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parisc: ensure broadcast tlb purge runs single threaded

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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>
This commit is contained in:
Helge Deller
2009-06-16 20:51:48 +00:00
committed by Kyle McMartin
parent 84be31be37
commit e82a3b7512
3 changed files with 30 additions and 19 deletions
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23
arch/parisc/kernel/cache.c
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@@ -397,12 +397,13 @@ EXPORT_SYMBOL(flush_kernel_icache_range_asm);
void clear_user_page_asm(void *page, unsigned long vaddr)
{
unsigned long flags;
/* This function is implemented in assembly in pacache.S */
extern void __clear_user_page_asm(void *page, unsigned long vaddr);
purge_tlb_start();
purge_tlb_start(flags);
__clear_user_page_asm(page, vaddr);
purge_tlb_end();
purge_tlb_end(flags);
}
#define FLUSH_THRESHOLD 0x80000 /* 0.5MB */
@@ -443,20 +444,24 @@ extern void clear_user_page_asm(void *page, unsigned long vaddr);
void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
{
unsigned long flags;
purge_kernel_dcache_page((unsigned long)page);
purge_tlb_start();
purge_tlb_start(flags);
pdtlb_kernel(page);
purge_tlb_end();
purge_tlb_end(flags);
clear_user_page_asm(page, vaddr);
}
EXPORT_SYMBOL(clear_user_page);
void flush_kernel_dcache_page_addr(void *addr)
{
unsigned long flags;
flush_kernel_dcache_page_asm(addr);
purge_tlb_start();
purge_tlb_start(flags);
pdtlb_kernel(addr);
purge_tlb_end();
purge_tlb_end(flags);
}
EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
@@ -489,8 +494,10 @@ void __flush_tlb_range(unsigned long sid, unsigned long start,
if (npages >= 512) /* 2MB of space: arbitrary, should be tuned */
flush_tlb_all();
else {
unsigned long flags;
mtsp(sid, 1);
purge_tlb_start();
purge_tlb_start(flags);
if (split_tlb) {
while (npages--) {
pdtlb(start);
@@ -503,7 +510,7 @@ void __flush_tlb_range(unsigned long sid, unsigned long start,
start += PAGE_SIZE;
}
}
purge_tlb_end();
purge_tlb_end(flags);
}
}