powerpc/pseries: Define common functions for RTAS sequence calls

The RTAS call can be normal where retrieves the data form the
hypervisor once or sequence based RTAS call which has to
issue multiple times until the complete data is obtained. For
some of these sequence RTAS calls, the OS should not interleave
calls with different input until the sequence is completed.
The data is collected for each call and copy to the buffer
for the entire sequence during ioctl() handle and then expose
this buffer to the user space with read() handle.

One such sequence RTAS call is ibm,get-vpd and its support is
already included in the current code. To add the similar support
for other sequence based calls, move the common functions in to
separate file and update papr_rtas_sequence struct with the
following callbacks so that RTAS call specific code will be
defined and executed to complete the sequence.

struct papr_rtas_sequence {
        int error;
        void params;
        void (*begin) (struct papr_rtas_sequence *);
        void (*end) (struct papr_rtas_sequence *);
        const char * (*work) (struct papr_rtas_sequence *, size_t *);
};

params: Input parameters used to pass for RTAS call.
Begin:	RTAS call specific function to initialize data
	including work area allocation.
End:	RTAS call specific function to free up resources
	(free work area) after the sequence is completed.
Work:	The actual RTAS call specific function which collects
	the data from the hypervisor.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250416225743.596462-2-haren@linux.ibm.com

0 files changed, 0 insertions, 0 deletions