1 files changed, 61 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/papr-rtas-common.h b/arch/powerpc/platforms/pseries/papr-rtas-common.h
new file mode 100644
index 000000000000..4ceabcaf4905
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/papr-rtas-common.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ASM_POWERPC_PAPR_RTAS_COMMON_H
+#define _ASM_POWERPC_PAPR_RTAS_COMMON_H
+
+#include <linux/types.h>
+
+/*
+ * Return codes for sequence based RTAS calls.
+ * Not listed under PAPR+ v2.13 7.2.8: "Return Codes".
+ * But defined in the specific section of each RTAS call.
+ */
+#define RTAS_SEQ_COMPLETE	0 /* All data has been retrieved. */
+#define RTAS_SEQ_MORE_DATA	1 /* More data is available */
+#define RTAS_SEQ_START_OVER	-4 /* Data changed, restart call sequence. */
+
+/*
+ * Internal "blob" APIs for accumulating RTAS call results into
+ * an immutable buffer to be attached to a file descriptor.
+ */
+struct papr_rtas_blob {
+	const char *data;
+	size_t len;
+};
+
+/**
+ * struct papr_sequence - State for managing a sequence of RTAS calls.
+ * @error:  Shall be zero as long as the sequence has not encountered an error,
+ *          -ve errno otherwise. Use papr_rtas_sequence_set_err() to update.
+ * @params: Parameter block to pass to rtas_*() calls.
+ * @begin: Work area allocation and initialize the needed parameter
+ *         values passed to RTAS call
+ * @end: Free the allocated work area
+ * @work: Obtain data with RTAS call and invoke it until the sequence is
+ *        completed.
+ *
+ */
+struct papr_rtas_sequence {
+	int error;
+	void *params;
+	void (*begin)(struct papr_rtas_sequence *seq);
+	void (*end)(struct papr_rtas_sequence *seq);
+	const char *(*work)(struct papr_rtas_sequence *seq, size_t *len);
+};
+
+extern bool papr_rtas_blob_has_data(const struct papr_rtas_blob *blob);
+extern void papr_rtas_blob_free(const struct papr_rtas_blob *blob);
+extern int papr_rtas_sequence_set_err(struct papr_rtas_sequence *seq,
+		int err);
+extern const struct papr_rtas_blob *papr_rtas_retrieve(struct papr_rtas_sequence *seq);
+extern long papr_rtas_setup_file_interface(struct papr_rtas_sequence *seq,
+			const struct file_operations *fops, char *name);
+extern bool papr_rtas_sequence_should_stop(const struct papr_rtas_sequence *seq,
+				s32 status, bool init_state);
+extern ssize_t papr_rtas_common_handle_read(struct file *file,
+			char __user *buf, size_t size, loff_t *off);
+extern int papr_rtas_common_handle_release(struct inode *inode,
+					struct file *file);
+extern loff_t papr_rtas_common_handle_seek(struct file *file, loff_t off,
+					int whence);
+#endif /* _ASM_POWERPC_PAPR_RTAS_COMMON_H */
+