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Message-Id: <d70936f77cbbf712cee505e7ec009ba1ddaf74e6.camel@au1.ibm.com>
Date: Fri, 13 Mar 2020 10:14:29 +1100
From: "Alastair D'Silva" <alastair@....ibm.com>
To: Andrew Donnellan <ajd@...ux.ibm.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@...ux.ibm.com>,
"Oliver O'Halloran" <oohall@...il.com>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
Michael Ellerman <mpe@...erman.id.au>,
Frederic Barrat <fbarrat@...ux.ibm.com>,
Arnd Bergmann <arnd@...db.de>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Dan Williams <dan.j.williams@...el.com>,
Vishal Verma <vishal.l.verma@...el.com>,
Dave Jiang <dave.jiang@...el.com>,
Ira Weiny <ira.weiny@...el.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Mauro Carvalho Chehab <mchehab+samsung@...nel.org>,
"David S. Miller" <davem@...emloft.net>,
Rob Herring <robh@...nel.org>,
Anton Blanchard <anton@...abs.org>,
Krzysztof Kozlowski <krzk@...nel.org>,
Mahesh Salgaonkar <mahesh@...ux.vnet.ibm.com>,
Madhavan Srinivasan <maddy@...ux.vnet.ibm.com>,
Cédric Le Goater <clg@...d.org>,
Anju T Sudhakar <anju@...ux.vnet.ibm.com>,
Hari Bathini <hbathini@...ux.ibm.com>,
Thomas Gleixner <tglx@...utronix.de>,
Greg Kurz <groug@...d.org>,
Nicholas Piggin <npiggin@...il.com>,
Masahiro Yamada <yamada.masahiro@...ionext.com>,
Alexey Kardashevskiy <aik@...abs.ru>,
linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
linux-nvdimm@...ts.01.org, linux-mm@...ck.org
Subject: Re: [PATCH v3 24/27] powerpc/powernv/pmem: Expose SMART data via
ndctl
On Thu, 2020-03-05 at 14:36 +1100, Andrew Donnellan wrote:
> On 21/2/20 2:27 pm, Alastair D'Silva wrote:
> > +static int ndctl_smart(struct ocxlpmem *ocxlpmem, struct
> > nd_cmd_pkg *pkg)
> > +{
> > + u32 length, i;
> > + struct nd_ocxl_smart *out;
> > + int rc;
> > +
> > + mutex_lock(&ocxlpmem->admin_command.lock);
> > +
> > + rc = admin_command_request(ocxlpmem, ADMIN_COMMAND_SMART);
> > + if (rc)
> > + goto out;
> > +
> > + rc = admin_command_execute(ocxlpmem);
> > + if (rc)
> > + goto out;
> > +
> > + rc = admin_command_complete_timeout(ocxlpmem,
> > ADMIN_COMMAND_SMART);
> > + if (rc < 0) {
> > + dev_err(&ocxlpmem->dev, "SMART timeout\n");
> > + goto out;
> > + }
> > +
> > + rc = admin_response(ocxlpmem);
> > + if (rc < 0)
> > + goto out;
> > + if (rc != STATUS_SUCCESS) {
> > + warn_status(ocxlpmem, "Unexpected status from SMART",
> > rc);
> > + goto out;
> > + }
> > +
> > + rc = smart_header_parse(ocxlpmem, &length);
> > + if (rc)
> > + goto out;
> > +
> > + pkg->nd_fw_size = length;
> > +
> > + length = min(length, pkg->nd_size_out); // bytes
> > + out = (struct nd_ocxl_smart *)pkg->nd_payload;
> > + // Each SMART attribute is 2 * 64 bits
> > + out->count = length / (2 * sizeof(u64)); // attributes
>
> From what I can tell - 8 bytes of nd_ocxl_smart are taken up for
> the
> count + reserved bytes, so this is going to potentially overrun the
> user
> buffer.
Ok
>
> > +
> > + for (i = 0; i < length; i += sizeof(u64)) {
>
> It might be neater to make i count up by 1 and then multiply by
> sizeof(u64) later.
>
I tried, it doesn't make much difference to the complexity, and makes
it less clear that we are stepping in 64bit chunks.
> > + rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> > + ocxlpmem-
> > >admin_command.data_offset + sizeof(u64) + i,
>
> + 0x08 rather than + sizeof(u64) for consistency.
>
We use sizeof(u64) in the rest of this function.
> > + OCXL_LITTLE_ENDIAN,
> > + &out-
> > >attribs[i/sizeof(u64)]);
> > + if (rc)
> > + goto out;
> > + }
> > +
> > + rc = admin_response_handled(ocxlpmem);
> > + if (rc)
> > + goto out;
> > +
> > + rc = 0;
> > + goto out;
> > +
> > +out:
> > + mutex_unlock(&ocxlpmem->admin_command.lock);
> > + return rc;
> > +}
> > +
> > +static int ndctl_call(struct ocxlpmem *ocxlpmem, void *buf,
> > unsigned int buf_len)
> > +{
> > + struct nd_cmd_pkg *pkg = buf;
> > +
> > + if (buf_len < sizeof(struct nd_cmd_pkg)) {
> > + dev_err(&ocxlpmem->dev, "Invalid ND_CALL size=%u\n",
> > buf_len);
> > + return -EINVAL;
> > + }
> > +
> > + if (pkg->nd_family != NVDIMM_FAMILY_OCXL) {
> > + dev_err(&ocxlpmem->dev, "Invalid ND_CALL
> > family=0x%llx\n", pkg->nd_family);
> > + return -EINVAL;
> > + }
> > +
> > + switch (pkg->nd_command) {
> > + case ND_CMD_OCXL_SMART:
> > + ndctl_smart(ocxlpmem, pkg);
>
> Did you intend to dispose of the return code here?
Whoops.
>
> > + break;
> > +
> > + default:
> > + dev_err(&ocxlpmem->dev, "Invalid ND_CALL
> > command=0x%llx\n", pkg->nd_command);
> > + return -EINVAL;
> > + }
> > +
> > +
> > + return 0;
> > +}
> > +
> > static int ndctl(struct nvdimm_bus_descriptor *nd_desc,
> > struct nvdimm *nvdimm,
> > unsigned int cmd, void *buf, unsigned int buf_len, int
> > *cmd_rc)
> > @@ -88,6 +211,10 @@ static int ndctl(struct nvdimm_bus_descriptor
> > *nd_desc,
> > struct ocxlpmem *ocxlpmem = container_of(nd_desc, struct
> > ocxlpmem, bus_desc);
> >
> > switch (cmd) {
> > + case ND_CMD_CALL:
> > + *cmd_rc = ndctl_call(ocxlpmem, buf, buf_len);
> > + return 0;
> > +
> > case ND_CMD_GET_CONFIG_SIZE:
> > *cmd_rc = ndctl_config_size(buf);
> > return 0;
> > @@ -171,6 +298,7 @@ static int register_lpc_mem(struct ocxlpmem
> > *ocxlpmem)
> > set_bit(ND_CMD_GET_CONFIG_SIZE, &nvdimm_cmd_mask);
> > set_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm_cmd_mask);
> > set_bit(ND_CMD_SET_CONFIG_DATA, &nvdimm_cmd_mask);
> > + set_bit(ND_CMD_CALL, &nvdimm_cmd_mask);
> >
> > set_bit(NDD_ALIASING, &nvdimm_flags);
> >
> > diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
> > b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
> > index 927690f4888f..0eb7a35d24ae 100644
> > --- a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
> > +++ b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
> > @@ -7,6 +7,7 @@
> > #include <linux/libnvdimm.h>
> > #include <uapi/nvdimm/ocxl-pmem.h>
> > #include <linux/mm.h>
> > +#include <linux/ndctl.h>
> >
> > #define LABEL_AREA_SIZE (1UL << PA_SECTION_SHIFT)
> > #define DEFAULT_TIMEOUT 100
> > @@ -98,6 +99,23 @@ struct ocxlpmem_function0 {
> > struct ocxl_fn *ocxl_fn;
> > };
> >
> > +struct nd_ocxl_smart {
> > + __u8 count;
> > + __u8 reserved[7];
> > + __u64 attribs[0];
> > +} __packed;
> > +
> > +struct nd_pkg_ocxl {
> > + struct nd_cmd_pkg gen;
> > + union {
> > + struct nd_ocxl_smart smart;
> > + };
> > +};
> > +
> > +enum nd_cmd_ocxl {
> > + ND_CMD_OCXL_SMART = 1,
> > +};
> > +
> > struct ocxlpmem {
> > struct device dev;
> > struct pci_dev *pdev;
> > diff --git a/include/uapi/linux/ndctl.h
> > b/include/uapi/linux/ndctl.h
> > index de5d90212409..2885052e7f40 100644
> > --- a/include/uapi/linux/ndctl.h
> > +++ b/include/uapi/linux/ndctl.h
> > @@ -244,6 +244,7 @@ struct nd_cmd_pkg {
> > #define NVDIMM_FAMILY_HPE2 2
> > #define NVDIMM_FAMILY_MSFT 3
> > #define NVDIMM_FAMILY_HYPERV 4
> > +#define NVDIMM_FAMILY_OCXL 6
> >
> > #define ND_IOCTL_CALL _IOWR(ND_IOCTL,
> > ND_CMD_CALL,\
> > struct nd_cmd_pkg)
> >
--
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819
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