powerpc/pseries: Define papr-hvpipe ioctl

PowerPC FW introduced HVPIPE RTAS calls such as
ibm,send-hvpipe-msg and ibm,receive-hvpipe-msg for the user space
to exchange information with different sources such as Hardware
Management Consoles (HMC).

HVPIPE_IOC_CREATE_HANDLE is defined to use /dev/papr-hvpipe
interface for ibm,send-hvpipe-msg and ibm,receive-hvpipe-msg
RTAS calls.

Also defined papr_hvpipe_hdr which will added in the payload
that is passed between the kernel and the user space.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Shashank MS <shashank.gowda@in.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250909084402.1488456-2-haren@linux.ibm.com

diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index 406a9f4d08694ef6ae841b2c4045cdb04a6f7e92..7c527a01d1cf5ae4b2d714d3f6b5f31ddaa7c937 100644 (file)
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -374,6 +374,8 @@ Code  Seq#    Include File                                             Comments
                                                                        <mailto:linuxppc-dev@lists.ozlabs.org>
 0xB2  08     arch/powerpc/include/uapi/asm/papr-physical-attestation.h powerpc/pseries Physical Attestation API
                                                                        <mailto:linuxppc-dev@lists.ozlabs.org>
+0xB2  09     arch/powerpc/include/uapi/asm/papr-hvpipe.h               powerpc/pseries HVPIPE API
+                                                                       <mailto:linuxppc-dev@lists.ozlabs.org>
 0xB3  00     linux/mmc/ioctl.h
 0xB4  00-0F  linux/gpio.h                                              <mailto:linux-gpio@vger.kernel.org>
 0xB5  00-0F  uapi/linux/rpmsg.h                                        <mailto:linux-remoteproc@vger.kernel.org>

diff --git a/arch/powerpc/include/uapi/asm/papr-hvpipe.h b/arch/powerpc/include/uapi/asm/papr-hvpipe.h
new file mode 100644 (file)
index 0000000..459a7bb
--- /dev/null
+++ b/arch/powerpc/include/uapi/asm/papr-hvpipe.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_PAPR_HVPIPE_H_
+#define _UAPI_PAPR_HVPIPE_H_
+
+#include <linux/types.h>
+#include <asm/ioctl.h>
+#include <asm/papr-miscdev.h>
+
+/*
+ * This header is included in payload between OS and the user
+ * space.
+ * flags: OS notifies the user space whether the hvpipe is
+ *        closed or the buffer has the payload.
+ */
+struct papr_hvpipe_hdr {
+       u8 version;
+       u8 reserved[3];
+       u32 flags;
+       u8 reserved2[40];
+};
+
+/*
+ * ioctl for /dev/papr-hvpipe
+ */
+#define PAPR_HVPIPE_IOC_CREATE_HANDLE  _IOW(PAPR_MISCDEV_IOC_ID, 9, __u32)
+
+/*
+ * hvpipe_hdr flags used for read()
+ */
+#define HVPIPE_MSG_AVAILABLE   0x01 /* Payload is available */
+#define HVPIPE_LOST_CONNECTION 0x02 /* Pipe connection is closed/unavailable */
+
+#endif /* _UAPI_PAPR_HVPIPE_H_ */