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

From: Alastair D'Silva
Date: Tue Mar 10 2020 - 23:32:41 EST

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On Wed, 2020-03-04 at 12:00 +0100, Frederic Barrat wrote:
>
> Le 21/02/2020 Ã 04:27, Alastair D'Silva a Ãcrit :
> > 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;
>
> EBUSY?
>
Ok

>
> > +
> > + ocxlpmem->ev_ctx = eventfd_ctx_fdget(args.eventfd);
> > + if (!ocxlpmem->ev_ctx)
> > + return -EFAULT;
>
> Why not use what eventfd_ctx_fdget() returned? (through some
> IS_ERR()
> and PTR_ERR() convolution)
>

Ok
>
> > +
> > + 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));
> > +
>
> copy_to_user doesn't return an errno. Should be:
>
> if (copy_to_user((u64 __user *) uarg, &val, sizeof(val)))
> return -EFAULT;
>
Ok

>
> > + 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);
> > + }
> > +
> > +
>
> (at least) one empty line too many.
>

Ok

>
> > + 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;
>
> That's a few lines of duplicate code. On the other hand, there's
> enough
> varying parameters between the 2 interrupts that factorizing in a
> subfunction would be slightly less readable. So duplicating is
> probably ok.
>
>
>
> > + 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);
>
> GLOBAL_MMIO_CHI_NSCRA doesn't seem to be handled in the handlers.
>

This will be moved to the overwrite patch.

>
>
> > + 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");
>
> Like with other patches, rc needs to be set.
>
ok

>
> > + 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];
>
> irq_pgmap is not used.

Ok
>
>
> > + 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)
> > +
>
> I'm not fond of adding a macro with such a generic name as BIT_ULL()
> in
> a user header file. What's wrong with:
>
> #define IOCTL_OCXL_PMEM_EVENT_CONTROLLER_DUMP_AVAILABLE 0x1
> #define IOCTL_OCXL_PMEM_EVENT_ERROR_LOG_AVAILABLE 0x2
> #define IOCTL_OCXL_PMEM_EVENT_HARDWARE_FATAL 0x4
> #define IOCTL_OCXL_PMEM_EVENT_FIRMWARE_FATAL 0x8
>
>

Nothing, I'll change it.

> Fred
>
>
> > /* 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(O
> > CXL_PMEM_MAGIC, 0x03, struct ioctl_ocxl_pmem_controller_dump_data)
> > #define IOCTL_OCXL_PMEM_CONTROLLER_DUMP_COMPLETE _IO(OCXL_PMEM_M
> > AGIC, 0x04)
> > #define IOCTL_OCXL_PMEM_CONTROLLER_STATS _IO(OCXL_PMEM_M
> > AGIC, 0x05)
> > +#define IOCTL_OCXL_PMEM_EVENTFD _IOW(OC
> > XL_PMEM_MAGIC, 0x06, struct ioctl_ocxl_pmem_eventfd)
> > +#define IOCTL_OCXL_PMEM_EVENT_CHECK _IOR(OC
> > XL_PMEM_MAGIC, 0x07, __u64)
> >
> > #endif /* _UAPI_OCXL_SCM_H */
> >
--
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819

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