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linux/arch/s390/include/uapi/asm/guarded_storage.h

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License cleanup: add SPDX license identifier to uapi header files with no license Many user space API headers are missing licensing information, which makes it hard for compliance tools to determine the correct license. By default are files without license information under the default license of the kernel, which is GPLV2. Marking them GPLV2 would exclude them from being included in non GPLV2 code, which is obviously not intended. The user space API headers fall under the syscall exception which is in the kernels COPYING file: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". otherwise syscall usage would not be possible. Update the files which contain no license information with an SPDX license identifier. The chosen identifier is 'GPL-2.0 WITH Linux-syscall-note' which is the officially assigned identifier for the Linux syscall exception. SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 14:08:43 +00:00
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
s390: add a system call for guarded storage This adds a new system call to enable the use of guarded storage for user space processes. The system call takes two arguments, a command and pointer to a guarded storage control block: s390_guarded_storage(int command, struct gs_cb *gs_cb); The second argument is relevant only for the GS_SET_BC_CB command. The commands in detail: 0 - GS_ENABLE Enable the guarded storage facility for the current task. The initial content of the guarded storage control block will be all zeros. After the enablement the user space code can use load-guarded-storage-controls instruction (LGSC) to load an arbitrary control block. While a task is enabled the kernel will save and restore the current content of the guarded storage registers on context switch. 1 - GS_DISABLE Disables the use of the guarded storage facility for the current task. The kernel will cease to save and restore the content of the guarded storage registers, the task specific content of these registers is lost. 2 - GS_SET_BC_CB Set a broadcast guarded storage control block. This is called per thread and stores a specific guarded storage control block in the task struct of the current task. This control block will be used for the broadcast event GS_BROADCAST. 3 - GS_CLEAR_BC_CB Clears the broadcast guarded storage control block. The guarded- storage control block is removed from the task struct that was established by GS_SET_BC_CB. 4 - GS_BROADCAST Sends a broadcast to all thread siblings of the current task. Every sibling that has established a broadcast guarded storage control block will load this control block and will be enabled for guarded storage. The broadcast guarded storage control block is used up, a second broadcast without a refresh of the stored control block with GS_SET_BC_CB will not have any effect. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-01-26 13:10:34 +00:00
#ifndef _GUARDED_STORAGE_H
#define _GUARDED_STORAGE_H
#include <linux/types.h>
struct gs_cb {
__u64 reserved;
__u64 gsd;
__u64 gssm;
__u64 gs_epl_a;
};
struct gs_epl {
__u8 pad1;
union {
__u8 gs_eam;
struct {
__u8 : 6;
__u8 e : 1;
__u8 b : 1;
};
};
union {
__u8 gs_eci;
struct {
__u8 tx : 1;
__u8 cx : 1;
__u8 : 5;
__u8 in : 1;
};
};
union {
__u8 gs_eai;
struct {
__u8 : 1;
__u8 t : 1;
__u8 as : 2;
__u8 ar : 4;
};
};
__u32 pad2;
__u64 gs_eha;
__u64 gs_eia;
__u64 gs_eoa;
__u64 gs_eir;
__u64 gs_era;
};
#define GS_ENABLE 0
#define GS_DISABLE 1
#define GS_SET_BC_CB 2
#define GS_CLEAR_BC_CB 3
#define GS_BROADCAST 4
static inline void load_gs_cb(struct gs_cb *gs_cb)
{
asm volatile(".insn rxy,0xe3000000004d,0,%0" : : "Q" (*gs_cb));
}
static inline void store_gs_cb(struct gs_cb *gs_cb)
{
asm volatile(".insn rxy,0xe30000000049,0,%0" : : "Q" (*gs_cb));
}
static inline void save_gs_cb(struct gs_cb *gs_cb)
{
if (gs_cb)
store_gs_cb(gs_cb);
}
static inline void restore_gs_cb(struct gs_cb *gs_cb)
{
if (gs_cb)
load_gs_cb(gs_cb);
}
#endif /* _GUARDED_STORAGE_H */
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