powerpc: Add prefixed instructions to instruction data type

For powerpc64, redefine the ppc_inst type so both word and prefixed
instructions can be represented. On powerpc32 the type will remain the
same. Update places which had assumed instructions to be 4 bytes long.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
[mpe: Rework the get_user_inst() macros to be parameterised, and don't
      assign to the dest if an error occurred. Use CONFIG_PPC64 not
      __powerpc64__ in a few places. Address other comments from
      Christophe. Fix some sparse complaints.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-24-jniethe5@gmail.com

1 files changed, 64 insertions, 6 deletions

diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h
index c7ea70e73073..d82e0c99cfa1 100644
--- a/arch/powerpc/include/asm/inst.h
+++ b/arch/powerpc/include/asm/inst.h
@@ -2,29 +2,80 @@
 #ifndef _ASM_POWERPC_INST_H
 #define _ASM_POWERPC_INST_H
 
+#include <asm/ppc-opcode.h>
+
 /*
  * Instruction data type for POWER
  */
 
 struct ppc_inst {
 	u32 val;
+#ifdef CONFIG_PPC64
+	u32 suffix;
+#endif
 } __packed;
 
-#define ppc_inst(x) ((struct ppc_inst){ .val = x })
-
 static inline u32 ppc_inst_val(struct ppc_inst x)
 {
 	return x.val;
 }
 
-static inline int ppc_inst_len(struct ppc_inst x)
+static inline int ppc_inst_primary_opcode(struct ppc_inst x)
 {
-	return sizeof(struct ppc_inst);
+	return ppc_inst_val(x) >> 26;
 }
 
-static inline int ppc_inst_primary_opcode(struct ppc_inst x)
+#ifdef CONFIG_PPC64
+#define ppc_inst(x) ((struct ppc_inst){ .val = (x), .suffix = 0xff })
+
+#define ppc_inst_prefix(x, y) ((struct ppc_inst){ .val = (x), .suffix = (y) })
+
+static inline u32 ppc_inst_suffix(struct ppc_inst x)
 {
-	return ppc_inst_val(x) >> 26;
+	return x.suffix;
+}
+
+static inline bool ppc_inst_prefixed(struct ppc_inst x)
+{
+	return (ppc_inst_primary_opcode(x) == 1) && ppc_inst_suffix(x) != 0xff;
+}
+
+static inline struct ppc_inst ppc_inst_swab(struct ppc_inst x)
+{
+	return ppc_inst_prefix(swab32(ppc_inst_val(x)),
+			       swab32(ppc_inst_suffix(x)));
+}
+
+static inline struct ppc_inst ppc_inst_read(const struct ppc_inst *ptr)
+{
+	u32 val, suffix;
+
+	val = *(u32 *)ptr;
+	if ((val >> 26) == OP_PREFIX) {
+		suffix = *((u32 *)ptr + 1);
+		return ppc_inst_prefix(val, suffix);
+	} else {
+		return ppc_inst(val);
+	}
+}
+
+static inline bool ppc_inst_equal(struct ppc_inst x, struct ppc_inst y)
+{
+	return *(u64 *)&x == *(u64 *)&y;
+}
+
+#else
+
+#define ppc_inst(x) ((struct ppc_inst){ .val = x })
+
+static inline bool ppc_inst_prefixed(struct ppc_inst x)
+{
+	return false;
+}
+
+static inline u32 ppc_inst_suffix(struct ppc_inst x)
+{
+	return 0;
 }
 
 static inline struct ppc_inst ppc_inst_swab(struct ppc_inst x)
@@ -42,6 +93,13 @@ static inline bool ppc_inst_equal(struct ppc_inst x, struct ppc_inst y)
 	return ppc_inst_val(x) == ppc_inst_val(y);
 }
 
+#endif /* CONFIG_PPC64 */
+
+static inline int ppc_inst_len(struct ppc_inst x)
+{
+	return ppc_inst_prefixed(x) ? 8 : 4;
+}
+
 int probe_user_read_inst(struct ppc_inst *inst,
 			 struct ppc_inst __user *nip);