From: Heiko Carstens Check if a command is available before executing. Saves some superfluous service calls that won't succeed anyway. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/early.c | 1 + drivers/s390/char/sclp.h | 5 +++++ drivers/s390/char/sclp_chp.c | 4 ++++ drivers/s390/char/sclp_info.c | 9 +++++++++ include/asm-s390/sclp.h | 1 + 5 files changed, 20 insertions(+) Index: quilt-2.6/arch/s390/kernel/early.c =================================================================== --- quilt-2.6.orig/arch/s390/kernel/early.c +++ quilt-2.6/arch/s390/kernel/early.c @@ -275,6 +275,7 @@ void __init startup_init(void) sort_main_extable(); setup_lowcore_early(); sclp_readinfo_early(); + sclp_facilities_detect(); memsize = sclp_memory_detect(); #ifndef CONFIG_64BIT /* Index: quilt-2.6/drivers/s390/char/sclp_chp.c =================================================================== --- quilt-2.6.orig/drivers/s390/char/sclp_chp.c +++ quilt-2.6/drivers/s390/char/sclp_chp.c @@ -55,6 +55,8 @@ static int do_configure(sclp_cmdw_t cmd) struct chp_cfg_data *data; int rc; + if (!SCLP_HAS_CHP_RECONFIG) + return -EOPNOTSUPP; /* Prepare sccb. */ data = (struct chp_cfg_data *) get_zeroed_page(GFP_KERNEL | GFP_DMA); if (!data) @@ -152,6 +154,8 @@ int sclp_chp_read_info(struct sclp_chp_i struct chp_info_data *data; int rc; + if (!SCLP_HAS_CHP_INFO) + return -EOPNOTSUPP; /* Prepare sccb. */ data = (struct chp_info_data *) get_zeroed_page(GFP_KERNEL | GFP_DMA); if (!data) Index: quilt-2.6/drivers/s390/char/sclp.h =================================================================== --- quilt-2.6.orig/drivers/s390/char/sclp.h +++ quilt-2.6/drivers/s390/char/sclp.h @@ -79,6 +79,11 @@ struct sccb_header { u16 response_code; } __attribute__((packed)); +extern u64 sclp_facilities; + +#define SCLP_HAS_CHP_INFO (sclp_facilities & 0x8000000000000000ULL) +#define SCLP_HAS_CHP_RECONFIG (sclp_facilities & 0x2000000000000000ULL) + struct gds_subvector { u8 length; u8 key; Index: quilt-2.6/drivers/s390/char/sclp_info.c =================================================================== --- quilt-2.6.orig/drivers/s390/char/sclp_info.c +++ quilt-2.6/drivers/s390/char/sclp_info.c @@ -30,6 +30,8 @@ struct sclp_readinfo_sccb { static struct sclp_readinfo_sccb __initdata early_readinfo_sccb; static int __initdata early_readinfo_sccb_valid; +u64 sclp_facilities; + void __init sclp_readinfo_early(void) { int ret; @@ -70,6 +72,13 @@ void __init sclp_readinfo_early(void) __ctl_clear_bit(0, 9); } +void __init sclp_facilities_detect(void) +{ + if (!early_readinfo_sccb_valid) + return; + sclp_facilities = early_readinfo_sccb.facilities; +} + unsigned long long __init sclp_memory_detect(void) { unsigned long long memsize; Index: quilt-2.6/include/asm-s390/sclp.h =================================================================== --- quilt-2.6.orig/include/asm-s390/sclp.h +++ quilt-2.6/include/asm-s390/sclp.h @@ -28,6 +28,7 @@ struct sclp_ipl_info { }; void sclp_readinfo_early(void); +void sclp_facilities_detect(void); unsigned long long sclp_memory_detect(void); int sclp_sdias_blk_count(void); int sclp_sdias_copy(void *dest, int blk_num, int nr_blks); -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/