From: Seunghun Han <kkamagui@gmail.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Peter Huewe <peterhuewe@gmx.de>,
Matthew Garrett <mjg59@srcf.ucam.org>,
linux-integrity@vger.kernel.org (open list:TPM DEVICE DRIVER),
linux-kernel@vger.kernel.org, Seunghun Han <kkamagui@gmail.com>
Subject: [PATCH v2 2/2] tpm: tpm_crb: enhance resource mapping mechanism for supporting AMD's fTPM
Date: Mon, 9 Sep 2019 18:09:06 +0900 [thread overview]
Message-ID: <20190909090906.28700-3-kkamagui@gmail.com> (raw)
In-Reply-To: <20190909090906.28700-1-kkamagui@gmail.com>
I got an AMD system which had a Ryzen Threadripper 1950X and MSI
mainboard, and I had a problem with AMD's fTPM. My machine showed an error
message below, and the fTPM didn't work because of it.
[ 5.732084] tpm_crb MSFT0101:00: can't request region for resource
[mem 0x79b4f000-0x79b4ffff]
[ 5.732089] tpm_crb: probe of MSFT0101:00 failed with error -16
When I saw the iomem, I found two fTPM regions were in the ACPI NVS area.
The regions are below.
79a39000-79b6afff : ACPI Non-volatile Storage
79b4b000-79b4bfff : MSFT0101:00
79b4f000-79b4ffff : MSFT0101:00
After analyzing this issue, I found that crb_map_io() function called
devm_ioremap_resource() and it failed. The ACPI NVS didn't allow the TPM
CRB driver to assign a resource in it because a busy bit was set to
the ACPI NVS area.
To support AMD's fTPM, I added a function to check intersects between
the TPM region and ACPI NVS before it mapped the region. If some
intersects are detected, the function just calls devm_ioremap() for
a workaround. If there is no intersect, it calls devm_ioremap_resource().
Signed-off-by: Seunghun Han <kkamagui@gmail.com>
---
Changes in v2: fix a warning of kbuild test robot. The link is below.
https://lkml.org/lkml/2019/8/31/217
drivers/char/tpm/tpm_crb.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 14f486c23af2..6b98a3a995b7 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -450,6 +450,27 @@ static int crb_check_resource(struct acpi_resource *ares, void *data)
return 1;
}
+static void __iomem *crb_ioremap_resource(struct device *dev,
+ const struct resource *res)
+{
+ int rc;
+ resource_size_t size = resource_size(res);
+
+ /* Broken BIOS assigns command and response buffers in ACPI NVS region.
+ * Check intersections between a resource and ACPI NVS for W/A.
+ */
+ rc = region_intersects(res->start, size, IORESOURCE_MEM |
+ IORESOURCE_BUSY, IORES_DESC_ACPI_NV_STORAGE);
+ if (rc != REGION_DISJOINT) {
+ dev_err(dev,
+ FW_BUG "Resource overlaps with a ACPI NVS. %pr\n",
+ res);
+ return devm_ioremap(dev, res->start, size);
+ }
+
+ return devm_ioremap_resource(dev, res);
+}
+
static void __iomem *crb_map_res(struct device *dev, struct crb_priv *priv,
struct resource *io_res, u64 start, u32 size)
{
@@ -464,7 +485,7 @@ static void __iomem *crb_map_res(struct device *dev, struct crb_priv *priv,
return (void __iomem *) ERR_PTR(-EINVAL);
if (!resource_contains(io_res, &new_res))
- return devm_ioremap_resource(dev, &new_res);
+ return crb_ioremap_resource(dev, &new_res);
return priv->iobase + (new_res.start - io_res->start);
}
@@ -536,7 +557,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
goto out_early;
}
- priv->iobase = devm_ioremap_resource(dev, &io_res);
+ priv->iobase = crb_ioremap_resource(dev, &io_res);
if (IS_ERR(priv->iobase)) {
ret = PTR_ERR(priv->iobase);
goto out_early;
--
2.21.0
next prev parent reply other threads:[~2019-09-09 9:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-09 9:09 [PATCH v2 0/2] Enhance support for the AMD's fTPM Seunghun Han
2019-09-09 9:09 ` [PATCH v2 1/2] tpm: tpm_crb: enhance command and response buffer size calculation code Seunghun Han
2019-09-10 12:34 ` Jarkko Sakkinen
2019-09-10 15:12 ` Seunghun Han
2019-09-09 9:09 ` Seunghun Han [this message]
2019-09-10 14:42 ` [PATCH v2 2/2] tpm: tpm_crb: enhance resource mapping mechanism for supporting AMD's fTPM Jarkko Sakkinen
2019-09-10 15:06 ` Jarkko Sakkinen
2019-09-10 15:28 ` Seunghun Han
2019-09-13 13:12 ` Jarkko Sakkinen
2019-09-16 8:18 ` Seunghun Han
2019-09-16 8:42 ` Seunghun Han
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