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* [kvm-unit-tests PATCH v2 0/6] s390x: Add multiboot and smp
@ 2019-09-05 10:39 Janosch Frank
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 1/6] s390x: Use interrupts in SCLP and add locking Janosch Frank
                   ` (5 more replies)
  0 siblings, 6 replies; 21+ messages in thread
From: Janosch Frank @ 2019-09-05 10:39 UTC (permalink / raw)
  To: kvm; +Cc: linux-s390, david, thuth

Cross testing emulated instructions has in the past brought up some
issues on all available IBM Z hypervisors. So let's upstream the last
part of multiboot: sclp interrupts and line mode console.

SMP tests are a great way to excercise external interruptions, cpu
resets and sigp. The smp library is always initialized and provides
very rudimentary CPU management for now.

v2:
* Fixed cr0 masks
* Replaced gotos with loops
* Addressed other review comments

Janosch Frank (6):
  s390x: Use interrupts in SCLP and add locking
  s390x: Add linemode console
  s390x: Add linemode buffer to fix newline on every print
  s390x: Add initial smp code
  s390x: Prepare for external calls
  s390x: SMP test

 lib/s390x/asm/arch_def.h  |  13 ++
 lib/s390x/asm/interrupt.h |   5 +
 lib/s390x/asm/sigp.h      |  28 +++-
 lib/s390x/interrupt.c     |  28 +++-
 lib/s390x/io.c            |   5 +-
 lib/s390x/sclp-console.c  | 243 ++++++++++++++++++++++++++++++---
 lib/s390x/sclp.c          |  55 +++++++-
 lib/s390x/sclp.h          |  59 +++++++-
 lib/s390x/smp.c           | 276 ++++++++++++++++++++++++++++++++++++++
 lib/s390x/smp.h           |  51 +++++++
 s390x/Makefile            |   2 +
 s390x/cstart64.S          |   7 +
 s390x/smp.c               | 242 +++++++++++++++++++++++++++++++++
 s390x/unittests.cfg       |   4 +
 14 files changed, 991 insertions(+), 27 deletions(-)
 create mode 100644 lib/s390x/smp.c
 create mode 100644 lib/s390x/smp.h
 create mode 100644 s390x/smp.c

-- 
2.17.0


^ permalink raw reply	[flat|nested] 21+ messages in thread

* [kvm-unit-tests PATCH v2 1/6] s390x: Use interrupts in SCLP and add locking
  2019-09-05 10:39 [kvm-unit-tests PATCH v2 0/6] s390x: Add multiboot and smp Janosch Frank
@ 2019-09-05 10:39 ` Janosch Frank
  2019-09-09  9:08   ` Thomas Huth
  2019-09-10 10:14   ` David Hildenbrand
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 2/6] s390x: Add linemode console Janosch Frank
                   ` (4 subsequent siblings)
  5 siblings, 2 replies; 21+ messages in thread
From: Janosch Frank @ 2019-09-05 10:39 UTC (permalink / raw)
  To: kvm; +Cc: linux-s390, david, thuth

We need to properly implement interrupt handling for SCLP, because on
z/VM and LPAR SCLP calls are not synchronous!

Also with smp CPUs have to compete for sclp. Let's add some locking,
so they execute sclp calls in an orderly fashion and don't compete for
the data buffer.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 lib/s390x/asm/interrupt.h |  2 ++
 lib/s390x/interrupt.c     | 12 +++++++--
 lib/s390x/sclp-console.c  |  2 ++
 lib/s390x/sclp.c          | 55 +++++++++++++++++++++++++++++++++++++--
 lib/s390x/sclp.h          |  3 +++
 5 files changed, 70 insertions(+), 4 deletions(-)

diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
index 013709f..f485e96 100644
--- a/lib/s390x/asm/interrupt.h
+++ b/lib/s390x/asm/interrupt.h
@@ -11,6 +11,8 @@
 #define _ASMS390X_IRQ_H_
 #include <asm/arch_def.h>
 
+#define EXT_IRQ_SERVICE_SIG	0x2401
+
 void handle_pgm_int(void);
 void handle_ext_int(void);
 void handle_mcck_int(void);
diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
index cf0a794..7832711 100644
--- a/lib/s390x/interrupt.c
+++ b/lib/s390x/interrupt.c
@@ -12,6 +12,7 @@
 #include <libcflat.h>
 #include <asm/interrupt.h>
 #include <asm/barrier.h>
+#include <sclp.h>
 
 static bool pgm_int_expected;
 static struct lowcore *lc;
@@ -107,8 +108,15 @@ void handle_pgm_int(void)
 
 void handle_ext_int(void)
 {
-	report_abort("Unexpected external call interrupt: at %#lx",
-		     lc->ext_old_psw.addr);
+	if (lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
+		report_abort("Unexpected external call interrupt: at %#lx",
+			     lc->ext_old_psw.addr);
+	} else {
+		lc->ext_old_psw.mask &= ~PSW_MASK_EXT;
+		lc->sw_int_cr0 &= ~(1UL << 9);
+		sclp_handle_ext();
+		lc->ext_int_code = 0;
+	}
 }
 
 void handle_mcck_int(void)
diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
index bc01f41..a5ef45f 100644
--- a/lib/s390x/sclp-console.c
+++ b/lib/s390x/sclp-console.c
@@ -17,6 +17,7 @@ static void sclp_set_write_mask(void)
 {
 	WriteEventMask *sccb = (void *)_sccb;
 
+	sclp_mark_busy();
 	sccb->h.length = sizeof(WriteEventMask);
 	sccb->mask_length = sizeof(unsigned int);
 	sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
@@ -37,6 +38,7 @@ void sclp_print(const char *str)
 	int len = strlen(str);
 	WriteEventData *sccb = (void *)_sccb;
 
+	sclp_mark_busy();
 	sccb->h.length = sizeof(WriteEventData) + len;
 	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
 	sccb->ebh.length = sizeof(EventBufferHeader) + len;
diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c
index b60f7a4..56fca0c 100644
--- a/lib/s390x/sclp.c
+++ b/lib/s390x/sclp.c
@@ -14,6 +14,8 @@
 #include <asm/page.h>
 #include <asm/arch_def.h>
 #include <asm/interrupt.h>
+#include <asm/barrier.h>
+#include <asm/spinlock.h>
 #include "sclp.h"
 #include <alloc_phys.h>
 #include <alloc_page.h>
@@ -25,6 +27,8 @@ static uint64_t max_ram_size;
 static uint64_t ram_size;
 
 char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096)));
+static volatile bool sclp_busy;
+static struct spinlock sclp_lock;
 
 static void mem_init(phys_addr_t mem_end)
 {
@@ -41,17 +45,62 @@ static void mem_init(phys_addr_t mem_end)
 	page_alloc_ops_enable();
 }
 
+static void sclp_setup_int(void)
+{
+	uint64_t mask;
+
+	ctl_set_bit(0, 9);
+
+	mask = extract_psw_mask();
+	mask |= PSW_MASK_EXT;
+	load_psw_mask(mask);
+}
+
+void sclp_handle_ext(void)
+{
+	ctl_clear_bit(0, 9);
+	spin_lock(&sclp_lock);
+	sclp_busy = false;
+	spin_unlock(&sclp_lock);
+}
+
+void sclp_wait_busy(void)
+{
+	while (sclp_busy)
+		mb();
+}
+
+void sclp_mark_busy(void)
+{
+	/*
+	 * With multiple CPUs we might need to wait for another CPU's
+	 * request before grabbing the busy indication.
+	 */
+	while (true) {
+		sclp_wait_busy();
+		spin_lock(&sclp_lock);
+		if (!sclp_busy) {
+			sclp_busy = true;
+			spin_unlock(&sclp_lock);
+			return;
+		}
+		spin_unlock(&sclp_lock);
+	}
+}
+
 static void sclp_read_scp_info(ReadInfo *ri, int length)
 {
 	unsigned int commands[] = { SCLP_CMDW_READ_SCP_INFO_FORCED,
 				    SCLP_CMDW_READ_SCP_INFO };
-	int i;
+	int i, cc;
 
 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
+		sclp_mark_busy();
 		memset(&ri->h, 0, sizeof(ri->h));
 		ri->h.length = length;
 
-		if (sclp_service_call(commands[i], ri))
+		cc = sclp_service_call(commands[i], ri);
+		if (cc)
 			break;
 		if (ri->h.response_code == SCLP_RC_NORMAL_READ_COMPLETION)
 			return;
@@ -66,12 +115,14 @@ int sclp_service_call(unsigned int command, void *sccb)
 {
 	int cc;
 
+	sclp_setup_int();
 	asm volatile(
 		"       .insn   rre,0xb2200000,%1,%2\n"  /* servc %1,%2 */
 		"       ipm     %0\n"
 		"       srl     %0,28"
 		: "=&d" (cc) : "d" (command), "a" (__pa(sccb))
 		: "cc", "memory");
+	sclp_wait_busy();
 	if (cc == 3)
 		return -1;
 	if (cc == 2)
diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
index 583c4e5..63cf609 100644
--- a/lib/s390x/sclp.h
+++ b/lib/s390x/sclp.h
@@ -213,6 +213,9 @@ typedef struct ReadEventData {
 } __attribute__((packed)) ReadEventData;
 
 extern char _sccb[];
+void sclp_handle_ext(void);
+void sclp_wait_busy(void);
+void sclp_mark_busy(void);
 void sclp_console_setup(void);
 void sclp_print(const char *str);
 int sclp_service_call(unsigned int command, void *sccb);
-- 
2.17.0


^ permalink raw reply	[flat|nested] 21+ messages in thread

* [kvm-unit-tests PATCH v2 2/6] s390x: Add linemode console
  2019-09-05 10:39 [kvm-unit-tests PATCH v2 0/6] s390x: Add multiboot and smp Janosch Frank
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 1/6] s390x: Use interrupts in SCLP and add locking Janosch Frank
@ 2019-09-05 10:39 ` Janosch Frank
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 3/6] s390x: Add linemode buffer to fix newline on every print Janosch Frank
                   ` (3 subsequent siblings)
  5 siblings, 0 replies; 21+ messages in thread
From: Janosch Frank @ 2019-09-05 10:39 UTC (permalink / raw)
  To: kvm; +Cc: linux-s390, david, thuth

z/VM isn't fond of vt220, so we need line mode when running under
z/VM.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Thomas Huth <thuth@redhat.com>
---
 lib/s390x/sclp-console.c | 181 +++++++++++++++++++++++++++++++++++----
 lib/s390x/sclp.h         |  55 +++++++++++-
 2 files changed, 218 insertions(+), 18 deletions(-)

diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
index a5ef45f..19416b5 100644
--- a/lib/s390x/sclp-console.c
+++ b/lib/s390x/sclp-console.c
@@ -11,21 +11,165 @@
 #include <libcflat.h>
 #include <string.h>
 #include <asm/page.h>
+#include <asm/arch_def.h>
+#include <asm/io.h>
 #include "sclp.h"
 
+/*
+ * ASCII (IBM PC 437) -> EBCDIC 037
+ */
+static uint8_t _ascebc[256] = {
+ /*00 NUL   SOH   STX   ETX   EOT   ENQ   ACK   BEL */
+     0x00, 0x01, 0x02, 0x03, 0x37, 0x2D, 0x2E, 0x2F,
+ /*08  BS    HT    LF    VT    FF    CR    SO    SI */
+ /*              ->NL                               */
+     0x16, 0x05, 0x15, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+ /*10 DLE   DC1   DC2   DC3   DC4   NAK   SYN   ETB */
+     0x10, 0x11, 0x12, 0x13, 0x3C, 0x3D, 0x32, 0x26,
+ /*18 CAN    EM   SUB   ESC    FS    GS    RS    US */
+ /*                               ->IGS ->IRS ->IUS */
+     0x18, 0x19, 0x3F, 0x27, 0x22, 0x1D, 0x1E, 0x1F,
+ /*20  SP     !     "     #     $     %     &     ' */
+     0x40, 0x5A, 0x7F, 0x7B, 0x5B, 0x6C, 0x50, 0x7D,
+ /*28   (     )     *     +     ,     -    .      / */
+     0x4D, 0x5D, 0x5C, 0x4E, 0x6B, 0x60, 0x4B, 0x61,
+ /*30   0     1     2     3     4     5     6     7 */
+     0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7,
+ /*38   8     9     :     ;     <     =     >     ? */
+     0xF8, 0xF9, 0x7A, 0x5E, 0x4C, 0x7E, 0x6E, 0x6F,
+ /*40   @     A     B     C     D     E     F     G */
+     0x7C, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7,
+ /*48   H     I     J     K     L     M     N     O */
+     0xC8, 0xC9, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6,
+ /*50   P     Q     R     S     T     U     V     W */
+     0xD7, 0xD8, 0xD9, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6,
+ /*58   X     Y     Z     [     \     ]     ^     _ */
+     0xE7, 0xE8, 0xE9, 0xBA, 0xE0, 0xBB, 0xB0, 0x6D,
+ /*60   `     a     b     c     d     e     f     g */
+     0x79, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+ /*68   h     i     j     k     l     m     n     o */
+     0x88, 0x89, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96,
+ /*70   p     q     r     s     t     u     v     w */
+     0x97, 0x98, 0x99, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6,
+ /*78   x     y     z     {     |     }     ~    DL */
+     0xA7, 0xA8, 0xA9, 0xC0, 0x4F, 0xD0, 0xA1, 0x07,
+ /*80*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*88*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*90*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*98*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*A0*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*A8*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*B0*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*B8*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*C0*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*C8*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*D0*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*D8*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*E0        sz	*/
+     0x3F, 0x59, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*E8*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*F0*/
+     0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
+ /*F8*/
+     0x90, 0x3F, 0x3F, 0x3F, 0x3F, 0xEA, 0x3F, 0xFF
+};
+
+static void sclp_print_ascii(const char *str)
+{
+	int len = strlen(str);
+	WriteEventData *sccb = (void *)_sccb;
+
+	sclp_mark_busy();
+	memset(sccb, 0, sizeof(*sccb));
+	sccb->h.length = offsetof(WriteEventData, msg) + len;
+	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
+	sccb->ebh.length = sizeof(EventBufferHeader) + len;
+	sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
+	memcpy(&sccb->msg, str, len);
+
+	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
+}
+
+static void sclp_print_lm(const char *str)
+{
+	unsigned char *ptr, *end, ch;
+	unsigned int count, offset, len;
+	struct WriteEventData *sccb;
+	struct mdb *mdb;
+	struct mto *mto;
+	struct go *go;
+
+	sclp_mark_busy();
+	sccb = (struct WriteEventData *) _sccb;
+	end = (unsigned char *) sccb + 4096 - 1;
+	memset(sccb, 0, sizeof(*sccb));
+	ptr = (unsigned char *) &sccb->msg.mdb.mto;
+	len = strlen(str);
+	offset = 0;
+	do {
+		for (count = sizeof(*mto); offset < len; count++) {
+			ch = str[offset++];
+			if (ch == 0x0a || ptr + count > end)
+				break;
+			ptr[count] = _ascebc[ch];
+		}
+		mto = (struct mto *) ptr;
+		mto->length = count;
+		mto->type = 4;
+		mto->line_type_flags = LNTPFLGS_ENDTEXT;
+		ptr += count;
+	} while (offset < len && ptr + sizeof(*mto) <= end);
+	len = ptr - (unsigned char *) sccb;
+	sccb->h.length = len - offsetof(struct WriteEventData, h);
+	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
+	sccb->ebh.type = EVTYP_MSG;
+	sccb->ebh.length = len - offsetof(struct WriteEventData, ebh);
+	mdb = &sccb->msg.mdb;
+	mdb->header.type = 1;
+	mdb->header.tag = 0xD4C4C240;
+	mdb->header.revision_code = 1;
+	mdb->header.length = len - offsetof(struct WriteEventData, msg.mdb.header);
+	go = &mdb->go;
+	go->length = sizeof(*go);
+	go->type = 1;
+	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
+}
+
+/*
+ * SCLP needs to be initialized by setting a send and receive mask,
+ * indicating which messages the control program (we) want(s) to
+ * send/receive.
+ */
 static void sclp_set_write_mask(void)
 {
 	WriteEventMask *sccb = (void *)_sccb;
 
 	sclp_mark_busy();
+	memset(_sccb, 0, sizeof(*sccb));
 	sccb->h.length = sizeof(WriteEventMask);
-	sccb->mask_length = sizeof(unsigned int);
-	sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
-	sccb->cp_receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
-	sccb->send_mask = SCLP_EVENT_MASK_MSG_ASCII;
-	sccb->cp_send_mask = SCLP_EVENT_MASK_MSG_ASCII;
+	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
+	sccb->mask_length = sizeof(sccb_mask_t);
+
+	/* For now we don't process sclp input. */
+	sccb->cp_receive_mask = 0;
+	/* We send ASCII and line mode. */
+	sccb->cp_send_mask = SCLP_EVENT_MASK_MSG_ASCII | SCLP_EVENT_MASK_MSG;
 
 	sclp_service_call(SCLP_CMD_WRITE_EVENT_MASK, sccb);
+	assert(sccb->h.response_code == SCLP_RC_NORMAL_COMPLETION);
 }
 
 void sclp_console_setup(void)
@@ -35,16 +179,19 @@ void sclp_console_setup(void)
 
 void sclp_print(const char *str)
 {
-	int len = strlen(str);
-	WriteEventData *sccb = (void *)_sccb;
-
-	sclp_mark_busy();
-	sccb->h.length = sizeof(WriteEventData) + len;
-	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
-	sccb->ebh.length = sizeof(EventBufferHeader) + len;
-	sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
-	sccb->ebh.flags = 0;
-	memcpy(sccb->data, str, len);
-
-	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
+	/*
+	 * z/VM advertises a vt220 console which is not functional:
+	 * (response code 05F0, "not active because of the state of
+	 * the machine"). Hence testing the masks would only work if
+	 * we also use stsi data to distinguish z/VM.
+	 *
+	 * Let's rather print on all available consoles.
+	 */
+	if (strlen(str) > (PAGE_SIZE / 2)) {
+		sclp_print_ascii("Warning: Printing is limited to 2KB of data.");
+		sclp_print_lm("Warning: Printing is limited to 2KB of data.");
+		return;
+	}
+	sclp_print_ascii(str);
+	sclp_print_lm(str);
 }
diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
index 63cf609..98c482a 100644
--- a/lib/s390x/sclp.h
+++ b/lib/s390x/sclp.h
@@ -179,6 +179,7 @@ typedef struct SCCB {
 /* SCLP event masks */
 #define SCLP_EVENT_MASK_SIGNAL_QUIESCE          0x00000008
 #define SCLP_EVENT_MASK_MSG_ASCII               0x00000040
+#define SCLP_EVENT_MASK_MSG          		0x40000000
 
 #define SCLP_UNCONDITIONAL_READ                 0x00
 #define SCLP_SELECTIVE_READ                     0x01
@@ -193,6 +194,55 @@ typedef struct WriteEventMask {
     uint32_t receive_mask;
 } __attribute__((packed)) WriteEventMask;
 
+#define MDBTYP_GO               0x0001
+#define MDBTYP_MTO              0x0004
+#define EVTYP_MSG               0x02
+#define LNTPFLGS_CNTLTEXT       0x8000
+#define LNTPFLGS_LABELTEXT      0x4000
+#define LNTPFLGS_DATATEXT       0x2000
+#define LNTPFLGS_ENDTEXT        0x1000
+#define LNTPFLGS_PROMPTTEXT     0x0800
+
+typedef uint32_t sccb_mask_t;
+
+/* SCLP line mode console related structures. */
+
+struct mto {
+	u16 length;
+	u16 type;
+	u16 line_type_flags;
+	u8  alarm_control;
+	u8  _reserved[3];
+} __attribute__((packed));
+
+struct go {
+	u16 length;
+	u16 type;
+	u32 domid;
+	u8  hhmmss_time[8];
+	u8  th_time[3];
+	u8  reserved_0;
+	u8  dddyyyy_date[7];
+	u8  _reserved_1;
+	u16 general_msg_flags;
+	u8  _reserved_2[10];
+	u8  originating_system_name[8];
+	u8  job_guest_name[8];
+} __attribute__((packed));
+
+struct mdb_header {
+	u16 length;
+	u16 type;
+	u32 tag;
+	u32 revision_code;
+} __attribute__((packed));
+
+struct mdb {
+	struct mdb_header header;
+	struct go go;
+	struct mto mto;
+} __attribute__((packed));
+
 typedef struct EventBufferHeader {
     uint16_t length;
     uint8_t  type;
@@ -203,7 +253,10 @@ typedef struct EventBufferHeader {
 typedef struct WriteEventData {
     SCCBHeader h;
     EventBufferHeader ebh;
-    char data[0];
+    union {
+	char data[0];
+	struct mdb mdb;
+    } msg;
 } __attribute__((packed)) WriteEventData;
 
 typedef struct ReadEventData {
-- 
2.17.0


^ permalink raw reply	[flat|nested] 21+ messages in thread

* [kvm-unit-tests PATCH v2 3/6] s390x: Add linemode buffer to fix newline on every print
  2019-09-05 10:39 [kvm-unit-tests PATCH v2 0/6] s390x: Add multiboot and smp Janosch Frank
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 1/6] s390x: Use interrupts in SCLP and add locking Janosch Frank
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 2/6] s390x: Add linemode console Janosch Frank
@ 2019-09-05 10:39 ` Janosch Frank
  2019-09-09  9:02   ` David Hildenbrand
  2019-09-11  7:57   ` David Hildenbrand
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 4/6] s390x: Add initial smp code Janosch Frank
                   ` (2 subsequent siblings)
  5 siblings, 2 replies; 21+ messages in thread
From: Janosch Frank @ 2019-09-05 10:39 UTC (permalink / raw)
  To: kvm; +Cc: linux-s390, david, thuth

Linemode seems to add a newline for each sent message which makes
reading rather hard. Hence we add a small buffer and only print if
it's full or a newline is encountered. Except for when the string is
longer than the buffer, then we flush the buffer and print directly.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
 lib/s390x/sclp-console.c | 70 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 66 insertions(+), 4 deletions(-)

diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
index 19416b5..7397dc1 100644
--- a/lib/s390x/sclp-console.c
+++ b/lib/s390x/sclp-console.c
@@ -13,6 +13,7 @@
 #include <asm/page.h>
 #include <asm/arch_def.h>
 #include <asm/io.h>
+#include <asm/spinlock.h>
 #include "sclp.h"
 
 /*
@@ -87,6 +88,10 @@ static uint8_t _ascebc[256] = {
      0x90, 0x3F, 0x3F, 0x3F, 0x3F, 0xEA, 0x3F, 0xFF
 };
 
+static char lm_buff[120];
+static unsigned char lm_buff_off;
+static struct spinlock lm_buff_lock;
+
 static void sclp_print_ascii(const char *str)
 {
 	int len = strlen(str);
@@ -103,10 +108,10 @@ static void sclp_print_ascii(const char *str)
 	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
 }
 
-static void sclp_print_lm(const char *str)
+static void lm_print(const char *buff, int len)
 {
 	unsigned char *ptr, *end, ch;
-	unsigned int count, offset, len;
+	unsigned int count, offset;
 	struct WriteEventData *sccb;
 	struct mdb *mdb;
 	struct mto *mto;
@@ -117,11 +122,10 @@ static void sclp_print_lm(const char *str)
 	end = (unsigned char *) sccb + 4096 - 1;
 	memset(sccb, 0, sizeof(*sccb));
 	ptr = (unsigned char *) &sccb->msg.mdb.mto;
-	len = strlen(str);
 	offset = 0;
 	do {
 		for (count = sizeof(*mto); offset < len; count++) {
-			ch = str[offset++];
+			ch = buff[offset++];
 			if (ch == 0x0a || ptr + count > end)
 				break;
 			ptr[count] = _ascebc[ch];
@@ -148,6 +152,64 @@ static void sclp_print_lm(const char *str)
 	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
 }
 
+
+/*
+ * In contrast to the ascii console, linemode produces a new
+ * line with every write of data. The report() function uses
+ * several printf() calls to generate a line of data which
+ * would all end up on different lines.
+ *
+ * Hence we buffer here until we encounter a \n or the buffer
+ * is full. That means that linemode output can look a bit
+ * different from ascii and that it takes a bit longer for
+ * lines to appear.
+ */
+static void sclp_print_lm(const char *str)
+{
+	int len;
+	char *nl;
+
+	spin_lock(&lm_buff_lock);
+
+	len = strlen(str);
+	/*
+	 * No use in copying into lm_buff, its time to flush the
+	 * buffer and print str until finished.
+	 */
+	if (len > sizeof(lm_buff)) {
+		if (lm_buff_off)
+			lm_print(lm_buff, lm_buff_off);
+		lm_print(str, len);
+		memset(lm_buff, 0 , sizeof(lm_buff));
+		lm_buff_off = 0;
+		goto out;
+	}
+
+fill:
+	len = len < (sizeof(lm_buff) - lm_buff_off) ? len : (sizeof(lm_buff) - lm_buff_off);
+	if ((lm_buff_off < sizeof(lm_buff) - 1)) {
+		memcpy(&lm_buff[lm_buff_off], str, len);
+		lm_buff_off += len;
+	}
+	/* Buffer not full and no newline */
+	nl = strchr(lm_buff, '\n');
+	if (lm_buff_off != sizeof(lm_buff) - 1 && !nl)
+		goto out;
+
+	lm_print(lm_buff, lm_buff_off);
+	memset(lm_buff, 0 , sizeof(lm_buff));
+	lm_buff_off = 0;
+
+	if (len < strlen(str)) {
+		str = &str[len];
+		len = strlen(str);
+		goto fill;
+	}
+
+out:
+	spin_unlock(&lm_buff_lock);
+}
+
 /*
  * SCLP needs to be initialized by setting a send and receive mask,
  * indicating which messages the control program (we) want(s) to
-- 
2.17.0


^ permalink raw reply	[flat|nested] 21+ messages in thread

* [kvm-unit-tests PATCH v2 4/6] s390x: Add initial smp code
  2019-09-05 10:39 [kvm-unit-tests PATCH v2 0/6] s390x: Add multiboot and smp Janosch Frank
                   ` (2 preceding siblings ...)
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 3/6] s390x: Add linemode buffer to fix newline on every print Janosch Frank
@ 2019-09-05 10:39 ` Janosch Frank
  2019-09-09 15:37   ` Thomas Huth
  2019-09-10 12:19   ` Thomas Huth
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 5/6] s390x: Prepare for external calls Janosch Frank
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 6/6] s390x: SMP test Janosch Frank
  5 siblings, 2 replies; 21+ messages in thread
From: Janosch Frank @ 2019-09-05 10:39 UTC (permalink / raw)
  To: kvm; +Cc: linux-s390, david, thuth

Let's add a rudimentary SMP library, which will scan for cpus and has
helper functions that manage the cpu state.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 lib/s390x/asm/arch_def.h |   8 ++
 lib/s390x/asm/sigp.h     |  28 +++-
 lib/s390x/io.c           |   5 +-
 lib/s390x/sclp.h         |   1 +
 lib/s390x/smp.c          | 276 +++++++++++++++++++++++++++++++++++++++
 lib/s390x/smp.h          |  51 ++++++++
 s390x/Makefile           |   1 +
 s390x/cstart64.S         |   7 +
 8 files changed, 371 insertions(+), 6 deletions(-)
 create mode 100644 lib/s390x/smp.c
 create mode 100644 lib/s390x/smp.h

diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index 5f8f45e..d5a7f51 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -157,6 +157,14 @@ struct cpuid {
 	uint64_t reserved : 15;
 };
 
+static inline unsigned short stap(void)
+{
+	unsigned short cpu_address;
+
+	asm volatile("stap %0" : "=Q" (cpu_address));
+	return cpu_address;
+}
+
 static inline int tprot(unsigned long addr)
 {
 	int cc;
diff --git a/lib/s390x/asm/sigp.h b/lib/s390x/asm/sigp.h
index fbd94fc..2d52313 100644
--- a/lib/s390x/asm/sigp.h
+++ b/lib/s390x/asm/sigp.h
@@ -46,14 +46,32 @@
 
 #ifndef __ASSEMBLER__
 
-static inline void sigp_stop(void)
+
+static inline int sigp(uint16_t addr, uint8_t order, unsigned long parm,
+		       uint32_t *status)
 {
-	register unsigned long status asm ("1") = 0;
-	register unsigned long cpu asm ("2") = 0;
+	register unsigned long reg1 asm ("1") = parm;
+	int cc;
 
 	asm volatile(
-		"	sigp %0,%1,0(%2)\n"
-		: "+d" (status)  : "d" (cpu), "d" (SIGP_STOP) : "cc");
+		"	sigp	%1,%2,0(%3)\n"
+		"	ipm	%0\n"
+		"	srl	%0,28\n"
+		: "=d" (cc), "+d" (reg1) : "d" (addr), "a" (order) : "cc");
+	if (status)
+		*status = reg1;
+	return cc;
+}
+
+static inline int sigp_retry(uint16_t addr, uint8_t order, unsigned long parm,
+			     uint32_t *status)
+{
+	int cc;
+
+	do {
+		cc = sigp(addr, order, parm, status);
+	} while (cc == 2);
+	return cc;
 }
 
 #endif /* __ASSEMBLER__ */
diff --git a/lib/s390x/io.c b/lib/s390x/io.c
index becadfc..32f09b5 100644
--- a/lib/s390x/io.c
+++ b/lib/s390x/io.c
@@ -16,6 +16,7 @@
 #include <asm/facility.h>
 #include <asm/sigp.h>
 #include "sclp.h"
+#include "smp.h"
 
 extern char ipl_args[];
 uint8_t stfl_bytes[NR_STFL_BYTES] __attribute__((aligned(8)));
@@ -37,12 +38,14 @@ void setup(void)
 	setup_facilities();
 	sclp_console_setup();
 	sclp_memory_setup();
+	smp_setup();
 }
 
 void exit(int code)
 {
+	smp_teardown();
 	printf("\nEXIT: STATUS=%d\n", ((code) << 1) | 1);
 	while (1) {
-		sigp_stop();
+		sigp(0, SIGP_STOP, 0, NULL);
 	}
 }
diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
index 98c482a..4e69845 100644
--- a/lib/s390x/sclp.h
+++ b/lib/s390x/sclp.h
@@ -19,6 +19,7 @@
 #define SCLP_CMD_CODE_MASK                      0xffff00ff
 
 /* SCLP command codes */
+#define SCLP_READ_CPU_INFO			0x00010001
 #define SCLP_CMDW_READ_SCP_INFO                 0x00020001
 #define SCLP_CMDW_READ_SCP_INFO_FORCED          0x00120001
 #define SCLP_READ_STORAGE_ELEMENT_INFO          0x00040001
diff --git a/lib/s390x/smp.c b/lib/s390x/smp.c
new file mode 100644
index 0000000..40c43ef
--- /dev/null
+++ b/lib/s390x/smp.c
@@ -0,0 +1,276 @@
+/*
+ * s390x smp
+ * Based on Linux's arch/s390/kernel/smp.c and
+ * arch/s390/include/asm/sigp.h
+ *
+ * Copyright (c) 2019 IBM Corp
+ *
+ * Authors:
+ *  Janosch Frank <frankja@linux.ibm.com>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2.
+ */
+#include <libcflat.h>
+#include <errno.h>
+#include <asm/arch_def.h>
+#include <asm/sigp.h>
+#include <asm/page.h>
+#include <asm/barrier.h>
+#include <asm/spinlock.h>
+#include <asm/asm-offsets.h>
+
+#include <alloc.h>
+#include <alloc_page.h>
+
+#include "smp.h"
+#include "sclp.h"
+
+static char cpu_info_buffer[PAGE_SIZE] __attribute__((__aligned__(4096)));
+static struct cpu *cpus;
+static struct cpu *cpu0;
+static struct spinlock lock;
+
+extern void smp_cpu_setup_state(void);
+
+int smp_query_num_cpus(void)
+{
+	struct ReadCpuInfo *info = (void *)cpu_info_buffer;
+	return info->nr_configured;
+}
+
+struct cpu *smp_cpu_from_addr(uint16_t addr)
+{
+	int i, num = smp_query_num_cpus();
+	struct cpu *cpu = NULL;
+
+	for (i = 0; i < num; i++) {
+		if (cpus[i].addr == addr)
+			cpu = &cpus[i];
+	}
+	return cpu;
+}
+
+bool smp_cpu_stopped(uint16_t addr)
+{
+	uint32_t status;
+
+	if (sigp(addr, SIGP_SENSE, 0, &status) != SIGP_CC_STATUS_STORED)
+		return 0;
+	return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
+}
+
+bool smp_cpu_running(uint16_t addr)
+{
+	if (sigp(addr, SIGP_SENSE_RUNNING, 0, NULL) != SIGP_CC_STATUS_STORED)
+		return 1;
+	/* Status stored condition code is equivalent to cpu not running. */
+	return 0;
+}
+
+static int smp_cpu_stop_nolock(uint16_t addr, bool store)
+{
+	struct cpu *cpu;
+	uint8_t order = store ? SIGP_STOP_AND_STORE_STATUS : SIGP_STOP;
+
+	cpu = smp_cpu_from_addr(addr);
+	if (cpu == cpu0)
+		return -EINVAL;
+	if (!cpu)
+		return -ENOENT;
+
+	if (sigp_retry(addr, order, 0, NULL))
+		return -EINVAL;
+
+	while (!smp_cpu_stopped(addr))
+		mb();
+	cpu->active = false;
+	return 0;
+}
+
+int smp_cpu_stop(uint16_t addr)
+{
+	int rc = 0;
+
+	spin_lock(&lock);
+	rc = smp_cpu_stop_nolock(addr, false);
+	spin_unlock(&lock);
+	return rc;
+}
+
+int smp_cpu_stop_store_status(uint16_t addr)
+{
+	int rc = 0;
+
+	spin_lock(&lock);
+	rc = smp_cpu_stop_nolock(addr, true);
+	spin_unlock(&lock);
+	return rc;
+}
+
+int smp_cpu_restart(uint16_t addr)
+{
+	int rc = 0;
+	struct cpu *cpu;
+
+	spin_lock(&lock);
+	cpu = smp_cpu_from_addr(addr);
+	if (!cpu) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	rc = sigp(addr, SIGP_RESTART, 0, NULL);
+	cpu->active = true;
+out:
+	spin_unlock(&lock);
+	return rc;
+}
+
+int smp_cpu_start(uint16_t addr, struct psw psw)
+{
+	int rc = 0;
+	struct cpu *cpu;
+	struct lowcore *lc;
+
+	spin_lock(&lock);
+	cpu = smp_cpu_from_addr(addr);
+	if (!cpu) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	lc = cpu->lowcore;
+	lc->restart_new_psw.mask = psw.mask;
+	lc->restart_new_psw.addr = psw.addr;
+	rc = sigp(addr, SIGP_RESTART, 0, NULL);
+out:
+	spin_unlock(&lock);
+	return rc;
+}
+
+int smp_cpu_destroy(uint16_t addr)
+{
+	struct cpu *cpu;
+	int rc = 0;
+
+	spin_lock(&lock);
+	rc = smp_cpu_stop_nolock(addr, false);
+	if (rc)
+		goto out;
+
+	cpu = smp_cpu_from_addr(addr);
+	free_pages(cpu->lowcore, 2 * PAGE_SIZE);
+	free_pages(cpu->stack, 4 * PAGE_SIZE);
+	cpu->lowcore = (void *)-1UL;
+	cpu->stack = (void *)-1UL;
+
+out:
+	spin_unlock(&lock);
+	return rc;
+}
+
+int smp_cpu_setup(uint16_t addr, struct psw psw)
+{
+	struct lowcore *lc;
+	struct cpu *cpu;
+	int rc = 0;
+
+	spin_lock(&lock);
+
+	if (!cpus) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	cpu = smp_cpu_from_addr(addr);
+
+	if (!cpu) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	if (cpu->active) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	sigp_retry(cpu->addr, SIGP_INITIAL_CPU_RESET, 0, NULL);
+
+	lc = alloc_pages(1);
+	cpu->lowcore = lc;
+	memset(lc, 0, PAGE_SIZE * 2);
+	sigp_retry(cpu->addr, SIGP_SET_PREFIX, (unsigned long )lc, NULL);
+
+	/* Copy all exception psws. */
+	memcpy(lc, cpu0->lowcore, 512);
+
+	/* Setup stack */
+	cpu->stack = (uint64_t *)alloc_pages(2);
+
+	/* Start without DAT and any other mask bits. */
+	cpu->lowcore->sw_int_grs[14] = psw.addr;
+	cpu->lowcore->sw_int_grs[15] = (uint64_t)cpu->stack + (PAGE_SIZE * 4);
+	lc->restart_new_psw.mask = 0x0000000180000000UL;
+	lc->restart_new_psw.addr = (uint64_t)smp_cpu_setup_state;
+	lc->sw_int_cr0 = 0x0000000000040000UL;
+
+	/* Start processing */
+	rc = sigp_retry(cpu->addr, SIGP_RESTART, 0, NULL);
+	if (!rc)
+		cpu->active = true;
+
+out:
+	spin_unlock(&lock);
+	return rc;
+}
+
+/*
+ * Disregarding state, stop all cpus that once were online except for
+ * calling cpu.
+ */
+void smp_teardown(void)
+{
+	int i = 0;
+	uint16_t this_cpu = stap();
+	struct ReadCpuInfo *info = (void *)cpu_info_buffer;
+
+	spin_lock(&lock);
+	for (; i < info->nr_configured; i++) {
+		if (cpus[i].active &&
+		    cpus[i].addr != this_cpu) {
+			sigp_retry(cpus[i].addr, SIGP_STOP, 0, NULL);
+		}
+	}
+	spin_unlock(&lock);
+}
+
+/*Expected to be called from boot cpu */
+extern uint64_t *stackptr;
+void smp_setup(void)
+{
+	int i = 0;
+	unsigned short cpu0_addr = stap();
+	struct ReadCpuInfo *info = (void *)cpu_info_buffer;
+
+	spin_lock(&lock);
+	sclp_mark_busy();
+	info->h.length = PAGE_SIZE;
+	sclp_service_call(SCLP_READ_CPU_INFO, cpu_info_buffer);
+
+	if (smp_query_num_cpus() > 1)
+		printf("SMP: Initializing, found %d cpus\n", info->nr_configured);
+
+	cpus = calloc(info->nr_configured, sizeof(cpus));
+	for (i = 0; i < info->nr_configured; i++) {
+		if (info->entries[i].address == cpu0_addr) {
+			cpu0 = &cpus[i];
+			cpu0->stack = stackptr;
+			cpu0->lowcore = (void *)0;
+			cpu0->active = true;
+		}
+		cpus[i].addr = info->entries[i].address;
+		cpus[i].active = false;
+	}
+	spin_unlock(&lock);
+}
diff --git a/lib/s390x/smp.h b/lib/s390x/smp.h
new file mode 100644
index 0000000..4476c31
--- /dev/null
+++ b/lib/s390x/smp.h
@@ -0,0 +1,51 @@
+/*
+ * s390x smp
+ *
+ * Copyright (c) 2019 IBM Corp
+ *
+ * Authors:
+ *  Janosch Frank <frankja@linux.ibm.com>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2.
+ */
+#ifndef SMP_H
+#define SMP_H
+
+struct cpu {
+	struct lowcore *lowcore;
+	uint64_t *stack;
+	uint16_t addr;
+	bool active;
+};
+
+struct cpu_status {
+    uint64_t    fprs[16];                       /* 0x0000 */
+    uint64_t    grs[16];                        /* 0x0080 */
+    struct psw  psw;                            /* 0x0100 */
+    uint8_t     pad_0x0110[0x0118 - 0x0110];    /* 0x0110 */
+    uint32_t    prefix;                         /* 0x0118 */
+    uint32_t    fpc;                            /* 0x011c */
+    uint8_t     pad_0x0120[0x0124 - 0x0120];    /* 0x0120 */
+    uint32_t    todpr;                          /* 0x0124 */
+    uint64_t    cputm;                          /* 0x0128 */
+    uint64_t    ckc;                            /* 0x0130 */
+    uint8_t     pad_0x0138[0x0140 - 0x0138];    /* 0x0138 */
+    uint32_t    ars[16];                        /* 0x0140 */
+    uint64_t    crs[16];                        /* 0x0384 */
+};
+
+int smp_query_num_cpus(void);
+struct cpu *smp_cpu_from_addr(uint16_t addr);
+bool smp_cpu_stopped(uint16_t addr);
+bool smp_cpu_running(uint16_t addr);
+int smp_cpu_restart(uint16_t addr);
+int smp_cpu_start(uint16_t addr, struct psw psw);
+int smp_cpu_stop(uint16_t addr);
+int smp_cpu_stop_store_status(uint16_t addr);
+int smp_cpu_destroy(uint16_t addr);
+int smp_cpu_setup(uint16_t addr, struct psw psw);
+void smp_teardown(void);
+void smp_setup(void);
+
+#endif
diff --git a/s390x/Makefile b/s390x/Makefile
index 96033dd..d83dd0b 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -48,6 +48,7 @@ cflatobjs += lib/s390x/sclp.o
 cflatobjs += lib/s390x/sclp-console.o
 cflatobjs += lib/s390x/interrupt.o
 cflatobjs += lib/s390x/mmu.o
+cflatobjs += lib/s390x/smp.o
 
 OBJDIRS += lib/s390x
 
diff --git a/s390x/cstart64.S b/s390x/cstart64.S
index 36f7cab..a45ea8f 100644
--- a/s390x/cstart64.S
+++ b/s390x/cstart64.S
@@ -172,6 +172,13 @@ diag308_load_reset:
 	lhi	%r2, 1
 	br	%r14
 
+.globl smp_cpu_setup_state
+smp_cpu_setup_state:
+	xgr	%r1, %r1
+	lmg     %r0, %r15, 512(%r1)
+	lctlg   %c0, %c0, 776(%r1)
+	br	%r14
+
 pgm_int:
 	SAVE_REGS
 	brasl	%r14, handle_pgm_int
-- 
2.17.0


^ permalink raw reply	[flat|nested] 21+ messages in thread

* [kvm-unit-tests PATCH v2 5/6] s390x: Prepare for external calls
  2019-09-05 10:39 [kvm-unit-tests PATCH v2 0/6] s390x: Add multiboot and smp Janosch Frank
                   ` (3 preceding siblings ...)
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 4/6] s390x: Add initial smp code Janosch Frank
@ 2019-09-05 10:39 ` Janosch Frank
  2019-09-09 15:47   ` Thomas Huth
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 6/6] s390x: SMP test Janosch Frank
  5 siblings, 1 reply; 21+ messages in thread
From: Janosch Frank @ 2019-09-05 10:39 UTC (permalink / raw)
  To: kvm; +Cc: linux-s390, david, thuth

With SMP we also get new external interrupts like external call and
emergency call. Let's make them known.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 lib/s390x/asm/arch_def.h  |  5 +++++
 lib/s390x/asm/interrupt.h |  3 +++
 lib/s390x/interrupt.c     | 24 ++++++++++++++++++++----
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index d5a7f51..96cca2e 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -19,6 +19,11 @@ struct psw {
 #define PSW_MASK_DAT			0x0400000000000000UL
 #define PSW_MASK_PSTATE			0x0001000000000000UL
 
+#define CR0_EXTM_SCLP			0X0000000000000200UL
+#define CR0_EXTM_EXTC			0X0000000000002000UL
+#define CR0_EXTM_EMGC			0X0000000000004000UL
+#define CR0_EXTM_MASK			0X0000000000006200UL
+
 struct lowcore {
 	uint8_t		pad_0x0000[0x0080 - 0x0000];	/* 0x0000 */
 	uint32_t	ext_int_param;			/* 0x0080 */
diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
index f485e96..4cfade9 100644
--- a/lib/s390x/asm/interrupt.h
+++ b/lib/s390x/asm/interrupt.h
@@ -11,6 +11,8 @@
 #define _ASMS390X_IRQ_H_
 #include <asm/arch_def.h>
 
+#define EXT_IRQ_EMERGENCY_SIG	0x1201
+#define EXT_IRQ_EXTERNAL_CALL	0x1202
 #define EXT_IRQ_SERVICE_SIG	0x2401
 
 void handle_pgm_int(void);
@@ -19,6 +21,7 @@ void handle_mcck_int(void);
 void handle_io_int(void);
 void handle_svc_int(void);
 void expect_pgm_int(void);
+void expect_ext_int(void);
 uint16_t clear_pgm_int(void);
 void check_pgm_int_code(uint16_t code);
 
diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
index 7832711..d4f279a 100644
--- a/lib/s390x/interrupt.c
+++ b/lib/s390x/interrupt.c
@@ -15,6 +15,7 @@
 #include <sclp.h>
 
 static bool pgm_int_expected;
+static bool ext_int_expected;
 static struct lowcore *lc;
 
 void expect_pgm_int(void)
@@ -24,6 +25,13 @@ void expect_pgm_int(void)
 	mb();
 }
 
+void expect_ext_int(void)
+{
+	ext_int_expected = true;
+	lc->ext_int_code = 0;
+	mb();
+}
+
 uint16_t clear_pgm_int(void)
 {
 	uint16_t code;
@@ -108,15 +116,23 @@ void handle_pgm_int(void)
 
 void handle_ext_int(void)
 {
-	if (lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
+	if (!ext_int_expected &&
+	    lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
 		report_abort("Unexpected external call interrupt: at %#lx",
 			     lc->ext_old_psw.addr);
-	} else {
-		lc->ext_old_psw.mask &= ~PSW_MASK_EXT;
+		return;
+	}
+
+	if (lc->ext_int_code == EXT_IRQ_SERVICE_SIG) {
 		lc->sw_int_cr0 &= ~(1UL << 9);
 		sclp_handle_ext();
-		lc->ext_int_code = 0;
 	}
+	if (lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
+		ext_int_expected = false;
+	}
+
+	if (!(lc->sw_int_cr0 & CR0_EXTM_MASK))
+		lc->ext_old_psw.mask &= ~PSW_MASK_EXT;
 }
 
 void handle_mcck_int(void)
-- 
2.17.0


^ permalink raw reply	[flat|nested] 21+ messages in thread

* [kvm-unit-tests PATCH v2 6/6] s390x: SMP test
  2019-09-05 10:39 [kvm-unit-tests PATCH v2 0/6] s390x: Add multiboot and smp Janosch Frank
                   ` (4 preceding siblings ...)
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 5/6] s390x: Prepare for external calls Janosch Frank
@ 2019-09-05 10:39 ` Janosch Frank
  2019-09-10  9:43   ` Thomas Huth
  5 siblings, 1 reply; 21+ messages in thread
From: Janosch Frank @ 2019-09-05 10:39 UTC (permalink / raw)
  To: kvm; +Cc: linux-s390, david, thuth

Testing SIGP emulation for the following order codes:
* start
* stop
* restart
* set prefix
* store status
* stop and store status
* reset
* initial reset
* external call
* emegergency call

restart and set prefix are part of the library and needed to start
other cpus.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 s390x/Makefile      |   1 +
 s390x/smp.c         | 242 ++++++++++++++++++++++++++++++++++++++++++++
 s390x/unittests.cfg |   4 +
 3 files changed, 247 insertions(+)
 create mode 100644 s390x/smp.c

diff --git a/s390x/Makefile b/s390x/Makefile
index d83dd0b..3744372 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -15,6 +15,7 @@ tests += $(TEST_DIR)/cpumodel.elf
 tests += $(TEST_DIR)/diag288.elf
 tests += $(TEST_DIR)/stsi.elf
 tests += $(TEST_DIR)/skrf.elf
+tests += $(TEST_DIR)/smp.elf
 tests_binary = $(patsubst %.elf,%.bin,$(tests))
 
 all: directories test_cases test_cases_binary
diff --git a/s390x/smp.c b/s390x/smp.c
new file mode 100644
index 0000000..f91d367
--- /dev/null
+++ b/s390x/smp.c
@@ -0,0 +1,242 @@
+/*
+ * Tests sigp emulation
+ *
+ * Copyright 2019 IBM Corp.
+ *
+ * Authors:
+ *    Janosch Frank <frankja@linux.ibm.com>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2.
+ */
+#include <libcflat.h>
+#include <asm/asm-offsets.h>
+#include <asm/interrupt.h>
+#include <asm/page.h>
+#include <asm/facility.h>
+#include <asm-generic/barrier.h>
+#include <asm/sigp.h>
+
+#include <smp.h>
+#include <alloc_page.h>
+
+static int testflag = 0;
+
+static void cpu_loop(void)
+{
+	for (;;) {}
+}
+
+static void test_func(void)
+{
+	testflag = 1;
+	mb();
+	cpu_loop();
+}
+
+static void test_start(void)
+{
+	struct psw psw;
+	psw.mask =  extract_psw_mask();
+	psw.addr = (unsigned long)test_func;
+
+	smp_cpu_setup(1, psw);
+	while (!testflag) {
+		mb();
+	}
+	report("start", 1);
+}
+
+static void test_stop(void)
+{
+	smp_cpu_stop(1);
+	/*
+	 * The smp library waits for the CPU to shut down, but let's
+	 * also do it here, so we don't rely on the library
+	 * implementation
+	 */
+	while (!smp_cpu_stopped(1)) {}
+	report("stop", 1);
+}
+
+static void test_stop_store_status(void)
+{
+	struct cpu *cpu = smp_cpu_from_addr(1);
+	struct lowcore *lc = (void *)0x0;
+
+	report_prefix_push("stop store status");
+	lc->prefix_sa = 0;
+	lc->grs_sa[15] = 0;
+	smp_cpu_stop_store_status(1);
+	mb();
+	report("prefix", lc->prefix_sa == (uint32_t)(uintptr_t)cpu->lowcore);
+	report("stack", lc->grs_sa[15]);
+	report_prefix_pop();
+}
+
+static void test_store_status(void)
+{
+	struct cpu_status *status = alloc_pages(1);
+	uint32_t r;
+
+	report_prefix_push("store status at address");
+	memset(status, 0, PAGE_SIZE * 2);
+
+	report_prefix_push("running");
+	smp_cpu_restart(1);
+	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, &r);
+	report("incorrect state", r == SIGP_STATUS_INCORRECT_STATE);
+	report("status not written", !memcmp(status, (void*)status + PAGE_SIZE, PAGE_SIZE));
+	report_prefix_pop();
+
+	memset(status, 0, PAGE_SIZE);
+	report_prefix_push("stopped");
+	smp_cpu_stop(1);
+	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);
+	while (!status->prefix) { mb(); }
+	report("status written", 1);
+	free_pages(status, PAGE_SIZE);
+	report_prefix_pop();
+
+	report_prefix_pop();
+}
+
+static void ecall(void)
+{
+	unsigned long mask;
+	struct lowcore *lc = (void *)0x0;
+
+	expect_ext_int();
+	ctl_set_bit(0, 13);
+	mask = extract_psw_mask();
+	mask |= PSW_MASK_EXT;
+	load_psw_mask(mask);
+	testflag = 1;
+	while (lc->ext_int_code != 0x1202) { mb(); }
+	report("ecall", 1);
+	testflag= 1;
+}
+
+static void test_ecall(void)
+{
+	struct psw psw;
+	psw.mask =  extract_psw_mask();
+	psw.addr = (unsigned long)ecall;
+
+	report_prefix_push("ecall");
+	testflag= 0;
+	smp_cpu_destroy(1);
+
+	smp_cpu_setup(1, psw);
+	while (!testflag) { mb(); }
+	testflag= 0;
+	sigp(1, SIGP_EXTERNAL_CALL, 0, NULL);
+	while(!testflag) {mb();}
+	smp_cpu_stop(1);
+	report_prefix_pop();
+}
+
+static void emcall(void)
+{
+	unsigned long mask;
+	struct lowcore *lc = (void *)0x0;
+
+	expect_ext_int();
+	ctl_set_bit(0, 14);
+	mask = extract_psw_mask();
+	mask |= PSW_MASK_EXT;
+	load_psw_mask(mask);
+	testflag= 1;
+	while (lc->ext_int_code != 0x1201) { mb(); }
+	report("ecall", 1);
+	testflag = 1;
+}
+
+static void test_emcall(void)
+{
+	struct psw psw;
+	psw.mask =  extract_psw_mask();
+	psw.addr = (unsigned long)emcall;
+
+	report_prefix_push("emcall");
+	testflag= 0;
+	smp_cpu_destroy(1);
+
+	smp_cpu_setup(1, psw);
+	while (!testflag) { mb(); }
+	testflag= 0;
+	sigp(1, SIGP_EMERGENCY_SIGNAL, 0, NULL);
+	while(!testflag) { mb(); }
+	smp_cpu_stop(1);
+	report_prefix_pop();
+}
+
+static void test_reset_initial(void)
+{
+	struct cpu_status *status = alloc_pages(0);
+	struct psw psw;
+
+	psw.mask =  extract_psw_mask();
+	psw.addr = (unsigned long)test_func;
+
+	report_prefix_push("reset initial");
+	smp_cpu_setup(1, psw);
+
+	sigp_retry(1, SIGP_INITIAL_CPU_RESET, 0, NULL);
+	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);
+
+	report_prefix_push("clear");
+	report("psw", !status->psw.mask && !status->psw.addr);
+	report("prefix", !status->prefix);
+	report("fpc", !status->fpc);
+	report("cpu timer", !status->cputm);
+	report("todpr", !status->todpr);
+	report_prefix_pop();
+
+	report_prefix_push("initialized");
+	report("cr0 == 0xE0", status->crs[0] == 0xE0UL);
+	report("cr14 == 0xC2000000", status->crs[14] == 0xC2000000UL);
+	report_prefix_pop();
+
+	report("cpu stopped", smp_cpu_stopped(1));
+	free_pages(status, PAGE_SIZE);
+	report_prefix_pop();
+}
+
+static void test_reset(void)
+{
+	struct psw psw;
+
+	psw.mask =  extract_psw_mask();
+	psw.addr = (unsigned long)test_func;
+
+	report_prefix_push("cpu reset");
+	smp_cpu_setup(1, psw);
+
+	sigp_retry(1, SIGP_CPU_RESET, 0, NULL);
+	report("cpu stopped", smp_cpu_stopped(1));
+	report_prefix_pop();
+}
+
+int main(void)
+{
+	report_prefix_push("smp");
+
+	if (smp_query_num_cpus() == 1) {
+		report_abort("need at least 2 cpus for this test");
+		goto done;
+	}
+
+	test_start();
+	test_stop();
+	test_stop_store_status();
+	test_store_status();
+	test_ecall();
+	test_emcall();
+	test_reset();
+	test_reset_initial();
+
+done:
+	report_prefix_pop();
+	return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index cc79a4e..f1b07cd 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -71,3 +71,7 @@ extra_params=-device diag288,id=watchdog0 --watchdog-action inject-nmi
 
 [stsi]
 file = stsi.elf
+
+[smp]
+file = smp.elf
+extra_params =-smp 2
-- 
2.17.0


^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 3/6] s390x: Add linemode buffer to fix newline on every print
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 3/6] s390x: Add linemode buffer to fix newline on every print Janosch Frank
@ 2019-09-09  9:02   ` David Hildenbrand
  2019-09-11  7:57   ` David Hildenbrand
  1 sibling, 0 replies; 21+ messages in thread
From: David Hildenbrand @ 2019-09-09  9:02 UTC (permalink / raw)
  To: Janosch Frank, kvm; +Cc: linux-s390, thuth

On 05.09.19 12:39, Janosch Frank wrote:
> Linemode seems to add a newline for each sent message which makes
> reading rather hard. Hence we add a small buffer and only print if
> it's full or a newline is encountered. Except for when the string is
> longer than the buffer, then we flush the buffer and print directly.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> ---
>  lib/s390x/sclp-console.c | 70 +++++++++++++++++++++++++++++++++++++---
>  1 file changed, 66 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
> index 19416b5..7397dc1 100644
> --- a/lib/s390x/sclp-console.c
> +++ b/lib/s390x/sclp-console.c
> @@ -13,6 +13,7 @@
>  #include <asm/page.h>
>  #include <asm/arch_def.h>
>  #include <asm/io.h>
> +#include <asm/spinlock.h>
>  #include "sclp.h"
>  
>  /*
> @@ -87,6 +88,10 @@ static uint8_t _ascebc[256] = {
>       0x90, 0x3F, 0x3F, 0x3F, 0x3F, 0xEA, 0x3F, 0xFF
>  };
>  
> +static char lm_buff[120];
> +static unsigned char lm_buff_off;
> +static struct spinlock lm_buff_lock;
> +
>  static void sclp_print_ascii(const char *str)
>  {
>  	int len = strlen(str);
> @@ -103,10 +108,10 @@ static void sclp_print_ascii(const char *str)
>  	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
>  }
>  
> -static void sclp_print_lm(const char *str)
> +static void lm_print(const char *buff, int len)
>  {
>  	unsigned char *ptr, *end, ch;
> -	unsigned int count, offset, len;
> +	unsigned int count, offset;
>  	struct WriteEventData *sccb;
>  	struct mdb *mdb;
>  	struct mto *mto;
> @@ -117,11 +122,10 @@ static void sclp_print_lm(const char *str)
>  	end = (unsigned char *) sccb + 4096 - 1;
>  	memset(sccb, 0, sizeof(*sccb));
>  	ptr = (unsigned char *) &sccb->msg.mdb.mto;
> -	len = strlen(str);
>  	offset = 0;
>  	do {
>  		for (count = sizeof(*mto); offset < len; count++) {
> -			ch = str[offset++];
> +			ch = buff[offset++];
>  			if (ch == 0x0a || ptr + count > end)
>  				break;
>  			ptr[count] = _ascebc[ch];
> @@ -148,6 +152,64 @@ static void sclp_print_lm(const char *str)
>  	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
>  }
>  
> +
> +/*
> + * In contrast to the ascii console, linemode produces a new
> + * line with every write of data. The report() function uses
> + * several printf() calls to generate a line of data which
> + * would all end up on different lines.
> + *
> + * Hence we buffer here until we encounter a \n or the buffer
> + * is full. That means that linemode output can look a bit
> + * different from ascii and that it takes a bit longer for
> + * lines to appear.
> + */
> +static void sclp_print_lm(const char *str)
> +{
> +	int len;
> +	char *nl;
> +
> +	spin_lock(&lm_buff_lock);
> +
> +	len = strlen(str);
> +	/*
> +	 * No use in copying into lm_buff, its time to flush the
> +	 * buffer and print str until finished.
> +	 */
> +	if (len > sizeof(lm_buff)) {
> +		if (lm_buff_off)
> +			lm_print(lm_buff, lm_buff_off);
> +		lm_print(str, len);
> +		memset(lm_buff, 0 , sizeof(lm_buff));
> +		lm_buff_off = 0;
> +		goto out;
> +	}
> +
> +fill:
> +	len = len < (sizeof(lm_buff) - lm_buff_off) ? len : (sizeof(lm_buff) - lm_buff_off);
> +	if ((lm_buff_off < sizeof(lm_buff) - 1)) {
> +		memcpy(&lm_buff[lm_buff_off], str, len);
> +		lm_buff_off += len;
> +	}
> +	/* Buffer not full and no newline */
> +	nl = strchr(lm_buff, '\n');
> +	if (lm_buff_off != sizeof(lm_buff) - 1 && !nl)
> +		goto out;
> +
> +	lm_print(lm_buff, lm_buff_off);
> +	memset(lm_buff, 0 , sizeof(lm_buff));
> +	lm_buff_off = 0;
> +
> +	if (len < strlen(str)) {
> +		str = &str[len];
> +		len = strlen(str);
> +		goto fill;
> +	}
> +
> +out:
> +	spin_unlock(&lm_buff_lock);
> +}
> +
>  /*
>   * SCLP needs to be initialized by setting a send and receive mask,
>   * indicating which messages the control program (we) want(s) to
> 

Acked-by: David Hildenbrand <david@redhat.com>

-- 

Thanks,

David / dhildenb

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 1/6] s390x: Use interrupts in SCLP and add locking
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 1/6] s390x: Use interrupts in SCLP and add locking Janosch Frank
@ 2019-09-09  9:08   ` Thomas Huth
  2019-09-10 10:14   ` David Hildenbrand
  1 sibling, 0 replies; 21+ messages in thread
From: Thomas Huth @ 2019-09-09  9:08 UTC (permalink / raw)
  To: Janosch Frank, kvm; +Cc: linux-s390, david

On 05/09/2019 12.39, Janosch Frank wrote:
> We need to properly implement interrupt handling for SCLP, because on
> z/VM and LPAR SCLP calls are not synchronous!
> 
> Also with smp CPUs have to compete for sclp. Let's add some locking,
> so they execute sclp calls in an orderly fashion and don't compete for
> the data buffer.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  lib/s390x/asm/interrupt.h |  2 ++
>  lib/s390x/interrupt.c     | 12 +++++++--
>  lib/s390x/sclp-console.c  |  2 ++
>  lib/s390x/sclp.c          | 55 +++++++++++++++++++++++++++++++++++++--
>  lib/s390x/sclp.h          |  3 +++
>  5 files changed, 70 insertions(+), 4 deletions(-)

Reviewed-by: Thomas Huth <thuth@redhat.com>

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 4/6] s390x: Add initial smp code
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 4/6] s390x: Add initial smp code Janosch Frank
@ 2019-09-09 15:37   ` Thomas Huth
  2019-09-11  8:33     ` Janosch Frank
  2019-09-10 12:19   ` Thomas Huth
  1 sibling, 1 reply; 21+ messages in thread
From: Thomas Huth @ 2019-09-09 15:37 UTC (permalink / raw)
  To: Janosch Frank, kvm; +Cc: linux-s390, david

On 05/09/2019 12.39, Janosch Frank wrote:
> Let's add a rudimentary SMP library, which will scan for cpus and has
> helper functions that manage the cpu state.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
[...]
> +/*Expected to be called from boot cpu */
> +extern uint64_t *stackptr;
> +void smp_setup(void)
> +{
> +	int i = 0;
> +	unsigned short cpu0_addr = stap();
> +	struct ReadCpuInfo *info = (void *)cpu_info_buffer;
> +
> +	spin_lock(&lock);
> +	sclp_mark_busy();
> +	info->h.length = PAGE_SIZE;
> +	sclp_service_call(SCLP_READ_CPU_INFO, cpu_info_buffer);
> +
> +	if (smp_query_num_cpus() > 1)
> +		printf("SMP: Initializing, found %d cpus\n", info->nr_configured);
> +
> +	cpus = calloc(info->nr_configured, sizeof(cpus));
> +	for (i = 0; i < info->nr_configured; i++) {
> +		if (info->entries[i].address == cpu0_addr) {
> +			cpu0 = &cpus[i];
> +			cpu0->stack = stackptr;
> +			cpu0->lowcore = (void *)0;
> +			cpu0->active = true;

So here cpus[i].active gets set to true ...

> +		}
> +		cpus[i].addr = info->entries[i].address;
> +		cpus[i].active = false;

... but here it is set back to false.

Maybe move the if-statement below this line?

> +	}
> +	spin_unlock(&lock);
> +}
[...]
> diff --git a/s390x/cstart64.S b/s390x/cstart64.S
> index 36f7cab..a45ea8f 100644
> --- a/s390x/cstart64.S
> +++ b/s390x/cstart64.S
> @@ -172,6 +172,13 @@ diag308_load_reset:
>  	lhi	%r2, 1
>  	br	%r14
>  
> +.globl smp_cpu_setup_state
> +smp_cpu_setup_state:
> +	xgr	%r1, %r1
> +	lmg     %r0, %r15, 512(%r1)

Can you use GEN_LC_SW_INT_GRS instead of 512?

> +	lctlg   %c0, %c0, 776(%r1)

... and here GEN_LC_SW_INT_CR0 instead of 776?

Apart from that, the patch looks fine to me.

 Thomas



^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 5/6] s390x: Prepare for external calls
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 5/6] s390x: Prepare for external calls Janosch Frank
@ 2019-09-09 15:47   ` Thomas Huth
  0 siblings, 0 replies; 21+ messages in thread
From: Thomas Huth @ 2019-09-09 15:47 UTC (permalink / raw)
  To: Janosch Frank, kvm; +Cc: linux-s390, david

On 05/09/2019 12.39, Janosch Frank wrote:
> With SMP we also get new external interrupts like external call and
> emergency call. Let's make them known.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
[...]
> @@ -108,15 +116,23 @@ void handle_pgm_int(void)
>  
>  void handle_ext_int(void)
>  {
> -	if (lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
> +	if (!ext_int_expected &&
> +	    lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
>  		report_abort("Unexpected external call interrupt: at %#lx",
>  			     lc->ext_old_psw.addr);
> -	} else {
> -		lc->ext_old_psw.mask &= ~PSW_MASK_EXT;
> +		return;
> +	}
> +
> +	if (lc->ext_int_code == EXT_IRQ_SERVICE_SIG) {
>  		lc->sw_int_cr0 &= ~(1UL << 9);
>  		sclp_handle_ext();
> -		lc->ext_int_code = 0;
>  	}
> +	if (lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {

I think you could simplify above line to "else {" ?

With that change:

Reviewed-by: Thomas Huth <thuth@redhat.com>

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 6/6] s390x: SMP test
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 6/6] s390x: SMP test Janosch Frank
@ 2019-09-10  9:43   ` Thomas Huth
  2019-09-10 11:11     ` Janosch Frank
  0 siblings, 1 reply; 21+ messages in thread
From: Thomas Huth @ 2019-09-10  9:43 UTC (permalink / raw)
  To: Janosch Frank, kvm; +Cc: linux-s390, david

On 05/09/2019 12.39, Janosch Frank wrote:
> Testing SIGP emulation for the following order codes:
> * start
> * stop
> * restart
> * set prefix
> * store status
> * stop and store status
> * reset
> * initial reset
> * external call
> * emegergency call
> 
> restart and set prefix are part of the library and needed to start
> other cpus.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
[...]
> +static void test_store_status(void)
> +{
> +	struct cpu_status *status = alloc_pages(1);
> +	uint32_t r;
> +
> +	report_prefix_push("store status at address");
> +	memset(status, 0, PAGE_SIZE * 2);
> +
> +	report_prefix_push("running");
> +	smp_cpu_restart(1);
> +	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, &r);
> +	report("incorrect state", r == SIGP_STATUS_INCORRECT_STATE);
> +	report("status not written", !memcmp(status, (void*)status + PAGE_SIZE, PAGE_SIZE));
> +	report_prefix_pop();
> +
> +	memset(status, 0, PAGE_SIZE);
> +	report_prefix_push("stopped");
> +	smp_cpu_stop(1);
> +	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);
> +	while (!status->prefix) { mb(); }
> +	report("status written", 1);
> +	free_pages(status, PAGE_SIZE);

Shouldn't that be PAGE_SIZE * 2 instead?

> +	report_prefix_pop();
> +
> +	report_prefix_pop();
> +}

The remaining part of the patch looks fine to me.

 Thomas

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 1/6] s390x: Use interrupts in SCLP and add locking
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 1/6] s390x: Use interrupts in SCLP and add locking Janosch Frank
  2019-09-09  9:08   ` Thomas Huth
@ 2019-09-10 10:14   ` David Hildenbrand
  2019-09-10 11:24     ` David Hildenbrand
  1 sibling, 1 reply; 21+ messages in thread
From: David Hildenbrand @ 2019-09-10 10:14 UTC (permalink / raw)
  To: Janosch Frank, kvm; +Cc: linux-s390, thuth

On 05.09.19 12:39, Janosch Frank wrote:
> We need to properly implement interrupt handling for SCLP, because on
> z/VM and LPAR SCLP calls are not synchronous!
> 
> Also with smp CPUs have to compete for sclp. Let's add some locking,
> so they execute sclp calls in an orderly fashion and don't compete for
> the data buffer.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  lib/s390x/asm/interrupt.h |  2 ++
>  lib/s390x/interrupt.c     | 12 +++++++--
>  lib/s390x/sclp-console.c  |  2 ++
>  lib/s390x/sclp.c          | 55 +++++++++++++++++++++++++++++++++++++--
>  lib/s390x/sclp.h          |  3 +++
>  5 files changed, 70 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
> index 013709f..f485e96 100644
> --- a/lib/s390x/asm/interrupt.h
> +++ b/lib/s390x/asm/interrupt.h
> @@ -11,6 +11,8 @@
>  #define _ASMS390X_IRQ_H_
>  #include <asm/arch_def.h>
>  
> +#define EXT_IRQ_SERVICE_SIG	0x2401
> +
>  void handle_pgm_int(void);
>  void handle_ext_int(void);
>  void handle_mcck_int(void);
> diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
> index cf0a794..7832711 100644
> --- a/lib/s390x/interrupt.c
> +++ b/lib/s390x/interrupt.c
> @@ -12,6 +12,7 @@
>  #include <libcflat.h>
>  #include <asm/interrupt.h>
>  #include <asm/barrier.h>
> +#include <sclp.h>
>  
>  static bool pgm_int_expected;
>  static struct lowcore *lc;
> @@ -107,8 +108,15 @@ void handle_pgm_int(void)
>  
>  void handle_ext_int(void)
>  {
> -	report_abort("Unexpected external call interrupt: at %#lx",
> -		     lc->ext_old_psw.addr);
> +	if (lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
> +		report_abort("Unexpected external call interrupt: at %#lx",
> +			     lc->ext_old_psw.addr);
> +	} else {
> +		lc->ext_old_psw.mask &= ~PSW_MASK_EXT;
> +		lc->sw_int_cr0 &= ~(1UL << 9);
> +		sclp_handle_ext();
> +		lc->ext_int_code = 0;
> +	}
>  }
>  
>  void handle_mcck_int(void)
> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
> index bc01f41..a5ef45f 100644
> --- a/lib/s390x/sclp-console.c
> +++ b/lib/s390x/sclp-console.c
> @@ -17,6 +17,7 @@ static void sclp_set_write_mask(void)
>  {
>  	WriteEventMask *sccb = (void *)_sccb;
>  
> +	sclp_mark_busy();
>  	sccb->h.length = sizeof(WriteEventMask);
>  	sccb->mask_length = sizeof(unsigned int);
>  	sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
> @@ -37,6 +38,7 @@ void sclp_print(const char *str)
>  	int len = strlen(str);
>  	WriteEventData *sccb = (void *)_sccb;
>  
> +	sclp_mark_busy();
>  	sccb->h.length = sizeof(WriteEventData) + len;
>  	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
>  	sccb->ebh.length = sizeof(EventBufferHeader) + len;
> diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c
> index b60f7a4..56fca0c 100644
> --- a/lib/s390x/sclp.c
> +++ b/lib/s390x/sclp.c
> @@ -14,6 +14,8 @@
>  #include <asm/page.h>
>  #include <asm/arch_def.h>
>  #include <asm/interrupt.h>
> +#include <asm/barrier.h>
> +#include <asm/spinlock.h>
>  #include "sclp.h"
>  #include <alloc_phys.h>
>  #include <alloc_page.h>
> @@ -25,6 +27,8 @@ static uint64_t max_ram_size;
>  static uint64_t ram_size;
>  
>  char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096)));
> +static volatile bool sclp_busy;
> +static struct spinlock sclp_lock;
>  
>  static void mem_init(phys_addr_t mem_end)
>  {
> @@ -41,17 +45,62 @@ static void mem_init(phys_addr_t mem_end)
>  	page_alloc_ops_enable();
>  }
>  
> +static void sclp_setup_int(void)
> +{
> +	uint64_t mask;
> +
> +	ctl_set_bit(0, 9);
> +
> +	mask = extract_psw_mask();
> +	mask |= PSW_MASK_EXT;
> +	load_psw_mask(mask);
> +}
> +
> +void sclp_handle_ext(void)
> +{
> +	ctl_clear_bit(0, 9);
> +	spin_lock(&sclp_lock);
> +	sclp_busy = false;
> +	spin_unlock(&sclp_lock);
> +}
> +
> +void sclp_wait_busy(void)
> +{
> +	while (sclp_busy)
> +		mb();
> +}
> +
> +void sclp_mark_busy(void)
> +{
> +	/*
> +	 * With multiple CPUs we might need to wait for another CPU's
> +	 * request before grabbing the busy indication.
> +	 */
> +	while (true) {
> +		sclp_wait_busy();
> +		spin_lock(&sclp_lock);
> +		if (!sclp_busy) {
> +			sclp_busy = true;
> +			spin_unlock(&sclp_lock);
> +			return;
> +		}
> +		spin_unlock(&sclp_lock);
> +	}
> +}
> +
>  static void sclp_read_scp_info(ReadInfo *ri, int length)
>  {
>  	unsigned int commands[] = { SCLP_CMDW_READ_SCP_INFO_FORCED,
>  				    SCLP_CMDW_READ_SCP_INFO };
> -	int i;
> +	int i, cc;
>  
>  	for (i = 0; i < ARRAY_SIZE(commands); i++) {
> +		sclp_mark_busy();
>  		memset(&ri->h, 0, sizeof(ri->h));
>  		ri->h.length = length;
>  
> -		if (sclp_service_call(commands[i], ri))
> +		cc = sclp_service_call(commands[i], ri);
> +		if (cc)
>  			break;
>  		if (ri->h.response_code == SCLP_RC_NORMAL_READ_COMPLETION)
>  			return;
> @@ -66,12 +115,14 @@ int sclp_service_call(unsigned int command, void *sccb)
>  {
>  	int cc;
>  
> +	sclp_setup_int();
>  	asm volatile(
>  		"       .insn   rre,0xb2200000,%1,%2\n"  /* servc %1,%2 */
>  		"       ipm     %0\n"
>  		"       srl     %0,28"
>  		: "=&d" (cc) : "d" (command), "a" (__pa(sccb))
>  		: "cc", "memory");
> +	sclp_wait_busy();
>  	if (cc == 3)
>  		return -1;
>  	if (cc == 2)
> diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
> index 583c4e5..63cf609 100644
> --- a/lib/s390x/sclp.h
> +++ b/lib/s390x/sclp.h
> @@ -213,6 +213,9 @@ typedef struct ReadEventData {
>  } __attribute__((packed)) ReadEventData;
>  
>  extern char _sccb[];
> +void sclp_handle_ext(void);
> +void sclp_wait_busy(void);
> +void sclp_mark_busy(void);
>  void sclp_console_setup(void);
>  void sclp_print(const char *str);
>  int sclp_service_call(unsigned int command, void *sccb);
> 

I was wondering whether it would make sense to enable sclp interrupts as
default for all CPUs (once in a reasonable state after brought up), and
simply let any CPU process the request. Initially, we could only let the
boot CPU handle them.

You already decoupled sclp_mark_busy() and sclp_setup_int() already. The
part would have to be moved to the CPU init stage and sclp_handle_ext()
would simply not clear the interrupt-enable flag.

Opinions?

-- 

Thanks,

David / dhildenb

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 6/6] s390x: SMP test
  2019-09-10  9:43   ` Thomas Huth
@ 2019-09-10 11:11     ` Janosch Frank
  0 siblings, 0 replies; 21+ messages in thread
From: Janosch Frank @ 2019-09-10 11:11 UTC (permalink / raw)
  To: Thomas Huth, kvm; +Cc: linux-s390, david

[-- Attachment #1.1: Type: text/plain, Size: 1551 bytes --]

On 9/10/19 11:43 AM, Thomas Huth wrote:
> On 05/09/2019 12.39, Janosch Frank wrote:
>> Testing SIGP emulation for the following order codes:
>> * start
>> * stop
>> * restart
>> * set prefix
>> * store status
>> * stop and store status
>> * reset
>> * initial reset
>> * external call
>> * emegergency call
>>
>> restart and set prefix are part of the library and needed to start
>> other cpus.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> ---
> [...]
>> +static void test_store_status(void)
>> +{
>> +	struct cpu_status *status = alloc_pages(1);
>> +	uint32_t r;
>> +
>> +	report_prefix_push("store status at address");
>> +	memset(status, 0, PAGE_SIZE * 2);
>> +
>> +	report_prefix_push("running");
>> +	smp_cpu_restart(1);
>> +	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, &r);
>> +	report("incorrect state", r == SIGP_STATUS_INCORRECT_STATE);
>> +	report("status not written", !memcmp(status, (void*)status + PAGE_SIZE, PAGE_SIZE));
>> +	report_prefix_pop();
>> +
>> +	memset(status, 0, PAGE_SIZE);
>> +	report_prefix_push("stopped");
>> +	smp_cpu_stop(1);
>> +	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);
>> +	while (!status->prefix) { mb(); }
>> +	report("status written", 1);
>> +	free_pages(status, PAGE_SIZE);
> 
> Shouldn't that be PAGE_SIZE * 2 instead?

Indeed

> 
>> +	report_prefix_pop();
>> +
>> +	report_prefix_pop();
>> +}
> 
> The remaining part of the patch looks fine to me.

Thanks for having a look

> 
>  Thomas
> 



[-- Attachment #2: OpenPGP digital signature --]
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^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 1/6] s390x: Use interrupts in SCLP and add locking
  2019-09-10 10:14   ` David Hildenbrand
@ 2019-09-10 11:24     ` David Hildenbrand
  2019-09-10 11:25       ` Janosch Frank
  0 siblings, 1 reply; 21+ messages in thread
From: David Hildenbrand @ 2019-09-10 11:24 UTC (permalink / raw)
  To: Janosch Frank, kvm; +Cc: linux-s390, thuth

On 10.09.19 12:14, David Hildenbrand wrote:
> On 05.09.19 12:39, Janosch Frank wrote:
>> We need to properly implement interrupt handling for SCLP, because on
>> z/VM and LPAR SCLP calls are not synchronous!
>>
>> Also with smp CPUs have to compete for sclp. Let's add some locking,
>> so they execute sclp calls in an orderly fashion and don't compete for
>> the data buffer.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> ---
>>  lib/s390x/asm/interrupt.h |  2 ++
>>  lib/s390x/interrupt.c     | 12 +++++++--
>>  lib/s390x/sclp-console.c  |  2 ++
>>  lib/s390x/sclp.c          | 55 +++++++++++++++++++++++++++++++++++++--
>>  lib/s390x/sclp.h          |  3 +++
>>  5 files changed, 70 insertions(+), 4 deletions(-)
>>
>> diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
>> index 013709f..f485e96 100644
>> --- a/lib/s390x/asm/interrupt.h
>> +++ b/lib/s390x/asm/interrupt.h
>> @@ -11,6 +11,8 @@
>>  #define _ASMS390X_IRQ_H_
>>  #include <asm/arch_def.h>
>>  
>> +#define EXT_IRQ_SERVICE_SIG	0x2401
>> +
>>  void handle_pgm_int(void);
>>  void handle_ext_int(void);
>>  void handle_mcck_int(void);
>> diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
>> index cf0a794..7832711 100644
>> --- a/lib/s390x/interrupt.c
>> +++ b/lib/s390x/interrupt.c
>> @@ -12,6 +12,7 @@
>>  #include <libcflat.h>
>>  #include <asm/interrupt.h>
>>  #include <asm/barrier.h>
>> +#include <sclp.h>
>>  
>>  static bool pgm_int_expected;
>>  static struct lowcore *lc;
>> @@ -107,8 +108,15 @@ void handle_pgm_int(void)
>>  
>>  void handle_ext_int(void)
>>  {
>> -	report_abort("Unexpected external call interrupt: at %#lx",
>> -		     lc->ext_old_psw.addr);
>> +	if (lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
>> +		report_abort("Unexpected external call interrupt: at %#lx",
>> +			     lc->ext_old_psw.addr);
>> +	} else {
>> +		lc->ext_old_psw.mask &= ~PSW_MASK_EXT;
>> +		lc->sw_int_cr0 &= ~(1UL << 9);
>> +		sclp_handle_ext();
>> +		lc->ext_int_code = 0;
>> +	}
>>  }
>>  
>>  void handle_mcck_int(void)
>> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
>> index bc01f41..a5ef45f 100644
>> --- a/lib/s390x/sclp-console.c
>> +++ b/lib/s390x/sclp-console.c
>> @@ -17,6 +17,7 @@ static void sclp_set_write_mask(void)
>>  {
>>  	WriteEventMask *sccb = (void *)_sccb;
>>  
>> +	sclp_mark_busy();
>>  	sccb->h.length = sizeof(WriteEventMask);
>>  	sccb->mask_length = sizeof(unsigned int);
>>  	sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
>> @@ -37,6 +38,7 @@ void sclp_print(const char *str)
>>  	int len = strlen(str);
>>  	WriteEventData *sccb = (void *)_sccb;
>>  
>> +	sclp_mark_busy();
>>  	sccb->h.length = sizeof(WriteEventData) + len;
>>  	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
>>  	sccb->ebh.length = sizeof(EventBufferHeader) + len;
>> diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c
>> index b60f7a4..56fca0c 100644
>> --- a/lib/s390x/sclp.c
>> +++ b/lib/s390x/sclp.c
>> @@ -14,6 +14,8 @@
>>  #include <asm/page.h>
>>  #include <asm/arch_def.h>
>>  #include <asm/interrupt.h>
>> +#include <asm/barrier.h>
>> +#include <asm/spinlock.h>
>>  #include "sclp.h"
>>  #include <alloc_phys.h>
>>  #include <alloc_page.h>
>> @@ -25,6 +27,8 @@ static uint64_t max_ram_size;
>>  static uint64_t ram_size;
>>  
>>  char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096)));
>> +static volatile bool sclp_busy;
>> +static struct spinlock sclp_lock;
>>  
>>  static void mem_init(phys_addr_t mem_end)
>>  {
>> @@ -41,17 +45,62 @@ static void mem_init(phys_addr_t mem_end)
>>  	page_alloc_ops_enable();
>>  }
>>  
>> +static void sclp_setup_int(void)
>> +{
>> +	uint64_t mask;
>> +
>> +	ctl_set_bit(0, 9);
>> +
>> +	mask = extract_psw_mask();
>> +	mask |= PSW_MASK_EXT;
>> +	load_psw_mask(mask);
>> +}
>> +
>> +void sclp_handle_ext(void)
>> +{
>> +	ctl_clear_bit(0, 9);
>> +	spin_lock(&sclp_lock);
>> +	sclp_busy = false;
>> +	spin_unlock(&sclp_lock);
>> +}
>> +
>> +void sclp_wait_busy(void)
>> +{
>> +	while (sclp_busy)
>> +		mb();
>> +}
>> +
>> +void sclp_mark_busy(void)
>> +{
>> +	/*
>> +	 * With multiple CPUs we might need to wait for another CPU's
>> +	 * request before grabbing the busy indication.
>> +	 */
>> +	while (true) {
>> +		sclp_wait_busy();
>> +		spin_lock(&sclp_lock);
>> +		if (!sclp_busy) {
>> +			sclp_busy = true;
>> +			spin_unlock(&sclp_lock);
>> +			return;
>> +		}
>> +		spin_unlock(&sclp_lock);
>> +	}
>> +}
>> +
>>  static void sclp_read_scp_info(ReadInfo *ri, int length)
>>  {
>>  	unsigned int commands[] = { SCLP_CMDW_READ_SCP_INFO_FORCED,
>>  				    SCLP_CMDW_READ_SCP_INFO };
>> -	int i;
>> +	int i, cc;
>>  
>>  	for (i = 0; i < ARRAY_SIZE(commands); i++) {
>> +		sclp_mark_busy();
>>  		memset(&ri->h, 0, sizeof(ri->h));
>>  		ri->h.length = length;
>>  
>> -		if (sclp_service_call(commands[i], ri))
>> +		cc = sclp_service_call(commands[i], ri);
>> +		if (cc)
>>  			break;
>>  		if (ri->h.response_code == SCLP_RC_NORMAL_READ_COMPLETION)
>>  			return;
>> @@ -66,12 +115,14 @@ int sclp_service_call(unsigned int command, void *sccb)
>>  {
>>  	int cc;
>>  
>> +	sclp_setup_int();
>>  	asm volatile(
>>  		"       .insn   rre,0xb2200000,%1,%2\n"  /* servc %1,%2 */
>>  		"       ipm     %0\n"
>>  		"       srl     %0,28"
>>  		: "=&d" (cc) : "d" (command), "a" (__pa(sccb))
>>  		: "cc", "memory");
>> +	sclp_wait_busy();
>>  	if (cc == 3)
>>  		return -1;
>>  	if (cc == 2)
>> diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
>> index 583c4e5..63cf609 100644
>> --- a/lib/s390x/sclp.h
>> +++ b/lib/s390x/sclp.h
>> @@ -213,6 +213,9 @@ typedef struct ReadEventData {
>>  } __attribute__((packed)) ReadEventData;
>>  
>>  extern char _sccb[];
>> +void sclp_handle_ext(void);
>> +void sclp_wait_busy(void);
>> +void sclp_mark_busy(void);
>>  void sclp_console_setup(void);
>>  void sclp_print(const char *str);
>>  int sclp_service_call(unsigned int command, void *sccb);
>>
> 
> I was wondering whether it would make sense to enable sclp interrupts as
> default for all CPUs (once in a reasonable state after brought up), and
> simply let any CPU process the request. Initially, we could only let the
> boot CPU handle them.
> 
> You already decoupled sclp_mark_busy() and sclp_setup_int() already. The
> part would have to be moved to the CPU init stage and sclp_handle_ext()
> would simply not clear the interrupt-enable flag.
> 
> Opinions?
> 

OTOH, the s390x-ccw bios enables interrupts on the single cpu after
sending the request, and disables them again in the interrupt handler. I
guess we should never get more than one interrupt per SCLP request?

-- 

Thanks,

David / dhildenb

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 1/6] s390x: Use interrupts in SCLP and add locking
  2019-09-10 11:24     ` David Hildenbrand
@ 2019-09-10 11:25       ` Janosch Frank
  2019-09-10 11:30         ` David Hildenbrand
  0 siblings, 1 reply; 21+ messages in thread
From: Janosch Frank @ 2019-09-10 11:25 UTC (permalink / raw)
  To: David Hildenbrand, kvm; +Cc: linux-s390, thuth

[-- Attachment #1.1: Type: text/plain, Size: 7112 bytes --]

On 9/10/19 1:24 PM, David Hildenbrand wrote:
> On 10.09.19 12:14, David Hildenbrand wrote:
>> On 05.09.19 12:39, Janosch Frank wrote:
>>> We need to properly implement interrupt handling for SCLP, because on
>>> z/VM and LPAR SCLP calls are not synchronous!
>>>
>>> Also with smp CPUs have to compete for sclp. Let's add some locking,
>>> so they execute sclp calls in an orderly fashion and don't compete for
>>> the data buffer.
>>>
>>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>>> ---
>>>  lib/s390x/asm/interrupt.h |  2 ++
>>>  lib/s390x/interrupt.c     | 12 +++++++--
>>>  lib/s390x/sclp-console.c  |  2 ++
>>>  lib/s390x/sclp.c          | 55 +++++++++++++++++++++++++++++++++++++--
>>>  lib/s390x/sclp.h          |  3 +++
>>>  5 files changed, 70 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
>>> index 013709f..f485e96 100644
>>> --- a/lib/s390x/asm/interrupt.h
>>> +++ b/lib/s390x/asm/interrupt.h
>>> @@ -11,6 +11,8 @@
>>>  #define _ASMS390X_IRQ_H_
>>>  #include <asm/arch_def.h>
>>>  
>>> +#define EXT_IRQ_SERVICE_SIG	0x2401
>>> +
>>>  void handle_pgm_int(void);
>>>  void handle_ext_int(void);
>>>  void handle_mcck_int(void);
>>> diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
>>> index cf0a794..7832711 100644
>>> --- a/lib/s390x/interrupt.c
>>> +++ b/lib/s390x/interrupt.c
>>> @@ -12,6 +12,7 @@
>>>  #include <libcflat.h>
>>>  #include <asm/interrupt.h>
>>>  #include <asm/barrier.h>
>>> +#include <sclp.h>
>>>  
>>>  static bool pgm_int_expected;
>>>  static struct lowcore *lc;
>>> @@ -107,8 +108,15 @@ void handle_pgm_int(void)
>>>  
>>>  void handle_ext_int(void)
>>>  {
>>> -	report_abort("Unexpected external call interrupt: at %#lx",
>>> -		     lc->ext_old_psw.addr);
>>> +	if (lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
>>> +		report_abort("Unexpected external call interrupt: at %#lx",
>>> +			     lc->ext_old_psw.addr);
>>> +	} else {
>>> +		lc->ext_old_psw.mask &= ~PSW_MASK_EXT;
>>> +		lc->sw_int_cr0 &= ~(1UL << 9);
>>> +		sclp_handle_ext();
>>> +		lc->ext_int_code = 0;
>>> +	}
>>>  }
>>>  
>>>  void handle_mcck_int(void)
>>> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
>>> index bc01f41..a5ef45f 100644
>>> --- a/lib/s390x/sclp-console.c
>>> +++ b/lib/s390x/sclp-console.c
>>> @@ -17,6 +17,7 @@ static void sclp_set_write_mask(void)
>>>  {
>>>  	WriteEventMask *sccb = (void *)_sccb;
>>>  
>>> +	sclp_mark_busy();
>>>  	sccb->h.length = sizeof(WriteEventMask);
>>>  	sccb->mask_length = sizeof(unsigned int);
>>>  	sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
>>> @@ -37,6 +38,7 @@ void sclp_print(const char *str)
>>>  	int len = strlen(str);
>>>  	WriteEventData *sccb = (void *)_sccb;
>>>  
>>> +	sclp_mark_busy();
>>>  	sccb->h.length = sizeof(WriteEventData) + len;
>>>  	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
>>>  	sccb->ebh.length = sizeof(EventBufferHeader) + len;
>>> diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c
>>> index b60f7a4..56fca0c 100644
>>> --- a/lib/s390x/sclp.c
>>> +++ b/lib/s390x/sclp.c
>>> @@ -14,6 +14,8 @@
>>>  #include <asm/page.h>
>>>  #include <asm/arch_def.h>
>>>  #include <asm/interrupt.h>
>>> +#include <asm/barrier.h>
>>> +#include <asm/spinlock.h>
>>>  #include "sclp.h"
>>>  #include <alloc_phys.h>
>>>  #include <alloc_page.h>
>>> @@ -25,6 +27,8 @@ static uint64_t max_ram_size;
>>>  static uint64_t ram_size;
>>>  
>>>  char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096)));
>>> +static volatile bool sclp_busy;
>>> +static struct spinlock sclp_lock;
>>>  
>>>  static void mem_init(phys_addr_t mem_end)
>>>  {
>>> @@ -41,17 +45,62 @@ static void mem_init(phys_addr_t mem_end)
>>>  	page_alloc_ops_enable();
>>>  }
>>>  
>>> +static void sclp_setup_int(void)
>>> +{
>>> +	uint64_t mask;
>>> +
>>> +	ctl_set_bit(0, 9);
>>> +
>>> +	mask = extract_psw_mask();
>>> +	mask |= PSW_MASK_EXT;
>>> +	load_psw_mask(mask);
>>> +}
>>> +
>>> +void sclp_handle_ext(void)
>>> +{
>>> +	ctl_clear_bit(0, 9);
>>> +	spin_lock(&sclp_lock);
>>> +	sclp_busy = false;
>>> +	spin_unlock(&sclp_lock);
>>> +}
>>> +
>>> +void sclp_wait_busy(void)
>>> +{
>>> +	while (sclp_busy)
>>> +		mb();
>>> +}
>>> +
>>> +void sclp_mark_busy(void)
>>> +{
>>> +	/*
>>> +	 * With multiple CPUs we might need to wait for another CPU's
>>> +	 * request before grabbing the busy indication.
>>> +	 */
>>> +	while (true) {
>>> +		sclp_wait_busy();
>>> +		spin_lock(&sclp_lock);
>>> +		if (!sclp_busy) {
>>> +			sclp_busy = true;
>>> +			spin_unlock(&sclp_lock);
>>> +			return;
>>> +		}
>>> +		spin_unlock(&sclp_lock);
>>> +	}
>>> +}
>>> +
>>>  static void sclp_read_scp_info(ReadInfo *ri, int length)
>>>  {
>>>  	unsigned int commands[] = { SCLP_CMDW_READ_SCP_INFO_FORCED,
>>>  				    SCLP_CMDW_READ_SCP_INFO };
>>> -	int i;
>>> +	int i, cc;
>>>  
>>>  	for (i = 0; i < ARRAY_SIZE(commands); i++) {
>>> +		sclp_mark_busy();
>>>  		memset(&ri->h, 0, sizeof(ri->h));
>>>  		ri->h.length = length;
>>>  
>>> -		if (sclp_service_call(commands[i], ri))
>>> +		cc = sclp_service_call(commands[i], ri);
>>> +		if (cc)
>>>  			break;
>>>  		if (ri->h.response_code == SCLP_RC_NORMAL_READ_COMPLETION)
>>>  			return;
>>> @@ -66,12 +115,14 @@ int sclp_service_call(unsigned int command, void *sccb)
>>>  {
>>>  	int cc;
>>>  
>>> +	sclp_setup_int();
>>>  	asm volatile(
>>>  		"       .insn   rre,0xb2200000,%1,%2\n"  /* servc %1,%2 */
>>>  		"       ipm     %0\n"
>>>  		"       srl     %0,28"
>>>  		: "=&d" (cc) : "d" (command), "a" (__pa(sccb))
>>>  		: "cc", "memory");
>>> +	sclp_wait_busy();
>>>  	if (cc == 3)
>>>  		return -1;
>>>  	if (cc == 2)
>>> diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
>>> index 583c4e5..63cf609 100644
>>> --- a/lib/s390x/sclp.h
>>> +++ b/lib/s390x/sclp.h
>>> @@ -213,6 +213,9 @@ typedef struct ReadEventData {
>>>  } __attribute__((packed)) ReadEventData;
>>>  
>>>  extern char _sccb[];
>>> +void sclp_handle_ext(void);
>>> +void sclp_wait_busy(void);
>>> +void sclp_mark_busy(void);
>>>  void sclp_console_setup(void);
>>>  void sclp_print(const char *str);
>>>  int sclp_service_call(unsigned int command, void *sccb);
>>>
>>
>> I was wondering whether it would make sense to enable sclp interrupts as
>> default for all CPUs (once in a reasonable state after brought up), and
>> simply let any CPU process the request. Initially, we could only let the
>> boot CPU handle them.
>>
>> You already decoupled sclp_mark_busy() and sclp_setup_int() already. The
>> part would have to be moved to the CPU init stage and sclp_handle_ext()
>> would simply not clear the interrupt-enable flag.
>>
>> Opinions?
>>
> 
> OTOH, the s390x-ccw bios enables interrupts on the single cpu after
> sending the request, and disables them again in the interrupt handler. I
> guess we should never get more than one interrupt per SCLP request?
> 

Didn't old qemu versions do exactly that an we currently catch that in
the kernel?


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^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 1/6] s390x: Use interrupts in SCLP and add locking
  2019-09-10 11:25       ` Janosch Frank
@ 2019-09-10 11:30         ` David Hildenbrand
  0 siblings, 0 replies; 21+ messages in thread
From: David Hildenbrand @ 2019-09-10 11:30 UTC (permalink / raw)
  To: Janosch Frank, kvm; +Cc: linux-s390, thuth

On 10.09.19 13:25, Janosch Frank wrote:
> On 9/10/19 1:24 PM, David Hildenbrand wrote:
>> On 10.09.19 12:14, David Hildenbrand wrote:
>>> On 05.09.19 12:39, Janosch Frank wrote:
>>>> We need to properly implement interrupt handling for SCLP, because on
>>>> z/VM and LPAR SCLP calls are not synchronous!
>>>>
>>>> Also with smp CPUs have to compete for sclp. Let's add some locking,
>>>> so they execute sclp calls in an orderly fashion and don't compete for
>>>> the data buffer.
>>>>
>>>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>>>> ---
>>>>  lib/s390x/asm/interrupt.h |  2 ++
>>>>  lib/s390x/interrupt.c     | 12 +++++++--
>>>>  lib/s390x/sclp-console.c  |  2 ++
>>>>  lib/s390x/sclp.c          | 55 +++++++++++++++++++++++++++++++++++++--
>>>>  lib/s390x/sclp.h          |  3 +++
>>>>  5 files changed, 70 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
>>>> index 013709f..f485e96 100644
>>>> --- a/lib/s390x/asm/interrupt.h
>>>> +++ b/lib/s390x/asm/interrupt.h
>>>> @@ -11,6 +11,8 @@
>>>>  #define _ASMS390X_IRQ_H_
>>>>  #include <asm/arch_def.h>
>>>>  
>>>> +#define EXT_IRQ_SERVICE_SIG	0x2401
>>>> +
>>>>  void handle_pgm_int(void);
>>>>  void handle_ext_int(void);
>>>>  void handle_mcck_int(void);
>>>> diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
>>>> index cf0a794..7832711 100644
>>>> --- a/lib/s390x/interrupt.c
>>>> +++ b/lib/s390x/interrupt.c
>>>> @@ -12,6 +12,7 @@
>>>>  #include <libcflat.h>
>>>>  #include <asm/interrupt.h>
>>>>  #include <asm/barrier.h>
>>>> +#include <sclp.h>
>>>>  
>>>>  static bool pgm_int_expected;
>>>>  static struct lowcore *lc;
>>>> @@ -107,8 +108,15 @@ void handle_pgm_int(void)
>>>>  
>>>>  void handle_ext_int(void)
>>>>  {
>>>> -	report_abort("Unexpected external call interrupt: at %#lx",
>>>> -		     lc->ext_old_psw.addr);
>>>> +	if (lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
>>>> +		report_abort("Unexpected external call interrupt: at %#lx",
>>>> +			     lc->ext_old_psw.addr);
>>>> +	} else {
>>>> +		lc->ext_old_psw.mask &= ~PSW_MASK_EXT;
>>>> +		lc->sw_int_cr0 &= ~(1UL << 9);
>>>> +		sclp_handle_ext();
>>>> +		lc->ext_int_code = 0;
>>>> +	}
>>>>  }
>>>>  
>>>>  void handle_mcck_int(void)
>>>> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
>>>> index bc01f41..a5ef45f 100644
>>>> --- a/lib/s390x/sclp-console.c
>>>> +++ b/lib/s390x/sclp-console.c
>>>> @@ -17,6 +17,7 @@ static void sclp_set_write_mask(void)
>>>>  {
>>>>  	WriteEventMask *sccb = (void *)_sccb;
>>>>  
>>>> +	sclp_mark_busy();
>>>>  	sccb->h.length = sizeof(WriteEventMask);
>>>>  	sccb->mask_length = sizeof(unsigned int);
>>>>  	sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
>>>> @@ -37,6 +38,7 @@ void sclp_print(const char *str)
>>>>  	int len = strlen(str);
>>>>  	WriteEventData *sccb = (void *)_sccb;
>>>>  
>>>> +	sclp_mark_busy();
>>>>  	sccb->h.length = sizeof(WriteEventData) + len;
>>>>  	sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
>>>>  	sccb->ebh.length = sizeof(EventBufferHeader) + len;
>>>> diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c
>>>> index b60f7a4..56fca0c 100644
>>>> --- a/lib/s390x/sclp.c
>>>> +++ b/lib/s390x/sclp.c
>>>> @@ -14,6 +14,8 @@
>>>>  #include <asm/page.h>
>>>>  #include <asm/arch_def.h>
>>>>  #include <asm/interrupt.h>
>>>> +#include <asm/barrier.h>
>>>> +#include <asm/spinlock.h>
>>>>  #include "sclp.h"
>>>>  #include <alloc_phys.h>
>>>>  #include <alloc_page.h>
>>>> @@ -25,6 +27,8 @@ static uint64_t max_ram_size;
>>>>  static uint64_t ram_size;
>>>>  
>>>>  char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096)));
>>>> +static volatile bool sclp_busy;
>>>> +static struct spinlock sclp_lock;
>>>>  
>>>>  static void mem_init(phys_addr_t mem_end)
>>>>  {
>>>> @@ -41,17 +45,62 @@ static void mem_init(phys_addr_t mem_end)
>>>>  	page_alloc_ops_enable();
>>>>  }
>>>>  
>>>> +static void sclp_setup_int(void)
>>>> +{
>>>> +	uint64_t mask;
>>>> +
>>>> +	ctl_set_bit(0, 9);
>>>> +
>>>> +	mask = extract_psw_mask();
>>>> +	mask |= PSW_MASK_EXT;
>>>> +	load_psw_mask(mask);
>>>> +}
>>>> +
>>>> +void sclp_handle_ext(void)
>>>> +{
>>>> +	ctl_clear_bit(0, 9);
>>>> +	spin_lock(&sclp_lock);
>>>> +	sclp_busy = false;
>>>> +	spin_unlock(&sclp_lock);
>>>> +}
>>>> +
>>>> +void sclp_wait_busy(void)
>>>> +{
>>>> +	while (sclp_busy)
>>>> +		mb();
>>>> +}
>>>> +
>>>> +void sclp_mark_busy(void)
>>>> +{
>>>> +	/*
>>>> +	 * With multiple CPUs we might need to wait for another CPU's
>>>> +	 * request before grabbing the busy indication.
>>>> +	 */
>>>> +	while (true) {
>>>> +		sclp_wait_busy();
>>>> +		spin_lock(&sclp_lock);
>>>> +		if (!sclp_busy) {
>>>> +			sclp_busy = true;
>>>> +			spin_unlock(&sclp_lock);
>>>> +			return;
>>>> +		}
>>>> +		spin_unlock(&sclp_lock);
>>>> +	}
>>>> +}
>>>> +
>>>>  static void sclp_read_scp_info(ReadInfo *ri, int length)
>>>>  {
>>>>  	unsigned int commands[] = { SCLP_CMDW_READ_SCP_INFO_FORCED,
>>>>  				    SCLP_CMDW_READ_SCP_INFO };
>>>> -	int i;
>>>> +	int i, cc;
>>>>  
>>>>  	for (i = 0; i < ARRAY_SIZE(commands); i++) {
>>>> +		sclp_mark_busy();
>>>>  		memset(&ri->h, 0, sizeof(ri->h));
>>>>  		ri->h.length = length;
>>>>  
>>>> -		if (sclp_service_call(commands[i], ri))
>>>> +		cc = sclp_service_call(commands[i], ri);
>>>> +		if (cc)
>>>>  			break;
>>>>  		if (ri->h.response_code == SCLP_RC_NORMAL_READ_COMPLETION)
>>>>  			return;
>>>> @@ -66,12 +115,14 @@ int sclp_service_call(unsigned int command, void *sccb)
>>>>  {
>>>>  	int cc;
>>>>  
>>>> +	sclp_setup_int();
>>>>  	asm volatile(
>>>>  		"       .insn   rre,0xb2200000,%1,%2\n"  /* servc %1,%2 */
>>>>  		"       ipm     %0\n"
>>>>  		"       srl     %0,28"
>>>>  		: "=&d" (cc) : "d" (command), "a" (__pa(sccb))
>>>>  		: "cc", "memory");
>>>> +	sclp_wait_busy();
>>>>  	if (cc == 3)
>>>>  		return -1;
>>>>  	if (cc == 2)
>>>> diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
>>>> index 583c4e5..63cf609 100644
>>>> --- a/lib/s390x/sclp.h
>>>> +++ b/lib/s390x/sclp.h
>>>> @@ -213,6 +213,9 @@ typedef struct ReadEventData {
>>>>  } __attribute__((packed)) ReadEventData;
>>>>  
>>>>  extern char _sccb[];
>>>> +void sclp_handle_ext(void);
>>>> +void sclp_wait_busy(void);
>>>> +void sclp_mark_busy(void);
>>>>  void sclp_console_setup(void);
>>>>  void sclp_print(const char *str);
>>>>  int sclp_service_call(unsigned int command, void *sccb);
>>>>
>>>
>>> I was wondering whether it would make sense to enable sclp interrupts as
>>> default for all CPUs (once in a reasonable state after brought up), and
>>> simply let any CPU process the request. Initially, we could only let the
>>> boot CPU handle them.
>>>
>>> You already decoupled sclp_mark_busy() and sclp_setup_int() already. The
>>> part would have to be moved to the CPU init stage and sclp_handle_ext()
>>> would simply not clear the interrupt-enable flag.
>>>
>>> Opinions?
>>>
>>
>> OTOH, the s390x-ccw bios enables interrupts on the single cpu after
>> sending the request, and disables them again in the interrupt handler. I
>> guess we should never get more than one interrupt per SCLP request?
>>
> 
> Didn't old qemu versions do exactly that an we currently catch that in
> the kernel?
> 

You mean, multiple interrupts? I remember that the old bios wouldn't
wait for the sclp interrupt at all - meaning one could have remain
pending for the kernel. But that was solved by always waiting for the
single interrupt.

-- 

Thanks,

David / dhildenb

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 4/6] s390x: Add initial smp code
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 4/6] s390x: Add initial smp code Janosch Frank
  2019-09-09 15:37   ` Thomas Huth
@ 2019-09-10 12:19   ` Thomas Huth
  1 sibling, 0 replies; 21+ messages in thread
From: Thomas Huth @ 2019-09-10 12:19 UTC (permalink / raw)
  To: Janosch Frank, kvm; +Cc: linux-s390, david

On 05/09/2019 12.39, Janosch Frank wrote:
> Let's add a rudimentary SMP library, which will scan for cpus and has
> helper functions that manage the cpu state.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  lib/s390x/asm/arch_def.h |   8 ++
>  lib/s390x/asm/sigp.h     |  28 +++-
>  lib/s390x/io.c           |   5 +-
>  lib/s390x/sclp.h         |   1 +
>  lib/s390x/smp.c          | 276 +++++++++++++++++++++++++++++++++++++++
>  lib/s390x/smp.h          |  51 ++++++++
>  s390x/Makefile           |   1 +
>  s390x/cstart64.S         |   7 +
>  8 files changed, 371 insertions(+), 6 deletions(-)
>  create mode 100644 lib/s390x/smp.c
>  create mode 100644 lib/s390x/smp.h
> 
> diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
> index 5f8f45e..d5a7f51 100644
> --- a/lib/s390x/asm/arch_def.h
> +++ b/lib/s390x/asm/arch_def.h
> @@ -157,6 +157,14 @@ struct cpuid {
>  	uint64_t reserved : 15;
>  };
>  
> +static inline unsigned short stap(void)
> +{
> +	unsigned short cpu_address;
> +
> +	asm volatile("stap %0" : "=Q" (cpu_address));
> +	return cpu_address;
> +}
> +
>  static inline int tprot(unsigned long addr)
>  {
>  	int cc;
> diff --git a/lib/s390x/asm/sigp.h b/lib/s390x/asm/sigp.h
> index fbd94fc..2d52313 100644
> --- a/lib/s390x/asm/sigp.h
> +++ b/lib/s390x/asm/sigp.h
> @@ -46,14 +46,32 @@
>  
>  #ifndef __ASSEMBLER__
>  
> -static inline void sigp_stop(void)
> +
> +static inline int sigp(uint16_t addr, uint8_t order, unsigned long parm,
> +		       uint32_t *status)
>  {
> -	register unsigned long status asm ("1") = 0;
> -	register unsigned long cpu asm ("2") = 0;
> +	register unsigned long reg1 asm ("1") = parm;
> +	int cc;
>  
>  	asm volatile(
> -		"	sigp %0,%1,0(%2)\n"
> -		: "+d" (status)  : "d" (cpu), "d" (SIGP_STOP) : "cc");
> +		"	sigp	%1,%2,0(%3)\n"
> +		"	ipm	%0\n"
> +		"	srl	%0,28\n"
> +		: "=d" (cc), "+d" (reg1) : "d" (addr), "a" (order) : "cc");
> +	if (status)
> +		*status = reg1;
> +	return cc;
> +}
> +
> +static inline int sigp_retry(uint16_t addr, uint8_t order, unsigned long parm,
> +			     uint32_t *status)
> +{
> +	int cc;
> +
> +	do {
> +		cc = sigp(addr, order, parm, status);
> +	} while (cc == 2);
> +	return cc;
>  }
>  
>  #endif /* __ASSEMBLER__ */
> diff --git a/lib/s390x/io.c b/lib/s390x/io.c
> index becadfc..32f09b5 100644
> --- a/lib/s390x/io.c
> +++ b/lib/s390x/io.c
> @@ -16,6 +16,7 @@
>  #include <asm/facility.h>
>  #include <asm/sigp.h>
>  #include "sclp.h"
> +#include "smp.h"
>  
>  extern char ipl_args[];
>  uint8_t stfl_bytes[NR_STFL_BYTES] __attribute__((aligned(8)));
> @@ -37,12 +38,14 @@ void setup(void)
>  	setup_facilities();
>  	sclp_console_setup();
>  	sclp_memory_setup();
> +	smp_setup();
>  }
>  
>  void exit(int code)
>  {
> +	smp_teardown();
>  	printf("\nEXIT: STATUS=%d\n", ((code) << 1) | 1);
>  	while (1) {
> -		sigp_stop();
> +		sigp(0, SIGP_STOP, 0, NULL);
>  	}
>  }
> diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
> index 98c482a..4e69845 100644
> --- a/lib/s390x/sclp.h
> +++ b/lib/s390x/sclp.h
> @@ -19,6 +19,7 @@
>  #define SCLP_CMD_CODE_MASK                      0xffff00ff
>  
>  /* SCLP command codes */
> +#define SCLP_READ_CPU_INFO			0x00010001
>  #define SCLP_CMDW_READ_SCP_INFO                 0x00020001
>  #define SCLP_CMDW_READ_SCP_INFO_FORCED          0x00120001
>  #define SCLP_READ_STORAGE_ELEMENT_INFO          0x00040001
> diff --git a/lib/s390x/smp.c b/lib/s390x/smp.c
> new file mode 100644
> index 0000000..40c43ef
> --- /dev/null
> +++ b/lib/s390x/smp.c
> @@ -0,0 +1,276 @@
> +/*
> + * s390x smp
> + * Based on Linux's arch/s390/kernel/smp.c and
> + * arch/s390/include/asm/sigp.h
> + *
> + * Copyright (c) 2019 IBM Corp
> + *
> + * Authors:
> + *  Janosch Frank <frankja@linux.ibm.com>
> + *
> + * This code is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2.
> + */
> +#include <libcflat.h>
> +#include <errno.h>

This breaks building on Travis:

 https://travis-ci.com/huth/kvm-unit-tests/jobs/232679058

I don't think that you can use the errno.h header from the system
library in kvm-unit-tests in a save way. It's likely better if you
define your own error codes instead.

 Thomas

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 3/6] s390x: Add linemode buffer to fix newline on every print
  2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 3/6] s390x: Add linemode buffer to fix newline on every print Janosch Frank
  2019-09-09  9:02   ` David Hildenbrand
@ 2019-09-11  7:57   ` David Hildenbrand
  2019-09-19 11:07     ` Janosch Frank
  1 sibling, 1 reply; 21+ messages in thread
From: David Hildenbrand @ 2019-09-11  7:57 UTC (permalink / raw)
  To: Janosch Frank, kvm; +Cc: linux-s390, thuth

On 05.09.19 12:39, Janosch Frank wrote:
> Linemode seems to add a newline for each sent message which makes
> reading rather hard. Hence we add a small buffer and only print if
> it's full or a newline is encountered. Except for when the string is
> longer than the buffer, then we flush the buffer and print directly.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> ---
>  lib/s390x/sclp-console.c | 70 +++++++++++++++++++++++++++++++++++++---
>  1 file changed, 66 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
> index 19416b5..7397dc1 100644
> --- a/lib/s390x/sclp-console.c
> +++ b/lib/s390x/sclp-console.c
> @@ -13,6 +13,7 @@
>  #include <asm/page.h>
>  #include <asm/arch_def.h>
>  #include <asm/io.h>
> +#include <asm/spinlock.h>
>  #include "sclp.h"
>  
>  /*
> @@ -87,6 +88,10 @@ static uint8_t _ascebc[256] = {
>       0x90, 0x3F, 0x3F, 0x3F, 0x3F, 0xEA, 0x3F, 0xFF
>  };
>  
> +static char lm_buff[120];

Just wondering, how did you come up with the 120? (my first guess would
have been something around 80)

> +static unsigned char lm_buff_off;
> +static struct spinlock lm_buff_lock;
> +
>  static void sclp_print_ascii(const char *str)
>  {
>  	int len = strlen(str);
> @@ -103,10 +108,10 @@ static void sclp_print_ascii(const char *str)
>  	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
>  }
>  
> -static void sclp_print_lm(const char *str)
> +static void lm_print(const char *buff, int len)
>  {

The rename of str->buff could have been avoided, however, the impact is
rather small.

>  	unsigned char *ptr, *end, ch;
> -	unsigned int count, offset, len;
> +	unsigned int count, offset;
>  	struct WriteEventData *sccb;
>  	struct mdb *mdb;
>  	struct mto *mto;
> @@ -117,11 +122,10 @@ static void sclp_print_lm(const char *str)
>  	end = (unsigned char *) sccb + 4096 - 1;
>  	memset(sccb, 0, sizeof(*sccb));
>  	ptr = (unsigned char *) &sccb->msg.mdb.mto;
> -	len = strlen(str);
>  	offset = 0;
>  	do {
>  		for (count = sizeof(*mto); offset < len; count++) {
> -			ch = str[offset++];
> +			ch = buff[offset++];
>  			if (ch == 0x0a || ptr + count > end)
>  				break;
>  			ptr[count] = _ascebc[ch];
> @@ -148,6 +152,64 @@ static void sclp_print_lm(const char *str)
>  	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
>  }
>  
> +
> +/*
> + * In contrast to the ascii console, linemode produces a new
> + * line with every write of data. The report() function uses
> + * several printf() calls to generate a line of data which
> + * would all end up on different lines.
> + *
> + * Hence we buffer here until we encounter a \n or the buffer
> + * is full. That means that linemode output can look a bit
> + * different from ascii and that it takes a bit longer for
> + * lines to appear.
> + */
> +static void sclp_print_lm(const char *str)
> +{
> +	int len;
> +	char *nl;
> +
> +	spin_lock(&lm_buff_lock);
> +
> +	len = strlen(str);

You could do that directly when declaring the variable, doesn't have to
be under the lock.

> +	/*
> +	 * No use in copying into lm_buff, its time to flush the
> +	 * buffer and print str until finished.
> +	 */
> +	if (len > sizeof(lm_buff)) {

I find ARRAY_SIZE(lm_buf) easier to understand than sizeof(lm_buff)

> +		if (lm_buff_off)
> +			lm_print(lm_buff, lm_buff_off);
> +		lm_print(str, len);
> +		memset(lm_buff, 0 , sizeof(lm_buff));
> +		lm_buff_off = 0;
> +		goto out;
> +	}
> +
> +fill:

Is there a way to remove this goto by using a simple while loop?

> +	len = len < (sizeof(lm_buff) - lm_buff_off) ? len : (sizeof(lm_buff) - lm_buff_off);
> +	if ((lm_buff_off < sizeof(lm_buff) - 1)) {

Drop one set of ()

> +		memcpy(&lm_buff[lm_buff_off], str, len);
> +		lm_buff_off += len;
> +	}
> +	/* Buffer not full and no newline */
> +	nl = strchr(lm_buff, '\n');

Why do we have to search? Shouldn't a newline be the last copied
character only?

> +	if (lm_buff_off != sizeof(lm_buff) - 1 && !nl)
> +		goto out;
> +
> +	lm_print(lm_buff, lm_buff_off);
> +	memset(lm_buff, 0 , sizeof(lm_buff));
> +	lm_buff_off = 0;
> +
> +	if (len < strlen(str)) {
> +		str = &str[len];
> +		len = strlen(str);
> +		goto fill;
> +	}

This looks too complicated for my taste :) Or my caffeine level is low.

I think we have the following cases:

1. String contains newline
 a) String fits into remaining buffer
	-> Copy into buffer, flush (last character is newline)
 b) String doesn't fit into remaining buffer
	-> Simply flush old buffer and print remaining string?
2. String doesn't contain newline.
 a) String fits into remaining buffer
	-> Copy into buffer, flush if full
 b) String doesn't fit into remaining buffer
	-> Simply flush old buffer and print remaining string?

Optimizing for 1b) or 2b) isn't really worth it I guess - unless we want
to wrap *any* string at 120 characters. But then, your pre-loop handling
would also have to be modified. I think this allow to simplify your code
a lot.

(how often does it happen in our current tests that we exceed 120
characters?)

> +
> +out:
> +	spin_unlock(&lm_buff_lock);
> +}
> +
>  /*
>   * SCLP needs to be initialized by setting a send and receive mask,
>   * indicating which messages the control program (we) want(s) to
> 


-- 

Thanks,

David / dhildenb

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 4/6] s390x: Add initial smp code
  2019-09-09 15:37   ` Thomas Huth
@ 2019-09-11  8:33     ` Janosch Frank
  0 siblings, 0 replies; 21+ messages in thread
From: Janosch Frank @ 2019-09-11  8:33 UTC (permalink / raw)
  To: Thomas Huth, kvm; +Cc: linux-s390, david

[-- Attachment #1.1: Type: text/plain, Size: 1917 bytes --]

On 9/9/19 5:37 PM, Thomas Huth wrote:
> On 05/09/2019 12.39, Janosch Frank wrote:
>> Let's add a rudimentary SMP library, which will scan for cpus and has
>> helper functions that manage the cpu state.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> ---
> [...]
>> +/*Expected to be called from boot cpu */
>> +extern uint64_t *stackptr;
>> +void smp_setup(void)
>> +{
>> +	int i = 0;
>> +	unsigned short cpu0_addr = stap();
>> +	struct ReadCpuInfo *info = (void *)cpu_info_buffer;
>> +
>> +	spin_lock(&lock);
>> +	sclp_mark_busy();
>> +	info->h.length = PAGE_SIZE;
>> +	sclp_service_call(SCLP_READ_CPU_INFO, cpu_info_buffer);
>> +
>> +	if (smp_query_num_cpus() > 1)
>> +		printf("SMP: Initializing, found %d cpus\n", info->nr_configured);
>> +
>> +	cpus = calloc(info->nr_configured, sizeof(cpus));
>> +	for (i = 0; i < info->nr_configured; i++) {
>> +		if (info->entries[i].address == cpu0_addr) {
>> +			cpu0 = &cpus[i];
>> +			cpu0->stack = stackptr;
>> +			cpu0->lowcore = (void *)0;
>> +			cpu0->active = true;
> 
> So here cpus[i].active gets set to true ...
> 
>> +		}
>> +		cpus[i].addr = info->entries[i].address;
>> +		cpus[i].active = false;
> 
> ... but here it is set back to false.
> 
> Maybe move the if-statement below this line?
> 
>> +	}
>> +	spin_unlock(&lock);
>> +}
> [...]
>> diff --git a/s390x/cstart64.S b/s390x/cstart64.S
>> index 36f7cab..a45ea8f 100644
>> --- a/s390x/cstart64.S
>> +++ b/s390x/cstart64.S
>> @@ -172,6 +172,13 @@ diag308_load_reset:
>>  	lhi	%r2, 1
>>  	br	%r14
>>  
>> +.globl smp_cpu_setup_state
>> +smp_cpu_setup_state:
>> +	xgr	%r1, %r1
>> +	lmg     %r0, %r15, 512(%r1)
> 
> Can you use GEN_LC_SW_INT_GRS instead of 512?
> 
>> +	lctlg   %c0, %c0, 776(%r1)
> 
> ... and here GEN_LC_SW_INT_CR0 instead of 776?
> 
> Apart from that, the patch looks fine to me.

Thanks, just fixed that



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^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [kvm-unit-tests PATCH v2 3/6] s390x: Add linemode buffer to fix newline on every print
  2019-09-11  7:57   ` David Hildenbrand
@ 2019-09-19 11:07     ` Janosch Frank
  0 siblings, 0 replies; 21+ messages in thread
From: Janosch Frank @ 2019-09-19 11:07 UTC (permalink / raw)
  To: David Hildenbrand, kvm; +Cc: linux-s390, thuth

[-- Attachment #1.1: Type: text/plain, Size: 6352 bytes --]

On 9/11/19 9:57 AM, David Hildenbrand wrote:
> On 05.09.19 12:39, Janosch Frank wrote:
>> Linemode seems to add a newline for each sent message which makes
>> reading rather hard. Hence we add a small buffer and only print if
>> it's full or a newline is encountered. Except for when the string is
>> longer than the buffer, then we flush the buffer and print directly.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>> ---
>>  lib/s390x/sclp-console.c | 70 +++++++++++++++++++++++++++++++++++++---
>>  1 file changed, 66 insertions(+), 4 deletions(-)
>>
>> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
>> index 19416b5..7397dc1 100644
>> --- a/lib/s390x/sclp-console.c
>> +++ b/lib/s390x/sclp-console.c
>> @@ -13,6 +13,7 @@
>>  #include <asm/page.h>
>>  #include <asm/arch_def.h>
>>  #include <asm/io.h>
>> +#include <asm/spinlock.h>
>>  #include "sclp.h"
>>  
>>  /*
>> @@ -87,6 +88,10 @@ static uint8_t _ascebc[256] = {
>>       0x90, 0x3F, 0x3F, 0x3F, 0x3F, 0xEA, 0x3F, 0xFF
>>  };
>>  
>> +static char lm_buff[120];
> 
> Just wondering, how did you come up with the 120? (my first guess would
> have been something around 80)
> 
>> +static unsigned char lm_buff_off;
>> +static struct spinlock lm_buff_lock;
>> +
>>  static void sclp_print_ascii(const char *str)
>>  {
>>  	int len = strlen(str);
>> @@ -103,10 +108,10 @@ static void sclp_print_ascii(const char *str)
>>  	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
>>  }
>>  
>> -static void sclp_print_lm(const char *str)
>> +static void lm_print(const char *buff, int len)
>>  {
> 
> The rename of str->buff could have been avoided, however, the impact is
> rather small.
> 
>>  	unsigned char *ptr, *end, ch;
>> -	unsigned int count, offset, len;
>> +	unsigned int count, offset;
>>  	struct WriteEventData *sccb;
>>  	struct mdb *mdb;
>>  	struct mto *mto;
>> @@ -117,11 +122,10 @@ static void sclp_print_lm(const char *str)
>>  	end = (unsigned char *) sccb + 4096 - 1;
>>  	memset(sccb, 0, sizeof(*sccb));
>>  	ptr = (unsigned char *) &sccb->msg.mdb.mto;
>> -	len = strlen(str);
>>  	offset = 0;
>>  	do {
>>  		for (count = sizeof(*mto); offset < len; count++) {
>> -			ch = str[offset++];
>> +			ch = buff[offset++];
>>  			if (ch == 0x0a || ptr + count > end)
>>  				break;
>>  			ptr[count] = _ascebc[ch];
>> @@ -148,6 +152,64 @@ static void sclp_print_lm(const char *str)
>>  	sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
>>  }
>>  
>> +
>> +/*
>> + * In contrast to the ascii console, linemode produces a new
>> + * line with every write of data. The report() function uses
>> + * several printf() calls to generate a line of data which
>> + * would all end up on different lines.
>> + *
>> + * Hence we buffer here until we encounter a \n or the buffer
>> + * is full. That means that linemode output can look a bit
>> + * different from ascii and that it takes a bit longer for
>> + * lines to appear.
>> + */
>> +static void sclp_print_lm(const char *str)
>> +{
>> +	int len;
>> +	char *nl;
>> +
>> +	spin_lock(&lm_buff_lock);
>> +
>> +	len = strlen(str);
> 
> You could do that directly when declaring the variable, doesn't have to
> be under the lock.
> 
>> +	/*
>> +	 * No use in copying into lm_buff, its time to flush the
>> +	 * buffer and print str until finished.
>> +	 */
>> +	if (len > sizeof(lm_buff)) {
> 
> I find ARRAY_SIZE(lm_buf) easier to understand than sizeof(lm_buff)
> 
>> +		if (lm_buff_off)
>> +			lm_print(lm_buff, lm_buff_off);
>> +		lm_print(str, len);
>> +		memset(lm_buff, 0 , sizeof(lm_buff));
>> +		lm_buff_off = 0;
>> +		goto out;
>> +	}
>> +
>> +fill:
> 
> Is there a way to remove this goto by using a simple while loop?
> 
>> +	len = len < (sizeof(lm_buff) - lm_buff_off) ? len : (sizeof(lm_buff) - lm_buff_off);
>> +	if ((lm_buff_off < sizeof(lm_buff) - 1)) {
> 
> Drop one set of ()
> 
>> +		memcpy(&lm_buff[lm_buff_off], str, len);
>> +		lm_buff_off += len;
>> +	}
>> +	/* Buffer not full and no newline */
>> +	nl = strchr(lm_buff, '\n');
> 
> Why do we have to search? Shouldn't a newline be the last copied
> character only?
> 
>> +	if (lm_buff_off != sizeof(lm_buff) - 1 && !nl)
>> +		goto out;
>> +
>> +	lm_print(lm_buff, lm_buff_off);
>> +	memset(lm_buff, 0 , sizeof(lm_buff));
>> +	lm_buff_off = 0;
>> +
>> +	if (len < strlen(str)) {
>> +		str = &str[len];
>> +		len = strlen(str);
>> +		goto fill;
>> +	}
> 
> This looks too complicated for my taste :) Or my caffeine level is low.
> 
> I think we have the following cases:
> 
> 1. String contains newline
>  a) String fits into remaining buffer
> 	-> Copy into buffer, flush (last character is newline)
>  b) String doesn't fit into remaining buffer
> 	-> Simply flush old buffer and print remaining string?
> 2. String doesn't contain newline.
>  a) String fits into remaining buffer
> 	-> Copy into buffer, flush if full
>  b) String doesn't fit into remaining buffer
> 	-> Simply flush old buffer and print remaining string?
> 
> Optimizing for 1b) or 2b) isn't really worth it I guess - unless we want
> to wrap *any* string at 120 characters. But then, your pre-loop handling
> would also have to be modified. I think this allow to simplify your code
> a lot.
> 
> (how often does it happen in our current tests that we exceed 120
> characters?)

How about this?

 	char *nl;
        int len = strlen(str), i = 0;

        spin_lock(&lm_buff_lock);

	while (len) {
                lm_buff[lm_buff_off] = str[i];
                lm_buff_off++;
                len--;
                /* Buffer full or newline? */
                if (str[i] == '\n' || lm_buff_off == (sizeof(lm_buff) -
1)) {
                        lm_print(lm_buff, lm_buff_off);
                        memset(lm_buff, 0 , sizeof(lm_buff));
                        lm_buff_off = 0;
                }
                i++;
        }
        spin_unlock(&lm_buff_lock);
        return;



> 
>> +
>> +out:
>> +	spin_unlock(&lm_buff_lock);
>> +}
>> +
>>  /*
>>   * SCLP needs to be initialized by setting a send and receive mask,
>>   * indicating which messages the control program (we) want(s) to
>>
> 
> 





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^ permalink raw reply	[flat|nested] 21+ messages in thread

end of thread, back to index

Thread overview: 21+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-09-05 10:39 [kvm-unit-tests PATCH v2 0/6] s390x: Add multiboot and smp Janosch Frank
2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 1/6] s390x: Use interrupts in SCLP and add locking Janosch Frank
2019-09-09  9:08   ` Thomas Huth
2019-09-10 10:14   ` David Hildenbrand
2019-09-10 11:24     ` David Hildenbrand
2019-09-10 11:25       ` Janosch Frank
2019-09-10 11:30         ` David Hildenbrand
2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 2/6] s390x: Add linemode console Janosch Frank
2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 3/6] s390x: Add linemode buffer to fix newline on every print Janosch Frank
2019-09-09  9:02   ` David Hildenbrand
2019-09-11  7:57   ` David Hildenbrand
2019-09-19 11:07     ` Janosch Frank
2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 4/6] s390x: Add initial smp code Janosch Frank
2019-09-09 15:37   ` Thomas Huth
2019-09-11  8:33     ` Janosch Frank
2019-09-10 12:19   ` Thomas Huth
2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 5/6] s390x: Prepare for external calls Janosch Frank
2019-09-09 15:47   ` Thomas Huth
2019-09-05 10:39 ` [kvm-unit-tests PATCH v2 6/6] s390x: SMP test Janosch Frank
2019-09-10  9:43   ` Thomas Huth
2019-09-10 11:11     ` Janosch Frank

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