGE_HASHPTE))
|
|
continue;
|
|
hpte_need_flush(mm, start, ptep, pte, 0);
|
|
}
|
|
arch_leave_lazy_mmu_mode();
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
#endif /* CONFIG_HOTPLUG */
|