[PATCH V4 03/12] PCI/TPH: Add pcie_tph_modes() to query TPH modes
From: Wei Huang <hidden>
Date: 2024-08-22 20:42:05
Also in:
linux-doc, linux-pci, lkml
Subsystem:
pci subsystem, the rest · Maintainers:
Bjorn Helgaas, Linus Torvalds
Add pcie_tph_modes() to allow drivers to query the TPH modes supported by an endpoint device, as reported in the TPH Requester Capability register. The modes are reported as a bitmask and current supported modes include: - PCI_TPH_CAP_NO_ST: NO ST Mode Supported - PCI_TPH_CAP_INT_VEC: Interrupt Vector Mode Supported - PCI_TPH_CAP_DEV_SPEC: Device Specific Mode Supported Co-developed-by: Eric Van Tassell <redacted> Signed-off-by: Eric Van Tassell <redacted> Signed-off-by: Wei Huang <redacted> Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com> Reviewed-by: Somnath Kotur <redacted> Reviewed-by: Andy Gospodarek <redacted> --- drivers/pci/pcie/tph.c | 33 +++++++++++++++++++++++++++++++++ include/linux/pci-tph.h | 18 ++++++++++++++++++ 2 files changed, 51 insertions(+) create mode 100644 include/linux/pci-tph.h
diff --git a/drivers/pci/pcie/tph.c b/drivers/pci/pcie/tph.c
index a547858c3f68..a28dced3097d 100644
--- a/drivers/pci/pcie/tph.c
+++ b/drivers/pci/pcie/tph.c@@ -6,9 +6,42 @@ * Eric Van Tassell <Eric.VanTassell@amd.com> * Wei Huang <wei.huang2@amd.com> */ +#include <linux/pci.h> +#include <linux/pci-tph.h> #include "../pci.h" +static u8 get_st_modes(struct pci_dev *pdev) +{ + u32 reg; + + pci_read_config_dword(pdev, pdev->tph_cap + PCI_TPH_CAP, ®); + reg &= PCI_TPH_CAP_NO_ST | PCI_TPH_CAP_INT_VEC | PCI_TPH_CAP_DEV_SPEC; + + return reg; +} + +/** + * pcie_tph_modes - Get the ST modes supported by device + * @pdev: PCI device + * + * Returns a bitmask with all TPH modes supported by a device as shown in the + * TPH capability register. Current supported modes include: + * PCI_TPH_CAP_NO_ST - NO ST Mode Supported + * PCI_TPH_CAP_INT_VEC - Interrupt Vector Mode Supported + * PCI_TPH_CAP_DEV_SPEC - Device Specific Mode Supported + * + * Return: 0 when TPH is not supported, otherwise bitmask of supported modes + */ +int pcie_tph_modes(struct pci_dev *pdev) +{ + if (!pdev->tph_cap) + return 0; + + return get_st_modes(pdev); +} +EXPORT_SYMBOL(pcie_tph_modes); + void pci_tph_init(struct pci_dev *pdev) { pdev->tph_cap = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_TPH);
diff --git a/include/linux/pci-tph.h b/include/linux/pci-tph.h
new file mode 100644
index 000000000000..fa378afe9c7e
--- /dev/null
+++ b/include/linux/pci-tph.h@@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * TPH (TLP Processing Hints) + * + * Copyright (C) 2024 Advanced Micro Devices, Inc. + * Eric Van Tassell <Eric.VanTassell@amd.com> + * Wei Huang <wei.huang2@amd.com> + */ +#ifndef LINUX_PCI_TPH_H +#define LINUX_PCI_TPH_H + +#ifdef CONFIG_PCIE_TPH +int pcie_tph_modes(struct pci_dev *pdev); +#else +static inline int pcie_tph_modes(struct pci_dev *pdev) { return 0; } +#endif + +#endif /* LINUX_PCI_TPH_H */
--
2.45.1