On 10/17/2017 04:58 PM, Cornelia Huck wrote: > On Tue, 17 Oct 2017 16:04:48 +0200 > Halil Pasic <pa...@linux.vnet.ibm.com> wrote: > >> CSS code needs to tell the IO instruction handlers located in how should >> the emulated instruction be ended. Currently this is done by returning >> generic (POSIX) error codes, and mapping them to outcomes like condition >> codes. This makes bugs easy to create and hard to recognise.
also s/recognise/recognize/ To on mix American and British. >> >> As a preparation for moving a way form (mis)using generic error codes for > > s/form/from/ > Sorry this seems to be a recurring typo of me (not detected by spell check because both valid). >> flow control let us introduce a type which tells the instruction >> handler function how to end the instruction, in a more straight-forward >> and less ambiguous way. >> >> Signed-off-by: Halil Pasic <pa...@linux.vnet.ibm.com> >> --- >> include/hw/s390x/css.h | 16 ++++++++++++++++ >> 1 file changed, 16 insertions(+) >> >> diff --git a/include/hw/s390x/css.h b/include/hw/s390x/css.h >> index 69b374730e..7e0dbd162f 100644 >> --- a/include/hw/s390x/css.h >> +++ b/include/hw/s390x/css.h >> @@ -99,6 +99,22 @@ typedef struct CcwDataStream { >> hwaddr cda; >> } CcwDataStream; >> >> +/* >> + * IO instructions conclude according this. Currently we have only > > s/this/to this/ > >> + * cc codes. Valid values are 0,1,2,3 and the generic semantic for > > blanks between numbers? Overrated. Just joking. Definitely blanks between numbers. > >> + * IO instructions is described briefly. For more details consult the PoP. >> + */ >> +typedef enum IOInstEnding { >> + /* produced expected result */ >> + IOINST_CC_EXPECTED = 0, >> + /* status conditions were present or produced alternate result */ >> + IOINST_CC_STATUS_PRESENT = 1, >> + /* inst. ineffective because busy with previously initiated function */ >> + IOINST_CC_BUSY = 2, >> + /* inst. ineffective because not operational */ >> + IOINST_CC_NOT_OPERATIONAL = 3 >> +} IOInstEnding; > > This looks a bit odd for some I/O instructions (STCRW, TPI, TSCH), but > is fine for the others. But as the PoP also defines the meanings as > above, it should be fine (and not confusing). Yeah. The original idea was to keep stuff abstract, but I decided to go with the names carrying meaning because Thomas seems to be more reliable than me when it comes to matters of taste, and also for consistency with SIGP_CC_*. I think, in the end it does not matter that much. > >> + >> typedef struct SubchDev SubchDev; >> struct SubchDev { >> /* channel-subsystem related things: */ > >