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path: root/drivers/pci/access.c
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Diffstat (limited to 'drivers/pci/access.c')
-rw-r--r--drivers/pci/access.c202
1 files changed, 202 insertions, 0 deletions
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index ba91a7e17519..3af0478c057b 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -469,3 +469,205 @@ void pci_cfg_access_unlock(struct pci_dev *dev)
raw_spin_unlock_irqrestore(&pci_lock, flags);
}
EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);
+
+static inline int pcie_cap_version(const struct pci_dev *dev)
+{
+ return dev->pcie_flags_reg & PCI_EXP_FLAGS_VERS;
+}
+
+static inline bool pcie_cap_has_devctl(const struct pci_dev *dev)
+{
+ return true;
+}
+
+static inline bool pcie_cap_has_lnkctl(const struct pci_dev *dev)
+{
+ int type = pci_pcie_type(dev);
+
+ return pcie_cap_version(dev) > 1 ||
+ type == PCI_EXP_TYPE_ROOT_PORT ||
+ type == PCI_EXP_TYPE_ENDPOINT ||
+ type == PCI_EXP_TYPE_LEG_END;
+}
+
+static inline bool pcie_cap_has_sltctl(const struct pci_dev *dev)
+{
+ int type = pci_pcie_type(dev);
+
+ return pcie_cap_version(dev) > 1 ||
+ type == PCI_EXP_TYPE_ROOT_PORT ||
+ (type == PCI_EXP_TYPE_DOWNSTREAM &&
+ dev->pcie_flags_reg & PCI_EXP_FLAGS_SLOT);
+}
+
+static inline bool pcie_cap_has_rtctl(const struct pci_dev *dev)
+{
+ int type = pci_pcie_type(dev);
+
+ return pcie_cap_version(dev) > 1 ||
+ type == PCI_EXP_TYPE_ROOT_PORT ||
+ type == PCI_EXP_TYPE_RC_EC;
+}
+
+static bool pcie_capability_reg_implemented(struct pci_dev *dev, int pos)
+{
+ if (!pci_is_pcie(dev))
+ return false;
+
+ switch (pos) {
+ case PCI_EXP_FLAGS_TYPE:
+ return true;
+ case PCI_EXP_DEVCAP:
+ case PCI_EXP_DEVCTL:
+ case PCI_EXP_DEVSTA:
+ return pcie_cap_has_devctl(dev);
+ case PCI_EXP_LNKCAP:
+ case PCI_EXP_LNKCTL:
+ case PCI_EXP_LNKSTA:
+ return pcie_cap_has_lnkctl(dev);
+ case PCI_EXP_SLTCAP:
+ case PCI_EXP_SLTCTL:
+ case PCI_EXP_SLTSTA:
+ return pcie_cap_has_sltctl(dev);
+ case PCI_EXP_RTCTL:
+ case PCI_EXP_RTCAP:
+ case PCI_EXP_RTSTA:
+ return pcie_cap_has_rtctl(dev);
+ case PCI_EXP_DEVCAP2:
+ case PCI_EXP_DEVCTL2:
+ case PCI_EXP_LNKCAP2:
+ case PCI_EXP_LNKCTL2:
+ case PCI_EXP_LNKSTA2:
+ return pcie_cap_version(dev) > 1;
+ default:
+ return false;
+ }
+}
+
+/*
+ * Note that these accessor functions are only for the "PCI Express
+ * Capability" (see PCIe spec r3.0, sec 7.8). They do not apply to the
+ * other "PCI Express Extended Capabilities" (AER, VC, ACS, MFVC, etc.)
+ */
+int pcie_capability_read_word(struct pci_dev *dev, int pos, u16 *val)
+{
+ int ret;
+
+ *val = 0;
+ if (pos & 1)
+ return -EINVAL;
+
+ if (pcie_capability_reg_implemented(dev, pos)) {
+ ret = pci_read_config_word(dev, pci_pcie_cap(dev) + pos, val);
+ /*
+ * Reset *val to 0 if pci_read_config_word() fails, it may
+ * have been written as 0xFFFF if hardware error happens
+ * during pci_read_config_word().
+ */
+ if (ret)
+ *val = 0;
+ return ret;
+ }
+
+ /*
+ * For Functions that do not implement the Slot Capabilities,
+ * Slot Status, and Slot Control registers, these spaces must
+ * be hardwired to 0b, with the exception of the Presence Detect
+ * State bit in the Slot Status register of Downstream Ports,
+ * which must be hardwired to 1b. (PCIe Base Spec 3.0, sec 7.8)
+ */
+ if (pci_is_pcie(dev) && pos == PCI_EXP_SLTSTA &&
+ pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM) {
+ *val = PCI_EXP_SLTSTA_PDS;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(pcie_capability_read_word);
+
+int pcie_capability_read_dword(struct pci_dev *dev, int pos, u32 *val)
+{
+ int ret;
+
+ *val = 0;
+ if (pos & 3)
+ return -EINVAL;
+
+ if (pcie_capability_reg_implemented(dev, pos)) {
+ ret = pci_read_config_dword(dev, pci_pcie_cap(dev) + pos, val);
+ /*
+ * Reset *val to 0 if pci_read_config_dword() fails, it may
+ * have been written as 0xFFFFFFFF if hardware error happens
+ * during pci_read_config_dword().
+ */
+ if (ret)
+ *val = 0;
+ return ret;
+ }
+
+ if (pci_is_pcie(dev) && pos == PCI_EXP_SLTCTL &&
+ pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM) {
+ *val = PCI_EXP_SLTSTA_PDS;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(pcie_capability_read_dword);
+
+int pcie_capability_write_word(struct pci_dev *dev, int pos, u16 val)
+{
+ if (pos & 1)
+ return -EINVAL;
+
+ if (!pcie_capability_reg_implemented(dev, pos))
+ return 0;
+
+ return pci_write_config_word(dev, pci_pcie_cap(dev) + pos, val);
+}
+EXPORT_SYMBOL(pcie_capability_write_word);
+
+int pcie_capability_write_dword(struct pci_dev *dev, int pos, u32 val)
+{
+ if (pos & 3)
+ return -EINVAL;
+
+ if (!pcie_capability_reg_implemented(dev, pos))
+ return 0;
+
+ return pci_write_config_dword(dev, pci_pcie_cap(dev) + pos, val);
+}
+EXPORT_SYMBOL(pcie_capability_write_dword);
+
+int pcie_capability_clear_and_set_word(struct pci_dev *dev, int pos,
+ u16 clear, u16 set)
+{
+ int ret;
+ u16 val;
+
+ ret = pcie_capability_read_word(dev, pos, &val);
+ if (!ret) {
+ val &= ~clear;
+ val |= set;
+ ret = pcie_capability_write_word(dev, pos, val);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(pcie_capability_clear_and_set_word);
+
+int pcie_capability_clear_and_set_dword(struct pci_dev *dev, int pos,
+ u32 clear, u32 set)
+{
+ int ret;
+ u32 val;
+
+ ret = pcie_capability_read_dword(dev, pos, &val);
+ if (!ret) {
+ val &= ~clear;
+ val |= set;
+ ret = pcie_capability_write_dword(dev, pos, val);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(pcie_capability_clear_and_set_dword);