From e82a3b75127188f20c7780bec580e148beb29da7 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Tue, 16 Jun 2009 20:51:48 +0000 Subject: 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 [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 --- arch/parisc/kernel/cache.c | 23 +++++++++++++++-------- arch/parisc/kernel/pci-dma.c | 12 ++++++++---- 2 files changed, 23 insertions(+), 12 deletions(-) (limited to 'arch/parisc/kernel') diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c index f34082d..b6ed34d 100644 --- a/arch/parisc/kernel/cache.c +++ b/arch/parisc/kernel/cache.c @@ -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); } } diff --git a/arch/parisc/kernel/pci-dma.c b/arch/parisc/kernel/pci-dma.c index 7d927ea..c07f618 100644 --- a/arch/parisc/kernel/pci-dma.c +++ b/arch/parisc/kernel/pci-dma.c @@ -90,12 +90,14 @@ static inline int map_pte_uncached(pte_t * pte, if (end > PMD_SIZE) end = PMD_SIZE; do { + unsigned long flags; + if (!pte_none(*pte)) printk(KERN_ERR "map_pte_uncached: page already exists\n"); set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC)); - purge_tlb_start(); + purge_tlb_start(flags); pdtlb_kernel(orig_vaddr); - purge_tlb_end(); + purge_tlb_end(flags); vaddr += PAGE_SIZE; orig_vaddr += PAGE_SIZE; (*paddr_ptr) += PAGE_SIZE; @@ -168,11 +170,13 @@ static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr, if (end > PMD_SIZE) end = PMD_SIZE; do { + unsigned long flags; pte_t page = *pte; + pte_clear(&init_mm, vaddr, pte); - purge_tlb_start(); + purge_tlb_start(flags); pdtlb_kernel(orig_vaddr); - purge_tlb_end(); + purge_tlb_end(flags); vaddr += PAGE_SIZE; orig_vaddr += PAGE_SIZE; pte++; -- cgit v1.1