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-rw-r--r--arch/blackfin/kernel/fixed_code.S132
1 files changed, 132 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/fixed_code.S b/arch/blackfin/kernel/fixed_code.S
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+/*
+ * This file contains sequences of code that will be copied to a
+ * fixed location, defined in <asm/atomic_seq.h>. The interrupt
+ * handlers ensure that these sequences appear to be atomic when
+ * executed from userspace.
+ * These are aligned to 16 bytes, so that we have some space to replace
+ * these sequences with something else (e.g. kernel traps if we ever do
+ * BF561 SMP).
+ */
+#include <linux/linkage.h>
+#include <linux/unistd.h>
+#include <asm/entry.h>
+
+.text
+ENTRY(_fixed_code_start)
+
+.align 16
+ENTRY(_sigreturn_stub)
+ P0 = __NR_rt_sigreturn;
+ EXCPT 0;
+ /* Speculative execution paranoia. */
+0: JUMP.S 0b;
+ENDPROC (_sigreturn_stub)
+
+.align 16
+ /*
+ * Atomic swap, 8 bit.
+ * Inputs: P0: memory address to use
+ * R1: value to store
+ * Output: R0: old contents of the memory address, zero extended.
+ */
+ENTRY(_atomic_xchg32)
+ R0 = [P0];
+ [P0] = R1;
+ rts;
+ENDPROC (_atomic_xchg32)
+
+.align 16
+ /*
+ * Compare and swap, 32 bit.
+ * Inputs: P0: memory address to use
+ * R1: compare value
+ * R2: new value to store
+ * The new value is stored if the contents of the memory
+ * address is equal to the compare value.
+ * Output: R0: old contents of the memory address.
+ */
+ENTRY(_atomic_cas32)
+ R0 = [P0];
+ CC = R0 == R1;
+ IF !CC JUMP 1f;
+ [P0] = R2;
+1:
+ rts;
+ENDPROC (_atomic_cas32)
+
+.align 16
+ /*
+ * Atomic add, 32 bit.
+ * Inputs: P0: memory address to use
+ * R0: value to add
+ * Outputs: R0: new contents of the memory address.
+ * R1: previous contents of the memory address.
+ */
+ENTRY(_atomic_add32)
+ R1 = [P0];
+ R0 = R1 + R0;
+ [P0] = R0;
+ rts;
+ENDPROC (_atomic_add32)
+
+.align 16
+ /*
+ * Atomic sub, 32 bit.
+ * Inputs: P0: memory address to use
+ * R0: value to subtract
+ * Outputs: R0: new contents of the memory address.
+ * R1: previous contents of the memory address.
+ */
+ENTRY(_atomic_sub32)
+ R1 = [P0];
+ R0 = R1 - R0;
+ [P0] = R0;
+ rts;
+ENDPROC (_atomic_sub32)
+
+.align 16
+ /*
+ * Atomic ior, 32 bit.
+ * Inputs: P0: memory address to use
+ * R0: value to ior
+ * Outputs: R0: new contents of the memory address.
+ * R1: previous contents of the memory address.
+ */
+ENTRY(_atomic_ior32)
+ R1 = [P0];
+ R0 = R1 | R0;
+ [P0] = R0;
+ rts;
+ENDPROC (_atomic_ior32)
+
+.align 16
+ /*
+ * Atomic ior, 32 bit.
+ * Inputs: P0: memory address to use
+ * R0: value to ior
+ * Outputs: R0: new contents of the memory address.
+ * R1: previous contents of the memory address.
+ */
+ENTRY(_atomic_and32)
+ R1 = [P0];
+ R0 = R1 & R0;
+ [P0] = R0;
+ rts;
+ENDPROC (_atomic_ior32)
+
+.align 16
+ /*
+ * Atomic ior, 32 bit.
+ * Inputs: P0: memory address to use
+ * R0: value to ior
+ * Outputs: R0: new contents of the memory address.
+ * R1: previous contents of the memory address.
+ */
+ENTRY(_atomic_xor32)
+ R1 = [P0];
+ R0 = R1 ^ R0;
+ [P0] = R0;
+ rts;
+ENDPROC (_atomic_ior32)
+
+ENTRY(_fixed_code_end)