diff mbox series

[RESEND] EINJ, CXL: Fix CXL device SBDF calculation

Message ID 20240927163428.366557-1-Benjamin.Cheatham@amd.com
State Accepted
Commit ee1e3c46ed19c096be22472c728fa7f68b1352c4
Headers show
Series [RESEND] EINJ, CXL: Fix CXL device SBDF calculation | expand

Commit Message

Ben Cheatham Sept. 27, 2024, 4:34 p.m. UTC
The SBDF of the target CXL 2.0 compliant root port is required to inject a CXL
protocol error as per ACPI 6.5. The SBDF given has to be in the
following format:

31     24 23    16 15    11 10      8  7        0
+-------------------------------------------------+
| segment |   bus  | device | function | reserved |
+-------------------------------------------------+

The SBDF calculated in cxl_dport_get_sbdf() doesn't account for
the reserved bits currently, causing the wrong SBDF to be used.
Fix said calculation to properly shift the SBDF.

Without this fix, error injection into CXL 2.0 root ports through the
CXL debugfs interface (<debugfs>/cxl) is broken. Injection
through the legacy interface (<debugfs>/apei/einj/) will still work
because the SBDF is manually provided by the user.

Fixes: 12fb28ea6b1cf ("EINJ: Add CXL error type support")
Signed-off-by: Ben Cheatham <Benjamin.Cheatham@amd.com>
---

Resent to add linux-cxl list and Srinivasulu to CC

---
 drivers/acpi/apei/einj-cxl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Dan Williams Sept. 27, 2024, 11:21 p.m. UTC | #1
Ben Cheatham wrote:
> The SBDF of the target CXL 2.0 compliant root port is required to inject a CXL
> protocol error as per ACPI 6.5. The SBDF given has to be in the
> following format:
> 
> 31     24 23    16 15    11 10      8  7        0
> +-------------------------------------------------+
> | segment |   bus  | device | function | reserved |
> +-------------------------------------------------+
> 
> The SBDF calculated in cxl_dport_get_sbdf() doesn't account for
> the reserved bits currently, causing the wrong SBDF to be used.
> Fix said calculation to properly shift the SBDF.
> 
> Without this fix, error injection into CXL 2.0 root ports through the
> CXL debugfs interface (<debugfs>/cxl) is broken. Injection
> through the legacy interface (<debugfs>/apei/einj/) will still work
> because the SBDF is manually provided by the user.
> 
> Fixes: 12fb28ea6b1cf ("EINJ: Add CXL error type support")
> Signed-off-by: Ben Cheatham <Benjamin.Cheatham@amd.com>

Looks good to me.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Srinivasulu Opensrc Sept. 29, 2024, 3:22 a.m. UTC | #2
Micron Confidential



Micron Confidential
>-----Original Message-----
>From: Ben Cheatham <Benjamin.Cheatham@amd.com>
>Sent: Friday, September 27, 2024 10:04 PM
>To: rafael@kernel.org; lenb@kernel.org; james.morse@arm.com;
>tony.luck@intel.com; bp@alien8.de
>Cc: linux-acpi@vger.kernel.org; linux-cxl@vger.kernel.org;
>dan.j.williams@intel.com; jonathan.cameron@huawei.com; Srinivasulu Thanneeru
><sthanneeru@micron.com>; Ben Cheatham <Benjamin.Cheatham@amd.com>
>Subject: [EXT] [RESEND][PATCH] EINJ, CXL: Fix CXL device SBDF calculation
>
>CAUTION: EXTERNAL EMAIL. Do not click links or open attachments unless you
>recognize the sender and were expecting this message.
>
>
>The SBDF of the target CXL 2.0 compliant root port is required to inject a CXL
>protocol error as per ACPI 6.5. The SBDF given has to be in the
>following format:
>
>31     24 23    16 15    11 10      8  7        0
>+-------------------------------------------------+
>| segment |   bus  | device | function | reserved |
>+-------------------------------------------------+
>
>The SBDF calculated in cxl_dport_get_sbdf() doesn't account for
>the reserved bits currently, causing the wrong SBDF to be used.
>Fix said calculation to properly shift the SBDF.
>
>Without this fix, error injection into CXL 2.0 root ports through the
>CXL debugfs interface (<debugfs>/cxl) is broken. Injection
>through the legacy interface (<debugfs>/apei/einj/) will still work
>because the SBDF is manually provided by the user.
>
>Fixes: 12fb28ea6b1cf ("EINJ: Add CXL error type support")
>Signed-off-by: Ben Cheatham <Benjamin.Cheatham@amd.com>

Tried this patch, working fine.

Tested-by: Srinivasulu Thanneeru <sthanneeru.opensrc@micron.com>
Reviewed-by: Srinivasulu Thanneeru <sthanneeru.opensrc@micron.com>

>---
>
>Resent to add linux-cxl list and Srinivasulu to CC
>
>---
> drivers/acpi/apei/einj-cxl.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/drivers/acpi/apei/einj-cxl.c b/drivers/acpi/apei/einj-cxl.c
>index 8b8be0c90709..d64e2713aae4 100644
>--- a/drivers/acpi/apei/einj-cxl.c
>+++ b/drivers/acpi/apei/einj-cxl.c
>@@ -63,7 +63,7 @@ static int cxl_dport_get_sbdf(struct pci_dev *dport_dev, u64
>*sbdf)
>                seg = bridge->domain_nr;
>
>        bus = pbus->number;
>-       *sbdf = (seg << 24) | (bus << 16) | dport_dev->devfn;
>+       *sbdf = (seg << 24) | (bus << 16) | (dport_dev->devfn << 8);
>
>        return 0;
> }
>--
>2.34.1
>
diff mbox series

Patch

diff --git a/drivers/acpi/apei/einj-cxl.c b/drivers/acpi/apei/einj-cxl.c
index 8b8be0c90709..d64e2713aae4 100644
--- a/drivers/acpi/apei/einj-cxl.c
+++ b/drivers/acpi/apei/einj-cxl.c
@@ -63,7 +63,7 @@  static int cxl_dport_get_sbdf(struct pci_dev *dport_dev, u64 *sbdf)
 		seg = bridge->domain_nr;
 
 	bus = pbus->number;
-	*sbdf = (seg << 24) | (bus << 16) | dport_dev->devfn;
+	*sbdf = (seg << 24) | (bus << 16) | (dport_dev->devfn << 8);
 
 	return 0;
 }