On Thu, 2020-02-27 at 19:22 +1100, Andrew Donnellan wrote:
> On 21/2/20 2:27 pm, Alastair D'Silva wrote:
> > From: Alastair D'Silva <alastair@xxxxxxxxxxx>
> >
> > This patch requests the metadata required to issue admin commands,
> > as well
> > as some helper functions to construct and check the completion of
> > the
> > commands.
> >
> > Signed-off-by: Alastair D'Silva <alastair@xxxxxxxxxxx>
> > ---
> > arch/powerpc/platforms/powernv/pmem/ocxl.c | 65 ++++++++
> > .../platforms/powernv/pmem/ocxl_internal.c | 153
> > ++++++++++++++++++
> > .../platforms/powernv/pmem/ocxl_internal.h | 61 +++++++
> > 3 files changed, 279 insertions(+)
> >
> > diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl.c
> > b/arch/powerpc/platforms/powernv/pmem/ocxl.c
> > index 431212c9f0cc..4e782d22605b 100644
> > --- a/arch/powerpc/platforms/powernv/pmem/ocxl.c
> > +++ b/arch/powerpc/platforms/powernv/pmem/ocxl.c
> > @@ -216,6 +216,58 @@ static int register_lpc_mem(struct ocxlpmem
> > *ocxlpmem)
> > return 0;
> > }
> >
> > +/**
> > + * extract_command_metadata() - Extract command data from MMIO &
> > save it for further use
> > + * @ocxlpmem: the device metadata
> > + * @offset: The base address of the command data structures
> > (address of CREQO)
> > + * @command_metadata: A pointer to the command metadata to
> > populate
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int extract_command_metadata(struct ocxlpmem *ocxlpmem, u32
> > offset,
> > + struct command_metadata
> > *command_metadata)
> > +{
> > + int rc;
> > + u64 tmp;
> > +
> > + rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu, offset,
> > OCXL_LITTLE_ENDIAN,
> > + &tmp);
> > + if (rc)
> > + return rc;
> > +
> > + command_metadata->request_offset = tmp >> 32;
> > + command_metadata->response_offset = tmp & 0xFFFFFFFF;
> > +
> > + rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu, offset + 8,
> > OCXL_LITTLE_ENDIAN,
> > + &tmp);
> > + if (rc)
> > + return rc;
> > +
> > + command_metadata->data_offset = tmp >> 32;
> > + command_metadata->data_size = tmp & 0xFFFFFFFF;
> > +
> > + command_metadata->id = 0;
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * setup_command_metadata() - Set up the command metadata
> > + * @ocxlpmem: the device metadata
> > + */
> > +static int setup_command_metadata(struct ocxlpmem *ocxlpmem)
> > +{
> > + int rc;
> > +
> > + mutex_init(&ocxlpmem->admin_command.lock);
> > +
> > + rc = extract_command_metadata(ocxlpmem, GLOBAL_MMIO_ACMA_CREQO,
> > + &ocxlpmem->admin_command);
> > + if (rc)
> > + return rc;
> > +
> > + return 0;
> > +}
> > +
> > /**
> > * is_usable() - Is a controller usable?
> > * @ocxlpmem: the device metadata
> > @@ -456,6 +508,14 @@ static int probe(struct pci_dev *pdev, const
> > struct pci_device_id *ent)
> > }
> > ocxlpmem->pdev = pdev;
> >
> > + ocxlpmem->timeouts[ADMIN_COMMAND_ERRLOG] = 2000; // ms
> > + ocxlpmem->timeouts[ADMIN_COMMAND_HEARTBEAT] = 100; // ms
> > + ocxlpmem->timeouts[ADMIN_COMMAND_SMART] = 100; // ms
> > + ocxlpmem->timeouts[ADMIN_COMMAND_CONTROLLER_DUMP] = 1000; // ms
> > + ocxlpmem->timeouts[ADMIN_COMMAND_CONTROLLER_STATS] = 100; // ms
> > + ocxlpmem->timeouts[ADMIN_COMMAND_SHUTDOWN] = 1000; // ms
> > + ocxlpmem->timeouts[ADMIN_COMMAND_FW_UPDATE] = 16000; // ms
>
> Why are we keeping these timeouts in a per device struct? I can't
> see
> anywhere where we change these values.
>
These are overwritten in a later patch, which I've missed! thanks for
pointing this out.
These initial values will be overwritten by card specific timeouts.
> > +
> > pci_set_drvdata(pdev, ocxlpmem);
> >
> > ocxlpmem->ocxl_fn = ocxl_function_open(pdev);
> > @@ -501,6 +561,11 @@ static int probe(struct pci_dev *pdev, const
> > struct pci_device_id *ent)
> > goto err;
> > }
> >
> > + if (setup_command_metadata(ocxlpmem)) {
> > + dev_err(&pdev->dev, "Could not read OCXL command
> > matada\n");
>
> metadata
Wow, not sure how that happened.
>
> Also, "OCXL command metadata" is misleading, this is a pmem specific
> thing, not an OpenCAPI thing, I would prefer just "command metadata".
>
Ok
> > + goto err;
> > + }
> > +
> > elapsed = 0;
> > timeout = ocxlpmem->readiness_timeout + ocxlpmem-
> > >memory_available_timeout;
> > while (!is_usable(ocxlpmem, false)) {
> > diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.c
> > b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.c
> > index 617ca943b1b8..583f48023025 100644
> > --- a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.c
> > +++ b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.c
> > @@ -17,3 +17,156 @@ int ocxlpmem_chi(const struct ocxlpmem
> > *ocxlpmem, u64 *chi)
> >
> > return 0;
> > }
> > +
> > +#define COMMAND_REQUEST_SIZE (8 * sizeof(u64))
> > +static int scm_command_request(const struct ocxlpmem *ocxlpmem,
> > + struct command_metadata *cmd, u8
> > op_code)
> > +{
> > + u64 val = op_code;
> > + int rc;
> > + u8 i;
> > +
> > + cmd->op_code = op_code;
> > + cmd->id++;
> > +
> > + val |= ((u64)cmd->id) << 16;
> > +
> > + rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu, cmd-
> > >request_offset,
> > + OCXL_LITTLE_ENDIAN, val);
> > + if (rc)
> > + return rc;
> > +
> > + for (i = sizeof(u64); i < COMMAND_REQUEST_SIZE; i +=
> > sizeof(u64)) {
> > + rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
> > + cmd->request_offset + i,
> > + OCXL_LITTLE_ENDIAN, 0);
> > + if (rc)
> > + return rc;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +int admin_command_request(struct ocxlpmem *ocxlpmem, u8 op_code)
> > +{
> > + u64 val;
> > + int rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> > GLOBAL_MMIO_CHI,
> > + OCXL_LITTLE_ENDIAN, &val);
> > + if (rc)
> > + return rc;
>
> Ignoring the value here expected, you're just trying to verify that
> you
> don't see an error on the read?
>
This was some vestigial code that should be removed.
> > +
> > + return scm_command_request(ocxlpmem, &ocxlpmem->admin_command,
> > op_code);
> > +}
> > +
> > +static int command_response(const struct ocxlpmem *ocxlpmem,
> > + const struct command_metadata *cmd)
> > +{
> > + u64 val;
> > + u16 id;
> > + u8 status;
> > + int rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> > + cmd->response_offset,
> > + OCXL_LITTLE_ENDIAN, &val);
> > + if (rc)
> > + return rc;
> > +
> > + status = val & 0xff;
> > + id = (val >> 16) & 0xffff;
> > +
> > + if (id != cmd->id) {
> > + dev_warn(&ocxlpmem->dev,
> > + "Expected response for command %d, but
> > received response for command %d instead.\n",
> > + cmd->id, id);
>
> If this happens I imagine something's gone pretty wrong - this
> should
> probably be a dev_err()? And perhaps we want to make sure we return
> an
> error code rather than whatever status code we get from the MMIO?
>
Ok
> > + }
> > +
> > + return status;
> > +}
> > +
> > +int admin_response(const struct ocxlpmem *ocxlpmem)
> > +{
> > + return command_response(ocxlpmem, &ocxlpmem->admin_command);
> > +}
> > +
> > +
> > +int admin_command_execute(const struct ocxlpmem *ocxlpmem)
> > +{
> > + return ocxl_global_mmio_set64(ocxlpmem->ocxl_afu,
> > GLOBAL_MMIO_HCI,
> > + OCXL_LITTLE_ENDIAN,
> > GLOBAL_MMIO_HCI_ACRW);
> > +}
> > +
> > +static bool admin_command_complete(const struct ocxlpmem
> > *ocxlpmem)
> > +{
> > + u64 val = 0;
> > +
> > + int rc = ocxlpmem_chi(ocxlpmem, &val);
> > +
> > + WARN_ON(rc);
> > +
> > + return (val & GLOBAL_MMIO_CHI_ACRA) != 0;
> > +}
> > +
> > +int admin_command_complete_timeout(const struct ocxlpmem
> > *ocxlpmem,
> > + int command)
> > +{
> > + u32 timeout = ocxlpmem->timeouts[command];
> > + // 32 is the next power of 2 greater than the 20ms minimum for
> > msleep
> > +#define TIMEOUT_SLEEP_MILLIS 32
> > + timeout /= TIMEOUT_SLEEP_MILLIS;
> > + if (!timeout)
> > + timeout = DEFAULT_TIMEOUT / TIMEOUT_SLEEP_MILLIS;
> > +
> > + while (timeout-- > 0) {
> > + if (admin_command_complete(ocxlpmem))
> > + return 0;
> > + msleep(TIMEOUT_SLEEP_MILLIS);
> > + }
>
> I think the more traditional way to implement timeouts is something
> more
> like:
>
> unsigned long timeout = jiffies + msecs_to_jiffies(<timeout
> period>);
> do {
> <check>
> <sleep>
> } while (time_before(jiffies, timeout));
>
ok
> > +
> > + if (admin_command_complete(ocxlpmem))
> > + return 0;
> > +
> > + return -EBUSY;
> > +}
> > +
> > +int admin_response_handled(const struct ocxlpmem *ocxlpmem)
> > +{
> > + return ocxl_global_mmio_set64(ocxlpmem->ocxl_afu,
> > GLOBAL_MMIO_CHIC,
> > + OCXL_LITTLE_ENDIAN,
> > GLOBAL_MMIO_CHI_ACRA);
> > +}
>
> This looks wrong? My reading of the spec is that you're meant to
> *clear*
> ACRA upon completion of handing, this looks like it's setting ACRA to
> 1.
>
Writing a 1 to the CHIC register clears the respective bit in the CHI
register. I'll add a comment.
> > +
> > +void warn_status(const struct ocxlpmem *ocxlpmem, const char
> > *message,
> > + u8 status)
> > +{
> > + const char *text = "Unknown";
> > +
> > + switch (status) {
> > + case STATUS_SUCCESS:
> > + text = "Success";
> > + break;
> > +
> > + case STATUS_MEM_UNAVAILABLE:
> > + text = "Persistent memory unavailable";
> > + break;
> > +
> > + case STATUS_BAD_OPCODE:
> > + text = "Bad opcode";
> > + break;
> > +
> > + case STATUS_BAD_REQUEST_PARM:
> > + text = "Bad request parameter";
> > + break;
> > +
> > + case STATUS_BAD_DATA_PARM:
> > + text = "Bad data parameter";
> > + break;
> > +
> > + case STATUS_DEBUG_BLOCKED:
> > + text = "Debug action blocked";
> > + break;
> > +
> > + case STATUS_FAIL:
> > + text = "Failed";
> > + break;
> > + }
> > +
> > + dev_warn(&ocxlpmem->dev, "%s: %s (%x)\n", message, text,
> > status);
> > +}
> > diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
> > b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
> > index ba0301533d00..2fef68c71271 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/mm.h>
> >
> > #define LABEL_AREA_SIZE (1UL << PA_SECTION_SHIFT)
> > +#define DEFAULT_TIMEOUT 100
> >
> > #define GLOBAL_MMIO_CHI 0x000
> > #define GLOBAL_MMIO_CHIC 0x008
> > @@ -80,6 +81,16 @@
> > #define STATUS_FW_ARG_INVALID 0x51
> > #define STATUS_FW_INVALID 0x52
> >
> > +struct command_metadata {
> > + u32 request_offset;
> > + u32 response_offset;
> > + u32 data_offset;
> > + u32 data_size;
> > + struct mutex lock;
> > + u16 id;
> > + u8 op_code;
> > +};
> > +
> > struct ocxlpmem_function0 {
> > struct pci_dev *pdev;
> > struct ocxl_fn *ocxl_fn;
> > @@ -95,9 +106,11 @@ struct ocxlpmem {
> > struct ocxl_afu *ocxl_afu;
> > struct ocxl_context *ocxl_context;
> > void *metadata_addr;
> > + struct command_metadata admin_command;
> > struct resource pmem_res;
> > struct nd_region *nd_region;
> > char fw_version[8+1];
> > + u32 timeouts[ADMIN_COMMAND_MAX+1];
> >
> > u32 max_controller_dump_size;
> > u16 scm_revision; // major/minor
> > @@ -122,3 +135,51 @@ struct ocxlpmem {
> > * Returns 0 on success, negative on error
> > */
> > int ocxlpmem_chi(const struct ocxlpmem *ocxlpmem, u64 *chi);
> > +
> > +/**
> > + * admin_command_request() - Issue an admin command request
> > + * @ocxlpmem: the device metadata
> > + * @op_code: The op-code for the command
> > + *
> > + * Returns an identifier for the command, or negative on error
> > + */
> > +int admin_command_request(struct ocxlpmem *ocxlpmem, u8 op_code);
> > +
> > +/**
> > + * admin_response() - Validate an admin response
> > + * @ocxlpmem: the device metadata
> > + * Returns the status code of the command, or negative on error
> > + */
> > +int admin_response(const struct ocxlpmem *ocxlpmem);
> > +
> > +/**
> > + * admin_command_execute() - Notify the controller to start
> > processing a pending admin command
> > + * @ocxlpmem: the device metadata
> > + * Returns 0 on success, negative on error
> > + */
> > +int admin_command_execute(const struct ocxlpmem *ocxlpmem);
> > +
> > +/**
> > + * admin_command_complete_timeout() - Wait for an admin command to
> > finish executing
> > + * @ocxlpmem: the device metadata
> > + * @command: the admin command to wait for completion (determines
> > the timeout)
> > + * Returns 0 on success, -EBUSY on timeout
> > + */
> > +int admin_command_complete_timeout(const struct ocxlpmem
> > *ocxlpmem,
> > + int command);
> > +
> > +/**
> > + * admin_response_handled() - Notify the controller that the admin
> > response has been handled
> > + * @ocxlpmem: the device metadata
> > + * Returns 0 on success, negative on failure
> > + */
> > +int admin_response_handled(const struct ocxlpmem *ocxlpmem);
> > +
> > +/**
> > + * warn_status() - Emit a kernel warning showing a command status.
> > + * @ocxlpmem: the device metadata
> > + * @message: A message to accompany the warning
> > + * @status: The command status
> > + */
> > +void warn_status(const struct ocxlpmem *ocxlpmem, const char
> > *message,
> > + u8 status);
> >
--
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819
