On 12/6/2021 2:20 PM, Arnd Bergmann wrote:
On Mon, Dec 6, 2021 at 9:28 AM Sai Prakash Ranjan
<quic_saipraka@xxxxxxxxxxx> wrote:
Remove custom arm64 MMIO accessors read{b,w,l,q} and their relaxed
versions in support to use asm-generic ones. Also define arm64
barrier macros to override the asm-generic defined barriers.
Suggested-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Sai Prakash Ranjan <quic_saipraka@xxxxxxxxxxx>
This looks correct, but I would change one detail:
+#define __io_ar(v) __io_par(v)
+#define __io_bw() __iowmb()
+#define __io_br(v)
+#define __io_aw(v)
The default __io_par() is defined in terms of __io_ar(), so it would
be more logical
to remove the custom __io_par() and just define __io_ar() here.
Makes sense, will do this.
I think it would be even better to flip these around and make the low-level
definitions __io_ar() and __io_bw(), and then defining the arm64 specific
macros based on those:
/* arm64-specific, don't use in portable drivers */
#define __iormb(v) __io_ar(v)
#define __iowmb() __io_bw()
#define __iomb() dma_mb()
So __iormb on arm64 has some dummy control dependency stuff as well based on
("arm64: io: Ensure calls to delay routines are ordered against prior
readX()") and then we would
need to change __iormb definition to __io_ar which doesn't seem like
__iormb definition to be exact
right?
Thanks,
Sai
