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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Ricardo Sandoval Torres <ricardo.sandoval.torres@intel.com>,
        Tony Luck <tony.luck@intel.com>,
        Omar Avelar <omar.avelar@intel.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Mark Gross <markgross@kernel.org>,
        Dan Williams <dan.j.williams@intel.com>
Subject: [PATCH 5.15 142/148] devdax: Fix soft-reservation memory description
Date:   Mon, 26 Sep 2022 12:12:56 +0200
Message-Id: <20220926100801.537407906@linuxfoundation.org>
In-Reply-To: <20220926100756.074519146@linuxfoundation.org>
References: <20220926100756.074519146@linuxfoundation.org>
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From: Dan Williams <dan.j.williams@intel.com>

commit 67feaba413ec68daf4124e9870878899b4ed9a0e upstream.

The "hmem" platform-devices that are created to represent the
platform-advertised "Soft Reserved" memory ranges end up inserting a
resource that causes the iomem_resource tree to look like this:

340000000-43fffffff : hmem.0
  340000000-43fffffff : Soft Reserved
    340000000-43fffffff : dax0.0

This is because insert_resource() reparents ranges when they completely
intersect an existing range.

This matters because code that uses region_intersects() to scan for a
given IORES_DESC will only check that top-level 'hmem.0' resource and
not the 'Soft Reserved' descendant.

So, to support EINJ (via einj_error_inject()) to inject errors into
memory hosted by a dax-device, be sure to describe the memory as
IORES_DESC_SOFT_RESERVED. This is a follow-on to:

commit b13a3e5fd40b ("ACPI: APEI: Fix _EINJ vs EFI_MEMORY_SP")

...that fixed EINJ support for "Soft Reserved" ranges in the first
instance.

Fixes: 262b45ae3ab4 ("x86/efi: EFI soft reservation to E820 enumeration")
Reported-by: Ricardo Sandoval Torres <ricardo.sandoval.torres@intel.com>
Tested-by: Ricardo Sandoval Torres <ricardo.sandoval.torres@intel.com>
Cc: <stable@vger.kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Omar Avelar <omar.avelar@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Mark Gross <markgross@kernel.org>
Link: https://lore.kernel.org/r/166397075670.389916.7435722208896316387.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/dax/hmem/device.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/dax/hmem/device.c
+++ b/drivers/dax/hmem/device.c
@@ -15,6 +15,7 @@ void hmem_register_device(int target_nid
 		.start = r->start,
 		.end = r->end,
 		.flags = IORESOURCE_MEM,
+		.desc = IORES_DESC_SOFT_RESERVED,
 	};
 	struct platform_device *pdev;
 	struct memregion_info info;