Add pcie_tph_enabled_req_type() so drivers can query the enabled TPH
requester mode without reaching into pci_dev internals.
Add pcie_tph_completer_type() so drivers that publish TPH metadata for
a device acting as a completer can gate on the "TPH Completer
Supported" field of Device Capabilities 2 (bits 13:12,
PCI_EXP_DEVCAP2_TPH_COMP_MASK) rather than reusing requester-side
state. Fold the reserved 0b10 encoding into NONE so callers only see
the defined values.
This keeps pci_dev::tph_req_type and the completer-capability decode
inside the PCI/TPH code and provides !CONFIG_PCIE_TPH stubs for
callers.
Signed-off-by: Zhiping Zhang <redacted>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/tph.c | 43 +++++++++++++++++++++++++++++++++++++++++
include/linux/pci-tph.h | 8 ++++++++
2 files changed, 51 insertions(+)
diff --git a/drivers/pci/tph.c b/drivers/pci/tph.c
index 91145e8d9d95..4fe076bba953 100644
--- a/drivers/pci/tph.c
+++ b/drivers/pci/tph.c
@@ -174,6 +174,49 @@ u32 pcie_tph_get_st_table_loc(struct pci_dev *pdev)
}
EXPORT_SYMBOL(pcie_tph_get_st_table_loc);
+/**
+ * pcie_tph_enabled_req_type - Return the device's enabled TPH requester type
+ * @pdev: PCI device to query
+ *
+ * Return: PCI_TPH_REQ_DISABLE, PCI_TPH_REQ_TPH_ONLY or PCI_TPH_REQ_EXT_TPH.
+ */
+u8 pcie_tph_enabled_req_type(struct pci_dev *pdev)
+{
+ return pdev->tph_req_type;
+}
+EXPORT_SYMBOL(pcie_tph_enabled_req_type);
+
+/**
+ * pcie_tph_completer_type - Return the device's TPH Completer support
+ * @pdev: PCI device to query
+ *
+ * Reads the "TPH Completer Supported" field (bits 13:12) of Device
+ * Capabilities 2. The reserved 0b10 encoding is folded into
+ * "not supported" so callers only need to compare against the three
+ * defined values.
+ *
+ * Return: one of %PCI_EXP_DEVCAP2_TPH_COMP_NONE,
+ * %PCI_EXP_DEVCAP2_TPH_COMP_TPH_ONLY or
+ * %PCI_EXP_DEVCAP2_TPH_COMP_EXT_TPH.
+ */
+u8 pcie_tph_completer_type(struct pci_dev *pdev)
+{
+ u32 reg;
+
+ if (pcie_capability_read_dword(pdev, PCI_EXP_DEVCAP2, ®))
+ return PCI_EXP_DEVCAP2_TPH_COMP_NONE;
+
+ switch (FIELD_GET(PCI_EXP_DEVCAP2_TPH_COMP_MASK, reg)) {
+ case PCI_EXP_DEVCAP2_TPH_COMP_TPH_ONLY:
+ return PCI_EXP_DEVCAP2_TPH_COMP_TPH_ONLY;
+ case PCI_EXP_DEVCAP2_TPH_COMP_EXT_TPH:
+ return PCI_EXP_DEVCAP2_TPH_COMP_EXT_TPH;
+ default:
+ return PCI_EXP_DEVCAP2_TPH_COMP_NONE;
+ }
+}
+EXPORT_SYMBOL(pcie_tph_completer_type);
+
/*
* Return the size of ST table. If ST table is not in TPH Requester Extended
* Capability space, return 0. Otherwise return the ST Table Size + 1.diff --git a/include/linux/pci-tph.h b/include/linux/pci-tph.h
index be68cd17f2f8..7743af6fe432 100644
--- a/include/linux/pci-tph.h
+++ b/include/linux/pci-tph.h
@@ -9,6 +9,8 @@
#ifndef LINUX_PCI_TPH_H
#define LINUX_PCI_TPH_H
+#include <linux/pci_regs.h>
+
/*
* According to the ECN for PCI Firmware Spec, Steering Tag can be different
* depending on the memory type: Volatile Memory or Persistent Memory. When a
@@ -30,6 +32,8 @@ void pcie_disable_tph(struct pci_dev *pdev);
int pcie_enable_tph(struct pci_dev *pdev, int mode);
u16 pcie_tph_get_st_table_size(struct pci_dev *pdev);
u32 pcie_tph_get_st_table_loc(struct pci_dev *pdev);
+u8 pcie_tph_enabled_req_type(struct pci_dev *pdev);
+u8 pcie_tph_completer_type(struct pci_dev *pdev);
#else
static inline int pcie_tph_set_st_entry(struct pci_dev *pdev,
unsigned int index, u16 tag)
@@ -41,6 +45,10 @@ static inline int pcie_tph_get_cpu_st(struct pci_dev *dev,
static inline void pcie_disable_tph(struct pci_dev *pdev) { }
static inline int pcie_enable_tph(struct pci_dev *pdev, int mode)
{ return -EINVAL; }
+static inline u8 pcie_tph_enabled_req_type(struct pci_dev *pdev)
+{ return PCI_TPH_REQ_DISABLE; }
+static inline u8 pcie_tph_completer_type(struct pci_dev *pdev)
+{ return PCI_EXP_DEVCAP2_TPH_COMP_NONE; }
#endif
#endif /* LINUX_PCI_TPH_H */--
2.53.0-Meta