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| author | Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> | 2017-11-08 05:23:57 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-11-12 01:03:10 +0300 |
| commit | 61f3cca8cda979646c24accd9dbf3e2de7ea6ceb (patch) | |
| tree | aa66625a3155327928bce31a68561945badafbba /arch/powerpc/platforms/powernv/vas.h | |
| parent | 5676be2fb7035ac32da3a96241611e7eddff6157 (diff) | |
| download | linux-61f3cca8cda979646c24accd9dbf3e2de7ea6ceb.tar.xz | |
powerpc/vas: Define vas_win_id()
Define an interface to return a system-wide unique id for a given VAS
window.
The vas_win_id() will be used in a follow-on patch to generate an unique
handle for a user space receive window. Applications can use this handle
to pair send and receive windows for fast thread-wakeup.
The hardware refers to this system-wide unique id as a Partition Send
Window ID which is expected to be used during fault handling. Hence the
"pswid" in the function names.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/platforms/powernv/vas.h')
| -rw-r--r-- | arch/powerpc/platforms/powernv/vas.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h index 756cbc5335bc..ae0100fd35bb 100644 --- a/arch/powerpc/platforms/powernv/vas.h +++ b/arch/powerpc/platforms/powernv/vas.h @@ -447,4 +447,32 @@ static inline u64 read_hvwc_reg(struct vas_window *win, return in_be64(win->hvwc_map+reg); } +/* + * Encode/decode the Partition Send Window ID (PSWID) for a window in + * a way that we can uniquely identify any window in the system. i.e. + * we should be able to locate the 'struct vas_window' given the PSWID. + * + * Bits Usage + * 0:7 VAS id (8 bits) + * 8:15 Unused, 0 (3 bits) + * 16:31 Window id (16 bits) + */ +static inline u32 encode_pswid(int vasid, int winid) +{ + u32 pswid = 0; + + pswid |= vasid << (31 - 7); + pswid |= winid; + + return pswid; +} + +static inline void decode_pswid(u32 pswid, int *vasid, int *winid) +{ + if (vasid) + *vasid = pswid >> (31 - 7) & 0xFF; + + if (winid) + *winid = pswid & 0xFFFF; +} #endif /* _VAS_H */ |