From 292841b09648ce7aee5df16ab72581f3b6c2bd7a Mon Sep 17 00:00:00 2001 From: Ian Munsie Date: Tue, 24 May 2016 02:14:05 +1000 Subject: cxl: Update process element after allocating interrupts In the kernel API, it is possible to attempt to allocate AFU interrupts after already starting a context. Since the process element structure used by the hardware is only filled out at the time the context is started, it will not be updated with the interrupt numbers that have just been allocated and therefore AFU interrupts will not work unless they were allocated prior to starting the context. This can present some difficulties as each CAPI enabled PCI device in the kernel API has a default context, which may need to be started very early to enable translations, potentially before interrupts can easily be set up. This patch makes the API more flexible to allow interrupts to be allocated after a context has already been started and takes care of updating the PE structure used by the hardware and notifying it to discard any cached copy it may have. The update is currently performed via a terminate/remove/add sequence. This is necessary on some hardware such as the XSL that does not properly support the update LLCMD. Note that this is only supported on powernv at present - attempting to perform this ordering on PowerVM will raise a warning. Signed-off-by: Ian Munsie Reviewed-by: Frederic Barrat Signed-off-by: Michael Ellerman --- drivers/misc/cxl/api.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'drivers/misc/cxl/api.c') diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index 6d228ccd884d..99081b821f12 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -102,7 +102,10 @@ int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num) if (num == 0) num = ctx->afu->pp_irqs; res = afu_allocate_irqs(ctx, num); - if (!res && !cpu_has_feature(CPU_FTR_HVMODE)) { + if (res) + return res; + + if (!cpu_has_feature(CPU_FTR_HVMODE)) { /* In a guest, the PSL interrupt is not multiplexed. It was * allocated above, and we need to set its handler */ @@ -110,6 +113,13 @@ int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num) if (hwirq) cxl_map_irq(ctx->afu->adapter, hwirq, cxl_ops->psl_interrupt, ctx, "psl"); } + + if (ctx->status == STARTED) { + if (cxl_ops->update_ivtes) + cxl_ops->update_ivtes(ctx); + else WARN(1, "BUG: cxl_allocate_afu_irqs must be called prior to starting the context on this platform\n"); + } + return res; } EXPORT_SYMBOL_GPL(cxl_allocate_afu_irqs); -- cgit v1.2.2 From b810253bd9342f863a86ec7dfff4a5a7a0394d2f Mon Sep 17 00:00:00 2001 From: Philippe Bergheaud Date: Thu, 23 Jun 2016 15:03:53 +0200 Subject: cxl: Add mechanism for delivering AFU driver specific events This adds an afu_driver_ops structure with fetch_event() and event_delivered() callbacks. An AFU driver such as cxlflash can fill this out and associate it with a context to enable passing custom AFU specific events to userspace. This also adds a new kernel API function cxl_context_pending_events(), that the AFU driver can use to notify the cxl driver that new specific events are ready to be delivered, and wake up anyone waiting on the context wait queue. The current count of AFU driver specific events is stored in the field afu_driver_events of the context structure. The cxl driver checks the afu_driver_events count during poll, select, read, etc. calls to check if an AFU driver specific event is pending, and calls fetch_event() to obtain and deliver that event. This way, the cxl driver takes care of all the usual locking semantics around these calls and handles all the generic cxl events, so that the AFU driver only needs to worry about it's own events. fetch_event() return a struct cxl_event_afu_driver_reserved, allocated by the AFU driver, and filled in with the specific event information and size. Total event size (header + data) should not be greater than CXL_READ_MIN_SIZE (4K). Th cxl driver prepends an appropriate cxl event header, copies the event to userspace, and finally calls event_delivered() to return the status of the operation to the AFU driver. The event is identified by the context and cxl_event_afu_driver_reserved pointers. Since AFU drivers provide their own means for userspace to obtain the AFU file descriptor (i.e. cxlflash uses an ioctl on their scsi file descriptor to obtain the AFU file descriptor) and the generic cxl driver will never use this event, the ABI of the event is up to each individual AFU driver. Signed-off-by: Philippe Bergheaud Signed-off-by: Michael Ellerman --- drivers/misc/cxl/api.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'drivers/misc/cxl/api.c') diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index 99081b821f12..f11dc0e5fdd6 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -333,6 +333,23 @@ struct cxl_context *cxl_fops_get_context(struct file *file) } EXPORT_SYMBOL_GPL(cxl_fops_get_context); +void cxl_set_driver_ops(struct cxl_context *ctx, + struct cxl_afu_driver_ops *ops) +{ + WARN_ON(!ops->fetch_event || !ops->event_delivered); + atomic_set(&ctx->afu_driver_events, 0); + ctx->afu_driver_ops = ops; +} +EXPORT_SYMBOL_GPL(cxl_set_driver_ops); + +void cxl_context_events_pending(struct cxl_context *ctx, + unsigned int new_events) +{ + atomic_add(new_events, &ctx->afu_driver_events); + wake_up_all(&ctx->wq); +} +EXPORT_SYMBOL_GPL(cxl_context_events_pending); + int cxl_start_work(struct cxl_context *ctx, struct cxl_ioctl_start_work *work) { -- cgit v1.2.2 From ad42de859ff14c079e966e61cbcba85265b982e1 Mon Sep 17 00:00:00 2001 From: Michael Neuling Date: Fri, 24 Jun 2016 08:47:07 +0200 Subject: cxl: Add set and get private data to context struct This provides AFU drivers a means to associate private data with a cxl context. This is particularly intended for make the new callbacks for driver specific events easier for AFU drivers to use, as they can easily get back to any private data structures they may use. Signed-off-by: Michael Neuling Signed-off-by: Ian Munsie Signed-off-by: Philippe Bergheaud Reviewed-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- drivers/misc/cxl/api.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'drivers/misc/cxl/api.c') diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index f11dc0e5fdd6..7707055d33ab 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -94,6 +94,27 @@ static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num) return 0; } + +int cxl_set_priv(struct cxl_context *ctx, void *priv) +{ + if (!ctx) + return -EINVAL; + + ctx->priv = priv; + + return 0; +} +EXPORT_SYMBOL_GPL(cxl_set_priv); + +void *cxl_get_priv(struct cxl_context *ctx) +{ + if (!ctx) + return ERR_PTR(-EINVAL); + + return ctx->priv; +} +EXPORT_SYMBOL_GPL(cxl_get_priv); + int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num) { int res; -- cgit v1.2.2 From 317f5ef1b363417b6f1e93b90dfd2ffd6be6e867 Mon Sep 17 00:00:00 2001 From: Ian Munsie Date: Thu, 14 Jul 2016 07:17:07 +1000 Subject: cxl: Add support for using the kernel API with a real PHB This hooks up support for using the kernel API with a real PHB. After the AFU initialisation has completed it calls into the PHB code to pass it the AFU that will be used by other peer physical functions on the adapter. The cxl_pci_to_afu API is extended to work with peer PCI devices, retrieving the peer AFU from the PHB. This API may also now return an error if it is called on a PCI device that is not associated with either a cxl vPHB or a peer PCI device to an AFU, and this error is propagated down. Signed-off-by: Ian Munsie Reviewed-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- drivers/misc/cxl/api.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/misc/cxl/api.c') diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index 7707055d33ab..6a030bf71655 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -13,6 +13,7 @@ #include #include #include +#include #include "cxl.h" @@ -24,6 +25,8 @@ struct cxl_context *cxl_dev_context_init(struct pci_dev *dev) int rc; afu = cxl_pci_to_afu(dev); + if (IS_ERR(afu)) + return ERR_CAST(afu); ctx = cxl_context_alloc(); if (IS_ERR(ctx)) { @@ -438,6 +441,8 @@ EXPORT_SYMBOL_GPL(cxl_perst_reloads_same_image); ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count) { struct cxl_afu *afu = cxl_pci_to_afu(dev); + if (IS_ERR(afu)) + return -ENODEV; return cxl_ops->read_adapter_vpd(afu->adapter, buf, count); } -- cgit v1.2.2 From 79384e4b71240abf50c375eea56060b0d79c242a Mon Sep 17 00:00:00 2001 From: Ian Munsie Date: Thu, 14 Jul 2016 07:17:08 +1000 Subject: cxl: Add kernel APIs to get & set the max irqs per context These APIs will be used by the Mellanox CX4 support. While they function standalone to configure existing behaviour, their primary purpose is to allow the Mellanox driver to inform the cxl driver of a hardware limitation, which will be used in a future patch. Signed-off-by: Ian Munsie Reviewed-by: Frederic Barrat Reviewed-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- drivers/misc/cxl/api.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'drivers/misc/cxl/api.c') diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index 6a030bf71655..1e2c0d9f1df7 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -447,3 +447,30 @@ ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count) return cxl_ops->read_adapter_vpd(afu->adapter, buf, count); } EXPORT_SYMBOL_GPL(cxl_read_adapter_vpd); + +int cxl_set_max_irqs_per_process(struct pci_dev *dev, int irqs) +{ + struct cxl_afu *afu = cxl_pci_to_afu(dev); + if (IS_ERR(afu)) + return -ENODEV; + + if (irqs > afu->adapter->user_irqs) + return -EINVAL; + + /* Limit user_irqs to prevent the user increasing this via sysfs */ + afu->adapter->user_irqs = irqs; + afu->irqs_max = irqs; + + return 0; +} +EXPORT_SYMBOL_GPL(cxl_set_max_irqs_per_process); + +int cxl_get_max_irqs_per_process(struct pci_dev *dev) +{ + struct cxl_afu *afu = cxl_pci_to_afu(dev); + if (IS_ERR(afu)) + return -ENODEV; + + return afu->irqs_max; +} +EXPORT_SYMBOL_GPL(cxl_get_max_irqs_per_process); -- cgit v1.2.2 From cbce0917e2e47d4bf5aa3b5fd6b1247f33e1a126 Mon Sep 17 00:00:00 2001 From: Ian Munsie Date: Thu, 14 Jul 2016 07:17:09 +1000 Subject: cxl: Add preliminary workaround for CX4 interrupt limitation The Mellanox CX4 has a hardware limitation where only 4 bits of the AFU interrupt number can be passed to the XSL when sending an interrupt, limiting it to only 15 interrupts per context (AFU interrupt number 0 is invalid). In order to overcome this, we will allocate additional contexts linked to the default context as extra address space for the extra interrupts - this will be implemented in the next patch. This patch adds the preliminary support to allow this, by way of adding a linked list in the context structure that we use to keep track of the contexts dedicated to interrupts, and an API to simultaneously iterate over the related context structures, AFU interrupt numbers and hardware interrupt numbers. The point of using a single API to iterate these is to hide some of the details of the iteration from external code, and to reduce the number of APIs that need to be exported via base.c to allow built in code to call. Signed-off-by: Ian Munsie Reviewed-by: Frederic Barrat Reviewed-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- drivers/misc/cxl/api.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/misc/cxl/api.c') diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index 1e2c0d9f1df7..f02a85974e49 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -97,6 +97,21 @@ static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num) return 0; } +int _cxl_next_msi_hwirq(struct pci_dev *pdev, struct cxl_context **ctx, int *afu_irq) +{ + if (*ctx == NULL || *afu_irq == 0) { + *afu_irq = 1; + *ctx = cxl_get_context(pdev); + } else { + (*afu_irq)++; + if (*afu_irq > cxl_get_max_irqs_per_process(pdev)) { + *ctx = list_next_entry(*ctx, extra_irq_contexts); + *afu_irq = 1; + } + } + return cxl_find_afu_irq(*ctx, *afu_irq); +} +/* Exported via cxl_base */ int cxl_set_priv(struct cxl_context *ctx, void *priv) { -- cgit v1.2.2 From a2f67d5ee8d950caaa7a6144cf0bfb256500b73e Mon Sep 17 00:00:00 2001 From: Ian Munsie Date: Thu, 14 Jul 2016 07:17:10 +1000 Subject: cxl: Add support for interrupts on the Mellanox CX4 The Mellanox CX4 in cxl mode uses a hybrid interrupt model, where interrupts are routed from the networking hardware to the XSL using the MSIX table, and from there will be transformed back into an MSIX interrupt using the cxl style interrupts (i.e. using IVTE entries and ranges to map a PE and AFU interrupt number to an MSIX address). We want to hide the implementation details of cxl interrupts as much as possible. To this end, we use a special version of the MSI setup & teardown routines in the PHB while in cxl mode to allocate the cxl interrupts and configure the IVTE entries in the process element. This function does not configure the MSIX table - the CX4 card uses a custom format in that table and it would not be appropriate to fill that out in generic code. The rest of the functionality is similar to the "Full MSI-X mode" described in the CAIA, and this could be easily extended to support other adapters that use that mode in the future. The interrupts will be associated with the default context. If the maximum number of interrupts per context has been limited (e.g. by the mlx5 driver), it will automatically allocate additional kernel contexts to associate extra interrupts as required. These contexts will be started using the same WED that was used to start the default context. Signed-off-by: Ian Munsie Reviewed-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- drivers/misc/cxl/api.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) (limited to 'drivers/misc/cxl/api.c') diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index f02a85974e49..f3d34b941f85 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -14,6 +14,7 @@ #include #include #include +#include #include "cxl.h" @@ -489,3 +490,73 @@ int cxl_get_max_irqs_per_process(struct pci_dev *dev) return afu->irqs_max; } EXPORT_SYMBOL_GPL(cxl_get_max_irqs_per_process); + +/* + * This is a special interrupt allocation routine called from the PHB's MSI + * setup function. When capi interrupts are allocated in this manner they must + * still be associated with a running context, but since the MSI APIs have no + * way to specify this we use the default context associated with the device. + * + * The Mellanox CX4 has a hardware limitation that restricts the maximum AFU + * interrupt number, so in order to overcome this their driver informs us of + * the restriction by setting the maximum interrupts per context, and we + * allocate additional contexts as necessary so that we can keep the AFU + * interrupt number within the supported range. + */ +int _cxl_cx4_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type) +{ + struct cxl_context *ctx, *new_ctx, *default_ctx; + int remaining; + int rc; + + ctx = default_ctx = cxl_get_context(pdev); + if (WARN_ON(!default_ctx)) + return -ENODEV; + + remaining = nvec; + while (remaining > 0) { + rc = cxl_allocate_afu_irqs(ctx, min(remaining, ctx->afu->irqs_max)); + if (rc) { + pr_warn("%s: Failed to find enough free MSIs\n", pci_name(pdev)); + return rc; + } + remaining -= ctx->afu->irqs_max; + + if (ctx != default_ctx && default_ctx->status == STARTED) { + WARN_ON(cxl_start_context(ctx, + be64_to_cpu(default_ctx->elem->common.wed), + NULL)); + } + + if (remaining > 0) { + new_ctx = cxl_dev_context_init(pdev); + if (!new_ctx) { + pr_warn("%s: Failed to allocate enough contexts for MSIs\n", pci_name(pdev)); + return -ENOSPC; + } + list_add(&new_ctx->extra_irq_contexts, &ctx->extra_irq_contexts); + ctx = new_ctx; + } + } + + return 0; +} +/* Exported via cxl_base */ + +void _cxl_cx4_teardown_msi_irqs(struct pci_dev *pdev) +{ + struct cxl_context *ctx, *pos, *tmp; + + ctx = cxl_get_context(pdev); + if (WARN_ON(!ctx)) + return; + + cxl_free_afu_irqs(ctx); + list_for_each_entry_safe(pos, tmp, &ctx->extra_irq_contexts, extra_irq_contexts) { + cxl_stop_context(pos); + cxl_free_afu_irqs(pos); + list_del(&pos->extra_irq_contexts); + cxl_release_context(pos); + } +} +/* Exported via cxl_base */ -- cgit v1.2.2