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Message-Id: <20230411213323.1362300-1-david.e.box@linux.intel.com>
Date: Tue, 11 Apr 2023 14:33:23 -0700
From: "David E. Box" <david.e.box@...ux.intel.com>
To: david.e.box@...ux.intel.com, ville.syrjala@...ux.intel.com,
nirmal.patel@...ux.intel.com, jonathan.derrick@...ux.dev,
lorenzo.pieralisi@....com, hch@...radead.org, kw@...ux.com,
robh@...nel.org, bhelgaas@...gle.com, michael.a.bottini@...el.com,
rafael@...nel.org
Cc: me@...ityamohan.in, linux-pci@...r.kernel.org,
linux-kernel@...r.kernel.org, intel-gfx@...ts.freedesktop.org
Subject: [PATCH V2] PCI: Move VMD ASPM/LTR fix to PCI quirk
In commit f492edb40b54 ("PCI: vmd: Add quirk to configure PCIe ASPM and
LTR") the VMD driver calls pci_enabled_link_state as a callback from
pci_bus_walk. Both will acquire the pci_bus_sem lock leading to a lockdep
warning. Instead of doing the pci_bus_walk, move the fix to quirks.c using
DECLARE_PCI_FIXUP_FINAL.
Fixes: f492edb40b54 ("PCI: vmd: Add quirk to configure PCIe ASPM and LTR")
Suggested-by: Bjorn Helgaas <bhelgaas@...gle.com>
Signed-off-by: David E. Box <david.e.box@...ux.intel.com>
---
V2 - Instead of adding a lock flag argument to pci_enabled_link_state, move
the fix to quirks.c
drivers/pci/controller/vmd.c | 55 +--------------------------
drivers/pci/quirks.c | 72 ++++++++++++++++++++++++++++++++++++
2 files changed, 73 insertions(+), 54 deletions(-)
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 990630ec57c6..47fa3e5f2dc5 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -66,22 +66,11 @@ enum vmd_features {
* interrupt handling.
*/
VMD_FEAT_CAN_BYPASS_MSI_REMAP = (1 << 4),
-
- /*
- * Enable ASPM on the PCIE root ports and set the default LTR of the
- * storage devices on platforms where these values are not configured by
- * BIOS. This is needed for laptops, which require these settings for
- * proper power management of the SoC.
- */
- VMD_FEAT_BIOS_PM_QUIRK = (1 << 5),
};
-#define VMD_BIOS_PM_QUIRK_LTR 0x1003 /* 3145728 ns */
-
#define VMD_FEATS_CLIENT (VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP | \
VMD_FEAT_HAS_BUS_RESTRICTIONS | \
- VMD_FEAT_OFFSET_FIRST_VECTOR | \
- VMD_FEAT_BIOS_PM_QUIRK)
+ VMD_FEAT_OFFSET_FIRST_VECTOR)
static DEFINE_IDA(vmd_instance_ida);
@@ -724,46 +713,6 @@ static void vmd_copy_host_bridge_flags(struct pci_host_bridge *root_bridge,
vmd_bridge->native_dpc = root_bridge->native_dpc;
}
-/*
- * Enable ASPM and LTR settings on devices that aren't configured by BIOS.
- */
-static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata)
-{
- unsigned long features = *(unsigned long *)userdata;
- u16 ltr = VMD_BIOS_PM_QUIRK_LTR;
- u32 ltr_reg;
- int pos;
-
- if (!(features & VMD_FEAT_BIOS_PM_QUIRK))
- return 0;
-
- pci_enable_link_state(pdev, PCIE_LINK_STATE_ALL);
-
- pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR);
- if (!pos)
- return 0;
-
- /*
- * Skip if the max snoop LTR is non-zero, indicating BIOS has set it
- * so the LTR quirk is not needed.
- */
- pci_read_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, <r_reg);
- if (!!(ltr_reg & (PCI_LTR_VALUE_MASK | PCI_LTR_SCALE_MASK)))
- return 0;
-
- /*
- * Set the default values to the maximum required by the platform to
- * allow the deepest power management savings. Write as a DWORD where
- * the lower word is the max snoop latency and the upper word is the
- * max non-snoop latency.
- */
- ltr_reg = (ltr << 16) | ltr;
- pci_write_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, ltr_reg);
- pci_info(pdev, "VMD: Default LTR value set by driver\n");
-
- return 0;
-}
-
static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
{
struct pci_sysdata *sd = &vmd->sysdata;
@@ -936,8 +885,6 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
pci_assign_unassigned_bus_resources(vmd->bus);
- pci_walk_bus(vmd->bus, vmd_pm_enable_quirk, &features);
-
/*
* VMD root buses are virtual and don't return true on pci_is_pcie()
* and will fail pcie_bus_configure_settings() early. It can instead be
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 44cab813bf95..2d86623f96e3 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -6023,3 +6023,75 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a2d, dpc_log_size);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a2f, dpc_log_size);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a31, dpc_log_size);
#endif
+
+#ifdef CONFIG_VMD
+/*
+ * Enable ASPM on the PCIE root ports under VMD and set the default LTR of the
+ * storage devices on platforms where these values are not configured by BIOS.
+ * This is needed for laptops, which require these settings for proper power
+ * management of the SoC.
+ */
+#define VMD_DEVICE_LTR 0x1003 /* 3145728 ns */
+static void quirk_intel_vmd(struct pci_dev *pdev)
+{
+ struct pci_dev *parent;
+ u16 ltr = VMD_DEVICE_LTR;
+ u32 ltr_reg;
+ int pos;
+
+ /* Check in VMD domain */
+ if (pci_domain_nr(pdev->bus) < 0x10000)
+ return;
+
+ /* Get Root Port */
+ parent = pci_upstream_bridge(pdev);
+ if (!parent || parent->vendor != PCI_VENDOR_ID_INTEL)
+ return;
+
+ /* Get VMD Host Bridge */
+ parent = to_pci_dev(parent->dev.parent);
+ if (!parent)
+ return;
+
+ /* Get RAID controller */
+ parent = to_pci_dev(parent->dev.parent);
+ if (!parent)
+ return;
+
+ switch (parent->device) {
+ case 0x467f:
+ case 0x4c3d:
+ case 0xa77f:
+ case 0x7d0b:
+ case 0xad0b:
+ case 0x9a0b:
+ break;
+ default:
+ return;
+ }
+
+ pci_enable_link_state(pdev, PCIE_LINK_STATE_ALL);
+
+ pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR);
+ if (!pos)
+ return;
+
+ /* Skip if the max snoop LTR is non-zero, indicating BIOS has set it */
+ pci_read_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, <r_reg);
+ if (!!(ltr_reg & (PCI_LTR_VALUE_MASK | PCI_LTR_SCALE_MASK)))
+ return;
+
+ /*
+ * Set the LTR values to the maximum required by the platform to
+ * allow the deepest power management savings. Write as a DWORD where
+ * the lower word is the max snoop latency and the upper word is the
+ * max non-snoop latency.
+ */
+ ltr_reg = (ltr << 16) | ltr;
+ pci_write_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, ltr_reg);
+ pci_info(pdev, "LTR set by VMD PCI quick\n");
+
+}
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_ANY_ID, PCI_ANY_ID,
+ PCI_CLASS_STORAGE_EXPRESS, 0, quirk_intel_vmd);
+#endif
--
2.34.1
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