On Thu, 19 Mar 2026 01:15:00 +0000 Smita Koralahalli <[email protected]> wrote:
> Reworked from a patch by Alison Schofield <[email protected]> > > Reintroduce Soft Reserved range into the iomem_resource tree for HMEM > to consume. > > This restores visibility in /proc/iomem for ranges actively in use, while > avoiding the early-boot conflicts that occurred when Soft Reserved was > published into iomem before CXL window and region discovery. > > Link: > https://lore.kernel.org/linux-cxl/29312c0765224ae76862d59a17748c8188fb95f1.1692638817.git.alison.schofi...@intel.com/ > Co-developed-by: Alison Schofield <[email protected]> > Signed-off-by: Alison Schofield <[email protected]> > Co-developed-by: Zhijian Li <[email protected]> > Signed-off-by: Zhijian Li <[email protected]> > Signed-off-by: Smita Koralahalli <[email protected]> > Reviewed-by: Dave Jiang <[email protected]> > Reviewed-by: Jonathan Cameron <[email protected]> > Reviewed-by: Dan Williams <[email protected]> One minor update needed as kmalloc_obj() has shown up in meantime. Thanks Jonathan > --- > drivers/dax/hmem/hmem.c | 32 +++++++++++++++++++++++++++++++- > 1 file changed, 31 insertions(+), 1 deletion(-) > > diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c > index 8c574123bd3b..15e462589b92 100644 > --- a/drivers/dax/hmem/hmem.c > +++ b/drivers/dax/hmem/hmem.c > @@ -72,6 +72,34 @@ void dax_hmem_flush_work(void) > } > EXPORT_SYMBOL_GPL(dax_hmem_flush_work); > > +static void remove_soft_reserved(void *r) > +{ > + remove_resource(r); > + kfree(r); > +} > + > +static int add_soft_reserve_into_iomem(struct device *host, > + const struct resource *res) > +{ > + int rc; > + > + struct resource *soft __free(kfree) = > + kmalloc(sizeof(*res), GFP_KERNEL); Update to struct resource *soft __free(kfree) = kmalloc_obj(*soft); Got added in 7.0 with lots of call sites updated via scripting. Not sure why this had sizeof(*res) rather than sizeof(*soft). Same type but should have been soft! If nothing else that would probably have broken the scripts looking for where we should be using kmalloc_obj(). > + if (!soft) > + return -ENOMEM; > + > + *soft = DEFINE_RES_NAMED_DESC(res->start, (res->end - res->start + 1), > + "Soft Reserved", IORESOURCE_MEM, > + IORES_DESC_SOFT_RESERVED); > + > + rc = insert_resource(&iomem_resource, soft); > + if (rc) > + return rc; > + > + return devm_add_action_or_reset(host, remove_soft_reserved, > + no_free_ptr(soft)); > +} > + > static int hmem_register_device(struct device *host, int target_nid, > const struct resource *res) > { > @@ -94,7 +122,9 @@ static int hmem_register_device(struct device *host, int > target_nid, > if (rc != REGION_INTERSECTS) > return 0; > > - /* TODO: Add Soft-Reserved memory back to iomem */ > + rc = add_soft_reserve_into_iomem(host, res); > + if (rc) > + return rc; > > id = memregion_alloc(GFP_KERNEL); > if (id < 0) {
