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authorHeiko Carstens <heiko.carstens@de.ibm.com>2017-08-07 15:16:15 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2017-08-09 09:09:35 -0400
commitcd4386a931b6310b05559d2e28efda04d30ab593 (patch)
treed1fbc2a6a8e86af9308ce8713e842e6717471c8e /arch/s390/include/asm
parents390/vmcp: fix uaccess check and avoid undefined behavior (diff)
downloadlinux-dev-cd4386a931b6310b05559d2e28efda04d30ab593.tar.xz
linux-dev-cd4386a931b6310b05559d2e28efda04d30ab593.zip
s390/cpcmd,vmcp: avoid GFP_DMA allocations
According to the CP Programming Services manual Diagnose Code 8 "Virtual Console Function" can be used in all addressing modes. Also the input and output buffers do not have a limitation which specifies they need to be below the 2GB line. This is true at least since z/VM 5.4. Therefore remove the sam31/64 instructions and allow for simple GFP_KERNEL allocations. This makes it easier to allocate a 1MB page if the user requested such a large return buffer. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm')
-rw-r--r--arch/s390/include/asm/cpcmd.h7
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/s390/include/asm/cpcmd.h b/arch/s390/include/asm/cpcmd.h
index 3dfadb5d648f..ca2b0624ad46 100644
--- a/arch/s390/include/asm/cpcmd.h
+++ b/arch/s390/include/asm/cpcmd.h
@@ -10,9 +10,8 @@
/*
* the lowlevel function for cpcmd
- * the caller of __cpcmd has to ensure that the response buffer is below 2 GB
*/
-extern int __cpcmd(const char *cmd, char *response, int rlen, int *response_code);
+int __cpcmd(const char *cmd, char *response, int rlen, int *response_code);
/*
* cpcmd is the in-kernel interface for issuing CP commands
@@ -25,8 +24,8 @@ extern int __cpcmd(const char *cmd, char *response, int rlen, int *response_code
* response_code: return pointer for VM's error code
* return value: the size of the response. The caller can check if the buffer
* was large enough by comparing the return value and rlen
- * NOTE: If the response buffer is not below 2 GB, cpcmd can sleep
+ * NOTE: If the response buffer is not in real storage, cpcmd can sleep
*/
-extern int cpcmd(const char *cmd, char *response, int rlen, int *response_code);
+int cpcmd(const char *cmd, char *response, int rlen, int *response_code);
#endif /* _ASM_S390_CPCMD_H */