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>

1 files changed, 8 insertions, 4 deletions

diff --git a/arch/parisc/kernel/pci-dma.c b/arch/parisc/kernel/pci-dma.c
index 7d927eac932b..c07f618ff7da 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++;