From: David S. Miller Date: Wed, 25 May 2016 19:51:20 +0000 (-0700) Subject: sparc64: Take ctx_alloc_lock properly in hugetlb_setup(). X-Git-Tag: firefly_0821_release~176^2~4^2~40^2~25 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=6bb3290ce9662055efcf13dc18c12bb62f6f39dc;p=firefly-linux-kernel-4.4.55.git sparc64: Take ctx_alloc_lock properly in hugetlb_setup(). [ Upstream commit 9ea46abe22550e3366ff7cee2f8391b35b12f730 ] On cheetahplus chips we take the ctx_alloc_lock in order to modify the TLB lookup parameters for the indexed TLBs, which are stored in the context register. This is called with interrupts disabled, however ctx_alloc_lock is an IRQ safe lock, therefore we must take acquire/release it properly with spin_{lock,unlock}_irq(). Reported-by: Meelis Roos Tested-by: Meelis Roos Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index 76d11d1c5995..3c4b8975fa76 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -2821,9 +2821,10 @@ void hugetlb_setup(struct pt_regs *regs) * the Data-TLB for huge pages. */ if (tlb_type == cheetah_plus) { + bool need_context_reload = false; unsigned long ctx; - spin_lock(&ctx_alloc_lock); + spin_lock_irq(&ctx_alloc_lock); ctx = mm->context.sparc64_ctx_val; ctx &= ~CTX_PGSZ_MASK; ctx |= CTX_PGSZ_BASE << CTX_PGSZ0_SHIFT; @@ -2842,9 +2843,12 @@ void hugetlb_setup(struct pt_regs *regs) * also executing in this address space. */ mm->context.sparc64_ctx_val = ctx; - on_each_cpu(context_reload, mm, 0); + need_context_reload = true; } - spin_unlock(&ctx_alloc_lock); + spin_unlock_irq(&ctx_alloc_lock); + + if (need_context_reload) + on_each_cpu(context_reload, mm, 0); } } #endif