On Wed, 30 Sep 2020 14:58:10 -0700
Sean V Kelley <seanvk.dev@xxxxxxxxxxxxxxxx> wrote:
> From: Sean V Kelley <sean.v.kelley@xxxxxxxxx>
>
> Extend support for Root Complex Event Collectors by decoding and
> caching the RCEC Endpoint Association Extended Capabilities when
> enumerating. Use that cached information for later error source
> reporting. See PCI Express Base Specification, version 5.0-1,
> section 7.9.10.
>
> Suggested-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Co-developed-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
> Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
> Signed-off-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---
> drivers/pci/pci.h | 17 +++++++++++
> drivers/pci/pcie/Makefile | 2 +-
> drivers/pci/pcie/rcec.c | 59 +++++++++++++++++++++++++++++++++++++++
> drivers/pci/probe.c | 2 ++
> include/linux/pci.h | 4 +++
> 5 files changed, 83 insertions(+), 1 deletion(-)
> create mode 100644 drivers/pci/pcie/rcec.c
>
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index fa12f7cbc1a0..88e27a98def5 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -449,6 +449,15 @@ int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info);
> void aer_print_error(struct pci_dev *dev, struct aer_err_info *info);
> #endif /* CONFIG_PCIEAER */
>
> +#ifdef CONFIG_PCIEPORTBUS
> +/* Cached RCEC Endpoint Association */
> +struct rcec_ea {
> + u8 nextbusn;
> + u8 lastbusn;
> + u32 bitmap;
> +};
> +#endif
> +
> #ifdef CONFIG_PCIE_DPC
> void pci_save_dpc_state(struct pci_dev *dev);
> void pci_restore_dpc_state(struct pci_dev *dev);
> @@ -461,6 +470,14 @@ static inline void pci_restore_dpc_state(struct pci_dev *dev) {}
> static inline void pci_dpc_init(struct pci_dev *pdev) {}
> #endif
>
> +#ifdef CONFIG_PCIEPORTBUS
> +int pci_rcec_init(struct pci_dev *dev);
> +void pci_rcec_exit(struct pci_dev *dev);
> +#else
> +static inline int pci_rcec_init(struct pci_dev *dev) {return 0;}
> +static inline void pci_rcec_exit(struct pci_dev *dev) {}
> +#endif
> +
> #ifdef CONFIG_PCI_ATS
> /* Address Translation Service */
> void pci_ats_init(struct pci_dev *dev);
> diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile
> index 68da9280ff11..d9697892fa3e 100644
> --- a/drivers/pci/pcie/Makefile
> +++ b/drivers/pci/pcie/Makefile
> @@ -2,7 +2,7 @@
> #
> # Makefile for PCI Express features and port driver
>
> -pcieportdrv-y := portdrv_core.o portdrv_pci.o err.o
> +pcieportdrv-y := portdrv_core.o portdrv_pci.o err.o rcec.o
>
> obj-$(CONFIG_PCIEPORTBUS) += pcieportdrv.o
>
> diff --git a/drivers/pci/pcie/rcec.c b/drivers/pci/pcie/rcec.c
> new file mode 100644
> index 000000000000..da02b0af442d
> --- /dev/null
> +++ b/drivers/pci/pcie/rcec.c
> @@ -0,0 +1,59 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Root Complex Event Collector Support
> + *
> + * Authors:
> + * Sean V Kelley <sean.v.kelley@xxxxxxxxx>
> + * Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
> + *
> + * Copyright (C) 2020 Intel Corp.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/pci.h>
> +#include <linux/pci_regs.h>
> +
> +#include "../pci.h"
> +
> +int pci_rcec_init(struct pci_dev *dev)
> +{
> + struct rcec_ea *rcec_ea;
> + u32 rcec, hdr, busn;
> + u8 ver;
> +
> + /* Only for Root Complex Event Collectors */
> + if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_EC)
> + return 0;
> +
> + rcec = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_RCEC);
> + if (!rcec)
> + return 0;
> +
> + rcec_ea = kzalloc(sizeof(*rcec_ea), GFP_KERNEL);
> + if (!rcec_ea)
> + return -ENOMEM;
> + dev->rcec_ea = rcec_ea;
> +
> + pci_read_config_dword(dev, rcec + PCI_RCEC_RCIEP_BITMAP, &rcec_ea->bitmap);
> +
> + /* Check whether RCEC BUSN register is present */
> + pci_read_config_dword(dev, rcec, &hdr);
> + ver = PCI_EXT_CAP_VER(hdr);
> + if (ver < PCI_RCEC_BUSN_REG_VER) {
> + /* Avoid later ver check by setting nextbusn */
> + rcec_ea->nextbusn = 0xff;
> + return 0;
> + }
> +
> + pci_read_config_dword(dev, rcec + PCI_RCEC_BUSN, &busn);
> + rcec_ea->nextbusn = PCI_RCEC_BUSN_NEXT(busn);
> + rcec_ea->lastbusn = PCI_RCEC_BUSN_LAST(busn);
> +
> + return 0;
> +}
> +
> +void pci_rcec_exit(struct pci_dev *dev)
> +{
> + kfree(dev->rcec_ea);
> + dev->rcec_ea = NULL;
> +}
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 03d37128a24f..25f01f841f2d 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -2201,6 +2201,7 @@ static void pci_configure_device(struct pci_dev *dev)
> static void pci_release_capabilities(struct pci_dev *dev)
> {
> pci_aer_exit(dev);
> + pci_rcec_exit(dev);
> pci_vpd_release(dev);
> pci_iov_release(dev);
> pci_free_cap_save_buffers(dev);
> @@ -2400,6 +2401,7 @@ static void pci_init_capabilities(struct pci_dev *dev)
> pci_ptm_init(dev); /* Precision Time Measurement */
> pci_aer_init(dev); /* Advanced Error Reporting */
> pci_dpc_init(dev); /* Downstream Port Containment */
> + pci_rcec_init(dev); /* Root Complex Event Collector */
>
> pcie_report_downtraining(dev);
>
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 835530605c0d..2290439e8bc0 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -304,6 +304,7 @@ struct pcie_link_state;
> struct pci_vpd;
> struct pci_sriov;
> struct pci_p2pdma;
> +struct rcec_ea;
>
> /* The pci_dev structure describes PCI devices */
> struct pci_dev {
> @@ -326,6 +327,9 @@ struct pci_dev {
> #ifdef CONFIG_PCIEAER
> u16 aer_cap; /* AER capability offset */
> struct aer_stats *aer_stats; /* AER stats for this device */
> +#endif
> +#ifdef CONFIG_PCIEPORTBUS
> + struct rcec_ea *rcec_ea; /* RCEC cached endpoint association */
> #endif
> u8 pcie_cap; /* PCIe capability offset */
> u8 msi_cap; /* MSI capability offset */
