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Commit bda3563f authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Martin Schwidefsky
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[S390] cpcmd with vmalloc addresses. 



Change the bounce buffer logic of cpcmd. diag8 needs _real_ memory below
2GB. Therefore vmalloced data does not work. As the data might cross a
page boundary, we cannot use virt_to_page either. The solution is to use
virt_to_page only in the check for a bounce buffer.

There was a redundant check for response==NULL. response < 2GB contains
this check as well.

I also removed the rlen==0 check, since rlen=0 and response!=NULL would
be a caller bug and response==NULL is already checked.

Signed-off-by: default avatarChristian Borntraeger <cborntra@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 60383201

arch/s390/kernel/cpcmd.c

+7 −7
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <asm/ebcdic.h>

#include <asm/cpcmd.h>

#include <asm/system.h>

#include <asm/io.h>



static DEFINE_SPINLOCK(cpcmd_lock);

static char cpcmd_buf[241];
@@ -88,13 +89,8 @@ int cpcmd(const char *cmd, char *response, int rlen, int *response_code) 
	int len;

	unsigned long flags;



	if ((rlen == 0) || (response == NULL)

	    || !((unsigned long)response >> 31)) {

		spin_lock_irqsave(&cpcmd_lock, flags);

		len = __cpcmd(cmd, response, rlen, response_code);

		spin_unlock_irqrestore(&cpcmd_lock, flags);

	}

	else {

	if ((virt_to_phys(response) != (unsigned long) response) ||

			(((unsigned long)response + rlen) >> 31)) {

		lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA);

		if (!lowbuf) {

			printk(KERN_WARNING
@@ -106,6 +102,10 @@ int cpcmd(const char *cmd, char *response, int rlen, int *response_code) 
		spin_unlock_irqrestore(&cpcmd_lock, flags);

		memcpy(response, lowbuf, rlen);

		kfree(lowbuf);

	} else {

		spin_lock_irqsave(&cpcmd_lock, flags);

		len = __cpcmd(cmd, response, rlen, response_code);

		spin_unlock_irqrestore(&cpcmd_lock, flags);

	}

	return len;

}