Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 64e2c673 authored by Sinan Kaya's avatar Sinan Kaya Committed by Arnd Bergmann
Browse files

io: define several IO & PIO barrier types for the asm-generic version 



Getting ready to harden readX()/writeX() and inX()/outX() semantics for the
generic implementation.

Defining two set of macros as __io_br() and __io_ar() to indicate actions
to be taken before and after MMIO read.

Defining two set of macros as __io_bw() and __io_aw() to indicate actions
to be taken before and after MMIO write.

Defining two set of macros as __io_pbw() and __io_paw() to indicate actions
to be taken before and after Port IO write.

Defining two set of macros as __io_pbr() and __io_par() to indicate actions
to be taken before and after Port IO read.

If rmb() is available for the architecture, prefer rmb() as the default
implementation of __io_ar()/__io_par().

If wmb() is available for the architecture, prefer wmb() as the default
implementation of __io_bw()/__io_pbw().

Signed-off-by: default avatarSinan Kaya <okaya@codeaurora.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 0adb3285

include/asm-generic/io.h

+44 −0
Original line number Original line Diff line number Diff line
@@ -25,6 +25,50 @@ 
#define mmiowb() do {} while (0)

#define mmiowb() do {} while (0)

#endif

#endif





#ifndef __io_br

#define __io_br()      barrier()

#endif



/* prevent prefetching of coherent DMA data ahead of a dma-complete */

#ifndef __io_ar

#ifdef rmb

#define __io_ar()      rmb()

#else

#define __io_ar()      barrier()

#endif

#endif



/* flush writes to coherent DMA data before possibly triggering a DMA read */

#ifndef __io_bw

#ifdef wmb

#define __io_bw()      wmb()

#else

#define __io_bw()      barrier()

#endif

#endif



/* serialize device access against a spin_unlock, usually handled there. */

#ifndef __io_aw

#define __io_aw()      barrier()

#endif



#ifndef __io_pbw

#define __io_pbw()     __io_bw()

#endif



#ifndef __io_paw

#define __io_paw()     __io_aw()

#endif



#ifndef __io_pbr

#define __io_pbr()     __io_br()

#endif



#ifndef __io_par

#define __io_par()     __io_ar()

#endif





/*

/*

 * __raw_{read,write}{b,w,l,q}() access memory in native endianness.

 * __raw_{read,write}{b,w,l,q}() access memory in native endianness.

 *

 *