On Wed, Sep 30, 2026 at 05:14:46PM +0300, Alexander Usyskin wrote:
> Add option to expose additional fixed-sized partition starting
> from the beginning of storage.
> Xe driver can request this partition exposure if firmware or hardware
> have detected failure that may involve corrupted partition table.
> Fixed-sized partition allows full storage re-write in this situation.
>
> Acked-by: Miquel Raynal <[email protected]>
> Signed-off-by: Alexander Usyskin <[email protected]>
> ---
> drivers/mtd/devices/mtd_intel_dg.c | 65
> ++++++++++++++++++++++++++++----------
> include/linux/intel_dg_nvm_aux.h | 1 +
> 2 files changed, 50 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/mtd/devices/mtd_intel_dg.c
> b/drivers/mtd/devices/mtd_intel_dg.c
> index a566e86eb5e3..976246e94e79 100644
> --- a/drivers/mtd/devices/mtd_intel_dg.c
> +++ b/drivers/mtd/devices/mtd_intel_dg.c
> @@ -31,6 +31,7 @@ struct intel_dg_nvm {
> void __iomem *base;
> void __iomem *base2;
> bool non_posted_erase;
> + bool survivability_enabled;
>
> size_t size;
> unsigned int nregions;
> @@ -430,6 +431,15 @@ static int intel_dg_nvm_init(struct intel_dg_nvm *nvm,
> struct device *device,
> /* clean error register, previous errors are ignored */
> idg_nvm_error(nvm);
>
> + if (nvm->survivability_enabled) {
> + nvm->size = nvm->regions[0].offset + nvm->regions[0].size - 1;
I see that this offset + region.size - 1 is also used in idg_nvm_get_region()
we could perhaps define a variable with this and document the - 1?!
But it looks right, no blocker...
> + dev_dbg(device, "Registered survivability region %s
> size=%lld\n",
> + nvm->regions[0].name,
> + nvm->regions[0].size);
> + n = 1;
> + goto out;
> + }
> +
> ret = idg_nvm_is_valid(nvm);
> if (ret) {
> dev_err(device, "The MEM is not valid %d\n", ret);
> @@ -481,6 +491,7 @@ static int intel_dg_nvm_init(struct intel_dg_nvm *nvm,
> struct device *device,
> n++;
> }
>
> +out:
> nvm->non_posted_erase = non_posted_erase;
>
> dev_dbg(device, "Registered %d regions\n", n);
> @@ -753,15 +764,19 @@ static int intel_dg_mtd_probe(struct auxiliary_device
> *aux_dev,
>
> device = &aux_dev->dev;
>
> - /* count available regions */
> - for (nregions = 0, i = 0; i < INTEL_DG_NVM_REGIONS; i++) {
> - if (invm->regions[i].name)
> - nregions++;
> - }
> + if (invm->survivability_size) {
> + nregions = 1;
> + } else {
> + /* count available regions */
> + for (nregions = 0, i = 0; i < INTEL_DG_NVM_REGIONS; i++) {
> + if (invm->regions[i].name)
> + nregions++;
> + }
>
> - if (!nregions) {
> - dev_err(device, "no regions defined\n");
> - return -ENODEV;
> + if (!nregions) {
> + dev_err(device, "no regions defined\n");
> + return -ENODEV;
> + }
> }
>
> nvm = kzalloc_flex(*nvm, regions, nregions);
> @@ -771,21 +786,39 @@ static int intel_dg_mtd_probe(struct auxiliary_device
> *aux_dev,
> kref_init(&nvm->refcnt);
> mutex_init(&nvm->lock);
> nvm->nregions = nregions;
> + nvm->survivability_enabled = !!invm->survivability_size;
>
> - for (n = 0, i = 0; i < INTEL_DG_NVM_REGIONS; i++) {
> - if (!invm->regions[i].name)
> - continue;
> -
> + if (invm->survivability_size) { /* survivability partition */
> char *name = kasprintf(GFP_KERNEL, "%s.%s",
> - dev_name(&aux_dev->dev),
> invm->regions[i].name);
> + dev_name(&aux_dev->dev), "DATA");
> if (!name) {
> ret = -ENOMEM;
> goto err_norpm;
> }
>
> - nvm->regions[n].name = name;
> - nvm->regions[n].id = i;
> - n++;
> + nvm->regions[0].name = name;
> + nvm->regions[0].id = 0;
> + nvm->regions[0].offset = 0;
> + nvm->regions[0].size = invm->survivability_size;
> + nvm->regions[0].is_readable = true;
> + nvm->regions[0].is_writable = true;
> + n = 1;
> + } else {
> + for (n = 0, i = 0; i < INTEL_DG_NVM_REGIONS; i++) {
> + if (!invm->regions[i].name)
> + continue;
> +
> + char *name = kasprintf(GFP_KERNEL, "%s.%s",
> + dev_name(&aux_dev->dev),
> invm->regions[i].name);
> + if (!name) {
> + ret = -ENOMEM;
> + goto err_norpm;
> + }
> +
> + nvm->regions[n].name = name;
> + nvm->regions[n].id = i;
> + n++;
> + }
here as well, I believe the if survivability block should only select the
different print name and fix the for delimiter to 1 iteraction, then
you don't duplicate the rest of the code...
but also no blocker from my side:
Reviewed-by: Rodrigo Vivi <[email protected]>
> }
>
> ret = devm_pm_runtime_enable(device);
> diff --git a/include/linux/intel_dg_nvm_aux.h
> b/include/linux/intel_dg_nvm_aux.h
> index 625d46a6b96e..84b5b6e0c4ea 100644
> --- a/include/linux/intel_dg_nvm_aux.h
> +++ b/include/linux/intel_dg_nvm_aux.h
> @@ -21,6 +21,7 @@ struct intel_dg_nvm_dev {
> struct auxiliary_device aux_dev;
> bool writable_override;
> bool non_posted_erase;
> + size_t survivability_size;
> struct resource bar;
> struct resource bar2;
> const struct intel_dg_nvm_region *regions;
>
> --
> 2.53.0
>
