linux_dsm_epyc7002/arch/parisc/include/asm/tlbflush.h
Helge Deller e82a3b7512 parisc: ensure broadcast tlb purge runs single threaded
The TLB flushing functions on hppa, which causes PxTLB broadcasts on the system
bus, needs to be protected by irq-safe spinlocks to avoid irq handlers to deadlock
the kernel. The deadlocks only happened during I/O intensive loads and triggered
pretty seldom, which is why this bug went so long unnoticed.

Signed-off-by: Helge Deller <deller@gmx.de>
[edited to use spin_lock_irqsave on UP as well since we'd been locking there
 all this time anyway, --kyle]
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
2009-07-03 03:34:09 +00:00

84 lines
2.3 KiB
C

#ifndef _PARISC_TLBFLUSH_H
#define _PARISC_TLBFLUSH_H
/* TLB flushing routines.... */
#include <linux/mm.h>
#include <linux/sched.h>
#include <asm/mmu_context.h>
/* This is for the serialisation of PxTLB broadcasts. At least on the
* N class systems, only one PxTLB inter processor broadcast can be
* active at any one time on the Merced bus. This tlb purge
* synchronisation is fairly lightweight and harmless so we activate
* it on all systems not just the N class.
*/
extern spinlock_t pa_tlb_lock;
#define purge_tlb_start(flags) spin_lock_irqsave(&pa_tlb_lock, flags)
#define purge_tlb_end(flags) spin_unlock_irqrestore(&pa_tlb_lock, flags)
extern void flush_tlb_all(void);
extern void flush_tlb_all_local(void *);
/*
* flush_tlb_mm()
*
* XXX This code is NOT valid for HP-UX compatibility processes,
* (although it will probably work 99% of the time). HP-UX
* processes are free to play with the space id's and save them
* over long periods of time, etc. so we have to preserve the
* space and just flush the entire tlb. We need to check the
* personality in order to do that, but the personality is not
* currently being set correctly.
*
* Of course, Linux processes could do the same thing, but
* we don't support that (and the compilers, dynamic linker,
* etc. do not do that).
*/
static inline void flush_tlb_mm(struct mm_struct *mm)
{
BUG_ON(mm == &init_mm); /* Should never happen */
#if 1 || defined(CONFIG_SMP)
flush_tlb_all();
#else
/* FIXME: currently broken, causing space id and protection ids
* to go out of sync, resulting in faults on userspace accesses.
*/
if (mm) {
if (mm->context != 0)
free_sid(mm->context);
mm->context = alloc_sid();
if (mm == current->active_mm)
load_context(mm->context);
}
#endif
}
static inline void flush_tlb_page(struct vm_area_struct *vma,
unsigned long addr)
{
unsigned long flags;
/* For one page, it's not worth testing the split_tlb variable */
mb();
mtsp(vma->vm_mm->context,1);
purge_tlb_start(flags);
pdtlb(addr);
pitlb(addr);
purge_tlb_end(flags);
}
void __flush_tlb_range(unsigned long sid,
unsigned long start, unsigned long end);
#define flush_tlb_range(vma,start,end) __flush_tlb_range((vma)->vm_mm->context,start,end)
#define flush_tlb_kernel_range(start, end) __flush_tlb_range(0,start,end)
#endif