diff mbox series

[kvm-unit-tests,v3,5/9] s390x: Library resources for CSS tests

Message ID 1575649588-6127-6-git-send-email-pmorel@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series s390x: Testing the Channel Subsystem I/O | expand

Commit Message

Pierre Morel Dec. 6, 2019, 4:26 p.m. UTC
These are the include and library utilities for the css tests patch
series.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
 lib/s390x/css.h      | 259 +++++++++++++++++++++++++++++++++++++++++++
 lib/s390x/css_dump.c | 156 ++++++++++++++++++++++++++
 2 files changed, 415 insertions(+)
 create mode 100644 lib/s390x/css.h
 create mode 100644 lib/s390x/css_dump.c

Comments

Thomas Huth Dec. 9, 2019, 11:49 a.m. UTC | #1
On 06/12/2019 17.26, Pierre Morel wrote:
> These are the include and library utilities for the css tests patch
> series.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  lib/s390x/css.h      | 259 +++++++++++++++++++++++++++++++++++++++++++
>  lib/s390x/css_dump.c | 156 ++++++++++++++++++++++++++
>  2 files changed, 415 insertions(+)
>  create mode 100644 lib/s390x/css.h
>  create mode 100644 lib/s390x/css_dump.c
> 
> diff --git a/lib/s390x/css.h b/lib/s390x/css.h
> new file mode 100644
> index 0000000..6f19bb5
> --- /dev/null
> +++ b/lib/s390x/css.h
[...]
> +/* Debug functions */
> +char *dump_pmcw_flags(uint16_t f);
> +char *dump_scsw_flags(uint32_t f);
> +#undef DEBUG
> +#ifdef DEBUG
> +void dump_scsw(struct scsw *);
> +void dump_irb(struct irb *irbp);
> +void dump_schib(struct schib *sch);
> +struct ccw *dump_ccw(struct ccw *cp);
> +#else
> +static inline void dump_scsw(struct scsw *scsw) {}
> +static inline void dump_irb(struct irb *irbp) {}
> +static inline void dump_pmcw(struct pmcw *p) {}
> +static inline void dump_schib(struct schib *sch) {}
> +static inline void dump_orb(struct orb *op) {}
> +static inline struct ccw *dump_ccw(struct ccw *cp)
> +{
> +	return NULL;
> +}
> +#endif

I'd prefer to not have a "#undef DEBUG" (or "#define DEBUG") statement
in the header here - it could trigger unexpected behavior with other
files that also use a DEBUG macro.

Could you please declare the prototypes here and move the "#else" part
to the .c file instead? Thanks!

 Thomas
Pierre Morel Dec. 9, 2019, 4:43 p.m. UTC | #2
On 2019-12-09 12:49, Thomas Huth wrote:
> On 06/12/2019 17.26, Pierre Morel wrote:
>> These are the include and library utilities for the css tests patch
>> series.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   lib/s390x/css.h      | 259 +++++++++++++++++++++++++++++++++++++++++++
>>   lib/s390x/css_dump.c | 156 ++++++++++++++++++++++++++
>>   2 files changed, 415 insertions(+)
>>   create mode 100644 lib/s390x/css.h
>>   create mode 100644 lib/s390x/css_dump.c
>>
>> diff --git a/lib/s390x/css.h b/lib/s390x/css.h
>> new file mode 100644
>> index 0000000..6f19bb5
>> --- /dev/null
>> +++ b/lib/s390x/css.h
> [...]
>> +/* Debug functions */
>> +char *dump_pmcw_flags(uint16_t f);
>> +char *dump_scsw_flags(uint32_t f);
>> +#undef DEBUG
>> +#ifdef DEBUG
>> +void dump_scsw(struct scsw *);
>> +void dump_irb(struct irb *irbp);
>> +void dump_schib(struct schib *sch);
>> +struct ccw *dump_ccw(struct ccw *cp);
>> +#else
>> +static inline void dump_scsw(struct scsw *scsw) {}
>> +static inline void dump_irb(struct irb *irbp) {}
>> +static inline void dump_pmcw(struct pmcw *p) {}
>> +static inline void dump_schib(struct schib *sch) {}
>> +static inline void dump_orb(struct orb *op) {}
>> +static inline struct ccw *dump_ccw(struct ccw *cp)
>> +{
>> +	return NULL;
>> +}
>> +#endif
> 
> I'd prefer to not have a "#undef DEBUG" (or "#define DEBUG") statement
> in the header here - it could trigger unexpected behavior with other
> files that also use a DEBUG macro.
> 
> Could you please declare the prototypes here and move the "#else" part
> to the .c file instead? Thanks!
> 
>   Thomas
> 

Yes, I can do this.
Thanks
Pierre
Pierre Morel Dec. 10, 2019, 10:07 a.m. UTC | #3
On 2019-12-09 12:49, Thomas Huth wrote:
> On 06/12/2019 17.26, Pierre Morel wrote:
>> These are the include and library utilities for the css tests patch
>> series.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   lib/s390x/css.h      | 259 +++++++++++++++++++++++++++++++++++++++++++
>>   lib/s390x/css_dump.c | 156 ++++++++++++++++++++++++++
>>   2 files changed, 415 insertions(+)
>>   create mode 100644 lib/s390x/css.h
>>   create mode 100644 lib/s390x/css_dump.c
>>
>> diff --git a/lib/s390x/css.h b/lib/s390x/css.h
>> new file mode 100644
>> index 0000000..6f19bb5
>> --- /dev/null
>> +++ b/lib/s390x/css.h
> [...]
>> +/* Debug functions */
>> +char *dump_pmcw_flags(uint16_t f);
>> +char *dump_scsw_flags(uint32_t f);
>> +#undef DEBUG
>> +#ifdef DEBUG
>> +void dump_scsw(struct scsw *);
>> +void dump_irb(struct irb *irbp);
>> +void dump_schib(struct schib *sch);
>> +struct ccw *dump_ccw(struct ccw *cp);
>> +#else
>> +static inline void dump_scsw(struct scsw *scsw) {}
>> +static inline void dump_irb(struct irb *irbp) {}
>> +static inline void dump_pmcw(struct pmcw *p) {}
>> +static inline void dump_schib(struct schib *sch) {}
>> +static inline void dump_orb(struct orb *op) {}
>> +static inline struct ccw *dump_ccw(struct ccw *cp)
>> +{
>> +	return NULL;
>> +}
>> +#endif
> 
> I'd prefer to not have a "#undef DEBUG" (or "#define DEBUG") statement

Anyway hawfull!

> in the header here - it could trigger unexpected behavior with other
> files that also use a DEBUG macro.
> 
> Could you please declare the prototypes here and move the "#else" part
> to the .c file instead? Thanks!

What if I use a CSS_DEBUG here instead of a simple DEBUG definition?

It can be enabled or not by defining CSS_ENABLED ahead of the include...?
Thomas Huth Dec. 10, 2019, 10:28 a.m. UTC | #4
On 10/12/2019 11.07, Pierre Morel wrote:
> 
> 
> On 2019-12-09 12:49, Thomas Huth wrote:
>> On 06/12/2019 17.26, Pierre Morel wrote:
>>> These are the include and library utilities for the css tests patch
>>> series.
>>>
>>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>>> ---
>>>   lib/s390x/css.h      | 259 +++++++++++++++++++++++++++++++++++++++++++
>>>   lib/s390x/css_dump.c | 156 ++++++++++++++++++++++++++
>>>   2 files changed, 415 insertions(+)
>>>   create mode 100644 lib/s390x/css.h
>>>   create mode 100644 lib/s390x/css_dump.c
>>>
>>> diff --git a/lib/s390x/css.h b/lib/s390x/css.h
>>> new file mode 100644
>>> index 0000000..6f19bb5
>>> --- /dev/null
>>> +++ b/lib/s390x/css.h
>> [...]
>>> +/* Debug functions */
>>> +char *dump_pmcw_flags(uint16_t f);
>>> +char *dump_scsw_flags(uint32_t f);
>>> +#undef DEBUG
>>> +#ifdef DEBUG
>>> +void dump_scsw(struct scsw *);
>>> +void dump_irb(struct irb *irbp);
>>> +void dump_schib(struct schib *sch);
>>> +struct ccw *dump_ccw(struct ccw *cp);
>>> +#else
>>> +static inline void dump_scsw(struct scsw *scsw) {}
>>> +static inline void dump_irb(struct irb *irbp) {}
>>> +static inline void dump_pmcw(struct pmcw *p) {}
>>> +static inline void dump_schib(struct schib *sch) {}
>>> +static inline void dump_orb(struct orb *op) {}
>>> +static inline struct ccw *dump_ccw(struct ccw *cp)
>>> +{
>>> +    return NULL;
>>> +}
>>> +#endif
>>
>> I'd prefer to not have a "#undef DEBUG" (or "#define DEBUG") statement
> 
> Anyway hawfull!
> 
>> in the header here - it could trigger unexpected behavior with other
>> files that also use a DEBUG macro.
>>
>> Could you please declare the prototypes here and move the "#else" part
>> to the .c file instead? Thanks!
> 
> What if I use a CSS_DEBUG here instead of a simple DEBUG definition?
> 
> It can be enabled or not by defining CSS_ENABLED ahead of the include...?

Why does it have to be in the header and not in the .c file?

 Thomas
Pierre Morel Dec. 10, 2019, 11:22 a.m. UTC | #5
On 2019-12-10 11:28, Thomas Huth wrote:
> On 10/12/2019 11.07, Pierre Morel wrote:
>>
>>
>> On 2019-12-09 12:49, Thomas Huth wrote:
>>> On 06/12/2019 17.26, Pierre Morel wrote:
>>>> These are the include and library utilities for the css tests patch
>>>> series.
>>>>
>>>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>>>> ---
>>>>    lib/s390x/css.h      | 259 +++++++++++++++++++++++++++++++++++++++++++
>>>>    lib/s390x/css_dump.c | 156 ++++++++++++++++++++++++++
>>>>    2 files changed, 415 insertions(+)
>>>>    create mode 100644 lib/s390x/css.h
>>>>    create mode 100644 lib/s390x/css_dump.c
>>>>
>>>> diff --git a/lib/s390x/css.h b/lib/s390x/css.h
>>>> new file mode 100644
>>>> index 0000000..6f19bb5
>>>> --- /dev/null
>>>> +++ b/lib/s390x/css.h
>>> [...]
>>>> +/* Debug functions */
>>>> +char *dump_pmcw_flags(uint16_t f);
>>>> +char *dump_scsw_flags(uint32_t f);
>>>> +#undef DEBUG
>>>> +#ifdef DEBUG
>>>> +void dump_scsw(struct scsw *);
>>>> +void dump_irb(struct irb *irbp);
>>>> +void dump_schib(struct schib *sch);
>>>> +struct ccw *dump_ccw(struct ccw *cp);
>>>> +#else
>>>> +static inline void dump_scsw(struct scsw *scsw) {}
>>>> +static inline void dump_irb(struct irb *irbp) {}
>>>> +static inline void dump_pmcw(struct pmcw *p) {}
>>>> +static inline void dump_schib(struct schib *sch) {}
>>>> +static inline void dump_orb(struct orb *op) {}
>>>> +static inline struct ccw *dump_ccw(struct ccw *cp)
>>>> +{
>>>> +    return NULL;
>>>> +}
>>>> +#endif
>>>
>>> I'd prefer to not have a "#undef DEBUG" (or "#define DEBUG") statement
>>
>> Anyway hawfull!
>>
>>> in the header here - it could trigger unexpected behavior with other
>>> files that also use a DEBUG macro.
>>>
>>> Could you please declare the prototypes here and move the "#else" part
>>> to the .c file instead? Thanks!
>>
>> What if I use a CSS_DEBUG here instead of a simple DEBUG definition?
>>
>> It can be enabled or not by defining CSS_ENABLED ahead of the include...?
> 
> Why does it have to be in the header and not in the .c file?

I too mean in the C file. :)
above the include.

> 
>   Thomas
>
Thomas Huth Dec. 10, 2019, 11:27 a.m. UTC | #6
On 10/12/2019 12.22, Pierre Morel wrote:
> 
> 
> On 2019-12-10 11:28, Thomas Huth wrote:
>> On 10/12/2019 11.07, Pierre Morel wrote:
>>>
>>>
>>> On 2019-12-09 12:49, Thomas Huth wrote:
>>>> On 06/12/2019 17.26, Pierre Morel wrote:
>>>>> These are the include and library utilities for the css tests patch
>>>>> series.
>>>>>
>>>>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>>>>> ---
>>>>>    lib/s390x/css.h      | 259
>>>>> +++++++++++++++++++++++++++++++++++++++++++
>>>>>    lib/s390x/css_dump.c | 156 ++++++++++++++++++++++++++
>>>>>    2 files changed, 415 insertions(+)
>>>>>    create mode 100644 lib/s390x/css.h
>>>>>    create mode 100644 lib/s390x/css_dump.c
>>>>>
>>>>> diff --git a/lib/s390x/css.h b/lib/s390x/css.h
>>>>> new file mode 100644
>>>>> index 0000000..6f19bb5
>>>>> --- /dev/null
>>>>> +++ b/lib/s390x/css.h
>>>> [...]
>>>>> +/* Debug functions */
>>>>> +char *dump_pmcw_flags(uint16_t f);
>>>>> +char *dump_scsw_flags(uint32_t f);
>>>>> +#undef DEBUG
>>>>> +#ifdef DEBUG
>>>>> +void dump_scsw(struct scsw *);
>>>>> +void dump_irb(struct irb *irbp);
>>>>> +void dump_schib(struct schib *sch);
>>>>> +struct ccw *dump_ccw(struct ccw *cp);
>>>>> +#else
>>>>> +static inline void dump_scsw(struct scsw *scsw) {}
>>>>> +static inline void dump_irb(struct irb *irbp) {}
>>>>> +static inline void dump_pmcw(struct pmcw *p) {}
>>>>> +static inline void dump_schib(struct schib *sch) {}
>>>>> +static inline void dump_orb(struct orb *op) {}
>>>>> +static inline struct ccw *dump_ccw(struct ccw *cp)
>>>>> +{
>>>>> +    return NULL;
>>>>> +}
>>>>> +#endif
>>>>
>>>> I'd prefer to not have a "#undef DEBUG" (or "#define DEBUG") statement
>>>
>>> Anyway hawfull!
>>>
>>>> in the header here - it could trigger unexpected behavior with other
>>>> files that also use a DEBUG macro.
>>>>
>>>> Could you please declare the prototypes here and move the "#else" part
>>>> to the .c file instead? Thanks!
>>>
>>> What if I use a CSS_DEBUG here instead of a simple DEBUG definition?
>>>
>>> It can be enabled or not by defining CSS_ENABLED ahead of the
>>> include...?
>>
>> Why does it have to be in the header and not in the .c file?
> 
> I too mean in the C file. :)
> above the include.

Well, as long as we don't have any generic "#undef DEBUG" statements in
the header anymore, I think I don't care too much either way.

 Thomas
Pierre Morel Dec. 10, 2019, 11:28 a.m. UTC | #7
On 2019-12-10 12:27, Thomas Huth wrote:
> On 10/12/2019 12.22, Pierre Morel wrote:
>>
>>
>> On 2019-12-10 11:28, Thomas Huth wrote:
>>> On 10/12/2019 11.07, Pierre Morel wrote:
>>>>
>>>>
>>>> On 2019-12-09 12:49, Thomas Huth wrote:
>>>>> On 06/12/2019 17.26, Pierre Morel wrote:
>>>>>> These are the include and library utilities for the css tests patch
>>>>>> series.
>>>>>>
>>>>>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>>>>>> ---
>>>>>>     lib/s390x/css.h      | 259
>>>>>> +++++++++++++++++++++++++++++++++++++++++++
>>>>>>     lib/s390x/css_dump.c | 156 ++++++++++++++++++++++++++
>>>>>>     2 files changed, 415 insertions(+)
>>>>>>     create mode 100644 lib/s390x/css.h
>>>>>>     create mode 100644 lib/s390x/css_dump.c
>>>>>>
>>>>>> diff --git a/lib/s390x/css.h b/lib/s390x/css.h
>>>>>> new file mode 100644
>>>>>> index 0000000..6f19bb5
>>>>>> --- /dev/null
>>>>>> +++ b/lib/s390x/css.h
>>>>> [...]
>>>>>> +/* Debug functions */
>>>>>> +char *dump_pmcw_flags(uint16_t f);
>>>>>> +char *dump_scsw_flags(uint32_t f);
>>>>>> +#undef DEBUG
>>>>>> +#ifdef DEBUG
>>>>>> +void dump_scsw(struct scsw *);
>>>>>> +void dump_irb(struct irb *irbp);
>>>>>> +void dump_schib(struct schib *sch);
>>>>>> +struct ccw *dump_ccw(struct ccw *cp);
>>>>>> +#else
>>>>>> +static inline void dump_scsw(struct scsw *scsw) {}
>>>>>> +static inline void dump_irb(struct irb *irbp) {}
>>>>>> +static inline void dump_pmcw(struct pmcw *p) {}
>>>>>> +static inline void dump_schib(struct schib *sch) {}
>>>>>> +static inline void dump_orb(struct orb *op) {}
>>>>>> +static inline struct ccw *dump_ccw(struct ccw *cp)
>>>>>> +{
>>>>>> +    return NULL;
>>>>>> +}
>>>>>> +#endif
>>>>>
>>>>> I'd prefer to not have a "#undef DEBUG" (or "#define DEBUG") statement
>>>>
>>>> Anyway hawfull!
>>>>
>>>>> in the header here - it could trigger unexpected behavior with other
>>>>> files that also use a DEBUG macro.
>>>>>
>>>>> Could you please declare the prototypes here and move the "#else" part
>>>>> to the .c file instead? Thanks!
>>>>
>>>> What if I use a CSS_DEBUG here instead of a simple DEBUG definition?
>>>>
>>>> It can be enabled or not by defining CSS_ENABLED ahead of the
>>>> include...?
>>>
>>> Why does it have to be in the header and not in the .c file?
>>
>> I too mean in the C file. :)
>> above the include.
> 
> Well, as long as we don't have any generic "#undef DEBUG" statements in
> the header anymore, I think I don't care too much either way.

Yes, it was not good, shoudn't have survive my first tests.

Thanks
Pierre

> 
>   Thomas
>
diff mbox series

Patch

diff --git a/lib/s390x/css.h b/lib/s390x/css.h
new file mode 100644
index 0000000..6f19bb5
--- /dev/null
+++ b/lib/s390x/css.h
@@ -0,0 +1,259 @@ 
+/*
+ * CSS definitions
+ *
+ * Copyright IBM, Corp. 2019
+ * Author: Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#ifndef CSS_H
+#define CSS_H
+
+#define CCW_F_CD	0x80
+#define CCW_F_CC	0x40
+#define CCW_F_SLI	0x20
+#define CCW_F_SKP	0x10
+#define CCW_F_PCI	0x08
+#define CCW_F_IDA	0x04
+#define CCW_F_S		0x02
+#define CCW_F_MIDA	0x01
+
+#define CCW_C_NOP	0x03
+#define CCW_C_TIC	0x08
+
+struct ccw1 {
+	unsigned char code;
+	unsigned char flags;
+	unsigned short count;
+	uint32_t data_address;
+} __attribute__ ((aligned(4)));
+
+#define ORB_M_KEY	0xf0000000
+#define ORB_F_SUSPEND	0x08000000
+#define ORB_F_STREAMING	0x04000000
+#define ORB_F_MODIFCTRL	0x02000000
+#define ORB_F_SYNC	0x01000000
+#define ORB_F_FORMAT	0x00800000
+#define ORB_F_PREFETCH	0x00400000
+#define ORB_F_INIT_IRQ	0x00200000
+#define ORB_F_ADDRLIMIT	0x00100000
+#define ORB_F_SUSP_IRQ	0x00080000
+#define ORB_F_TRANSPORT	0x00040000
+#define ORB_F_IDAW2	0x00020000
+#define ORB_F_IDAW_2K	0x00010000
+#define ORB_M_LPM	0x0000ff00
+#define ORB_F_LPM_DFLT	0x00008000
+#define ORB_F_ILSM	0x00000080
+#define ORB_F_CCW_IND	0x00000040
+#define ORB_F_ORB_EXT	0x00000001
+
+struct orb {
+	uint32_t intparm;
+	uint32_t ctrl;
+	uint32_t cpa;
+	uint32_t prio;
+	uint32_t reserved[4];
+} __attribute__ ((aligned(4)));
+
+struct scsw {
+	uint32_t ctrl;
+	uint32_t ccw_addr;
+	uint8_t  dev_stat;
+	uint8_t  sch_stat;
+	uint16_t count;
+};
+
+struct pmcw {
+	uint32_t intparm;
+#define PMCW_DNV        0x0001
+#define PMCW_ENABLE     0x0080
+	uint16_t flags;
+	uint16_t devnum;
+	uint8_t  lpm;
+	uint8_t  pnom;
+	uint8_t  lpum;
+	uint8_t  pim;
+	uint16_t mbi;
+	uint8_t  pom;
+	uint8_t  pam;
+	uint8_t  chpid[8];
+	uint16_t flags2;
+};
+
+struct schib {
+	struct pmcw pmcw;
+	struct scsw scsw;
+	uint8_t  md[12];
+} __attribute__ ((aligned(4)));
+
+struct irb {
+	struct scsw scsw;
+	uint32_t esw[5];
+	uint32_t ecw[8];
+	uint32_t emw[8];
+} __attribute__ ((aligned(4)));
+
+/* CSS low level access functions */
+
+static inline int ssch(unsigned long schid, struct orb *addr)
+{
+	register long long reg1 asm("1") = schid;
+	int cc = -1;
+
+	asm volatile(
+		"	   ssch	0(%2)\n"
+		"0:	 ipm	 %0\n"
+		"	   srl	 %0,28\n"
+		"1:\n"
+		: "+d" (cc)
+		: "d" (reg1), "a" (addr), "m" (*addr)
+		: "cc", "memory");
+	return cc;
+}
+
+static inline int stsch(unsigned long schid, struct schib *addr)
+{
+	register unsigned long reg1 asm ("1") = schid;
+	int cc;
+
+	asm volatile(
+		"	   stsch	0(%3)\n"
+		"	   ipm	 %0\n"
+		"	   srl	 %0,28"
+		: "=d" (cc), "=m" (*addr)
+		: "d" (reg1), "a" (addr)
+		: "cc");
+	return cc;
+}
+
+static inline int msch(unsigned long schid, struct schib *addr)
+{
+	register unsigned long reg1 asm ("1") = schid;
+	int cc;
+
+	asm volatile(
+		"	   msch	0(%3)\n"
+		"	   ipm	 %0\n"
+		"	   srl	 %0,28"
+		: "=d" (cc), "=m" (*addr)
+		: "d" (reg1), "a" (addr)
+		: "cc");
+	return cc;
+}
+
+static inline int tsch(unsigned long schid, struct irb *addr)
+{
+	register unsigned long reg1 asm ("1") = schid;
+	int cc;
+
+	asm volatile(
+		"	   tsch	0(%3)\n"
+		"	   ipm	 %0\n"
+		"	   srl	 %0,28"
+		: "=d" (cc), "=m" (*addr)
+		: "d" (reg1), "a" (addr)
+		: "cc");
+	return cc;
+}
+
+static inline int hsch(unsigned long schid)
+{
+	register unsigned long reg1 asm("1") = schid;
+	int cc;
+
+	asm volatile(
+		"	hsch\n"
+		"	ipm	%0\n"
+		"	srl	%0,28"
+		: "=d" (cc)
+		: "d" (reg1)
+		: "cc");
+	return cc;
+}
+
+static inline int xsch(unsigned long schid)
+{
+	register unsigned long reg1 asm("1") = schid;
+	int cc;
+
+	asm volatile(
+		"	xsch\n"
+		"	ipm	%0\n"
+		"	srl	%0,28"
+		: "=d" (cc)
+		: "d" (reg1)
+		: "cc");
+	return cc;
+}
+
+static inline int csch(unsigned long schid)
+{
+	register unsigned long reg1 asm("1") = schid;
+	int cc;
+
+	asm volatile(
+		"	csch\n"
+		"	ipm	%0\n"
+		"	srl	%0,28"
+		: "=d" (cc)
+		: "d" (reg1)
+		: "cc");
+	return cc;
+}
+
+static inline int rsch(unsigned long schid)
+{
+	register unsigned long reg1 asm("1") = schid;
+	int cc;
+
+	asm volatile(
+		"	rsch\n"
+		"	ipm	%0\n"
+		"	srl	%0,28"
+		: "=d" (cc)
+		: "d" (reg1)
+		: "cc");
+	return cc;
+}
+
+static inline int rchp(unsigned long chpid)
+{
+	register unsigned long reg1 asm("1") = chpid;
+	int cc;
+
+	asm volatile(
+		"	rchp\n"
+		"	ipm	%0\n"
+		"	srl	%0,28"
+		: "=d" (cc)
+		: "d" (reg1)
+		: "cc");
+	return cc;
+}
+
+/* Debug functions */
+char *dump_pmcw_flags(uint16_t f);
+char *dump_scsw_flags(uint32_t f);
+#undef DEBUG
+#ifdef DEBUG
+void dump_scsw(struct scsw *);
+void dump_irb(struct irb *irbp);
+void dump_schib(struct schib *sch);
+struct ccw *dump_ccw(struct ccw *cp);
+#else
+static inline void dump_scsw(struct scsw *scsw) {}
+static inline void dump_irb(struct irb *irbp) {}
+static inline void dump_pmcw(struct pmcw *p) {}
+static inline void dump_schib(struct schib *sch) {}
+static inline void dump_orb(struct orb *op) {}
+static inline struct ccw *dump_ccw(struct ccw *cp)
+{
+	return NULL;
+}
+#endif
+
+extern unsigned long stacktop;
+#endif
diff --git a/lib/s390x/css_dump.c b/lib/s390x/css_dump.c
new file mode 100644
index 0000000..651755d
--- /dev/null
+++ b/lib/s390x/css_dump.c
@@ -0,0 +1,156 @@ 
+/*
+ * Channel subsystem structures dumping
+ *
+ * Copyright (c) 2019 IBM Corp.
+ *
+ * Authors:
+ *  Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Library General Public License version 2.
+ *
+ * Description:
+ * Provides the dumping functions for various structures used by subchannels:
+ * - ORB  : Operation request block, describes the I/O operation and points to
+ *          a CCW chain
+ * - CCW  : Channel Command Word, describes the data and flow control
+ * - IRB  : Interuption response Block, describes the result of an operation
+ *          holds a SCSW and model-dependent data.
+ * - SCHIB: SubCHannel Information Block composed of:
+ *   - SCSW: SubChannel Status Word, status of the channel.
+ *   - PMCW: Path Management Control Word
+ * You need the QEMU ccw-pong device in QEMU to answer the I/O transfers.
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <css.h>
+
+/*
+ * Try to have a more human representation of the SCSW flags:
+ * each letter in the two strings he under represent the first
+ * letter of the associated bit in the flag.
+ */
+static const char *scsw_str = "kkkkslccfpixuzen";
+static const char *scsw_str2 = "1SHCrshcsdsAIPSs";
+static char scsw_line[64] = {};
+
+char *dump_scsw_flags(uint32_t f)
+{
+	int i;
+
+	for (i = 0; i < 16; i++) {
+		if ((f << i) & 0x80000000)
+			scsw_line[i] = scsw_str[i];
+		else
+			scsw_line[i] = '_';
+	}
+	scsw_line[i] = ' ';
+	for (; i < 32; i++) {
+		if ((f << i) & 0x80000000)
+			scsw_line[i + 1] = scsw_str2[i - 16];
+		else
+			scsw_line[i + 1] = '_';
+	}
+	return scsw_line;
+}
+
+/*
+ * Try o have a more human representation of the PMCW flags
+ * each letter in the two strings he under represent the first
+ * letter of the associated bit in the flag.
+ */
+static const char *pmcw_str = "11iii111ellmmdtv";
+static char pcmw_line[32] = {};
+char *dump_pmcw_flags(uint16_t f)
+{
+	int i;
+
+	for (i = 0; i < 16; i++) {
+		if ((f << i) & 0x8000)
+			pcmw_line[i] = pmcw_str[i];
+		else
+			pcmw_line[i] = '_';
+	}
+	return pcmw_line;
+}
+
+#ifdef DEBUG
+void dump_scsw(struct scsw *s)
+{
+	dump_scsw_flags(s->ctrl);
+	printf("scsw->flags: %s\n", line);
+	printf("scsw->addr : %08x\n", s->addr);
+	printf("scsw->devs : %02x\n", s->devs);
+	printf("scsw->schs : %02x\n", s->schs);
+	printf("scsw->count: %04x\n", s->count);
+}
+
+void dump_irb(struct irb *irbp)
+{
+	int i;
+	uint32_t *p = (uint32_t *)irbp;
+
+	dump_scsw(&irbp->scsw);
+	for (i = 0; i < sizeof(*irbp)/sizeof(*p); i++, p++)
+		printf("irb[%02x] : %08x\n", i, *p);
+}
+
+void dump_pmcw(struct pmcw *p)
+{
+	int i;
+
+	printf("pmcw->intparm  : %08x\n", p->intparm);
+	printf("pmcw->flags    : %04x\n", p->flags);
+	dump_pmcw_flags(p->flags);
+	printf("pmcw->devnum   : %04x\n", p->devnum);
+	printf("pmcw->lpm      : %02x\n", p->lpm);
+	printf("pmcw->pnom     : %02x\n", p->pnom);
+	printf("pmcw->lpum     : %02x\n", p->lpum);
+	printf("pmcw->pim      : %02x\n", p->pim);
+	printf("pmcw->mbi      : %04x\n", p->mbi);
+	printf("pmcw->pom      : %02x\n", p->pom);
+	printf("pmcw->pam      : %02x\n", p->pam);
+	printf("pmcw->mbi      : %04x\n", p->mbi);
+	for (i = 0; i < 8; i++)
+		printf("pmcw->chpid[%d]: %02x\n", i, p->chpid[i]);
+	printf("pmcw->flags2  : %08x\n", p->flags2);
+}
+
+void dump_schib(struct schib *sch)
+{
+	struct pmcw *p = &sch->pmcw;
+	struct scsw *s = &sch->scsw;
+
+	printf("--SCHIB--\n");
+	dump_pmcw(p);
+	dump_scsw(s);
+}
+
+struct ccw *dump_ccw(struct ccw *cp)
+{
+	printf("CCW: code: %02x flags: %02x count: %04x data: %08x\n", cp->code,
+	    cp->flags, cp->count, cp->data);
+
+	if (cp->code == CCW_C_TIC)
+		return (struct ccw *)(long)cp->data;
+
+	return (cp->flags & CCW_F_CC) ? cp + 1 : NULL;
+}
+
+void dump_orb(struct orb *op)
+{
+	struct ccw *cp;
+
+	printf("ORB: intparm : %08x\n", op->intparm);
+	printf("ORB: ctrl    : %08x\n", op->ctrl);
+	printf("ORB: prio    : %08x\n", op->prio);
+	cp = (struct ccw *)(long) (op->cpa);
+	while (cp)
+		cp = dump_ccw(cp);
+}
+
+#endif