xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

powerpc/vphn: parsing code rewrite

Browse Source 
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>
This commit is contained in:
Greg Kurz
2015-02-23 16:14:37 +01:00
committed by Michael Ellerman
parent 4b6cfb2a8c
commit 3338a65bad
2 changed files with 40 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
arch/powerpc/mm/vphn.h
View File

@@ -6,10 +6,10 @@
#define VPHN_REGISTER_COUNT 6
/*
* 6 64-bit registers unpacked into 12 32-bit associativity values. To form
* the complete property we have to add the length in the first cell.
* 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(u32) + 1)
#define VPHN_ASSOC_BUFSIZE (VPHN_REGISTER_COUNT*sizeof(u64)/sizeof(u16) + 1)
extern int vphn_unpack_associativity(const long *packed, __be32 *unpacked);