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-rw-r--r--arch/xtensa/Kconfig26
-rw-r--r--arch/xtensa/kernel/entry.S28
2 files changed, 54 insertions, 0 deletions
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 3d83c29c9232..49c6c3d94449 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -238,6 +238,32 @@ config HIGHMEM
If unsure, say Y.
+config FAST_SYSCALL_XTENSA
+ bool "Enable fast atomic syscalls"
+ default n
+ help
+ fast_syscall_xtensa is a syscall that can make atomic operations
+ on UP kernel when processor has no s32c1i support.
+
+ This syscall is deprecated. It may have issues when called with
+ invalid arguments. It is provided only for backwards compatibility.
+ Only enable it if your userspace software requires it.
+
+ If unsure, say N.
+
+config FAST_SYSCALL_SPILL_REGISTERS
+ bool "Enable spill registers syscall"
+ default n
+ help
+ fast_syscall_spill_registers is a syscall that spills all active
+ register windows of a calling userspace task onto its stack.
+
+ This syscall is deprecated. It may have issues when called with
+ invalid arguments. It is provided only for backwards compatibility.
+ Only enable it if your userspace software requires it.
+
+ If unsure, say N.
+
endmenu
config XTENSA_CALIBRATE_CCOUNT
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index a06b7efaae82..82bbfa5a05b3 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -986,6 +986,8 @@ ENDPROC(fast_syscall_unrecoverable)
* j done
*/
+#ifdef CONFIG_FAST_SYSCALL_XTENSA
+
#define TRY \
.section __ex_table, "a"; \
.word 66f, 67f; \
@@ -1049,6 +1051,18 @@ CATCH
ENDPROC(fast_syscall_xtensa)
+#else /* CONFIG_FAST_SYSCALL_XTENSA */
+
+ENTRY(fast_syscall_xtensa)
+
+ l32i a0, a2, PT_AREG0 # restore a0
+ movi a2, -ENOSYS
+ rfe
+
+ENDPROC(fast_syscall_xtensa)
+
+#endif /* CONFIG_FAST_SYSCALL_XTENSA */
+
/* fast_syscall_spill_registers.
*
@@ -1064,6 +1078,8 @@ ENDPROC(fast_syscall_xtensa)
* Note: We assume the stack pointer is EXC_TABLE_KSTK in the fixup handler.
*/
+#ifdef CONFIG_FAST_SYSCALL_SPILL_REGISTERS
+
ENTRY(fast_syscall_spill_registers)
/* Register a FIXUP handler (pass current wb as a parameter) */
@@ -1398,6 +1414,18 @@ ENTRY(fast_syscall_spill_registers_fixup_return)
ENDPROC(fast_syscall_spill_registers_fixup_return)
+#else /* CONFIG_FAST_SYSCALL_SPILL_REGISTERS */
+
+ENTRY(fast_syscall_spill_registers)
+
+ l32i a0, a2, PT_AREG0 # restore a0
+ movi a2, -ENOSYS
+ rfe
+
+ENDPROC(fast_syscall_spill_registers)
+
+#endif /* CONFIG_FAST_SYSCALL_SPILL_REGISTERS */
+
#ifdef CONFIG_MMU
/*
* We should never get here. Bail out!