83119ad4a1
Check if a command is available before executing. Saves some superfluous service calls that won't succeed anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
117 lines
2.8 KiB
C
117 lines
2.8 KiB
C
/*
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* drivers/s390/char/sclp_info.c
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*
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* Copyright IBM Corp. 2007
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* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
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*/
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <asm/sclp.h>
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#include "sclp.h"
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struct sclp_readinfo_sccb {
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struct sccb_header header; /* 0-7 */
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u16 rnmax; /* 8-9 */
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u8 rnsize; /* 10 */
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u8 _reserved0[24 - 11]; /* 11-23 */
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u8 loadparm[8]; /* 24-31 */
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u8 _reserved1[48 - 32]; /* 32-47 */
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u64 facilities; /* 48-55 */
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u8 _reserved2[91 - 56]; /* 56-90 */
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u8 flags; /* 91 */
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u8 _reserved3[100 - 92]; /* 92-99 */
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u32 rnsize2; /* 100-103 */
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u64 rnmax2; /* 104-111 */
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u8 _reserved4[4096 - 112]; /* 112-4095 */
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} __attribute__((packed, aligned(4096)));
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static struct sclp_readinfo_sccb __initdata early_readinfo_sccb;
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static int __initdata early_readinfo_sccb_valid;
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u64 sclp_facilities;
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void __init sclp_readinfo_early(void)
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{
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int ret;
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int i;
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struct sclp_readinfo_sccb *sccb;
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sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
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SCLP_CMDW_READ_SCP_INFO};
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/* Enable service signal subclass mask. */
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__ctl_set_bit(0, 9);
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sccb = &early_readinfo_sccb;
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for (i = 0; i < ARRAY_SIZE(commands); i++) {
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do {
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memset(sccb, 0, sizeof(*sccb));
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sccb->header.length = sizeof(*sccb);
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sccb->header.control_mask[2] = 0x80;
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ret = sclp_service_call(commands[i], sccb);
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} while (ret == -EBUSY);
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if (ret)
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break;
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__load_psw_mask(PSW_BASE_BITS | PSW_MASK_EXT |
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PSW_MASK_WAIT | PSW_DEFAULT_KEY);
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local_irq_disable();
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/*
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* Contents of the sccb might have changed
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* therefore a barrier is needed.
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*/
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barrier();
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if (sccb->header.response_code == 0x10) {
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early_readinfo_sccb_valid = 1;
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break;
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}
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if (sccb->header.response_code != 0x1f0)
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break;
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}
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/* Disable service signal subclass mask again. */
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__ctl_clear_bit(0, 9);
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}
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void __init sclp_facilities_detect(void)
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{
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if (!early_readinfo_sccb_valid)
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return;
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sclp_facilities = early_readinfo_sccb.facilities;
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}
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unsigned long long __init sclp_memory_detect(void)
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{
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unsigned long long memsize;
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struct sclp_readinfo_sccb *sccb;
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if (!early_readinfo_sccb_valid)
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return 0;
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sccb = &early_readinfo_sccb;
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if (sccb->rnsize)
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memsize = sccb->rnsize << 20;
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else
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memsize = sccb->rnsize2 << 20;
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if (sccb->rnmax)
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memsize *= sccb->rnmax;
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else
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memsize *= sccb->rnmax2;
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return memsize;
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}
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/*
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* This function will be called after sclp_memory_detect(), which gets called
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* early from early.c code. Therefore the sccb should have valid contents.
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*/
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void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
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{
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struct sclp_readinfo_sccb *sccb;
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if (!early_readinfo_sccb_valid)
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return;
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sccb = &early_readinfo_sccb;
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info->is_valid = 1;
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if (sccb->flags & 0x2)
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info->has_dump = 1;
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memcpy(&info->loadparm, &sccb->loadparm, LOADPARM_LEN);
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}
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