hw/registerfields.h: Pull FIELD etc macros out of hw/register.h

hw/register.h provides macros like FIELD which make it easy to define
shift, mask and length constants for the fields within a register.
Unfortunately register.h also includes a lot of other things, some
of which will only compile in the softmmu build.

Pull the FIELD macro and friends out into a separate header file,
so they can be used in places like target/arm files which also
get built in the user-only configs.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1484937883-1068-5-git-send-email-peter.maydell@linaro.org

1 files changed, 60 insertions, 0 deletions

diff --git a/include/hw/registerfields.h b/include/hw/registerfields.h
new file mode 100644
index 0000000000..af101d5ae6
--- /dev/null
+++ b/include/hw/registerfields.h
@@ -0,0 +1,60 @@
+/*
+ * Register Definition API: field macros
+ *
+ * Copyright (c) 2016 Xilinx Inc.
+ * Copyright (c) 2013 Peter Crosthwaite <peter.crosthwaite@xilinx.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ */
+
+#ifndef REGISTERFIELDS_H
+#define REGISTERFIELDS_H
+
+/* Define constants for a 32 bit register */
+
+/* This macro will define A_FOO, for the byte address of a register
+ * as well as R_FOO for the uint32_t[] register number (A_FOO / 4).
+ */
+#define REG32(reg, addr)                                                  \
+    enum { A_ ## reg = (addr) };                                          \
+    enum { R_ ## reg = (addr) / 4 };
+
+/* Define SHIFT, LENGTH and MASK constants for a field within a register */
+
+/* This macro will define FOO_BAR_MASK, FOO_BAR_SHIFT and FOO_BAR_LENGTH 
+ * constants for field BAR in register FOO.
+ */
+#define FIELD(reg, field, shift, length)                                  \
+    enum { R_ ## reg ## _ ## field ## _SHIFT = (shift)};                  \
+    enum { R_ ## reg ## _ ## field ## _LENGTH = (length)};                \
+    enum { R_ ## reg ## _ ## field ## _MASK =                             \
+                                        MAKE_64BIT_MASK(shift, length)};
+
+/* Extract a field from a register */
+#define FIELD_EX32(storage, reg, field)                                   \
+    extract32((storage), R_ ## reg ## _ ## field ## _SHIFT,               \
+              R_ ## reg ## _ ## field ## _LENGTH)
+
+/* Extract a field from an array of registers */
+#define ARRAY_FIELD_EX32(regs, reg, field)                                \
+    FIELD_EX32((regs)[R_ ## reg], reg, field)
+
+/* Deposit a register field.
+ * Assigning values larger then the target field will result in
+ * compilation warnings.
+ */
+#define FIELD_DP32(storage, reg, field, val) ({                           \
+    struct {                                                              \
+        unsigned int v:R_ ## reg ## _ ## field ## _LENGTH;                \
+    } v = { .v = val };                                                   \
+    uint32_t d;                                                           \
+    d = deposit32((storage), R_ ## reg ## _ ## field ## _SHIFT,           \
+                  R_ ## reg ## _ ## field ## _LENGTH, v.v);               \
+    d; })
+
+/* Deposit a field to array of registers.  */
+#define ARRAY_FIELD_DP32(regs, reg, field, val)                           \
+    (regs)[R_ ## reg] = FIELD_DP32((regs)[R_ ## reg], reg, field, val);
+
+#endif