Re: [PATCH v2 14/24] EDAC, ghes: Rework memory hierarchy detection

Borislav Petkov
2019-08-20T08:56:52Z

On Mon, Jun 24, 2019 at 03:09:24PM +0000, Robert Richter wrote:
> In a later patch we want to add more information about the memory
> hierarchy (NUMA topology, DIMM label information). Rework memory
> hierarchy detection to make the code extendable for this.
>
> The general approach is roughly like:
>
> mem_info_setup();
> for_each_node(nid) {
> mci = edac_mc_alloc(nid);
> mem_info_prepare_mci(mci);
> edac_mc_add_mc(mci);
> };
>
> This patch introduces mem_info_setup() and mem_info_prepare_mci().

Avoid having "This patch" or "This commit" in the commit message. It is
tautologically useless.

> All data of the memory hierarchy is collected in a local struct
> ghes_mem_info.
>
> Note: Per (NUMA) node registration will be implemented in a later
> patch.

That sentence is not needed in the commit message.

> Signed-off-by: Robert Richter <rrichter@marvell.com>
> ---
> drivers/edac/ghes_edac.c | 166 ++++++++++++++++++++++++++++++---------
> 1 file changed, 127 insertions(+), 39 deletions(-)
>
> diff --git a/drivers/edac/ghes_edac.c b/drivers/edac/ghes_edac.c
> index 8063996a311d..44bfb499b147 100644
> --- a/drivers/edac/ghes_edac.c
> +++ b/drivers/edac/ghes_edac.c
> @@ -65,17 +65,53 @@ struct memdev_dmi_entry {
> u16 conf_mem_clk_speed;
> } __attribute__((__packed__));
>
> -struct ghes_edac_dimm_fill {
> - struct mem_ctl_info *mci;
> - unsigned count;

All those "dimm" and "info" words everywhere are making my head spin.
Let's make it more readable:

> +struct ghes_dimm_info {
> + struct dimm_info dimm_info;
> + int idx;
> +};
> +
> +struct ghes_mem_info {
> + int num_dimm;
> + struct ghes_dimm_info *dimms;
> };
>
> +static struct ghes_mem_info mem_info;

/* A DIMM */
struct ghes_dimm {
struct dimm_info dimm;
int idx;
};

/* The memory layout of the system */
struct ghes_memory {
struct ghes_dimm *dimms;
int num_dimms;
};

static struct ghes_memory mem;

> +
> +#define for_each_dimm(dimm) \
> + for (dimm = mem_info.dimms; \
> + dimm < mem_info.dimms + mem_info.num_dimm; \
> + dimm++)
> +
> static void ghes_edac_count_dimms(const struct dmi_header *dh, void *arg)
> {
> - int *num_dimm = arg;
> + int *num = arg;
>
> if (dh->type == DMI_ENTRY_MEM_DEVICE)
> - (*num_dimm)++;
> + (*num)++;
> +}
> +
> +static int ghes_dimm_info_init(int num)

ghes_dimm_init()

... you get the idea - let's drop the _info crap.

> +{
> + struct ghes_dimm_info *dimm;
> + int idx = 0;
> +
> + memset(&mem_info, 0, sizeof(mem_info));
> +
> + if (num <= 0)
> + return -EINVAL;

Move that check into the caller mem_info_setup() so that you don't do
the memset unnecessarily.

> +
> + mem_info.dimms = kcalloc(num, sizeof(*mem_info.dimms), GFP_KERNEL);
> + if (!mem_info.dimms)
> + return -ENOMEM;
> +
> + mem_info.num_dimm = num;
> +
> + for_each_dimm(dimm) {
> + dimm->idx = idx;
> + idx++;
> + }

or simply

for_each_dimm(dimm)
dimm->idx = idx++;

> +
> + return 0;
> }
>
> static int get_dimm_smbios_index(u16 handle)

--
Regards/Gruss,
Boris.

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