From: "Alastair D'Silva" <alastair@au1.ibm.com>
To: Frederic Barrat <fbarrat@linux.ibm.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
"Benjamin Herrenschmidt" <benh@kernel.crashing.org>,
"Paul Mackerras" <paulus@samba.org>,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Andrew Donnellan" <ajd@linux.ibm.com>,
"Arnd Bergmann" <arnd@arndb.de>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Mauro Carvalho Chehab" <mchehab+samsung@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
"Rob Herring" <robh@kernel.org>,
"Anton Blanchard" <anton@ozlabs.org>,
"Krzysztof Kozlowski" <krzk@kernel.org>,
"Mahesh Salgaonkar" <mahesh@linux.vnet.ibm.com>,
"Madhavan Srinivasan" <maddy@linux.vnet.ibm.com>,
"Cédric Le Goater" <clg@kaod.org>,
"Anju T Sudhakar" <anju@linux.vnet.ibm.com>,
"Hari Bathini" <hbathini@linux.ibm.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Greg Kurz" <groug@kaod.org>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Masahiro Yamada" <yamada.masahiro@socionext.com>,
"Alexey Kardashevskiy" <aik@ozlabs.ru>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 18/27] powerpc/powernv/pmem: Add controller dump IOCTLs
Date: Fri, 06 Mar 2020 10:37:12 +1100 [thread overview]
Message-ID: <6410f5f56e6d0c902026b7e323c352d5d1f7bb17.camel@au1.ibm.com> (raw)
In-Reply-To: <6d1f28bc-334c-e85b-9974-71cf88a1ad20@linux.ibm.com>
On Tue, 2020-03-03 at 19:04 +0100, Frederic Barrat wrote:
>
> Le 21/02/2020 à 04:27, Alastair D'Silva a écrit :
> > From: Alastair D'Silva <alastair@d-silva.org>
> >
> > This patch adds IOCTLs to allow userspace to request & fetch dumps
> > of the internal controller state.
> >
> > This is useful during debugging or when a fatal error on the
> > controller
> > has occurred.
> >
> > Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
> > ---
> > arch/powerpc/platforms/powernv/pmem/ocxl.c | 132
> > +++++++++++++++++++++
> > include/uapi/nvdimm/ocxl-pmem.h | 15 +++
> > 2 files changed, 147 insertions(+)
> >
> > diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl.c
> > b/arch/powerpc/platforms/powernv/pmem/ocxl.c
> > index 2b64504f9129..2cabafe1fc58 100644
> > --- a/arch/powerpc/platforms/powernv/pmem/ocxl.c
> > +++ b/arch/powerpc/platforms/powernv/pmem/ocxl.c
> > @@ -640,6 +640,124 @@ static int ioctl_error_log(struct ocxlpmem
> > *ocxlpmem,
> > return 0;
> > }
> >
> > +static int ioctl_controller_dump_data(struct ocxlpmem *ocxlpmem,
> > + struct ioctl_ocxl_pmem_controller_dump_data __user
> > *uarg)
> > +{
> > + struct ioctl_ocxl_pmem_controller_dump_data args;
> > + u16 i;
> > + u64 val;
> > + int rc;
> > +
> > + if (copy_from_user(&args, uarg, sizeof(args)))
> > + return -EFAULT;
> > +
> > + if (args.buf_size % 8)
> > + return -EINVAL;
> > +
> > + if (args.buf_size > ocxlpmem->admin_command.data_size)
> > + return -EINVAL;
> > +
> > + mutex_lock(&ocxlpmem->admin_command.lock);
> > +
> > + rc = admin_command_request(ocxlpmem,
> > ADMIN_COMMAND_CONTROLLER_DUMP);
> > + if (rc)
> > + goto out;
> > +
> > + val = ((u64)args.offset) << 32;
> > + val |= args.buf_size;
> > + rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
> > + ocxlpmem-
> > >admin_command.request_offset + 0x08,
> > + OCXL_LITTLE_ENDIAN, val);
> > + if (rc)
> > + goto out;
> > +
> > + rc = admin_command_execute(ocxlpmem);
> > + if (rc)
> > + goto out;
> > +
> > + rc = admin_command_complete_timeout(ocxlpmem,
> > + ADMIN_COMMAND_CONTROLLER_DU
> > MP);
> > + if (rc < 0) {
> > + dev_warn(&ocxlpmem->dev, "Controller dump timed
> > out\n");
> > + goto out;
> > + }
> > +
> > + rc = admin_response(ocxlpmem);
> > + if (rc < 0)
> > + goto out;
> > + if (rc != STATUS_SUCCESS) {
> > + warn_status(ocxlpmem,
> > + "Unexpected status from retrieve error
> > log",
> > + rc);
> > + goto out;
> > + }
>
>
> It would help if there was a comment indicating how the 3 ioctls are
> used. My understanding is that the userland is:
> - requesting the controller to prepare a state dump
> - then one or more ioctls to fetch the data. The number of calls
> required to get the full state really depends on the size of the
> buffer
> passed by user
> - a last ioctl to tell the controller that we're done, presumably to
> let
> it free some resources.
>
Ok, will add it to the blurb.
>
> > +
> > + for (i = 0; i < args.buf_size; i += 8) {
> > + u64 val;
> > +
> > + rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> > + ocxlpmem-
> > >admin_command.data_offset + i,
> > + OCXL_HOST_ENDIAN, &val);
> > + if (rc)
> > + goto out;
> > +
> > + if (copy_to_user(&args.buf[i], &val, sizeof(u64))) {
> > + rc = -EFAULT;
> > + goto out;
> > + }
> > + }
> > +
> > + if (copy_to_user(uarg, &args, sizeof(args))) {
> > + rc = -EFAULT;
> > + goto out;
> > + }
> > +
> > + rc = admin_response_handled(ocxlpmem);
> > + if (rc)
> > + goto out;
> > +
> > +out:
> > + mutex_unlock(&ocxlpmem->admin_command.lock);
> > + return rc;
> > +}
> > +
> > +int request_controller_dump(struct ocxlpmem *ocxlpmem)
> > +{
> > + int rc;
> > + u64 busy = 1;
> > +
> > + rc = ocxl_global_mmio_set64(ocxlpmem->ocxl_afu,
> > GLOBAL_MMIO_CHIC,
> > + OCXL_LITTLE_ENDIAN,
> > + GLOBAL_MMIO_CHI_CDA);
> > +
>
> rc is not checked here.
Whoops
>
>
> > +
> > + rc = ocxl_global_mmio_set64(ocxlpmem->ocxl_afu,
> > GLOBAL_MMIO_HCI,
> > + OCXL_LITTLE_ENDIAN,
> > + GLOBAL_MMIO_HCI_CONTROLLER_DUMP);
> > + if (rc)
> > + return rc;
> > +
> > + while (busy) {
> > + rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> > + GLOBAL_MMIO_HCI,
> > + OCXL_LITTLE_ENDIAN,
> > &busy);
> > + if (rc)
> > + return rc;
> > +
> > + busy &= GLOBAL_MMIO_HCI_CONTROLLER_DUMP;
>
> Setting 'busy' doesn't hurt, but it's not really useful, is it?
>
> We should add some kind of timeout so that if the controller hits an
> issue, we don't spin in kernel space endlessly.
>
>
Here we are polling the controller dump bit of the HCI register until
the controller clears it - that line is masking off the bits we don't
care about.
I'll talk to the firmware team about adding a timeout for that to the
spec so we know how long to wait for before giving up.
>
> > + cond_resched();
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int ioctl_controller_dump_complete(struct ocxlpmem
> > *ocxlpmem)
> > +{
> > + return ocxl_global_mmio_set64(ocxlpmem->ocxl_afu,
> > GLOBAL_MMIO_HCI,
> > + OCXL_LITTLE_ENDIAN,
> > + GLOBAL_MMIO_HCI_CONTROLLER_DUMP_COL
> > LECTED);
> > +}
> > +
> > static long file_ioctl(struct file *file, unsigned int cmd,
> > unsigned long args)
> > {
> > struct ocxlpmem *ocxlpmem = file->private_data;
> > @@ -650,7 +768,21 @@ static long file_ioctl(struct file *file,
> > unsigned int cmd, unsigned long args)
> > rc = ioctl_error_log(ocxlpmem,
> > (struct ioctl_ocxl_pmem_error_log
> > __user *)args);
> > break;
> > +
> > + case IOCTL_OCXL_PMEM_CONTROLLER_DUMP:
> > + rc = request_controller_dump(ocxlpmem);
> > + break;
> > +
> > + case IOCTL_OCXL_PMEM_CONTROLLER_DUMP_DATA:
> > + rc = ioctl_controller_dump_data(ocxlpmem,
> > + (struct
> > ioctl_ocxl_pmem_controller_dump_data __user *)args);
> > + break;
> > +
> > + case IOCTL_OCXL_PMEM_CONTROLLER_DUMP_COMPLETE:
> > + rc = ioctl_controller_dump_complete(ocxlpmem);
> > + break;
> > }
> > +
> > return rc;
> > }
> >
> > diff --git a/include/uapi/nvdimm/ocxl-pmem.h
> > b/include/uapi/nvdimm/ocxl-pmem.h
> > index b10f8ac0c20f..d4d8512d03f7 100644
> > --- a/include/uapi/nvdimm/ocxl-pmem.h
> > +++ b/include/uapi/nvdimm/ocxl-pmem.h
> > @@ -38,9 +38,24 @@ struct ioctl_ocxl_pmem_error_log {
> > __u8 *buf; /* pointer to output buffer */
> > };
> >
> > +struct ioctl_ocxl_pmem_controller_dump_data {
> > + __u8 *buf; /* pointer to output buffer */
>
> We only support 64-bit user app on powerpc, but using a pointer type
> in
> a kernel ABI is unusual. We should use a know size like __u64.
> (also applies to buf pointer in struct ioctl_ocxl_pmem_error_log
> from
> previous patch too)
>
> The rest of the structure will also be padded by the compiler, which
> we
> should avoid.
>
> Fred
>
Ok, I'll co-erce the pointers into a __u64.
>
>
> > + __u16 buf_size; /* in/out, buffer size provided/required.
> > + * If required is greater than provided, the
> > buffer
> > + * will be truncated to the amount provided. If
> > its
> > + * less, then only the required bytes will be
> > populated.
> > + * If it is 0, then there is no more dump data
> > available.
> > + */
> > + __u32 offset; /* in, Offset within the dump */
> > + __u64 reserved[8];
> > +};
> > +
> > /* ioctl numbers */
> > #define OCXL_PMEM_MAGIC 0x5C
> > /* SCM devices */
> > #define IOCTL_OCXL_PMEM_ERROR_LOG _IOWR(OCXL_PMEM
> > _MAGIC, 0x01, struct ioctl_ocxl_pmem_error_log)
> > +#define IOCTL_OCXL_PMEM_CONTROLLER_DUMP _IO(OCX
> > L_PMEM_MAGIC, 0x02)
> > +#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)
> >
> > #endif /* _UAPI_OCXL_SCM_H */
> >
--
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819
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next prev parent reply other threads:[~2020-03-05 23:37 UTC|newest]
Thread overview: 130+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-21 3:26 [PATCH v3 00/27] Add support for OpenCAPI Persistent Memory devices Alastair D'Silva
2020-02-21 3:26 ` [PATCH v3 01/27] powerpc: Add OPAL calls for LPC memory alloc/release Alastair D'Silva
2020-02-24 5:49 ` Andrew Donnellan
2020-02-24 5:50 ` Alastair D'Silva
2020-02-21 3:26 ` [PATCH v3 02/27] mm/memory_hotplug: Allow check_hotplug_memory_addressable to be called from drivers Alastair D'Silva
2020-02-21 7:03 ` Andrew Donnellan
2020-02-21 3:26 ` [PATCH v3 03/27] powerpc: Map & release OpenCAPI LPC memory Alastair D'Silva
2020-02-24 2:51 ` Andrew Donnellan
2020-02-24 5:49 ` Andrew Donnellan
2020-02-25 10:02 ` Frederic Barrat
2020-02-26 0:19 ` Alastair D'Silva
2020-03-03 6:10 ` Andrew Donnellan
2020-03-04 5:33 ` Alastair D'Silva
2020-02-21 3:26 ` [PATCH v3 04/27] ocxl: Remove unnecessary externs Alastair D'Silva
2020-02-21 6:06 ` Andrew Donnellan
2020-02-25 13:23 ` Frederic Barrat
2020-02-26 8:14 ` Baoquan He
2020-02-26 8:26 ` Alastair D'Silva
2020-02-26 9:01 ` Greg Kurz
2020-02-26 14:15 ` 'Baoquan He'
2020-02-26 14:20 ` Greg Kurz
2020-02-26 14:54 ` 'Baoquan He'
2020-02-21 3:26 ` [PATCH v3 05/27] ocxl: Address kernel doc errors & warnings Alastair D'Silva
2020-02-24 2:11 ` Andrew Donnellan
2020-02-21 3:26 ` [PATCH v3 06/27] ocxl: Tally up the LPC memory on a link & allow it to be mapped Alastair D'Silva
2020-02-24 5:25 ` Andrew Donnellan
2020-02-24 5:36 ` Alastair D'Silva
2020-02-25 16:30 ` Frederic Barrat
2020-02-26 0:29 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 07/27] ocxl: Add functions to map/unmap LPC memory Alastair D'Silva
2020-02-24 6:02 ` Andrew Donnellan
2020-02-24 6:08 ` Alastair D'Silva
2020-02-25 17:01 ` Frederic Barrat
2020-02-21 3:27 ` [PATCH v3 08/27] ocxl: Emit a log message showing how much LPC memory was detected Alastair D'Silva
2020-02-24 6:06 ` Andrew Donnellan
2020-02-24 6:10 ` Alastair D'Silva
2020-02-24 6:13 ` Andrew Donnellan
2020-02-25 17:03 ` Frederic Barrat
2020-02-21 3:27 ` [PATCH v3 09/27] ocxl: Save the device serial number in ocxl_fn Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 10/27] powerpc: Add driver for OpenCAPI Persistent Memory Alastair D'Silva
2020-02-26 5:07 ` Andrew Donnellan
2020-02-26 5:49 ` Alastair D'Silva
2020-02-27 20:44 ` Frederic Barrat
2020-02-28 0:54 ` Alastair D'Silva
2020-02-28 18:32 ` Frederic Barrat
2020-02-21 3:27 ` [PATCH v3 11/27] powerpc: Enable the OpenCAPI Persistent Memory driver for powernv_defconfig Alastair D'Silva
2020-02-25 3:01 ` Andrew Donnellan
2020-02-21 3:27 ` [PATCH v3 12/27] powerpc/powernv/pmem: Add register addresses & status values to the header Alastair D'Silva
2020-02-27 5:08 ` Andrew Donnellan
2020-02-27 5:16 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 13/27] powerpc/powernv/pmem: Read the capability registers & wait for device ready Alastair D'Silva
2020-02-27 3:54 ` Andrew Donnellan
2020-02-27 3:58 ` Alastair D'Silva
2020-03-02 17:51 ` Frederic Barrat
2020-03-04 4:15 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 14/27] powerpc/powernv/pmem: Add support for Admin commands Alastair D'Silva
2020-02-27 8:22 ` Andrew Donnellan
2020-02-27 8:27 ` Andrew Donnellan
2020-02-27 23:54 ` Alastair D'Silva
2020-02-27 23:51 ` Alastair D'Silva
2020-02-27 17:01 ` Dan Williams
2020-02-27 23:57 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 15/27] powerpc/powernv/pmem: Add support for near storage commands Alastair D'Silva
2020-02-27 8:30 ` Andrew Donnellan
2020-02-27 23:56 ` Alastair D'Silva
2020-02-27 17:02 ` Dan Williams
2020-03-02 17:58 ` Frederic Barrat
2020-03-02 18:42 ` Dan Williams
2020-03-04 4:42 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 16/27] powerpc/powernv/pmem: Register a character device for userspace to interact with Alastair D'Silva
2020-03-02 5:34 ` Andrew Donnellan
2020-03-02 6:05 ` Alastair D'Silva
2020-03-03 9:28 ` Frederic Barrat
2020-03-05 3:38 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 17/27] powerpc/powernv/pmem: Implement the Read Error Log command Alastair D'Silva
2020-03-03 10:36 ` Frederic Barrat
2020-03-05 4:31 ` Alastair D'Silva
2020-03-05 9:33 ` Frederic Barrat
2020-03-04 5:58 ` Andrew Donnellan
2020-02-21 3:27 ` [PATCH v3 18/27] powerpc/powernv/pmem: Add controller dump IOCTLs Alastair D'Silva
2020-03-03 18:04 ` Frederic Barrat
2020-03-05 23:37 ` Alastair D'Silva [this message]
2020-03-04 6:53 ` Andrew Donnellan
2020-03-06 3:34 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 19/27] powerpc/powernv/pmem: Add an IOCTL to report controller statistics Alastair D'Silva
2020-03-04 9:25 ` Frederic Barrat
2020-03-12 0:15 ` Alastair D'Silva
2020-03-05 0:46 ` Andrew Donnellan
2020-03-12 4:47 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 20/27] powerpc/powernv/pmem: Forward events to userspace Alastair D'Silva
2020-03-03 7:02 ` Andrew Donnellan
2020-03-04 5:48 ` Alastair D'Silva
2020-03-04 11:00 ` Frederic Barrat
2020-03-11 3:32 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 21/27] powerpc/powernv/pmem: Add an IOCTL to request controller health & perf data Alastair D'Silva
2020-02-28 6:12 ` Andrew Donnellan
2020-03-02 5:40 ` Alastair D'Silva
2020-03-04 11:06 ` Frederic Barrat
2020-03-11 3:38 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 22/27] powerpc/powernv/pmem: Implement the heartbeat command Alastair D'Silva
2020-02-28 6:20 ` Andrew Donnellan
2020-03-04 14:25 ` Frederic Barrat
2020-02-21 3:27 ` [PATCH v3 23/27] powerpc/powernv/pmem: Add debug IOCTLs Alastair D'Silva
2020-03-04 15:21 ` Frederic Barrat
2020-03-12 4:24 ` Alastair D'Silva
2020-03-05 3:11 ` Andrew Donnellan
2020-03-12 4:58 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 24/27] powerpc/powernv/pmem: Expose SMART data via ndctl Alastair D'Silva
2020-03-04 15:40 ` Frederic Barrat
2020-03-05 3:36 ` Andrew Donnellan
2020-03-12 23:14 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 25/27] powerpc/powernv/pmem: Expose the serial number in sysfs Alastair D'Silva
2020-02-28 6:25 ` Andrew Donnellan
2020-02-28 7:15 ` Greg Kroah-Hartman
2020-03-01 23:42 ` Alastair D'Silva
2020-03-02 5:38 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 26/27] powerpc/powernv/pmem: Expose the firmware version " Alastair D'Silva
2020-03-02 7:35 ` Andrew Donnellan
2020-03-04 4:11 ` Alastair D'Silva
2020-02-21 3:27 ` [PATCH v3 27/27] MAINTAINERS: Add myself & nvdimm/ocxl to ocxl Alastair D'Silva
2020-02-21 5:35 ` Andrew Donnellan
2020-02-21 16:21 ` [PATCH v3 00/27] Add support for OpenCAPI Persistent Memory devices Dan Williams
2020-02-21 16:24 ` Dan Williams
2020-02-24 4:34 ` Alastair D'Silva
2020-02-24 4:37 ` Matthew Wilcox
2020-02-24 4:42 ` Alastair D'Silva
2020-02-24 6:51 ` Oliver O'Halloran
2020-02-26 0:13 ` Alastair D'Silva
2020-02-26 0:32 ` Dan Williams
2020-02-26 0:35 ` Alastair D'Silva
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