Hi--
On 2/10/21 6:52 AM, Mukesh Ojha wrote:
> There could be a sceanario where we define some region
scenario
> in normal memory and use them store to logs which is later
> retrieved by bootloader during warm reset.
>
> In this scenario, we wanted to treat this memory as normal
> cacheable memory instead of default behaviour which
> is an overhead. Making it cacheable could improve
> performance.
>
> This commit gives control to change mem_type from Device
> tree, and also documents the value for normal memory.
>
> Signed-off-by: Huang Yiwei <hyi...@codeaurora.org>
> Signed-off-by: Mukesh Ojha <mo...@codeaurora.org>
> ---
> Documentation/admin-guide/ramoops.rst | 4 +++-
> fs/pstore/ram.c | 1 +
> fs/pstore/ram_core.c | 10 ++++++++--
> 3 files changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/admin-guide/ramoops.rst
> b/Documentation/admin-guide/ramoops.rst
> index b0a1ae7..8f107d8 100644
> --- a/Documentation/admin-guide/ramoops.rst
> +++ b/Documentation/admin-guide/ramoops.rst
> @@ -3,7 +3,7 @@ Ramoops oops/panic logger
>
> Sergiu Iordache <ser...@chromium.org>
>
> -Updated: 17 November 2011
> +Updated: 10 Feb 2021
>
> Introduction
> ------------
> @@ -30,6 +30,8 @@ mapping to pgprot_writecombine. Setting ``mem_type=1``
> attempts to use
> depends on atomic operations. At least on ARM, pgprot_noncached causes the
> memory to be mapped strongly ordered, and atomic operations on strongly
> ordered
> memory are implementation defined, and won't work on many ARMs such as omaps.
> +Setting ``mem_type=2`` attempts to treat the memory region as normal memory,
Does "mem_type=" work? or does it need to be "mem-type=", as below?
I.e., do both of them work?
> +which enables full cache on it. This can improve the performance.
>
> The memory area is divided into ``record_size`` chunks (also rounded down to
> power of two) and each kmesg dump writes a ``record_size`` chunk of
> diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
> index ca6d8a8..b262c57 100644
> --- a/fs/pstore/ram.c
> +++ b/fs/pstore/ram.c
> @@ -666,6 +666,7 @@ static int ramoops_parse_dt(struct platform_device *pdev,
> field = value; \
> }
>
> + parse_u32("mem-type", pdata->record_size, pdata->mem_type);
here^^^^^^^^^^
thanks.
--
~Randy
