linux/linux-5.4.31/drivers/s390/char/sclp_early.c

// SPDX-License-Identifier: GPL-2.0
/*
 * SCLP early driver
 *
 * Copyright IBM Corp. 2013
 */

#define KMSG_COMPONENT "sclp_early"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/errno.h>
#include <asm/ctl_reg.h>
#include <asm/sclp.h>
#include <asm/ipl.h>
#include "sclp_sdias.h"
#include "sclp.h"

static struct sclp_ipl_info sclp_ipl_info;

struct sclp_info sclp;
EXPORT_SYMBOL(sclp);

static void __init sclp_early_facilities_detect(struct read_info_sccb *sccb)
{
	struct sclp_core_entry *cpue;
	u16 boot_cpu_address, cpu;

	if (sclp_early_get_info(sccb))
		return;

	sclp.facilities = sccb->facilities;
	sclp.has_sprp = !!(sccb->fac84 & 0x02);
	sclp.has_core_type = !!(sccb->fac84 & 0x01);
	sclp.has_gsls = !!(sccb->fac85 & 0x80);
	sclp.has_64bscao = !!(sccb->fac116 & 0x80);
	sclp.has_cmma = !!(sccb->fac116 & 0x40);
	sclp.has_esca = !!(sccb->fac116 & 0x08);
	sclp.has_pfmfi = !!(sccb->fac117 & 0x40);
	sclp.has_ibs = !!(sccb->fac117 & 0x20);
	sclp.has_gisaf = !!(sccb->fac118 & 0x08);
	sclp.has_hvs = !!(sccb->fac119 & 0x80);
	sclp.has_kss = !!(sccb->fac98 & 0x01);
	sclp.has_sipl = !!(sccb->cbl & 0x4000);
	if (sccb->fac85 & 0x02)
		S390_lowcore.machine_flags |= MACHINE_FLAG_ESOP;
	if (sccb->fac91 & 0x40)
		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_GUEST;
	if (sccb->cpuoff > 134)
		sclp.has_diag318 = !!(sccb->byte_134 & 0x80);
	sclp.rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
	sclp.rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
	sclp.rzm <<= 20;
	sclp.ibc = sccb->ibc;

	if (sccb->hamaxpow && sccb->hamaxpow < 64)
		sclp.hamax = (1UL << sccb->hamaxpow) - 1;
	else
		sclp.hamax = U64_MAX;

	if (!sccb->hcpua) {
		if (MACHINE_IS_VM)
			sclp.max_cores = 64;
		else
			sclp.max_cores = sccb->ncpurl;
	} else {
		sclp.max_cores = sccb->hcpua + 1;
	}

	boot_cpu_address = stap();
	cpue = (void *)sccb + sccb->cpuoff;
	for (cpu = 0; cpu < sccb->ncpurl; cpue++, cpu++) {
		if (boot_cpu_address != cpue->core_id)
			continue;
		sclp.has_siif = cpue->siif;
		sclp.has_sigpif = cpue->sigpif;
		sclp.has_sief2 = cpue->sief2;
		sclp.has_gpere = cpue->gpere;
		sclp.has_ib = cpue->ib;
		sclp.has_cei = cpue->cei;
		sclp.has_skey = cpue->skey;
		break;
	}

	/* Save IPL information */
	sclp_ipl_info.is_valid = 1;
	if (sccb->fac91 & 0x2)
		sclp_ipl_info.has_dump = 1;
	memcpy(&sclp_ipl_info.loadparm, &sccb->loadparm, LOADPARM_LEN);

	if (sccb->hsa_size)
		sclp.hsa_size = (sccb->hsa_size - 1) * PAGE_SIZE;
	sclp.mtid = (sccb->fac42 & 0x80) ? (sccb->fac42 & 31) : 0;
	sclp.mtid_cp = (sccb->fac42 & 0x80) ? (sccb->fac43 & 31) : 0;
	sclp.mtid_prev = (sccb->fac42 & 0x80) ? (sccb->fac66 & 31) : 0;

	sclp.hmfai = sccb->hmfai;
	sclp.has_dirq = !!(sccb->cpudirq & 0x80);
}

/*
 * This function will be called after sclp_early_facilities_detect(), which gets
 * called from early.c code. The sclp_early_facilities_detect() function retrieves
 * and saves the IPL information.
 */
void __init sclp_early_get_ipl_info(struct sclp_ipl_info *info)
{
	*info = sclp_ipl_info;
}

static struct sclp_core_info sclp_early_core_info __initdata;
static int sclp_early_core_info_valid __initdata;

static void __init sclp_early_init_core_info(struct read_cpu_info_sccb *sccb)
{
	if (!SCLP_HAS_CPU_INFO)
		return;
	memset(sccb, 0, sizeof(*sccb));
	sccb->header.length = sizeof(*sccb);
	if (sclp_early_cmd(SCLP_CMDW_READ_CPU_INFO, sccb))
		return;
	if (sccb->header.response_code != 0x0010)
		return;
	sclp_fill_core_info(&sclp_early_core_info, sccb);
	sclp_early_core_info_valid = 1;
}

int __init sclp_early_get_core_info(struct sclp_core_info *info)
{
	if (!sclp_early_core_info_valid)
		return -EIO;
	*info = sclp_early_core_info;
	return 0;
}

static void __init sclp_early_console_detect(struct init_sccb *sccb)
{
	if (sccb->header.response_code != 0x20)
		return;

	if (sclp_early_con_check_vt220(sccb))
		sclp.has_vt220 = 1;

	if (sclp_early_con_check_linemode(sccb))
		sclp.has_linemode = 1;
}

void __init sclp_early_detect(void)
{
	void *sccb = sclp_early_sccb;

	sclp_early_facilities_detect(sccb);
	sclp_early_init_core_info(sccb);

	/*
	 * Turn off SCLP event notifications.  Also save remote masks in the
	 * sccb.  These are sufficient to detect sclp console capabilities.
	 */
	sclp_early_set_event_mask(sccb, 0, 0);
	sclp_early_console_detect(sccb);
}