ahci-remap.h: add ahci remapping definitions

Signed-off-by: NDan Williams <dan.j.williams@intel.com>
[hch: split into a separate header and commit]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
[tj: dropped duplicate definition of AHCI_VSCAP spotted by Sergei]
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

include/linux/ahci-remap.h

+#ifndef _LINUX_AHCI_REMAP_H
+#define _LINUX_AHCI_REMAP_H
+
+#include <linux/sizes.h>
+
+#define AHCI_VSCAP		0xa4
+#define AHCI_REMAP_CAP		0x800
+
+/* device class code */
+#define AHCI_REMAP_N_DCC	0x880
+
+/* remap-device base relative to ahci-bar */
+#define AHCI_REMAP_N_OFFSET	SZ_16K
+#define AHCI_REMAP_N_SIZE	SZ_16K
+
+#define AHCI_MAX_REMAP		3
+
+static inline unsigned int ahci_remap_dcc(int i)
+{
+	return AHCI_REMAP_N_DCC + i * 0x80;
+}
+
+static inline unsigned int ahci_remap_base(int i)
+{
+	return AHCI_REMAP_N_OFFSET + i * AHCI_REMAP_N_SIZE;
+}
+
+#endif /* _LINUX_AHCI_REMAP_H */