From: Jiang Liu <jiang....@huawei.com>
Introduce four configuration access functions for PCIe capabilities to
hide difference among PCIe Base Spec versions. With these functions,
we can remove callers responsible for using pci_pcie_cap_has_*().
pci_pcie_cap_read_word/dword() functions will store the pcie cap register
value by passed parameter val,if related pcie cap register is not implemented
on the pcie device, the passed parameter val will be set 0 and return -EINVAL.
pci_pcie_capability_write_word/dowrd() functions will write the value to pcie
cap registers,if related pcie cap register is not implemented on the pcie
device, it will return -EINVAL.
Signed-off-by: Jiang Liu <liu...@gmail.com>
Signed-off-by: Yijing Wang <wangyij...@huawei.com>
---
drivers/pci/access.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++
include/linux/pci.h | 10 ++++++
include/linux/pci_regs.h | 19 ++++++++--
3 files changed, 115 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index ba91a7e..80ae022 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -469,3 +469,91 @@ void pci_cfg_access_unlock(struct pci_dev *dev)
raw_spin_unlock_irqrestore(&pci_lock, flags);
}
EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);
+
+static int
+pci_pcie_cap_get_offset(struct pci_dev *dev, int where, size_t sz)
+{
+ bool valid;
+
+ if (!pci_is_pcie(dev))
+ return -EINVAL;
+ if (where & (sz - 1))
+ return -EINVAL;
+
+ if (where < 0)
+ valid = false;
+ else if (where < PCI_EXP_DEVCAP)
+ valid = true;
+ else if (where < PCI_EXP_LNKCAP)
+ valid = pci_pcie_cap_has_devctl(dev);
+ else if (where < PCI_EXP_SLTCAP)
+ valid = pci_pcie_cap_has_lnkctl(dev);
+ else if (where < PCI_EXP_RTCTL)
+ valid = pci_pcie_cap_has_sltctl(dev);
+ else if (where < PCI_EXP_DEVCAP2)
+ valid = pci_pcie_cap_has_rtctl(dev);
+ else if (where < PCI_EXP_CAP2_SIZE)
+ valid = pci_pcie_cap_has_cap2(dev);
+ else
+ valid = false;
+
+ return valid ? where + pci_pcie_cap(dev) : -EINVAL;
+}
+
+int pci_pcie_cap_read_word(struct pci_dev *dev, int where, u16 *valp)
+{
+ *valp = 0;
+ where = pci_pcie_cap_get_offset(dev, where, sizeof(u16));
+ if (where >= 0)
+ return pci_read_config_word(dev, where, valp);
+
+ if (pci_is_pcie(dev) && where == PCI_EXP_SLTSTA &&
+ pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM)
+ *valp = PCI_EXP_SLTSTA_PDS;
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(pci_pcie_cap_read_word);
+
+int pci_pcie_cap_read_dword(struct pci_dev *dev, int where, u32 *valp)
+{
+ *valp = 0;
+ where = pci_pcie_cap_get_offset(dev, where, sizeof(u32));
+ if (where >= 0)
+ return pci_read_config_dword(dev, where, valp);
+
+ /*
+ * Quotation from PCIe Base Spec 3.0:
+ * 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.
+ */
+ if (pci_is_pcie(dev) && where == PCI_EXP_SLTCTL &&
+ pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM)
+ *valp = PCI_EXP_SLTSTA_PDS << 16;
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(pci_pcie_cap_read_dword);
+
+int pci_pcie_cap_write_word(struct pci_dev *dev, int where, u16 val)
+{
+ where = pci_pcie_cap_get_offset(dev, where, sizeof(u16));
+ if (where >= 0)
+ return pci_write_config_word(dev, where, val);
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(pci_pcie_cap_write_word);
+
+int pci_pcie_cap_write_dword(struct pci_dev *dev, int where, u32 val)
+{
+ where = pci_pcie_cap_get_offset(dev, where, sizeof(u32));
+ if (where >= 0)
+ return pci_write_config_dword(dev, where, val);
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(pci_pcie_cap_write_dword);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 346b2d9..78767b2 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1703,6 +1703,11 @@ static inline bool pci_pcie_cap_has_rtctl(const struct
pci_dev *pdev)
type == PCI_EXP_TYPE_RC_EC;
}
+extern int pci_pcie_cap_read_word(struct pci_dev *dev, int where, u16 *valp);
+extern int pci_pcie_cap_read_dword(struct pci_dev *dev, int where, u32 *valp);
+extern int pci_pcie_cap_write_word(struct pci_dev *dev, int where, u16 val);
+extern int pci_pcie_cap_write_dword(struct pci_dev *dev, int where, u32 val);
+
void pci_request_acs(void);
bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags);
bool pci_acs_path_enabled(struct pci_dev *start,
@@ -1843,5 +1848,10 @@ static inline struct eeh_dev *pci_dev_to_eeh_dev(struct
pci_dev *pdev)
*/
struct pci_dev *pci_find_upstream_pcie_bridge(struct pci_dev *pdev);
+int pci_pcie_capability_read_word(struct pci_dev *dev, int where, u16 *val);
+int pci_pcie_capability_read_dword(struct pci_dev *dev, int where, u32 *val);
+int pci_pcie_capability_write_word(struct pci_dev *dev, int where, u16 val);
+int pci_pcie_capability_write_dword(struct pci_dev *dev, int where, u32 val);
+
#endif /* __KERNEL__ */
#endif /* LINUX_PCI_H */
diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h
index 53274bf..ac60e22 100644
--- a/include/linux/pci_regs.h
+++ b/include/linux/pci_regs.h
@@ -542,9 +542,24 @@
#define PCI_EXP_OBFF_MSGA_EN 0x2000 /* OBFF enable with Message type A */
#define PCI_EXP_OBFF_MSGB_EN 0x4000 /* OBFF enable with Message type B */
#define PCI_EXP_OBFF_WAKE_EN 0x6000 /* OBFF using WAKE# signaling */
-#define PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 44 /* v2 endpoints end here */
+#define PCI_EXP_DEVSTA2 42 /* Device Status 2 */
+#define PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 44 /* v2 endpoints end here */
+#define PCI_EXP_LNKCAP2 44 /* Link Capabilities 2 */
#define PCI_EXP_LNKCTL2 48 /* Link Control 2 */
-#define PCI_EXP_SLTCTL2 56 /* Slot Control 2 */
+#define PCI_EXP_LNKCTL2_TLS 0x0f /* Target Link Speed */
+#define PCI_EXP_LNKCTL2_EC 0x10 /* Enter Compliance */
+#define PCI_EXP_LNKCTL2_HASD 0x20 /* Hardware Autonomous Speed Disable */
+#define PCI_EXP_LNKCTL2_SD 0x40 /* Selectable De-emphasis */
+#define PCI_EXP_LNKCTL2_TM 0x380 /* Transmit Margin */
+#define PCI_EXP_LNKCTL2_EMC 0x400 /* Enter Modified Compliance */
+#define PCI_EXP_LNKCTL2_CS 0x800 /* Compliance SOS */
+#define PCI_EXP_LNKCTL2_CD 0x1000 /* Compliance De-emphasis */
+#define PCI_EXP_LNKSTA2 50 /* Link Status 2 */
+#define PCI_EXP_LNKSTA2_CDL 0x01 /* Current De-emphasis Level */
+#define PCI_EXP_SLTCAP2 52 /* Slot Capabilities 2 */
+#define PCI_EXP_SLTCTL2 56 /* Slot Control 2*/
+#define PCI_EXP_SLTSTA2 58 /* Slot Status 2*/
+#define PCI_EXP_CAP2_SIZE 60
/* Extended Capabilities (PCI-X 2.0 and Express) */
#define PCI_EXT_CAP_ID(header) (header & 0x0000ffff)
--
1.7.9.5
--
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