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From:   Xiaochun Lee <lixiaochun.2888@163.com>
To:     bhelgaas@google.com, linux-pci@vger.kernel.org
Cc:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org,
        hpa@zytor.com, linux-kernel@vger.kernel.org,
        Xiaochun Lee <lixc17@lenovo.com>
Subject: [PATCH] x86/PCI: Mark Ice Lake Power Control Unit as having non-compliant BARs
Date:   Thu, 14 May 2020 23:31:07 -0400
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From: Xiaochun Lee <lixc17@lenovo.com>

The device [8086:a26c] have the same PCI BARs problem as
the device [8086:2fc0], it is a  Power Control Unit of
Intel Ice Lake Server Processor, kernel treats the
"Power Control Unit's CONFIG_TDP_NOMINAL CSR" as a base
address register leading to a boot failure like
"pci 0000:00:11.0: [Firmware Bug]: reg 0x30: invalid BAR (can't size)".

The information of the device list as below:
00:11.0 Unassigned class [ff00]: Intel Corporation Device a26c (rev 03)
        Subsystem: Lenovo Device 7811
        Flags: fast devsel, NUMA node 0
        Expansion ROM at <ignored> [disabled]
        Capabilities: [80] Power Management version 3

There are no other BARs on this device, so mark the PCU as having
non-compliant BARs, therefore we don't try to probe any of them.

Signed-off-by: Xiaochun Lee <lixc17@lenovo.com>
---
 arch/x86/pci/fixup.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index e723559..d1170c8 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -563,6 +563,8 @@ static void twinhead_reserve_killing_zone(struct pci_dev *dev)
  * Erratum BDF2
  * PCI BARs in the Home Agent Will Return Non-Zero Values During Enumeration
  * http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-v4-spec-update.html
+ *
+ * Device [8086:a26c]
  */
 static void pci_invalid_bar(struct pci_dev *dev)
 {
@@ -572,6 +574,7 @@ static void pci_invalid_bar(struct pci_dev *dev)
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6f60, pci_invalid_bar);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fa0, pci_invalid_bar);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, pci_invalid_bar);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0xa26c, pci_invalid_bar);
 
 /*
  * Device [1022:7808]
-- 
1.8.3.1