• Peter Zijlstra's avatar
    mm: stack based kmap_atomic() · 3e4d3af5
    Peter Zijlstra authored
    Keep the current interface but ignore the KM_type and use a stack based
    approach.
    
    The advantage is that we get rid of crappy code like:
    
    	#define __KM_PTE			\
    		(in_nmi() ? KM_NMI_PTE : 	\
    		 in_irq() ? KM_IRQ_PTE :	\
    		 KM_PTE0)
    
    and in general can stop worrying about what context we're in and what kmap
    slots might be appropriate for that.
    
    The downside is that FRV kmap_atomic() gets more expensive.
    
    For now we use a CPP trick suggested by Andrew:
    
      #define kmap_atomic(page, args...) __kmap_atomic(page)
    
    to avoid having to touch all kmap_atomic() users in a single patch.
    
    [ not compiled on:
      - mn10300: the arch doesn't actually build with highmem to begin with ]
    
    [akpm@linux-foundation.org: coding-style fixes]
    [akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
    Acked-by: default avatarRik van Riel <riel@redhat.com>
    Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
    Acked-by: default avatarChris Metcalf <cmetcalf@tilera.com>
    Cc: David Howells <dhowells@redhat.com>
    Cc: Hugh Dickins <hughd@google.com>
    Cc: Ingo Molnar <mingo@elte.hu>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: "H. Peter Anvin" <hpa@zytor.com>
    Cc: Steven Rostedt <rostedt@goodmis.org>
    Cc: Russell King <rmk@arm.linux.org.uk>
    Cc: Ralf Baechle <ralf@linux-mips.org>
    Cc: David Miller <davem@davemloft.net>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    Cc: Dave Airlie <airlied@linux.ie>
    Cc: Li Zefan <lizf@cn.fujitsu.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    3e4d3af5
io-mapping.h 3.58 KB