diff options
| -rw-r--r-- | drivers/misc/cxl/cxl.h | 1 | ||||
| -rw-r--r-- | drivers/misc/cxl/pci.c | 253 | ||||
| -rw-r--r-- | drivers/misc/cxl/vphb.c | 8 |
3 files changed, 262 insertions, 0 deletions
diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h index cda02412b01e..6f5386653dae 100644 --- a/drivers/misc/cxl/cxl.h +++ b/drivers/misc/cxl/cxl.h @@ -726,6 +726,7 @@ int cxl_psl_purge(struct cxl_afu *afu); void cxl_stop_trace(struct cxl *cxl); int cxl_pci_vphb_add(struct cxl_afu *afu); +void cxl_pci_vphb_reconfigure(struct cxl_afu *afu); void cxl_pci_vphb_remove(struct cxl_afu *afu); extern struct pci_driver cxl_pci_driver; diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index bfbd6478c0c5..03ddb2d8f974 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -24,6 +24,7 @@ #include <asm/io.h> #include "cxl.h" +#include <misc/cxl.h> #define CXL_PCI_VSEC_ID 0x1280 @@ -1252,10 +1253,262 @@ static void cxl_remove(struct pci_dev *dev) cxl_remove_adapter(adapter); } +static pci_ers_result_t cxl_vphb_error_detected(struct cxl_afu *afu, + pci_channel_state_t state) +{ + struct pci_dev *afu_dev; + pci_ers_result_t result = PCI_ERS_RESULT_NEED_RESET; + pci_ers_result_t afu_result = PCI_ERS_RESULT_NEED_RESET; + + /* There should only be one entry, but go through the list + * anyway + */ + list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) { + if (!afu_dev->driver) + continue; + + afu_dev->error_state = state; + + if (afu_dev->driver->err_handler) + afu_result = afu_dev->driver->err_handler->error_detected(afu_dev, + state); + /* Disconnect trumps all, NONE trumps NEED_RESET */ + if (afu_result == PCI_ERS_RESULT_DISCONNECT) + result = PCI_ERS_RESULT_DISCONNECT; + else if ((afu_result == PCI_ERS_RESULT_NONE) && + (result == PCI_ERS_RESULT_NEED_RESET)) + result = PCI_ERS_RESULT_NONE; + } + return result; +} + +static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev, + pci_channel_state_t state) +{ + struct cxl *adapter = pci_get_drvdata(pdev); + struct cxl_afu *afu; + pci_ers_result_t result = PCI_ERS_RESULT_NEED_RESET; + int i; + + /* At this point, we could still have an interrupt pending. + * Let's try to get them out of the way before they do + * anything we don't like. + */ + schedule(); + + /* If we're permanently dead, give up. */ + if (state == pci_channel_io_perm_failure) { + /* Tell the AFU drivers; but we don't care what they + * say, we're going away. + */ + for (i = 0; i < adapter->slices; i++) { + afu = adapter->afu[i]; + cxl_vphb_error_detected(afu, state); + } + return PCI_ERS_RESULT_DISCONNECT; + } + + /* Are we reflashing? + * + * If we reflash, we could come back as something entirely + * different, including a non-CAPI card. As such, by default + * we don't participate in the process. We'll be unbound and + * the slot re-probed. (TODO: check EEH doesn't blindly rebind + * us!) + * + * However, this isn't the entire story: for reliablity + * reasons, we usually want to reflash the FPGA on PERST in + * order to get back to a more reliable known-good state. + * + * This causes us a bit of a problem: if we reflash we can't + * trust that we'll come back the same - we could have a new + * image and been PERSTed in order to load that + * image. However, most of the time we actually *will* come + * back the same - for example a regular EEH event. + * + * Therefore, we allow the user to assert that the image is + * indeed the same and that we should continue on into EEH + * anyway. + */ + if (adapter->perst_loads_image && !adapter->perst_same_image) { + /* TODO take the PHB out of CXL mode */ + dev_info(&pdev->dev, "reflashing, so opting out of EEH!\n"); + return PCI_ERS_RESULT_NONE; + } + + /* + * At this point, we want to try to recover. We'll always + * need a complete slot reset: we don't trust any other reset. + * + * Now, we go through each AFU: + * - We send the driver, if bound, an error_detected callback. + * We expect it to clean up, but it can also tell us to give + * up and permanently detach the card. To simplify things, if + * any bound AFU driver doesn't support EEH, we give up on EEH. + * + * - We detach all contexts associated with the AFU. This + * does not free them, but puts them into a CLOSED state + * which causes any the associated files to return useful + * errors to userland. It also unmaps, but does not free, + * any IRQs. + * + * - We clean up our side: releasing and unmapping resources we hold + * so we can wire them up again when the hardware comes back up. + * + * Driver authors should note: + * + * - Any contexts you create in your kernel driver (except + * those associated with anonymous file descriptors) are + * your responsibility to free and recreate. Likewise with + * any attached resources. + * + * - We will take responsibility for re-initialising the + * device context (the one set up for you in + * cxl_pci_enable_device_hook and accessed through + * cxl_get_context). If you've attached IRQs or other + * resources to it, they remains yours to free. + * + * You can call the same functions to release resources as you + * normally would: we make sure that these functions continue + * to work when the hardware is down. + * + * Two examples: + * + * 1) If you normally free all your resources at the end of + * each request, or if you use anonymous FDs, your + * error_detected callback can simply set a flag to tell + * your driver not to start any new calls. You can then + * clear the flag in the resume callback. + * + * 2) If you normally allocate your resources on startup: + * * Set a flag in error_detected as above. + * * Let CXL detach your contexts. + * * In slot_reset, free the old resources and allocate new ones. + * * In resume, clear the flag to allow things to start. + */ + for (i = 0; i < adapter->slices; i++) { + afu = adapter->afu[i]; + + result = cxl_vphb_error_detected(afu, state); + + /* Only continue if everyone agrees on NEED_RESET */ + if (result != PCI_ERS_RESULT_NEED_RESET) + return result; + + cxl_context_detach_all(afu); + cxl_afu_deactivate_mode(afu); + cxl_deconfigure_afu(afu); + } + cxl_deconfigure_adapter(adapter); + + return result; +} + +static pci_ers_result_t cxl_pci_slot_reset(struct pci_dev *pdev) +{ + struct cxl *adapter = pci_get_drvdata(pdev); + struct cxl_afu *afu; + struct cxl_context *ctx; + struct pci_dev *afu_dev; + pci_ers_result_t afu_result = PCI_ERS_RESULT_RECOVERED; + pci_ers_result_t result = PCI_ERS_RESULT_RECOVERED; + int i; + + if (cxl_configure_adapter(adapter, pdev)) + goto err; + + for (i = 0; i < adapter->slices; i++) { + afu = adapter->afu[i]; + + if (cxl_configure_afu(afu, adapter, pdev)) + goto err; + + if (cxl_afu_select_best_mode(afu)) + goto err; + + cxl_pci_vphb_reconfigure(afu); + + list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) { + /* Reset the device context. + * TODO: make this less disruptive + */ + ctx = cxl_get_context(afu_dev); + + if (ctx && cxl_release_context(ctx)) + goto err; + + ctx = cxl_dev_context_init(afu_dev); + if (!ctx) + goto err; + + afu_dev->dev.archdata.cxl_ctx = ctx; + + if (cxl_afu_check_and_enable(afu)) + goto err; + + afu_dev->error_state = pci_channel_io_normal; + + /* If there's a driver attached, allow it to + * chime in on recovery. Drivers should check + * if everything has come back OK, but + * shouldn't start new work until we call + * their resume function. + */ + if (!afu_dev->driver) + continue; + + if (afu_dev->driver->err_handler && + afu_dev->driver->err_handler->slot_reset) + afu_result = afu_dev->driver->err_handler->slot_reset(afu_dev); + + if (afu_result == PCI_ERS_RESULT_DISCONNECT) + result = PCI_ERS_RESULT_DISCONNECT; + } + } + return result; + +err: + /* All the bits that happen in both error_detected and cxl_remove + * should be idempotent, so we don't need to worry about leaving a mix + * of unconfigured and reconfigured resources. + */ + dev_err(&pdev->dev, "EEH recovery failed. Asking to be disconnected.\n"); + return PCI_ERS_RESULT_DISCONNECT; +} + +static void cxl_pci_resume(struct pci_dev *pdev) +{ + struct cxl *adapter = pci_get_drvdata(pdev); + struct cxl_afu *afu; + struct pci_dev *afu_dev; + int i; + + /* Everything is back now. Drivers should restart work now. + * This is not the place to be checking if everything came back up + * properly, because there's no return value: do that in slot_reset. + */ + for (i = 0; i < adapter->slices; i++) { + afu = adapter->afu[i]; + + list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) { + if (afu_dev->driver && afu_dev->driver->err_handler && + afu_dev->driver->err_handler->resume) + afu_dev->driver->err_handler->resume(afu_dev); + } + } +} + +static const struct pci_error_handlers cxl_err_handler = { + .error_detected = cxl_pci_error_detected, + .slot_reset = cxl_pci_slot_reset, + .resume = cxl_pci_resume, +}; + struct pci_driver cxl_pci_driver = { .name = "cxl-pci", .id_table = cxl_pci_tbl, .probe = cxl_probe, .remove = cxl_remove, .shutdown = cxl_remove, + .err_handler = &cxl_err_handler, }; diff --git a/drivers/misc/cxl/vphb.c b/drivers/misc/cxl/vphb.c index 2930911c1e42..6dd16a6d153f 100644 --- a/drivers/misc/cxl/vphb.c +++ b/drivers/misc/cxl/vphb.c @@ -266,6 +266,14 @@ int cxl_pci_vphb_add(struct cxl_afu *afu) return 0; } +void cxl_pci_vphb_reconfigure(struct cxl_afu *afu) +{ + /* When we are reconfigured, the AFU's MMIO space is unmapped + * and remapped. We need to reflect this in the PHB's view of + * the world. + */ + afu->phb->cfg_addr = afu->afu_desc_mmio + afu->crs_offset; +} void cxl_pci_vphb_remove(struct cxl_afu *afu) { |