Re: [PATCH v3 01/14] KVM: s390: pv: add macros for UVC CC values

From: David Hildenbrand
Date: Fri Aug 06 2021 - 03:26:42 EST


On 04.08.21 17:40, Claudio Imbrenda wrote:
Add macros to describe the 4 possible CC values returned by the UVC
instruction.

Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
---
arch/s390/include/asm/uv.h | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index 12c5f006c136..b35add51b967 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -18,6 +18,11 @@
#include <asm/page.h>
#include <asm/gmap.h>
+#define UVC_CC_OK 0
+#define UVC_CC_ERROR 1
+#define UVC_CC_BUSY 2
+#define UVC_CC_PARTIAL 3
+
#define UVC_RC_EXECUTED 0x0001
#define UVC_RC_INV_CMD 0x0002
#define UVC_RC_INV_STATE 0x0003


Do we have any users we could directly fix up? AFAIKs, most users don't really care about the cc value, only about cc vs !cc.

The only instances I was able to spot quickly:


diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index 12c5f006c136..dd72d325f9e8 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -233,7 +233,7 @@ static inline int uv_call(unsigned long r1, unsigned long r2)

do {
cc = __uv_call(r1, r2);
- } while (cc > 1);
+ } while (cc >= UVC_CC_BUSY);
return cc;
}

@@ -245,7 +245,7 @@ static inline int uv_call_sched(unsigned long r1, unsigned long r2)
do {
cc = __uv_call(r1, r2);
cond_resched();
- } while (cc > 1);
+ } while (cc >= UVC_CC_BUSY);
return cc;
}


Of course, we could replace all checks for cc vs !cc with "cc != UVC_CC_OK" vs "cc == UVC_CC_OK".

--
Thanks,

David / dhildenb