s390: add support for transactional memory
Allow user-space processes to use transactional execution (TX).
If the TX facility is available user space programs can use
transactions for fine-grained serialization based on the data
objects that are referenced during a transaction. This is
useful for lockless data structures and speculative compiler
optimizations.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index 01775c0..29af526 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -57,6 +57,23 @@
static int kstack_depth_to_print = 20;
#endif /* CONFIG_64BIT */
+static inline void __user *get_trap_ip(struct pt_regs *regs)
+{
+#ifdef CONFIG_64BIT
+ unsigned long address;
+
+ if (regs->int_code & 0x200)
+ address = *(unsigned long *)(current->thread.trap_tdb + 24);
+ else
+ address = regs->psw.addr;
+ return (void __user *)
+ ((address - (regs->int_code >> 16)) & PSW_ADDR_INSN);
+#else
+ return (void __user *)
+ ((regs->psw.addr - (regs->int_code >> 16)) & PSW_ADDR_INSN);
+#endif
+}
+
/*
* For show_trace we have tree different stack to consider:
* - the panic stack which is used if the kernel stack has overflown
@@ -285,12 +302,6 @@
return 1;
}
-static inline void __user *get_psw_address(struct pt_regs *regs)
-{
- return (void __user *)
- ((regs->psw.addr - (regs->int_code >> 16)) & PSW_ADDR_INSN);
-}
-
static void __kprobes do_trap(struct pt_regs *regs,
int si_signo, int si_code, char *str)
{
@@ -304,7 +315,7 @@
info.si_signo = si_signo;
info.si_errno = 0;
info.si_code = si_code;
- info.si_addr = get_psw_address(regs);
+ info.si_addr = get_trap_ip(regs);
force_sig_info(si_signo, &info, current);
report_user_fault(regs, si_signo);
} else {
@@ -381,6 +392,11 @@
DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
"translation exception")
+#ifdef CONFIG_64BIT
+DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
+ "transaction constraint exception")
+#endif
+
static inline void do_fp_trap(struct pt_regs *regs, int fpc)
{
int si_code = 0;
@@ -408,7 +424,7 @@
__u16 __user *location;
int signal = 0;
- location = get_psw_address(regs);
+ location = get_trap_ip(regs);
if (user_mode(regs)) {
if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
@@ -476,7 +492,7 @@
__u16 __user *location = NULL;
int signal = 0;
- location = (__u16 __user *) get_psw_address(regs);
+ location = (__u16 __user *) get_trap_ip(regs);
if (user_mode(regs)) {
get_user(*((__u16 *) opcode), location);
@@ -525,7 +541,7 @@
__u16 __user *location;
int signal = 0;
- location = get_psw_address(regs);
+ location = get_trap_ip(regs);
if (MACHINE_HAS_IEEE)
asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
@@ -641,6 +657,7 @@
pgm_check_table[0x12] = &translation_exception;
pgm_check_table[0x13] = &special_op_exception;
#ifdef CONFIG_64BIT
+ pgm_check_table[0x18] = &transaction_exception;
pgm_check_table[0x38] = &do_asce_exception;
pgm_check_table[0x39] = &do_dat_exception;
pgm_check_table[0x3A] = &do_dat_exception;