[PATCH v3 20/27] powerpc/powernv/pmem: Forward events to userspace

From: Alastair D'Silva
Date: Thu Feb 20 2020 - 22:34:07 EST


From: Alastair D'Silva <alastair@xxxxxxxxxxx>

Some of the interrupts that the card generates are better handled
by the userspace daemon, in particular:
Controller Hardware/Firmware Fatal
Controller Dump Available
Error Log available

This patch allows a userspace application to register an eventfd with
the driver via SCM_IOCTL_EVENTFD to receive notifications of these
interrupts.

Userspace can then identify what events have occurred by calling
SCM_IOCTL_EVENT_CHECK and checking against the SCM_IOCTL_EVENT_FOO
masks.

Signed-off-by: Alastair D'Silva <alastair@xxxxxxxxxxx>
---
arch/powerpc/platforms/powernv/pmem/ocxl.c | 216 ++++++++++++++++++
.../platforms/powernv/pmem/ocxl_internal.h | 5 +
include/uapi/nvdimm/ocxl-pmem.h | 16 ++
3 files changed, 237 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl.c b/arch/powerpc/platforms/powernv/pmem/ocxl.c
index 009d4fd29e7d..e46696d3cc36 100644
--- a/arch/powerpc/platforms/powernv/pmem/ocxl.c
+++ b/arch/powerpc/platforms/powernv/pmem/ocxl.c
@@ -10,6 +10,7 @@
#include <misc/ocxl.h>
#include <linux/delay.h>
#include <linux/ndctl.h>
+#include <linux/eventfd.h>
#include <linux/fs.h>
#include <linux/mm_types.h>
#include <linux/memory_hotplug.h>
@@ -335,11 +336,22 @@ static void free_ocxlpmem(struct ocxlpmem *ocxlpmem)
{
int rc;

+ // Disable doorbells
+ (void)ocxl_global_mmio_set64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_CHIEC,
+ OCXL_LITTLE_ENDIAN,
+ GLOBAL_MMIO_CHI_ALL);
+
if (ocxlpmem->nvdimm_bus)
nvdimm_bus_unregister(ocxlpmem->nvdimm_bus);

free_minor(ocxlpmem);

+ if (ocxlpmem->irq_addr[1])
+ iounmap(ocxlpmem->irq_addr[1]);
+
+ if (ocxlpmem->irq_addr[0])
+ iounmap(ocxlpmem->irq_addr[0]);
+
if (ocxlpmem->cdev.owner)
cdev_del(&ocxlpmem->cdev);

@@ -443,6 +455,11 @@ static int file_release(struct inode *inode, struct file *file)
{
struct ocxlpmem *ocxlpmem = file->private_data;

+ if (ocxlpmem->ev_ctx) {
+ eventfd_ctx_put(ocxlpmem->ev_ctx);
+ ocxlpmem->ev_ctx = NULL;
+ }
+
ocxlpmem_put(ocxlpmem);
return 0;
}
@@ -938,6 +955,51 @@ static int ioctl_controller_stats(struct ocxlpmem *ocxlpmem,
return rc;
}

+static int ioctl_eventfd(struct ocxlpmem *ocxlpmem,
+ struct ioctl_ocxl_pmem_eventfd __user *uarg)
+{
+ struct ioctl_ocxl_pmem_eventfd args;
+
+ if (copy_from_user(&args, uarg, sizeof(args)))
+ return -EFAULT;
+
+ if (ocxlpmem->ev_ctx)
+ return -EINVAL;
+
+ ocxlpmem->ev_ctx = eventfd_ctx_fdget(args.eventfd);
+ if (!ocxlpmem->ev_ctx)
+ return -EFAULT;
+
+ return 0;
+}
+
+static int ioctl_event_check(struct ocxlpmem *ocxlpmem, u64 __user *uarg)
+{
+ u64 val = 0;
+ int rc;
+ u64 chi = 0;
+
+ rc = ocxlpmem_chi(ocxlpmem, &chi);
+ if (rc < 0)
+ return rc;
+
+ if (chi & GLOBAL_MMIO_CHI_ELA)
+ val |= IOCTL_OCXL_PMEM_EVENT_ERROR_LOG_AVAILABLE;
+
+ if (chi & GLOBAL_MMIO_CHI_CDA)
+ val |= IOCTL_OCXL_PMEM_EVENT_CONTROLLER_DUMP_AVAILABLE;
+
+ if (chi & GLOBAL_MMIO_CHI_CFFS)
+ val |= IOCTL_OCXL_PMEM_EVENT_FIRMWARE_FATAL;
+
+ if (chi & GLOBAL_MMIO_CHI_CHFS)
+ val |= IOCTL_OCXL_PMEM_EVENT_HARDWARE_FATAL;
+
+ rc = copy_to_user((u64 __user *) uarg, &val, sizeof(val));
+
+ return rc;
+}
+
static long file_ioctl(struct file *file, unsigned int cmd, unsigned long args)
{
struct ocxlpmem *ocxlpmem = file->private_data;
@@ -966,6 +1028,15 @@ static long file_ioctl(struct file *file, unsigned int cmd, unsigned long args)
rc = ioctl_controller_stats(ocxlpmem,
(struct ioctl_ocxl_pmem_controller_stats __user *)args);
break;
+
+ case IOCTL_OCXL_PMEM_EVENTFD:
+ rc = ioctl_eventfd(ocxlpmem,
+ (struct ioctl_ocxl_pmem_eventfd __user *)args);
+ break;
+
+ case IOCTL_OCXL_PMEM_EVENT_CHECK:
+ rc = ioctl_event_check(ocxlpmem, (u64 __user *)args);
+ break;
}

return rc;
@@ -1107,6 +1178,146 @@ static void dump_error_log(struct ocxlpmem *ocxlpmem)
kfree(buf);
}

+static irqreturn_t imn0_handler(void *private)
+{
+ struct ocxlpmem *ocxlpmem = private;
+ u64 chi = 0;
+
+ (void)ocxlpmem_chi(ocxlpmem, &chi);
+
+ if (chi & GLOBAL_MMIO_CHI_ELA) {
+ dev_warn(&ocxlpmem->dev, "Error log is available\n");
+
+ if (ocxlpmem->ev_ctx)
+ eventfd_signal(ocxlpmem->ev_ctx, 1);
+ }
+
+ if (chi & GLOBAL_MMIO_CHI_CDA) {
+ dev_warn(&ocxlpmem->dev, "Controller dump is available\n");
+
+ if (ocxlpmem->ev_ctx)
+ eventfd_signal(ocxlpmem->ev_ctx, 1);
+ }
+
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t imn1_handler(void *private)
+{
+ struct ocxlpmem *ocxlpmem = private;
+ u64 chi = 0;
+
+ (void)ocxlpmem_chi(ocxlpmem, &chi);
+
+ if (chi & (GLOBAL_MMIO_CHI_CFFS | GLOBAL_MMIO_CHI_CHFS)) {
+ dev_err(&ocxlpmem->dev,
+ "Controller status is fatal, chi=0x%llx, going offline\n", chi);
+
+ if (ocxlpmem->nvdimm_bus) {
+ nvdimm_bus_unregister(ocxlpmem->nvdimm_bus);
+ ocxlpmem->nvdimm_bus = NULL;
+ }
+
+ if (ocxlpmem->ev_ctx)
+ eventfd_signal(ocxlpmem->ev_ctx, 1);
+ }
+
+ return IRQ_HANDLED;
+}
+
+
+/**
+ * ocxlpmem_setup_irq() - Set up the IRQs for the OpenCAPI Persistent Memory device
+ * @ocxlpmem: the device metadata
+ * Return: 0 on success, negative on failure
+ */
+static int ocxlpmem_setup_irq(struct ocxlpmem *ocxlpmem)
+{
+ int rc;
+ u64 irq_addr;
+
+ rc = ocxl_afu_irq_alloc(ocxlpmem->ocxl_context, &ocxlpmem->irq_id[0]);
+ if (rc)
+ return rc;
+
+ rc = ocxl_irq_set_handler(ocxlpmem->ocxl_context, ocxlpmem->irq_id[0],
+ imn0_handler, NULL, ocxlpmem);
+
+ irq_addr = ocxl_afu_irq_get_addr(ocxlpmem->ocxl_context, ocxlpmem->irq_id[0]);
+ if (!irq_addr)
+ return -EINVAL;
+
+ ocxlpmem->irq_addr[0] = ioremap(irq_addr, PAGE_SIZE);
+ if (!ocxlpmem->irq_addr[0])
+ return -EINVAL;
+
+ rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_IMA0_OHP,
+ OCXL_LITTLE_ENDIAN,
+ (u64)ocxlpmem->irq_addr[0]);
+ if (rc)
+ goto out_irq0;
+
+ rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_IMA0_CFP,
+ OCXL_LITTLE_ENDIAN, 0);
+ if (rc)
+ goto out_irq0;
+
+ rc = ocxl_afu_irq_alloc(ocxlpmem->ocxl_context, &ocxlpmem->irq_id[1]);
+ if (rc)
+ goto out_irq0;
+
+
+ rc = ocxl_irq_set_handler(ocxlpmem->ocxl_context, ocxlpmem->irq_id[1],
+ imn1_handler, NULL, ocxlpmem);
+ if (rc)
+ goto out_irq0;
+
+ irq_addr = ocxl_afu_irq_get_addr(ocxlpmem->ocxl_context, ocxlpmem->irq_id[1]);
+ if (!irq_addr) {
+ rc = -EFAULT;
+ goto out_irq0;
+ }
+
+ ocxlpmem->irq_addr[1] = ioremap(irq_addr, PAGE_SIZE);
+ if (!ocxlpmem->irq_addr[1]) {
+ rc = -EINVAL;
+ goto out_irq0;
+ }
+
+ rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_IMA1_OHP,
+ OCXL_LITTLE_ENDIAN,
+ (u64)ocxlpmem->irq_addr[1]);
+ if (rc)
+ goto out_irq1;
+
+ rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_IMA1_CFP,
+ OCXL_LITTLE_ENDIAN, 0);
+ if (rc)
+ goto out_irq1;
+
+ // Enable doorbells
+ rc = ocxl_global_mmio_set64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_CHIE,
+ OCXL_LITTLE_ENDIAN,
+ GLOBAL_MMIO_CHI_ELA | GLOBAL_MMIO_CHI_CDA |
+ GLOBAL_MMIO_CHI_CFFS | GLOBAL_MMIO_CHI_CHFS |
+ GLOBAL_MMIO_CHI_NSCRA);
+ if (rc)
+ goto out_irq1;
+
+ return 0;
+
+out_irq1:
+ iounmap(ocxlpmem->irq_addr[1]);
+ ocxlpmem->irq_addr[1] = NULL;
+
+out_irq0:
+ iounmap(ocxlpmem->irq_addr[0]);
+ ocxlpmem->irq_addr[0] = NULL;
+
+ return rc;
+}
+
/**
* probe_function0() - Set up function 0 for an OpenCAPI persistent memory device
* This is important as it enables templates higher than 0 across all other functions,
@@ -1216,6 +1427,11 @@ static int probe(struct pci_dev *pdev, const struct pci_device_id *ent)
goto err;
}

+ if (ocxlpmem_setup_irq(ocxlpmem)) {
+ dev_err(&pdev->dev, "Could not set up OCXL IRQs\n");
+ goto err;
+ }
+
if (setup_command_metadata(ocxlpmem)) {
dev_err(&pdev->dev, "Could not read OCXL command matada\n");
goto err;
diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
index b953ee522ed4..927690f4888f 100644
--- a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
+++ b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
@@ -103,6 +103,10 @@ struct ocxlpmem {
struct pci_dev *pdev;
struct cdev cdev;
struct ocxl_fn *ocxl_fn;
+#define SCM_IRQ_COUNT 2
+ int irq_id[SCM_IRQ_COUNT];
+ struct dev_pagemap irq_pgmap[SCM_IRQ_COUNT];
+ void *irq_addr[SCM_IRQ_COUNT];
struct nd_interleave_set nd_set;
struct nvdimm_bus_descriptor bus_desc;
struct nvdimm_bus *nvdimm_bus;
@@ -113,6 +117,7 @@ struct ocxlpmem {
struct command_metadata ns_command;
struct resource pmem_res;
struct nd_region *nd_region;
+ struct eventfd_ctx *ev_ctx;
char fw_version[8+1];
u32 timeouts[ADMIN_COMMAND_MAX+1];

diff --git a/include/uapi/nvdimm/ocxl-pmem.h b/include/uapi/nvdimm/ocxl-pmem.h
index add223aa2fdb..988eb0bc413d 100644
--- a/include/uapi/nvdimm/ocxl-pmem.h
+++ b/include/uapi/nvdimm/ocxl-pmem.h
@@ -66,6 +66,20 @@ struct ioctl_ocxl_pmem_controller_stats {
__u64 cache_write_latency; /* nanoseconds */
};

+struct ioctl_ocxl_pmem_eventfd {
+ __s32 eventfd;
+ __u32 reserved;
+};
+
+#ifndef BIT_ULL
+#define BIT_ULL(nr) (1ULL << (nr))
+#endif
+
+#define IOCTL_OCXL_PMEM_EVENT_CONTROLLER_DUMP_AVAILABLE BIT_ULL(0)
+#define IOCTL_OCXL_PMEM_EVENT_ERROR_LOG_AVAILABLE BIT_ULL(1)
+#define IOCTL_OCXL_PMEM_EVENT_HARDWARE_FATAL BIT_ULL(2)
+#define IOCTL_OCXL_PMEM_EVENT_FIRMWARE_FATAL BIT_ULL(3)
+
/* ioctl numbers */
#define OCXL_PMEM_MAGIC 0x5C
/* SCM devices */
@@ -74,5 +88,7 @@ struct ioctl_ocxl_pmem_controller_stats {
#define IOCTL_OCXL_PMEM_CONTROLLER_DUMP_DATA _IOWR(OCXL_PMEM_MAGIC, 0x03, struct ioctl_ocxl_pmem_controller_dump_data)
#define IOCTL_OCXL_PMEM_CONTROLLER_DUMP_COMPLETE _IO(OCXL_PMEM_MAGIC, 0x04)
#define IOCTL_OCXL_PMEM_CONTROLLER_STATS _IO(OCXL_PMEM_MAGIC, 0x05)
+#define IOCTL_OCXL_PMEM_EVENTFD _IOW(OCXL_PMEM_MAGIC, 0x06, struct ioctl_ocxl_pmem_eventfd)
+#define IOCTL_OCXL_PMEM_EVENT_CHECK _IOR(OCXL_PMEM_MAGIC, 0x07, __u64)

#endif /* _UAPI_OCXL_SCM_H */
--
2.24.1