Re: [PATCH v2 08/24] EDAC: Introduce mci_for_each_dimm() iterator

Borislav Petkov
2019-08-14T15:17:42Z

On Mon, Jun 24, 2019 at 03:09:11PM +0000, Robert Richter wrote:
> Make code more readable by introducing a mci_for_each_dimm() iterator.
> Now, we just get a pointer to a struct dimm_info. Direct array access
> using an index is no longer needed to iterate.
>
> Signed-off-by: Robert Richter <rrichter@marvell.com>
> ---
> drivers/edac/edac_mc.c | 18 ++++++++++--------
> drivers/edac/edac_mc_sysfs.c | 34 +++++++++++++++-------------------
> drivers/edac/ghes_edac.c | 8 ++++----
> drivers/edac/i5100_edac.c | 11 +++++------
> include/linux/edac.h | 7 +++++++
> 5 files changed, 41 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
> index c44bc83e8502..27277ca46ab3 100644
> --- a/drivers/edac/edac_mc.c
> +++ b/drivers/edac/edac_mc.c
> @@ -145,15 +145,18 @@ static void edac_mc_dump_channel(struct rank_info *chan)
> edac_dbg(4, " channel->dimm = %p\n", chan->dimm);
> }
>
> -static void edac_mc_dump_dimm(struct dimm_info *dimm, int number)
> +static void edac_mc_dump_dimm(struct dimm_info *dimm)
> {
> char location[80];
>
> + if (!dimm->nr_pages)
> + return;
> +

What's that for?

> edac_dimm_info_location(dimm, location, sizeof(location));
>
> edac_dbg(4, "%s%i: %smapped as virtual row %d, chan %d\n",
> dimm->mci->csbased ? "rank" : "dimm",
> - number, location, dimm->csrow, dimm->cschannel);
> + dimm->idx, location, dimm->csrow, dimm->cschannel);
> edac_dbg(4, " dimm = %p\n", dimm);
> edac_dbg(4, " dimm->label = '%s'\n", dimm->label);
> edac_dbg(4, " dimm->nr_pages = 0x%x\n", dimm->nr_pages);
> @@ -703,6 +706,7 @@ EXPORT_SYMBOL_GPL(edac_get_owner);
> int edac_mc_add_mc_with_groups(struct mem_ctl_info *mci,
> const struct attribute_group **groups)
> {
> + struct dimm_info *dimm;
> int ret = -EINVAL;
> edac_dbg(0, "\n");
>
> @@ -727,9 +731,8 @@ int edac_mc_add_mc_with_groups(struct mem_ctl_info *mci,
> if (csrow->channels[j]->dimm->nr_pages)
> edac_mc_dump_channel(csrow->channels[j]);
> }
> - for (i = 0; i < mci->tot_dimms; i++)
> - if (mci->dimms[i]->nr_pages)
> - edac_mc_dump_dimm(mci->dimms[i], i);

<---- newline here.

> + mci_for_each_dimm(mci, dimm)
> + edac_mc_dump_dimm(dimm);
> }
> #endif
> mutex_lock(&mem_ctls_mutex);

...

> @@ -950,9 +949,10 @@ int edac_create_sysfs_mci_device(struct mem_ctl_info *mci,
> printk(KERN_CONT "\n");
> }
> #endif
> - err = edac_create_dimm_object(mci, dimm, i);
> + err = edac_create_dimm_object(mci, dimm);
> if (err) {
> - edac_dbg(1, "failure: create dimm %d obj\n", i);
> + edac_dbg(1, "failure: create dimm %d obj\n",
> + dimm->idx);
> goto fail_unregister_dimm;
> }
> }

Since you're touching this, pls do

s/dimm/DIMM/g

in the user-visible strings because it is an abbreviation.

> @@ -967,12 +967,9 @@ int edac_create_sysfs_mci_device(struct mem_ctl_info *mci,
> return 0;
>
> fail_unregister_dimm:
> - for (i--; i >= 0; i--) {
> - struct dimm_info *dimm = mci->dimms[i];
> - if (!dimm->nr_pages)
> - continue;
> -
> - device_unregister(&dimm->dev);
> + mci_for_each_dimm(mci, dimm) {
> + if (device_is_registered(&dimm->dev))
> + device_unregister(&dimm->dev);
> }
> device_unregister(&mci->dev);
>
> @@ -984,7 +981,7 @@ int edac_create_sysfs_mci_device(struct mem_ctl_info *mci,
> */
> void edac_remove_sysfs_mci_device(struct mem_ctl_info *mci)
> {
> - int i;
> + struct dimm_info *dimm;
>
> edac_dbg(0, "\n");
>
> @@ -995,8 +992,7 @@ void edac_remove_sysfs_mci_device(struct mem_ctl_info *mci)
> edac_delete_csrow_objects(mci);
> #endif
>
> - for (i = 0; i < mci->tot_dimms; i++) {
> - struct dimm_info *dimm = mci->dimms[i];
> + mci_for_each_dimm(mci, dimm) {
> if (dimm->nr_pages == 0)
> continue;
> edac_dbg(0, "removing device %s\n", dev_name(&dimm->dev));
> diff --git a/drivers/edac/ghes_edac.c b/drivers/edac/ghes_edac.c
> index 8050f9577fe6..72e75ea5526c 100644
> --- a/drivers/edac/ghes_edac.c
> +++ b/drivers/edac/ghes_edac.c
> @@ -81,11 +81,11 @@ static void ghes_edac_count_dimms(const struct dmi_header *dh, void *arg)
> static int get_dimm_smbios_index(u16 handle)
> {
> struct mem_ctl_info *mci = ghes_pvt->mci;
> - int i;
> + struct dimm_info *dimm;
>
> - for (i = 0; i < mci->tot_dimms; i++) {
> - if (mci->dimms[i]->smbios_handle == handle)
> - return i;
> + mci_for_each_dimm(mci, dimm) {
> + if (dimm->smbios_handle == handle)
> + return dimm->idx;
> }
> return -1;
> }
> diff --git a/drivers/edac/i5100_edac.c b/drivers/edac/i5100_edac.c
> index 39ba7f2414ae..7ec42b26a716 100644
> --- a/drivers/edac/i5100_edac.c
> +++ b/drivers/edac/i5100_edac.c
> @@ -846,14 +846,13 @@ static void i5100_init_interleaving(struct pci_dev *pdev,
>
> static void i5100_init_csrows(struct mem_ctl_info *mci)
> {
> - int i;
> struct i5100_priv *priv = mci->pvt_info;
> + struct dimm_info *dimm;
>
> - for (i = 0; i < mci->tot_dimms; i++) {
> - struct dimm_info *dimm;
> - const unsigned long npages = i5100_npages(mci, i);
> - const unsigned chan = i5100_csrow_to_chan(mci, i);
> - const unsigned rank = i5100_csrow_to_rank(mci, i);
> + mci_for_each_dimm(mci, dimm) {
> + const unsigned long npages = i5100_npages(mci, dimm->idx);
> + const unsigned chan = i5100_csrow_to_chan(mci, dimm->idx);
> + const unsigned rank = i5100_csrow_to_rank(mci, dimm->idx);
>
> if (!npages)
> continue;

This cannot be right: the code here under this does now:

dimm = edac_get_dimm(mci, chan, rank, 0);

but dimm is already set. It used to get the DIMM using chan and rank but
now you're iterating over the already initialized pointers. So I think
you don't need the edac_get_dimm() anymore.

Also fix those up too, while at it pls:

WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
#235: FILE: drivers/edac/i5100_edac.c:854:
+ const unsigned chan = i5100_csrow_to_chan(mci, dimm->idx);

WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
#236: FILE: drivers/edac/i5100_edac.c:855:
+ const unsigned rank = i5100_csrow_to_rank(mci, dimm->idx);

> diff --git a/include/linux/edac.h b/include/linux/edac.h
> index 2ee9b8598ae0..20a04f48616c 100644
> --- a/include/linux/edac.h
> +++ b/include/linux/edac.h
> @@ -599,6 +599,13 @@ struct mem_ctl_info {
> u16 fake_inject_count;
> };
>
> +#define mci_for_each_dimm(mci, dimm) \
> + for ((dimm) = (mci)->dimms[0]; \
> + (dimm); \
> + (dimm) = (dimm)->idx < (mci)->tot_dimms \
> + ? (mci)->dimms[(dimm)->idx + 1] \
> + : NULL)
> +
> /**
> * edac_get_dimm_by_index - Get DIMM info from a memory controller
> * given by an index
> --

Thx.

--
Regards/Gruss,
Boris.

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