We need to properly implement interrupt handling for SCLP, because on
z/VM and LPAR SCLP calls are not synchronous!
Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
---
lib/s390x/asm/arch_def.h | 1 +
lib/s390x/asm/interrupt.h | 2 ++
lib/s390x/interrupt.c | 12 ++++++++++--
lib/s390x/io.c | 2 +-
lib/s390x/sclp-console.c | 3 +++
lib/s390x/sclp.c | 39 +++++++++++++++++++++++++++++++++++++--
lib/s390x/sclp.h | 4 ++++
7 files changed, 58 insertions(+), 5 deletions(-)
diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index d2d6e02..27c6b85 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -33,6 +33,7 @@ struct psw {
uint64_t addr;
};
+#define PSW_MASK_EXT 0x0100000000000000UL
#define PSW_MASK_DAT 0x0400000000000000UL
#define PSW_MASK_PSTATE 0x0001000000000000UL
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..7118577 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/io.c b/lib/s390x/io.c
index 05a0765..7294165 100644
--- a/lib/s390x/io.c
+++ b/lib/s390x/io.c
@@ -45,8 +45,8 @@ void setup(void)
{
setup_args_progname(ipl_args);
setup_facilities();
- sclp_console_setup();
sclp_memory_setup();
+ sclp_console_setup();
}
void exit(int code)
diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
index bc01f41..2016ea0 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;
@@ -45,4 +47,5 @@ void sclp_print(const char *str)
memcpy(sccb->data, str, len);
sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
+ sclp_wait_busy();
}
diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c
index 7f556e5..eed51ef 100644
--- a/lib/s390x/sclp.c
+++ b/lib/s390x/sclp.c
@@ -14,6 +14,7 @@
#include <asm/page.h>
#include <asm/arch_def.h>
#include <asm/interrupt.h>
+#include <asm/barrier.h>
#include "sclp.h"
#include <alloc_phys.h>
@@ -24,6 +25,7 @@ static uint64_t max_ram_size;
static uint64_t ram_size;
char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096)));
+volatile bool sclp_busy;
static void mem_init(phys_addr_t mem_end)
{
@@ -32,17 +34,49 @@ static void mem_init(phys_addr_t mem_end)
phys_alloc_init(freemem_start, mem_end - freemem_start);
}
+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);
+ sclp_busy = false;
+}
+
+void sclp_wait_busy(void)
+{
+ mb();
+ while (sclp_busy)
+ /* Wait for SCLP request to complete */;
+}
+
+void sclp_mark_busy(void)
+{
+ sclp_busy = true;
+}
+
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++) {
memset(&ri->h, 0, sizeof(ri->h));
ri->h.length = length;
- if (sclp_service_call(commands[i], ri))
+ sclp_mark_busy();
+ cc = sclp_service_call(commands[i], ri);
+ sclp_wait_busy();
+ if (cc)
break;
if (ri->h.response_code == SCLP_RC_NORMAL_READ_COMPLETION)
return;
@@ -57,6 +91,7 @@ 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"
diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
index 583c4e5..427b0d7 100644
--- a/lib/s390x/sclp.h
+++ b/lib/s390x/sclp.h
@@ -213,6 +213,10 @@ typedef struct ReadEventData {
} __attribute__((packed)) ReadEventData;
extern char _sccb[];
+volatile bool sclp_busy;
+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);
--
2.14.3
