Lukas Wunner wrote:
> Currently a DOE instance cannot be shared by multiple drivers because
> each driver creates its own pci_doe_mb struct for a given DOE instance.
> For the same reason a DOE instance cannot be shared between the PCI core
> and a driver.
>
> Overcome this limitation by creating mailboxes in the PCI core on device
> enumeration. Provide a pci_find_doe_mailbox() API call to allow drivers
> to get a pci_doe_mb for a given (pci_dev, vendor, protocol) triple.
>
> On device removal, tear down mailboxes in two steps:
>
> In pci_stop_dev(), before the driver is unbound, stop ongoing DOE
> exchanges and prevent new ones from being scheduled. This ensures that
> a hot-removed device doesn't needlessly wait for a running exchange to
> time out.
>
> In pci_destroy_dev(), after the driver is unbound, free the mailboxes
> and their internal data structures.
>
> Tested-by: Ira Weiny <ira.weiny@xxxxxxxxx>
I rather like this. Much cleaner, thanks!
Minor comment below.
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
> ---
> drivers/pci/doe.c | 71 +++++++++++++++++++++++++++++++++++++++++
> drivers/pci/pci.h | 10 ++++++
> drivers/pci/probe.c | 1 +
> drivers/pci/remove.c | 2 ++
> include/linux/pci-doe.h | 2 ++
> include/linux/pci.h | 3 ++
> 6 files changed, 89 insertions(+)
>
> diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c
> index cc1fdd75ad2a..06c57af05570 100644
> --- a/drivers/pci/doe.c
> +++ b/drivers/pci/doe.c
> @@ -20,6 +20,8 @@
> #include <linux/pci-doe.h>
> #include <linux/workqueue.h>
>
> +#include "pci.h"
> +
> #define PCI_DOE_PROTOCOL_DISCOVERY 0
>
> /* Timeout of 1 second from 6.30.2 Operation, PCI Spec r6.0 */
> @@ -662,3 +664,72 @@ int pci_doe(struct pci_doe_mb *doe_mb, u16 vendor, u8 type,
> return task.rv;
> }
> EXPORT_SYMBOL_GPL(pci_doe);
> +
> +/**
> + * pci_find_doe_mailbox() - Find Data Object Exchange mailbox
> + *
> + * @pdev: PCI device
> + * @vendor: Vendor ID
> + * @type: Data Object Type
> + *
> + * Find first DOE mailbox of a PCI device which supports the given protocol.
> + *
> + * RETURNS: Pointer to the DOE mailbox or NULL if none was found.
> + */
> +struct pci_doe_mb *pci_find_doe_mailbox(struct pci_dev *pdev, u16 vendor,
> + u8 type)
> +{
> + struct pci_doe_mb *doe_mb;
> + unsigned long index;
> +
> + xa_for_each(&pdev->doe_mbs, index, doe_mb)
> + if (pci_doe_supports_prot(doe_mb, vendor, type))
> + return doe_mb;
> +
> + return NULL;
> +}
> +EXPORT_SYMBOL_GPL(pci_find_doe_mailbox);
> +
> +void pci_doe_init(struct pci_dev *pdev)
> +{
> + struct pci_doe_mb *doe_mb;
> + u16 offset = 0;
> + int rc;
> +
> + xa_init(&pdev->doe_mbs);
> +
> + while ((offset = pci_find_next_ext_capability(pdev, offset,
> + PCI_EXT_CAP_ID_DOE))) {
> + doe_mb = pci_doe_create_mb(pdev, offset);
> + if (IS_ERR(doe_mb))
> + continue;
I feel like a pci_dbg() would be nice here. But not needed.
Ira
> +
> + rc = xa_insert(&pdev->doe_mbs, offset, doe_mb, GFP_KERNEL);
> + if (rc) {
> + pci_doe_flush_mb(doe_mb);
> + pci_doe_destroy_mb(doe_mb);
> + pci_err(pdev, "[%x] failed to insert mailbox: %d\n",
> + offset, rc);
> + }
> + }
> +}
> +
> +void pci_doe_stop(struct pci_dev *pdev)
> +{
> + struct pci_doe_mb *doe_mb;
> + unsigned long index;
> +
> + xa_for_each(&pdev->doe_mbs, index, doe_mb)
> + pci_doe_flush_mb(doe_mb);
> +}
> +
> +void pci_doe_destroy(struct pci_dev *pdev)
> +{
> + struct pci_doe_mb *doe_mb;
> + unsigned long index;
> +
> + xa_for_each(&pdev->doe_mbs, index, doe_mb)
> + pci_doe_destroy_mb(doe_mb);
> +
> + xa_destroy(&pdev->doe_mbs);
> +}
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 9ed3b5550043..94656c1a01c0 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -777,6 +777,16 @@ static inline pci_power_t mid_pci_get_power_state(struct pci_dev *pdev)
> }
> #endif
>
> +#ifdef CONFIG_PCI_DOE
> +void pci_doe_init(struct pci_dev *pdev);
> +void pci_doe_stop(struct pci_dev *pdev);
> +void pci_doe_destroy(struct pci_dev *pdev);
> +#else
> +static inline void pci_doe_init(struct pci_dev *pdev) { }
> +static inline void pci_doe_stop(struct pci_dev *pdev) { }
> +static inline void pci_doe_destroy(struct pci_dev *pdev) { }
> +#endif
> +
> /*
> * Config Address for PCI Configuration Mechanism #1
> *
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 1779582fb500..65e60ee50489 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -2476,6 +2476,7 @@ static void pci_init_capabilities(struct pci_dev *dev)
> pci_aer_init(dev); /* Advanced Error Reporting */
> pci_dpc_init(dev); /* Downstream Port Containment */
> pci_rcec_init(dev); /* Root Complex Event Collector */
> + pci_doe_init(dev); /* Data Object Exchange */
>
> pcie_report_downtraining(dev);
> pci_init_reset_methods(dev);
> diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
> index 0145aef1b930..739c7b0f5b91 100644
> --- a/drivers/pci/remove.c
> +++ b/drivers/pci/remove.c
> @@ -16,6 +16,7 @@ static void pci_free_resources(struct pci_dev *dev)
>
> static void pci_stop_dev(struct pci_dev *dev)
> {
> + pci_doe_stop(dev);
> pci_pme_active(dev, false);
>
> if (pci_dev_is_added(dev)) {
> @@ -39,6 +40,7 @@ static void pci_destroy_dev(struct pci_dev *dev)
> list_del(&dev->bus_list);
> up_write(&pci_bus_sem);
>
> + pci_doe_destroy(dev);
> pcie_aspm_exit_link_state(dev);
> pci_bridge_d3_update(dev);
> pci_free_resources(dev);
> diff --git a/include/linux/pci-doe.h b/include/linux/pci-doe.h
> index 7f16749c6aa3..d6192ee0ac07 100644
> --- a/include/linux/pci-doe.h
> +++ b/include/linux/pci-doe.h
> @@ -29,6 +29,8 @@ struct pci_doe_mb;
>
> struct pci_doe_mb *pcim_doe_create_mb(struct pci_dev *pdev, u16 cap_offset);
> bool pci_doe_supports_prot(struct pci_doe_mb *doe_mb, u16 vid, u8 type);
> +struct pci_doe_mb *pci_find_doe_mailbox(struct pci_dev *pdev, u16 vendor,
> + u8 type);
>
> int pci_doe(struct pci_doe_mb *doe_mb, u16 vendor, u8 type,
> const void *request, size_t request_sz,
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index adffd65e84b4..254c79f9013a 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -511,6 +511,9 @@ struct pci_dev {
> #endif
> #ifdef CONFIG_PCI_P2PDMA
> struct pci_p2pdma __rcu *p2pdma;
> +#endif
> +#ifdef CONFIG_PCI_DOE
> + struct xarray doe_mbs; /* Data Object Exchange mailboxes */
> #endif
> u16 acs_cap; /* ACS Capability offset */
> phys_addr_t rom; /* Physical address if not from BAR */
> --
> 2.39.1
>
