linux/arch/powerpc/mm/vphn.h
Greg Kurz 3338a65bad powerpc/vphn: parsing code rewrite
The current VPHN parsing logic has some flaws that this patch aims to fix:

1) when the value 0xffff is read, the value 0xffffffff gets added to the
   the output list and its element count isn't incremented. This is wrong.
   According to PAPR+ the domain identifiers are packed into a sequence
   terminated by the "reserved value of all ones". This means that 0xffff
   is a stream terminator.

2) the combination of byteswaps and casts make the code hardly readable.
   Let's parse the stream one 16-bit field at a time instead.

3) it is assumed that the hypercall returns 12 32-bit values packed into
   6 64-bit registers. According to PAPR+, the domain identifiers may be
   streamed as 16-bit values. Let's increase the number of expected numbers
   to 24.

Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-18 10:48:59 +11:00

17 lines
489 B
C

#ifndef _ARCH_POWERPC_MM_VPHN_H_
#define _ARCH_POWERPC_MM_VPHN_H_
/* The H_HOME_NODE_ASSOCIATIVITY h_call returns 6 64-bit registers.
*/
#define VPHN_REGISTER_COUNT 6
/*
* 6 64-bit registers unpacked into up to 24 be32 associativity values. To
* form the complete property we have to add the length in the first cell.
*/
#define VPHN_ASSOC_BUFSIZE (VPHN_REGISTER_COUNT*sizeof(u64)/sizeof(u16) + 1)
extern int vphn_unpack_associativity(const long *packed, __be32 *unpacked);
#endif