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EINJ, CXL: Fix CXL device SBDF calculation

Message ID 20240828160403.65771-1-Benjamin.Cheatham@amd.com
State New
Headers show
Series EINJ, CXL: Fix CXL device SBDF calculation | expand

Commit Message

Ben Cheatham Aug. 28, 2024, 4:04 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>
---
 drivers/acpi/apei/einj-cxl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
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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;
 }