Commit 08ab919d authored by Sumanth Korikkar's avatar Sumanth Korikkar Committed by Heiko Carstens
Browse files

s390/sclp: use memblock for early read cpu info 



sclp early read cpu info is used to detect the number of configured
cpus, which is utilized by smp_detect_cpus() in early startup.

* For read cpu info, the sccb block should be below 2gb.
* smp_detect_cpus() utilizes read cpu info early, but after memblock
  initialization. Thus use memblock_allow_low() instead.
* Avoid copy of sclp_core_info structure.
* sclp_early_init_core_info(), sclp_early_core_info and
  sclp_early_core_info_valid initdata are no longer required.
* smp_get_core_info() is called only once during early stage.  Hence for
  early sclp_get_core_info(), directly call read cpu command. No need to
  maintain sclp_early_core_info_valid.

Signed-off-by: default avatarSumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent da78693e

drivers/s390/char/sclp_early.c

+28 −22
Original line number Diff line number Diff line
@@ -9,9 +9,11 @@ 
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt



#include <linux/errno.h>

#include <linux/memblock.h>

#include <asm/ctl_reg.h>

#include <asm/sclp.h>

#include <asm/ipl.h>

#include <asm/setup.h>

#include "sclp_sdias.h"

#include "sclp.h"
@@ -107,29 +109,34 @@ 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)

int __init sclp_early_get_core_info(struct sclp_core_info *info)

{

	struct read_cpu_info_sccb *sccb;

	int length = PAGE_SIZE;

	int rc = 0;



	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;

		return -EOPNOTSUPP;



	sccb = memblock_alloc_low(length, PAGE_SIZE);

	if (!sccb)

		return -ENOMEM;



	memset(sccb, 0, length);

	sccb->header.length = length;

	sccb->header.control_mask[2] = 0x80;

	if (sclp_early_cmd(SCLP_CMDW_READ_CPU_INFO, sccb)) {

		rc = -EIO;

		goto out;

	}



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;

	if (sccb->header.response_code != 0x0010) {

		rc = -EIO;

		goto out;

	}

	sclp_fill_core_info(info, sccb);

out:

	memblock_free_early((unsigned long)sccb, length);

	return rc;

}



static void __init sclp_early_console_detect(struct init_sccb *sccb)
@@ -149,7 +156,6 @@ 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