[PATCHv2 2/2] x86/vmd: Add PCI domain specific LED option

[Keith Busch <keith.busch@intel.com>]

This patch adds a new function to set PCI domain specific options as
devices are added. The usage included in this patch is for LED indicator
control in VMD domains, but may be extended in the future as new domain
specific options are required.

PCIe LED Slot Control in a VMD domain is repurposed to a non-standard
implementation. As such, all devices in a VMD domain will be flagged so
that pciehp does not attempt to use LED indicators. This user_led flag
has pciehp provide a different sysfs entry for user exclusive control
over the domain's slot indicators.

In order to determine if a bus is within a PCI domain, the patch appends
a bool to the pci_sysdata structure that the VMD driver sets during
initialization.

Requested-by: Kapil Karkra <kapil.karkra@intel.com>
Tested-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
---
 arch/x86/include/asm/pci.h | 14 ++++++++++++++
 arch/x86/pci/common.c      |  7 +++++++
 arch/x86/pci/vmd.c         |  1 +
 3 files changed, 22 insertions(+)

diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
index 9ab7507..1411dbe 100644
--- a/arch/x86/include/asm/pci.h
+++ b/arch/x86/include/asm/pci.h
@@ -23,6 +23,9 @@ struct pci_sysdata {
 #ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
 	void		*fwnode;	/* IRQ domain for MSI assignment */
 #endif
+#if IS_ENABLED(CONFIG_VMD)
+	bool vmd_domain;		/* True if in Intel VMD domain */
+#endif
 };
 
 extern int pci_routeirq;
@@ -56,6 +59,17 @@ static inline void *_pci_root_bus_fwnode(struct pci_bus *bus)
 #define pci_root_bus_fwnode	_pci_root_bus_fwnode
 #endif
 
+static inline bool is_vmd(struct pci_bus *bus)
+{
+#if IS_ENABLED(CONFIG_VMD)
+	struct pci_sysdata *sd = bus->sysdata;
+
+	return sd->vmd_domain;
+#else
+	return false;
+#endif
+}
+
 /* Can be used to override the logic in pci_scan_bus for skipping
    already-configured bus numbers - to be used for buggy BIOSes
    or architectures with incomplete PCI setup by the loader */
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 7b6a9d1..ccf696c 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -677,6 +677,12 @@ static void set_dma_domain_ops(struct pci_dev *pdev)
 static void set_dma_domain_ops(struct pci_dev *pdev) {}
 #endif
 
+static void set_dev_domain_options(struct pci_dev *pdev)
+{
+	if (is_vmd(pdev->bus))
+		pdev->user_leds = 1;
+}
+
 int pcibios_add_device(struct pci_dev *dev)
 {
 	struct setup_data *data;
@@ -707,6 +713,7 @@ int pcibios_add_device(struct pci_dev *dev)
 		iounmap(data);
 	}
 	set_dma_domain_ops(dev);
+	set_dev_domain_options(dev);
 	return 0;
 }
 
diff --git a/arch/x86/pci/vmd.c b/arch/x86/pci/vmd.c
index b73da50..3014f8e 100644
--- a/arch/x86/pci/vmd.c
+++ b/arch/x86/pci/vmd.c
@@ -604,6 +604,7 @@ static int vmd_enable_domain(struct vmd_dev *vmd)
 		.parent = res,
 	};
 
+	sd->vmd_domain = true;
 	sd->domain = vmd_find_free_domain();
 	if (sd->domain < 0)
 		return sd->domain;
-- 
2.7.2