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| author | Nathan Lynch <nathanl@linux.ibm.com> | 2021-04-08 09:06:26 -0500 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-04-14 23:04:15 +1000 |
| commit | c13ff6f3251318f5e1ff5b1a6d05f76996db672a (patch) | |
| tree | 08c302fbc967c01a5dd5658b809cacab406a63a6 /arch/powerpc | |
| parent | 5ae5bc12d0728db60a0aa9b62160ffc038875f1a (diff) | |
| download | linux-c13ff6f3251318f5e1ff5b1a6d05f76996db672a.tar.bz2 | |
powerpc/rtas: improve ppc_rtas_rmo_buf_show documentation
Add kerneldoc for ppc_rtas_rmo_buf_show(), the callback for
/proc/powerpc/rtas/rmo_buffer, explaining its expected use.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210408140630.205502-2-nathanl@linux.ibm.com
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/rtas-proc.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/rtas-proc.c b/arch/powerpc/kernel/rtas-proc.c index 2d33f342a293..e0f8329966d6 100644 --- a/arch/powerpc/kernel/rtas-proc.c +++ b/arch/powerpc/kernel/rtas-proc.c @@ -757,7 +757,16 @@ static int ppc_rtas_tone_volume_show(struct seq_file *m, void *v) #define RMO_READ_BUF_MAX 30 -/* RTAS Userspace access */ +/** + * ppc_rtas_rmo_buf_show() - Describe RTAS-addressable region for user space. + * + * Base + size description of a range of RTAS-addressable memory set + * aside for user space to use as work area(s) for certain RTAS + * functions. User space accesses this region via /dev/mem. Apart from + * security policies, the kernel does not arbitrate or serialize + * access to this region, and user space must ensure that concurrent + * users do not interfere with each other. + */ static int ppc_rtas_rmo_buf_show(struct seq_file *m, void *v) { seq_printf(m, "%016lx %x\n", rtas_rmo_buf, RTAS_RMOBUF_MAX); |