cxlflash: Superpipe support

Add superpipe supporting infrastructure to device driver for the IBM CXL
Flash adapter. This patch allows userspace applications to take advantage
of the accelerated I/O features that this adapter provides and bypass the
traditional filesystem stack.

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

2 files changed, 141 insertions, 0 deletions

diff --git a/include/uapi/scsi/Kbuild b/include/uapi/scsi/Kbuild
index 75746d52f208..d791e0ad509d 100644
--- a/include/uapi/scsi/Kbuild
+++ b/include/uapi/scsi/Kbuild
@@ -3,3 +3,4 @@ header-y += fc/
 header-y += scsi_bsg_fc.h
 header-y += scsi_netlink.h
 header-y += scsi_netlink_fc.h
+header-y += cxlflash_ioctl.h
diff --git a/include/uapi/scsi/cxlflash_ioctl.h b/include/uapi/scsi/cxlflash_ioctl.h
new file mode 100644
index 000000000000..570773406531
--- /dev/null
+++ b/include/uapi/scsi/cxlflash_ioctl.h
@@ -0,0 +1,140 @@
+/*
+ * CXL Flash Device Driver
+ *
+ * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
+ *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
+ *
+ * Copyright (C) 2015 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _CXLFLASH_IOCTL_H
+#define _CXLFLASH_IOCTL_H
+
+#include <linux/types.h>
+
+/*
+ * Structure and flag definitions CXL Flash superpipe ioctls
+ */
+
+#define DK_CXLFLASH_VERSION_0	0
+
+struct dk_cxlflash_hdr {
+	__u16 version;			/* Version data */
+	__u16 rsvd[3];			/* Reserved for future use */
+	__u64 flags;			/* Input flags */
+	__u64 return_flags;		/* Returned flags */
+};
+
+/*
+ * Notes:
+ * -----
+ * The 'context_id' field of all ioctl structures contains the context
+ * identifier for a context in the lower 32-bits (upper 32-bits are not
+ * to be used when identifying a context to the AFU). That said, the value
+ * in its entirety (all 64-bits) is to be treated as an opaque cookie and
+ * should be presented as such when issuing ioctls.
+ *
+ * For DK_CXLFLASH_ATTACH ioctl, user specifies read/write access
+ * permissions via the O_RDONLY, O_WRONLY, and O_RDWR flags defined in
+ * the fcntl.h header file.
+ */
+#define DK_CXLFLASH_ATTACH_REUSE_CONTEXT	0x8000000000000000ULL
+
+struct dk_cxlflash_attach {
+	struct dk_cxlflash_hdr hdr;	/* Common fields */
+	__u64 num_interrupts;		/* Requested number of interrupts */
+	__u64 context_id;		/* Returned context */
+	__u64 mmio_size;		/* Returned size of MMIO area */
+	__u64 block_size;		/* Returned block size, in bytes */
+	__u64 adap_fd;			/* Returned adapter file descriptor */
+	__u64 last_lba;			/* Returned last LBA on the device */
+	__u64 max_xfer;			/* Returned max transfer size, blocks */
+	__u64 reserved[8];		/* Reserved for future use */
+};
+
+struct dk_cxlflash_detach {
+	struct dk_cxlflash_hdr hdr;	/* Common fields */
+	__u64 context_id;		/* Context to detach */
+	__u64 reserved[8];		/* Reserved for future use */
+};
+
+struct dk_cxlflash_udirect {
+	struct dk_cxlflash_hdr hdr;	/* Common fields */
+	__u64 context_id;		/* Context to own physical resources */
+	__u64 rsrc_handle;		/* Returned resource handle */
+	__u64 last_lba;			/* Returned last LBA on the device */
+	__u64 reserved[8];		/* Reserved for future use */
+};
+
+struct dk_cxlflash_release {
+	struct dk_cxlflash_hdr hdr;	/* Common fields */
+	__u64 context_id;		/* Context owning resources */
+	__u64 rsrc_handle;		/* Resource handle to release */
+	__u64 reserved[8];		/* Reserved for future use */
+};
+
+#define DK_CXLFLASH_VERIFY_SENSE_LEN	18
+#define DK_CXLFLASH_VERIFY_HINT_SENSE	0x8000000000000000ULL
+
+struct dk_cxlflash_verify {
+	struct dk_cxlflash_hdr hdr;	/* Common fields */
+	__u64 context_id;		/* Context owning resources to verify */
+	__u64 rsrc_handle;		/* Resource handle of LUN */
+	__u64 hint;			/* Reasons for verify */
+	__u64 last_lba;			/* Returned last LBA of device */
+	__u8 sense_data[DK_CXLFLASH_VERIFY_SENSE_LEN]; /* SCSI sense data */
+	__u8 pad[6];			/* Pad to next 8-byte boundary */
+	__u64 reserved[8];		/* Reserved for future use */
+};
+
+#define DK_CXLFLASH_RECOVER_AFU_CONTEXT_RESET	0x8000000000000000ULL
+
+struct dk_cxlflash_recover_afu {
+	struct dk_cxlflash_hdr hdr;	/* Common fields */
+	__u64 reason;			/* Reason for recovery request */
+	__u64 context_id;		/* Context to recover / updated ID */
+	__u64 mmio_size;		/* Returned size of MMIO area */
+	__u64 adap_fd;			/* Returned adapter file descriptor */
+	__u64 reserved[8];		/* Reserved for future use */
+};
+
+#define DK_CXLFLASH_MANAGE_LUN_WWID_LEN			16
+#define DK_CXLFLASH_MANAGE_LUN_ENABLE_SUPERPIPE		0x8000000000000000ULL
+#define DK_CXLFLASH_MANAGE_LUN_DISABLE_SUPERPIPE	0x4000000000000000ULL
+#define DK_CXLFLASH_MANAGE_LUN_ALL_PORTS_ACCESSIBLE	0x2000000000000000ULL
+
+struct dk_cxlflash_manage_lun {
+	struct dk_cxlflash_hdr hdr;			/* Common fields */
+	__u8 wwid[DK_CXLFLASH_MANAGE_LUN_WWID_LEN];	/* Page83 WWID, NAA-6 */
+	__u64 reserved[8];				/* Rsvd, future use */
+};
+
+union cxlflash_ioctls {
+	struct dk_cxlflash_attach attach;
+	struct dk_cxlflash_detach detach;
+	struct dk_cxlflash_udirect udirect;
+	struct dk_cxlflash_release release;
+	struct dk_cxlflash_verify verify;
+	struct dk_cxlflash_recover_afu recover_afu;
+	struct dk_cxlflash_manage_lun manage_lun;
+};
+
+#define MAX_CXLFLASH_IOCTL_SZ	(sizeof(union cxlflash_ioctls))
+
+#define CXL_MAGIC 0xCA
+#define CXL_IOWR(_n, _s)	_IOWR(CXL_MAGIC, _n, struct _s)
+
+#define DK_CXLFLASH_ATTACH		CXL_IOWR(0x80, dk_cxlflash_attach)
+#define DK_CXLFLASH_USER_DIRECT		CXL_IOWR(0x81, dk_cxlflash_udirect)
+#define DK_CXLFLASH_RELEASE		CXL_IOWR(0x82, dk_cxlflash_release)
+#define DK_CXLFLASH_DETACH		CXL_IOWR(0x83, dk_cxlflash_detach)
+#define DK_CXLFLASH_VERIFY		CXL_IOWR(0x84, dk_cxlflash_verify)
+#define DK_CXLFLASH_RECOVER_AFU		CXL_IOWR(0x85, dk_cxlflash_recover_afu)
+#define DK_CXLFLASH_MANAGE_LUN		CXL_IOWR(0x86, dk_cxlflash_manage_lun)
+
+#endif /* ifndef _CXLFLASH_IOCTL_H */