[PATCH] s390: qdio V=V pass-through

New feature V=V qdio pass-through.

QDIO and HiperSockets processing in z/VM V=V guest environments (as well as
V=R with z/VM running in LPAR mode) requires shadowing of all QDIO
architecture queue elements.  Especially the shadowing of SBALs and SLSBs
structures in the hypervisor, and the need to issue SIGA SYNC operations to
observe state changes, eventually causes significant CPU processing overhead
in the hypervisor.

The QDIO pass-through support for V=V guests avoids the shadowing of SBALs and
SLSBs.  This significantly reduces the hypervisor overhead for QDIO based I/O.
Signed-off-by: Frank Pavlic <pavlic@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/s390/Kconfig

@@ -240,8 +240,8 @@ config MACHCHK_WARNING
 config QDIO
 	tristate "QDIO support"
 	---help---
-	  This driver provides the Queued Direct I/O base support for the
-	  IBM S/390 (G5 and G6) and eServer zSeries (z800, z890, z900 and z990).
+	  This driver provides the Queued Direct I/O base support for
+	  IBM mainframes.
 
 	  For details please refer to the documentation provided by IBM at
 	  <http://www10.software.ibm.com/developerworks/opensource/linux390>
@@ -263,7 +263,8 @@ config QDIO_DEBUG
 	bool "Extended debugging information"
 	depends on QDIO
 	help
-	  Say Y here to get extended debugging output in /proc/s390dbf/qdio...
+	  Say Y here to get extended debugging output in
+	    /sys/kernel/debug/s390dbf/qdio...
 	  Warning: this option reduces the performance of the QDIO module.
 
 	  If unsure, say N.

drivers/s390/cio/chsc.h

@@ -43,7 +43,9 @@ struct css_general_char {
 	u32 ext_mb : 1;  /* bit 48 */
 	u32 : 7;
 	u32 aif_tdd : 1; /* bit 56 */
-	u32 : 10;
+	u32 : 1;
+	u32 qebsm : 1;   /* bit 58 */
+	u32 : 8;
 	u32 aif_osa : 1; /* bit 67 */
 	u32 : 28;
 }__attribute__((packed));

drivers/s390/cio/qdio.h

@@ -3,14 +3,13 @@
 
 #include <asm/page.h>
 
-#define VERSION_CIO_QDIO_H "$Revision: 1.33 $"
+#define VERSION_CIO_QDIO_H "$Revision: 1.37 $"
 
 #ifdef CONFIG_QDIO_DEBUG
 #define QDIO_VERBOSE_LEVEL 9
 #else /* CONFIG_QDIO_DEBUG */
 #define QDIO_VERBOSE_LEVEL 5
 #endif /* CONFIG_QDIO_DEBUG */
-
 #define QDIO_USE_PROCESSING_STATE
 
 #ifdef CONFIG_QDIO_PERF_STATS
@@ -265,6 +264,58 @@ QDIO_PRINT_##importance(header "%02x %02x %02x %02x  %02x %02x %02x %02x  " \
 /*
  * Some instructions as assembly
  */
+
+static inline int
+do_sqbs(unsigned long sch, unsigned char state, int queue,
+       unsigned int *start, unsigned int *count)
+{
+#ifdef CONFIG_ARCH_S390X
+       register unsigned long _ccq asm ("0") = *count;
+       register unsigned long _sch asm ("1") = sch;
+       unsigned long _queuestart = ((unsigned long)queue << 32) | *start;
+
+       asm volatile (
+              " .insn rsy,0xeb000000008A,%1,0,0(%2)\n\t"
+              : "+d" (_ccq), "+d" (_queuestart)
+              : "d" ((unsigned long)state), "d" (_sch)
+              : "memory", "cc"
+       );
+       *count = _ccq & 0xff;
+       *start = _queuestart & 0xff;
+
+       return (_ccq >> 32) & 0xff;
+#else
+       return 0;
+#endif
+}
+
+static inline int
+do_eqbs(unsigned long sch, unsigned char *state, int queue,
+	unsigned int *start, unsigned int *count)
+{
+#ifdef CONFIG_ARCH_S390X
+	register unsigned long _ccq asm ("0") = *count;
+	register unsigned long _sch asm ("1") = sch;
+	unsigned long _queuestart = ((unsigned long)queue << 32) | *start;
+	unsigned long _state = 0;
+
+	asm volatile (
+	      " .insn rrf,0xB99c0000,%1,%2,0,0  \n\t"
+	      : "+d" (_ccq), "+d" (_queuestart), "+d" (_state)
+	      : "d" (_sch)
+	      : "memory", "cc"
+	);
+	*count = _ccq & 0xff;
+	*start = _queuestart & 0xff;
+	*state = _state & 0xff;
+
+	return (_ccq >> 32) & 0xff;
+#else
+	return 0;
+#endif
+}
+
+
 static inline int
 do_siga_sync(unsigned int irq, unsigned int mask1, unsigned int mask2)
 {
@@ -280,7 +331,7 @@ do_siga_sync(unsigned int irq, unsigned int mask1, unsigned int mask2)
 		"ipm	%0	\n\t"
 		"srl	%0,28	\n\t"
 		: "=d" (cc)
-		: "d" (0x10000|irq), "d" (mask1), "d" (mask2)
+		: "d" (irq), "d" (mask1), "d" (mask2)
 		: "cc", "0", "1", "2", "3"
 		);
 #else /* CONFIG_ARCH_S390X */
@@ -293,7 +344,7 @@ do_siga_sync(unsigned int irq, unsigned int mask1, unsigned int mask2)
 		"ipm	%0	\n\t"
 		"srl	%0,28	\n\t"
 		: "=d" (cc)
-		: "d" (0x10000|irq), "d" (mask1), "d" (mask2)
+		: "d" (irq), "d" (mask1), "d" (mask2)
 		: "cc", "0", "1", "2", "3"
 		);
 #endif /* CONFIG_ARCH_S390X */
@@ -314,7 +365,7 @@ do_siga_input(unsigned int irq, unsigned int mask)
 		"ipm	%0	\n\t"
 		"srl	%0,28	\n\t"
 		: "=d" (cc)
-		: "d" (0x10000|irq), "d" (mask)
+		: "d" (irq), "d" (mask)
 		: "cc", "0", "1", "2", "memory"
 		);
 #else /* CONFIG_ARCH_S390X */
@@ -326,7 +377,7 @@ do_siga_input(unsigned int irq, unsigned int mask)
 		"ipm	%0	\n\t"
 		"srl	%0,28	\n\t"
 		: "=d" (cc)
-		: "d" (0x10000|irq), "d" (mask)
+		: "d" (irq), "d" (mask)
 		: "cc", "0", "1", "2", "memory"
 		);
 #endif /* CONFIG_ARCH_S390X */
@@ -335,7 +386,8 @@ do_siga_input(unsigned int irq, unsigned int mask)
 }
 
 static inline int
-do_siga_output(unsigned long irq, unsigned long mask, __u32 *bb)
+do_siga_output(unsigned long irq, unsigned long mask, __u32 *bb,
+	       unsigned int fc)
 {
 	int cc;
 	__u32 busy_bit;
@@ -366,14 +418,14 @@ do_siga_output(unsigned long irq, unsigned long mask, __u32 *bb)
 		".long	0b,2b	\n\t"
 		".previous	\n\t"
 		: "=d" (cc), "=d" (busy_bit)
-		: "d" (0x10000|irq), "d" (mask),
+		: "d" (irq), "d" (mask),
 		"i" (QDIO_SIGA_ERROR_ACCESS_EXCEPTION)
 		: "cc", "0", "1", "2", "memory"
 		);
 #else /* CONFIG_ARCH_S390X */
 	asm volatile (
-		"lghi	0,0	\n\t"
-		"llgfr	1,%2	\n\t"
+        	"llgfr  0,%5    \n\t"
+                "lgr    1,%2    \n\t"
 		"llgfr	2,%3	\n\t"
 		"siga	0	\n\t"
 		"0:"
@@ -391,8 +443,8 @@ do_siga_output(unsigned long irq, unsigned long mask, __u32 *bb)
 		".quad	0b,1b	\n\t"
 		".previous	\n\t"
 		: "=d" (cc), "=d" (busy_bit)
-		: "d" (0x10000|irq), "d" (mask),
-		"i" (QDIO_SIGA_ERROR_ACCESS_EXCEPTION)
+		: "d" (irq), "d" (mask),
+		"i" (QDIO_SIGA_ERROR_ACCESS_EXCEPTION), "d" (fc)
 		: "cc", "0", "1", "2", "memory"
 		);
 #endif /* CONFIG_ARCH_S390X */
@@ -494,33 +546,12 @@ struct qdio_perf_stats {
 #define QDIO_GET_ADDR(x) ((__u32)(long)x)
 #endif /* CONFIG_ARCH_S390X */
 
-#ifdef CONFIG_QDIO_DEBUG
-#define set_slsb(x,y) \
-  if(q->queue_type==QDIO_TRACE_QTYPE) { \
-        if(q->is_input_q) { \
-            QDIO_DBF_HEX2(0,slsb_in,&q->slsb,QDIO_MAX_BUFFERS_PER_Q); \
-        } else { \
-            QDIO_DBF_HEX2(0,slsb_out,&q->slsb,QDIO_MAX_BUFFERS_PER_Q); \
-        } \
-  } \
-  qdio_set_slsb(x,y); \
-  if(q->queue_type==QDIO_TRACE_QTYPE) { \
-        if(q->is_input_q) { \
-            QDIO_DBF_HEX2(0,slsb_in,&q->slsb,QDIO_MAX_BUFFERS_PER_Q); \
-        } else { \
-            QDIO_DBF_HEX2(0,slsb_out,&q->slsb,QDIO_MAX_BUFFERS_PER_Q); \
-        } \
-  }
-#else /* CONFIG_QDIO_DEBUG */
-#define set_slsb(x,y) qdio_set_slsb(x,y)
-#endif /* CONFIG_QDIO_DEBUG */
-
 struct qdio_q {
 	volatile struct slsb slsb;
 
 	char unused[QDIO_MAX_BUFFERS_PER_Q];
 
-	__u32 * volatile dev_st_chg_ind;
+	__u32 * dev_st_chg_ind;
 
 	int is_input_q;
 	int irq;
@@ -568,6 +599,7 @@ struct qdio_q {
 	struct tasklet_struct tasklet;
 #endif /* QDIO_USE_TIMERS_FOR_POLLING */
 
+
 	enum qdio_irq_states state;
 
 	/* used to store the error condition during a data transfer */
@@ -624,6 +656,10 @@ struct qdio_irq {
 	unsigned int hydra_gives_outbound_pcis;
 	unsigned int sync_done_on_outb_pcis;
 
+	/* QEBSM facility */
+	unsigned int is_qebsm;
+	unsigned long sch_token;
+
 	enum qdio_irq_states state;
 
 	unsigned int no_input_qs;

include/asm-s390/qdio.h

@@ -195,12 +195,14 @@ struct qdr {
 /*
  * queue information block (QIB)
  */
-#define QIB_AC_INBOUND_PCI_SUPPORTED 0x80
-#define QIB_AC_OUTBOUND_PCI_SUPPORTED 0x40
+#define QIB_AC_INBOUND_PCI_SUPPORTED 	0x80
+#define QIB_AC_OUTBOUND_PCI_SUPPORTED 	0x40
+#define QIB_RFLAGS_ENABLE_QEBSM		0x80
+
 struct qib {
 	unsigned int  qfmt    :  8;     /* queue format */
 	unsigned int  pfmt    :  8;     /* impl. dep. parameter format */
-	unsigned int  res1    :  8;     /* reserved */
+	unsigned int  rflags  :  8;	/* QEBSM */
 	unsigned int  ac      :  8;     /* adapter characteristics */
 	unsigned int  res2;             /* reserved */
 #ifdef QDIO_32_BIT