s390/smp: limit number of cpus in possible cpu mask
Limit the number of bits to the maximum number of cpus a machine
can have.
possible_cpu_mask typically will have more bits set than a machine
may physically have. This results in wasted memory during per-cpu
memory allocations, if the possible mask contains more cpus than
physically possible for a given configuration.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/sclp_early.c b/drivers/s390/char/sclp_early.c
index 2c6aac6..14196ea 100644
--- a/drivers/s390/char/sclp_early.c
+++ b/drivers/s390/char/sclp_early.c
@@ -20,7 +20,9 @@
struct sccb_header header; /* 0-7 */
u16 rnmax; /* 8-9 */
u8 rnsize; /* 10 */
- u8 _reserved0[24 - 11]; /* 11-15 */
+ u8 _reserved0[16 - 11]; /* 11-15 */
+ u16 ncpurl; /* 16-17 */
+ u8 _reserved7[24 - 18]; /* 18-23 */
u8 loadparm[8]; /* 24-31 */
u8 _reserved1[48 - 32]; /* 32-47 */
u64 facilities; /* 48-55 */
@@ -32,13 +34,16 @@
u8 _reserved4[100 - 92]; /* 92-99 */
u32 rnsize2; /* 100-103 */
u64 rnmax2; /* 104-111 */
- u8 _reserved5[4096 - 112]; /* 112-4095 */
+ u8 _reserved5[120 - 112]; /* 112-119 */
+ u16 hcpua; /* 120-121 */
+ u8 _reserved6[4096 - 122]; /* 122-4095 */
} __packed __aligned(PAGE_SIZE);
static char sccb_early[PAGE_SIZE] __aligned(PAGE_SIZE) __initdata;
static unsigned int sclp_con_has_vt220 __initdata;
static unsigned int sclp_con_has_linemode __initdata;
static unsigned long sclp_hsa_size;
+static unsigned int sclp_max_cpu;
static struct sclp_ipl_info sclp_ipl_info;
u64 sclp_facilities;
@@ -102,6 +107,15 @@
sclp_rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
sclp_rzm <<= 20;
+ if (!sccb->hcpua) {
+ if (MACHINE_IS_VM)
+ sclp_max_cpu = 64;
+ else
+ sclp_max_cpu = sccb->ncpurl;
+ } else {
+ sclp_max_cpu = sccb->hcpua + 1;
+ }
+
/* Save IPL information */
sclp_ipl_info.is_valid = 1;
if (sccb->flags & 0x2)
@@ -129,6 +143,11 @@
return sclp_rzm;
}
+unsigned int sclp_get_max_cpu(void)
+{
+ return sclp_max_cpu;
+}
+
/*
* This function will be called after sclp_facilities_detect(), which gets
* called from early.c code. The sclp_facilities_detect() function retrieves