[kvm-unit-tests PATCH v4 2/9] s390x: Consolidate sclp read info

Janosch Frank
2021-01-12T13:22:32Z

Let's only read the information once and pass a pointer to it instead
of calling sclp multiple times.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Thomas Huth <thuth@redhat.com>
---
lib/s390x/io.c | 1 +
lib/s390x/sclp.c | 31 +++++++++++++++++++++++++------
lib/s390x/sclp.h | 3 +++
lib/s390x/smp.c | 27 +++++++++++----------------
4 files changed, 40 insertions(+), 22 deletions(-)

diff --git a/lib/s390x/io.c b/lib/s390x/io.c
index 1ff0589..6a1da63 100644
--- a/lib/s390x/io.c
+++ b/lib/s390x/io.c
@@ -34,6 +34,7 @@ void setup(void)
{
setup_args_progname(ipl_args);
setup_facilities();
+ sclp_read_info();
sclp_console_setup();
sclp_memory_setup();
smp_setup();
diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c
index 08a4813..12916f5 100644
--- a/lib/s390x/sclp.c
+++ b/lib/s390x/sclp.c
@@ -23,6 +23,8 @@ extern unsigned long stacktop;
static uint64_t storage_increment_size;
static uint64_t max_ram_size;
static uint64_t ram_size;
+char _read_info[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+static ReadInfo *read_info;

char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096)));
static volatile bool sclp_busy;
@@ -108,6 +110,24 @@ static void sclp_read_scp_info(ReadInfo *ri, int length)
report_abort("READ_SCP_INFO failed");
}

+void sclp_read_info(void)
+{
+ sclp_read_scp_info((void *)_read_info, SCCB_SIZE);
+ read_info = (ReadInfo *)_read_info;
+}
+
+int sclp_get_cpu_num(void)
+{
+ assert(read_info);
+ return read_info->entries_cpu;
+}
+
+CPUEntry *sclp_get_cpu_entries(void)
+{
+ assert(read_info);
+ return (CPUEntry *)(_read_info + read_info->offset_cpu);
+}
+
/* Perform service call. Return 0 on success, non-zero otherwise. */
int sclp_service_call(unsigned int command, void *sccb)
{
@@ -125,23 +145,22 @@ int sclp_service_call(unsigned int command, void *sccb)

void sclp_memory_setup(void)
{
- ReadInfo *ri = (void *)_sccb;
uint64_t rnmax, rnsize;
int cc;

- sclp_read_scp_info(ri, SCCB_SIZE);
+ assert(read_info);

/* calculate the storage increment size */
- rnsize = ri->rnsize;
+ rnsize = read_info->rnsize;
if (!rnsize) {
- rnsize = ri->rnsize2;
+ rnsize = read_info->rnsize2;
}
storage_increment_size = rnsize << 20;

/* calculate the maximum memory size */
- rnmax = ri->rnmax;
+ rnmax = read_info->rnmax;
if (!rnmax) {
- rnmax = ri->rnmax2;
+ rnmax = read_info->rnmax2;
}
max_ram_size = rnmax * storage_increment_size;

diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
index 9a6aad0..acd86d5 100644
--- a/lib/s390x/sclp.h
+++ b/lib/s390x/sclp.h
@@ -268,6 +268,9 @@ void sclp_wait_busy(void);
void sclp_mark_busy(void);
void sclp_console_setup(void);
void sclp_print(const char *str);
+void sclp_read_info(void);
+int sclp_get_cpu_num(void);
+CPUEntry *sclp_get_cpu_entries(void);
int sclp_service_call(unsigned int command, void *sccb);
void sclp_memory_setup(void);
uint64_t get_ram_size(void);
diff --git a/lib/s390x/smp.c b/lib/s390x/smp.c
index c4f02dc..dfcfd28 100644
--- a/lib/s390x/smp.c
+++ b/lib/s390x/smp.c
@@ -23,7 +23,6 @@
#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;
@@ -32,8 +31,7 @@ extern void smp_cpu_setup_state(void);

int smp_query_num_cpus(void)
{
- struct ReadCpuInfo *info = (void *)cpu_info_buffer;
- return info->nr_configured;
+ return sclp_get_cpu_num();
}

struct cpu *smp_cpu_from_addr(uint16_t addr)
@@ -226,10 +224,10 @@ void smp_teardown(void)
{
int i = 0;
uint16_t this_cpu = stap();
- struct ReadCpuInfo *info = (void *)cpu_info_buffer;
+ int num = smp_query_num_cpus();

spin_lock(&lock);
- for (; i < info->nr_configured; i++) {
+ for (; i < num; i++) {
if (cpus[i].active &&
cpus[i].addr != this_cpu) {
sigp_retry(cpus[i].addr, SIGP_STOP, 0, NULL);
@@ -243,22 +241,19 @@ extern uint64_t *stackptr;
void smp_setup(void)
{
int i = 0;
+ int num = smp_query_num_cpus();
unsigned short cpu0_addr = stap();
- struct ReadCpuInfo *info = (void *)cpu_info_buffer;
+ struct CPUEntry *entry = sclp_get_cpu_entries();

spin_lock(&lock);
- sclp_mark_busy();
- info->h.length = PAGE_SIZE;
- sclp_service_call(SCLP_READ_CPU_INFO, cpu_info_buffer);
+ if (num > 1)
+ printf("SMP: Initializing, found %d cpus\n", num);

- 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++) {
- cpus[i].addr = info->entries[i].address;
+ cpus = calloc(num, sizeof(cpus));
+ for (i = 0; i < num; i++) {
+ cpus[i].addr = entry[i].address;
cpus[i].active = false;
- if (info->entries[i].address == cpu0_addr) {
+ if (entry[i].address == cpu0_addr) {
cpu0 = &cpus[i];
cpu0->stack = stackptr;
cpu0->lowcore = (void *)0;
--
2.25.1