Reworked from a patch by Alison Schofield <alison.schofi...@intel.com>
Reintroduce Soft Reserved range into the iomem_resource tree for dax_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 <alison.schofi...@intel.com> Signed-off-by: Alison Schofield <alison.schofi...@intel.com> Signed-off-by: Smita Koralahalli <smita.koralahallichannabasa...@amd.com> --- drivers/dax/hmem/hmem.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c index 90978518e5f4..24a6e7e3d916 100644 --- a/drivers/dax/hmem/hmem.c +++ b/drivers/dax/hmem/hmem.c @@ -93,6 +93,40 @@ static void process_defer_work(struct work_struct *_work) walk_hmem_resources(&pdev->dev, handle_deferred_cxl); } +static void remove_soft_reserved(void *data) +{ + struct resource *r = data; + + remove_resource(r); + kfree(r); +} + +static int add_soft_reserve_into_iomem(struct device *host, + const struct resource *res) +{ + struct resource *soft = kzalloc(sizeof(*soft), GFP_KERNEL); + int rc; + + 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) { + kfree(soft); + return rc; + } + + rc = devm_add_action_or_reset(host, remove_soft_reserved, soft); + if (rc) + return rc; + + return 0; +} + static int hmem_register_device(struct device *host, int target_nid, const struct resource *res) { @@ -125,6 +159,10 @@ static int hmem_register_device(struct device *host, int target_nid, IORES_DESC_SOFT_RESERVED); if (rc != REGION_INTERSECTS) return 0; + + rc = add_soft_reserve_into_iomem(host, res); + if (rc) + return rc; #else rc = region_intersects(res->start, resource_size(res), IORESOURCE_MEM, IORES_DESC_SOFT_RESERVED); -- 2.17.1
