CC Rashmica Gupta <rashm...@gmail.com>
On Wed, 2020-11-11 at 16:55 +1100, Jordan Niethe wrote:
> The hardware trace macros which use the memory provided by memtrace are
> able to use trace sizes as small as 16MB. Only memblock aligned values
> can be removed from each NUMA node by writing that value to
> memtrace/enable in debugfs. This means setting up, say, a 16MB trace is
> not possible. To allow such a trace size, instead align whatever value
> is written to memtrace/enable to the memblock size for the purpose of
> removing it from each NUMA node but report the written value from
> memtrace/enable and memtrace/x/size in debugfs.
>
> Signed-off-by: Jordan Niethe <jniet...@gmail.com>
> ---
> arch/powerpc/platforms/powernv/memtrace.c | 20 ++++++--------------
> 1 file changed, 6 insertions(+), 14 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/memtrace.c
> b/arch/powerpc/platforms/powernv/memtrace.c
> index 6828108486f8..1188bc8fd090 100644
> --- a/arch/powerpc/platforms/powernv/memtrace.c
> +++ b/arch/powerpc/platforms/powernv/memtrace.c
> @@ -191,7 +191,7 @@ static int memtrace_init_debugfs(void)
> ent->dir = dir;
> debugfs_create_file("trace", 0400, dir, ent, &memtrace_fops);
> debugfs_create_x64("start", 0400, dir, &ent->start);
> - debugfs_create_x64("size", 0400, dir, &ent->size);
> + debugfs_create_x64("size", 0400, dir, &memtrace_size);
> }
>
> return ret;
> @@ -259,33 +259,25 @@ static int memtrace_enable_set(void *data, u64 val)
> {
> u64 bytes;
>
> - /*
> - * Don't attempt to do anything if size isn't aligned to a memory
> - * block or equal to zero.
> - */
> - bytes = memory_block_size_bytes();
> - if (val & (bytes - 1)) {
> - pr_err("Value must be aligned with 0x%llx\n", bytes);
> - return -EINVAL;
> - }
> -
> /* Re-add/online previously removed/offlined memory */
> if (memtrace_size) {
> if (memtrace_online())
> return -EAGAIN;
> }
>
> + memtrace_size = val;
> +
> if (!val)
> return 0;
>
> - /* Offline and remove memory */
> - if (memtrace_init_regions_runtime(val))
> + /* Offline and remove memory aligned to memory blocks */
> + bytes = memory_block_size_bytes();
> + if (memtrace_init_regions_runtime(ALIGN(val, bytes)))
> return -EINVAL;
>
> if (memtrace_init_debugfs())
> return -EINVAL;
>
> - memtrace_size = val;
>
> return 0;
> }
