Re: [PATCH 08/10] nvdimm: Add driver for OpenCAPI Storage Class Memory

["Alastair D'Silva" <alastair@au1.ibm.com>]

On Thu, 2019-11-14 at 14:41 +0100, Frederic Barrat wrote:
> Hi Alastair,
> 
> The patch is huge and could/should probably be split in smaller
> pieces 
> to ease the review. However, having sinned on that same topic in the 
> past, I made a first pass anyway. I haven't covered everything but
> tried 
> to focus on the general setup of the driver for now.
> Since the patch is very long, I'm writing all the comments in one
> chunk 
> here instead of spreading them over a few thousand lines, where some 
> would be easy to miss.
> 
> 
> Update MAINTAINERS for the new files
> 
> Have you discussed with the directory owner if it's ok to split the 
> driver over several files?
> 

Not yet, I do have a request as to whether drivers/nvdimm is actually
the right place for this though.

> 
> Kconfig
> =======
> Does it make sense to keep OCXL_SCM_DEBUG separate? Why not enabling
> it 
> by default?

I think so, these features are a bit dangerous for general users, but
very useful for developers.

> 
> 
> ocxl_scm.c
> ==========
> 
> scm_file_init()
> ---------------
> on error paths, should call idr_destroy() (same pb found in base
> ocxl 
> driver)
> 

Ok.

> 
> scm_probe() and _function_0()
> -----------------------------
> 
> The different init between function 0 and 1 looks a bit off and it
> seems 
> they could be unified. Function 1 does the same thing as function 0 
> (call ocxl_function_open()) then some AFU-specific init, which we
> could 
> skip if there's no AFU found on the function. And log a WARN if we
> find 
> an AFU on something else than function 1, since, unlike ocxl, we
> know 
> exactly what the device is like for SCM. But keep an common probe() 
> function. It would also simplify the flow on scm_remove() and avoid 
> problems (currently ocxl_function_close() is not called for function
> 1).

Hmm, the 2 functions do very different things. Function 0 only exists
for link negotiation, and there is a huge amount of other bits & pieces
in the scm_data struct that will never be used for it.

ocxl_function_close() is called in free_scm() via the release handler
for the device.

> 
> scm-data->timeouts: array of size 9 declared, we only init 7
> members. 
> With the zalloc() the others are at 0, is that correct?
> 

Yes, these will be queried dynamically from the card in a later patch,
but that feature is not yet ready for testing.

The timeouts that are currently 0 are never read in the current
implementation of the driver.

> 
> Something looks wrong regarding data release in the error path(s).
> IIUC, 
> we register the device early and rely on the release callback of the 
> device to free all resources (in free_scm_dev()). We should probably 
> have a comment in probe() to make it obvious. Or maybe better, have
> a 

I'll add a comment.

> subfunction to keep doing the rest of the inits which are dependent
> on 
> the device release to be cleaned up. In the subsequent error paths
> in 
> scm_probe(), we are missing a device_unregister()
> 

This is intentional, I want to keep the device online (but not
registered with libnvdimm) in the event of an error as the card can be
interrogated via IOCTLs to find out what wrong.

> Could log 120 times the same "Waiting for SCM to become usable"
> message, 
> which is not really helping much.
> 

I'll quieten that, it was useful during development to identify whether
the machine had locked up or was still waiting on the card.

> 
> free_scm()
> ---------
> Related to above comment in probe(), it would help to be able to
> easily 
> match the what's done in probe vs. undone here. For example, in
> probe(), 
> there's scm_setup_irq(), where we do all things related to
> interrupts. 
> But we don't have a subfunction to clean the interrupts state. It
> would 
> help for readability and track potential misses. I didn't tried to
> match 
> all of them, but the following calls seem missing:
> 
> ocxl_context_detach()
> ocxl_afu_irq_free()

Hmm, we call ocxl_context_detach_all() in ocxl/core.c:remove_afu() (via
ocxl_function_close), but by that stage, I've already called
ocxl_context_free(), so that's clearly a bug.

I'll add in the missing ocxl_context_detach call in the scm_driver, and
in a seperate patch, free the context in ocxl_context_detach_all().

I'll also add in the missing calls to ocxl_afu_irq_free(), but I wonder
whether we should also clean all the IRQ allocations in remove_afu()
too?

> 
> 
> ocxl_remove()
> -------------
> see comment above about unifying function 0 and 1 case.
> Why is nvdimm_bus_unregister() treated separately? Can't it be part
> of 
> the "normal" freeing of resources done implicitly when calling 
> device_unregister() in the free_scm() callback?
> 

Yeah, good observation.

> 
> scm_setup_device_metadata()
> ---------------------------
> function doesn't do any setup, so the name is misleading.
> 

renamed to read_device_metadata().

> 	for (i = 0; i < 8; i++)
> 		scm_data->fw_version[i] = (val >> (i * 8)) & 0xff;
> => looks like an endianess conversion? Can't we use the
> OCXL_BIG_ENDIAN 
> when doing the mmio read?

It's extracting bytes of text out, I've replaced it with a native
endian read & a comment.

> 
> scm_setup_irq()
> ---------------
> if ocxl_afu_irq_get_addr(irq 1) or the ioremap(irq 1) fail, we jump
> to 
> the label 'out_irq0' and will exit the function with rc = 0, instead
> of 
> failing.
> 

Good catch, thanks.

> 
> 
> scm_setup_command_metadata()
> ----------------------------
> it would make sense to initialize the mutex in the struct 
> command_metadata in this function instead of the top of scm_probe(),
> to 
> group all the related data inits.
> 

Agreed.

> 
> 
> scm_probe_function_0()
> ----------------------
> comment above function:
>   * This is important as it enables higher than 0 across all other 
> functions,
>   * which in turn enables higher bandwidth accesses
> 
> "higher than 0"?
> I'm guessing you want to say function 0 configures the link, to
> ensure 
> maximum bandwidth
> 

Ugh, that's terrible, it looks like some words are missing. It should
say "templates higher than 0".

> EFAULT is usually reserved for an invalid memory access. Why not 
> PTR_ERR() of the returned value from ocxl_function_open()?
> 

Agreed.

> 
> 
> struct scm_fops has a wrong indentation (spaces between .open and
> '=')
> 

Thanks.

> 
> 
> scm_heartbeat()
> ---------------
> the "goto out" at the end of the good path is useless and unusual in
> the 
> kernel, I think.
> 

Ok, I tend to add these to show I intended to fall through and didn't
forget to do something else, but I'll remove it for consistency.

> 
> scm_register_lpc_mem()
> ----------------------
> lpc_mem = ocxl_afu_lpc_mem(scm_data->ocxl_afu);
> => lpc_mem is allocated as part of the afu structure in ocxl, so
> that 
> shouldn't be NULL. Still worth keeping, but I think lpc_mem->start
> is 
> what really needs testing
> 

I'll test both, thanks.

> 
> scm_imn0_handler()
> -----------------
> I don't think we should return IRQ_NONE. As far as the kernel is 
> concerned, an interrupt was raised. So it should be acknowledged,
> even 
> if the fgpa is somehow in an incorrect state. So the IRQ_NONE should
> be 
> IRQ_HANDLED
> 

OK.

> 
> scm_imn1_handler()
> ------------------
> for the sake of clarity, the potential error when calling scm_chi() 
> should be treated the same in the 2 handlers.

Agreed.

> What's the effect of nvdimm_bus_unregister() on any application
> using 
> the memory?
> 

Good question, I haven't checked, but I would expect a segfault as the
memory is yanked out.

The situation in which we do this is where the card is in a FATAL
state, so would be unable to satisfy any requests.

> 
> #ifdef CONFIG_OCXL_SCM_DEBUG
> It's usual and it helps navigate the code, to comment the config
> macro 
> on the else and endif lines:
> #endif /* CONFIG_OCXL_SCM_DEBUG */
> 
> 
Agreed.

> 
> 
> ocxl-scm_internal.c
> ====================
> 
> scm_admin_command_request
> -------------------------
> Hardening: would it make sense to test and error out if the ACRA bit 
> (used to test command is complete) is at 0 before submitting a new
> request?
> 

Yes, I'll do that.

> 
> scm_admin_command_complete_timeout
> ----------------------------------
> A delay of 32ms is not that usual. A comment explaining why would be 
> interesting.
> 
Ok, also replaced with a define.

> Why timeout++ ?
Stray code, I'll remove it.

> 
> 
> 
> ocxl-scm_sysfs.c
> ================
> No reason to export the scm_sysfs_add symbol
> 
Ok.

> 
> 
> ocxl_scm.h
> ==========
> struct scm_ioctl_error_log:
> char  fw_revision[8+1]
> exposed to uncontrolled padding, which is a problem for a KABI
> Remove the extra char?
> 

This is always an output field, so the kernel has control of the
padding.

> 
> 
> memory_hotplug.c
> ================
> whitespace diff shouldn't be here
> 

Ok.

> 
>    Fred
> 
> 
> Le 25/10/2019 à 06:47, Alastair D'Silva a écrit :
> > From: Alastair D'Silva <alastair@d-silva.org>
> > 
> > This driver exposes LPC memory on OpenCAPI SCM cards
> > as an NVDIMM, allowing the existing nvram infrastructure
> > to be used.
> > 
> > Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
> > ---
> >   drivers/nvdimm/Kconfig             |   17 +
> >   drivers/nvdimm/Makefile            |    3 +
> >   drivers/nvdimm/ocxl-scm.c          | 2210
> > ++++++++++++++++++++++++++++
> >   drivers/nvdimm/ocxl-scm_internal.c |  232 +++
> >   drivers/nvdimm/ocxl-scm_internal.h |  331 +++++
> >   drivers/nvdimm/ocxl-scm_sysfs.c    |  219 +++
> >   include/uapi/linux/ocxl-scm.h      |  128 ++
> >   mm/memory_hotplug.c                |    2 +-
> >   8 files changed, 3141 insertions(+), 1 deletion(-)
> >   create mode 100644 drivers/nvdimm/ocxl-scm.c
> >   create mode 100644 drivers/nvdimm/ocxl-scm_internal.c
> >   create mode 100644 drivers/nvdimm/ocxl-scm_internal.h
> >   create mode 100644 drivers/nvdimm/ocxl-scm_sysfs.c
> >   create mode 100644 include/uapi/linux/ocxl-scm.h
> > 
> > diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
> > index 36af7af6b7cf..e4f7b6b08efd 100644
> > --- a/drivers/nvdimm/Kconfig
> > +++ b/drivers/nvdimm/Kconfig
> > @@ -130,4 +130,21 @@ config NVDIMM_TEST_BUILD
> >   	  core devm_memremap_pages() implementation and other
> >   	  infrastructure.
> >   
> > +config OCXL_SCM
> > +	tristate "OpenCAPI Storage Class Memory"
> > +	depends on LIBNVDIMM
> > +	select ZONE_DEVICE
> > +	select OCXL
> > +	help
> > +	  Exposes devices that implement the OpenCAPI Storage Class
> > Memory
> > +	  specification as persistent memory regions.
> > +
> > +	  Select N if unsure.
> > +
> > +config OCXL_SCM_DEBUG
> > +	bool "OpenCAPI Storage Class Memory debugging"
> > +	depends on OCXL_SCM
> > +	help
> > +	  Enables low level IOCTLs for OpenCAPI SCM firmware
> > development
> > +
> >   endif
> > diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile
> > index 29203f3d3069..43d826397bfc 100644
> > --- a/drivers/nvdimm/Makefile
> > +++ b/drivers/nvdimm/Makefile
> > @@ -6,6 +6,9 @@ obj-$(CONFIG_ND_BLK) += nd_blk.o
> >   obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o
> >   obj-$(CONFIG_OF_PMEM) += of_pmem.o
> >   obj-$(CONFIG_VIRTIO_PMEM) += virtio_pmem.o nd_virtio.o
> > +obj-$(CONFIG_OCXL_SCM) += ocxlscm.o
> > +
> > +ocxlscm-y := ocxl-scm.o ocxl-scm_internal.o ocxl-scm_sysfs.o
> >   
> >   nd_pmem-y := pmem.o
> >   
> > diff --git a/drivers/nvdimm/ocxl-scm.c b/drivers/nvdimm/ocxl-scm.c
> > new file mode 100644
> > index 000000000000..f4e6cc022de8
> > --- /dev/null
> > +++ b/drivers/nvdimm/ocxl-scm.c
> > @@ -0,0 +1,2210 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +// Copyright 2019 IBM Corp.
> > +
> > +/*
> > + * A driver for Storage Class Memory, connected via OpenCAPI
> > + */
> > +
> > +#include <linux/module.h>
> > +#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>
> > +#include "ocxl-scm_internal.h"
> > +
> > +
> > +static const struct pci_device_id scm_pci_tbl[] = {
> > +	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, 0x0625), },
> > +	{ }
> > +};
> > +
> > +MODULE_DEVICE_TABLE(pci, scm_pci_tbl);
> > +
> > +#define SCM_NUM_MINORS 256 // Total to reserve
> > +#define SCM_USABLE_TIMEOUT 120 // seconds
> > +
> > +static dev_t scm_dev;
> > +static struct class *scm_class;
> > +static struct mutex minors_idr_lock;
> > +static struct idr minors_idr;
> > +
> > +static const struct attribute_group *scm_pmem_attribute_groups[] =
> > {
> > +	&nvdimm_bus_attribute_group,
> > +	NULL,
> > +};
> > +
> > +static const struct attribute_group
> > *scm_pmem_region_attribute_groups[] = {
> > +	&nd_region_attribute_group,
> > +	&nd_device_attribute_group,
> > +	&nd_mapping_attribute_group,
> > +	&nd_numa_attribute_group,
> > +	NULL,
> > +};
> > +
> > +/**
> > + * scm_ndctl_config_write() - Handle a ND_CMD_SET_CONFIG_DATA
> > command from ndctl
> > + * @scm_data: the SCM metadata
> > + * @command: the incoming data to write
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int scm_ndctl_config_write(struct scm_data *scm_data,
> > +				  struct nd_cmd_set_config_hdr
> > *command)
> > +{
> > +	if (command->in_offset + command->in_length >
> > SCM_LABEL_AREA_SIZE)
> > +		return -EINVAL;
> > +
> > +	memcpy_flushcache(scm_data->metadata_addr + command->in_offset, 
> > command->in_buf,
> > +			  command->in_length);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * scm_ndctl_config_read() - Handle a ND_CMD_GET_CONFIG_DATA
> > command from ndctl
> > + * @scm_data: the SCM metadata
> > + * @command: the read request
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int scm_ndctl_config_read(struct scm_data *scm_data,
> > +				 struct nd_cmd_get_config_data_hdr
> > *command)
> > +{
> > +	if (command->in_offset + command->in_length >
> > SCM_LABEL_AREA_SIZE)
> > +		return -EINVAL;
> > +
> > +	memcpy(command->out_buf, scm_data->metadata_addr + command-
> > >in_offset,
> > +	       command->in_length);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * scm_ndctl_config_size() - Handle a ND_CMD_GET_CONFIG_SIZE
> > command from ndctl
> > + * @scm_data: the SCM metadata
> > + * @command: the read request
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int scm_ndctl_config_size(struct nd_cmd_get_config_size
> > *command)
> > +{
> > +	command->status = 0;
> > +	command->config_size = SCM_LABEL_AREA_SIZE;
> > +	command->max_xfer = PAGE_SIZE;
> > +
> > +	return 0;
> > +}
> > +
> > +static int read_smart_attrib(struct scm_data *scm_data, u16
> > offset,
> > +			     struct scm_smart_attribs *attribs)
> > +{
> > +	u64 val;
> > +	int rc;
> > +	struct scm_smart_attrib *attrib;
> > +	u8 attrib_id;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, offset,
> > OCXL_LITTLE_ENDIAN,
> > +				     &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	attrib_id = (val >> 56) & 0xff;
> > +	switch (attrib_id) {
> > +	case SCM_SMART_ATTR_POWER_ON_HOURS:
> > +		attrib = &attribs->power_on_hours;
> > +		break;
> > +
> > +	case SCM_SMART_ATTR_TEMPERATURE:
> > +		attrib = &attribs->temperature;
> > +		break;
> > +
> > +	case SCM_SMART_ATTR_LIFE_REMAINING:
> > +		attrib = &attribs->life_remaining;
> > +		break;
> > +
> > +	default:
> > +		dev_err(&scm_data->dev, "Unknown smart attrib '%d'",
> > attrib_id);
> > +		return -EFAULT;
> > +	}
> > +
> > +	attrib->id = attrib_id;
> > +	attrib->attribute_flags = (val >> 40) & 0xffff;
> > +	attrib->current_val = (val >> 32) & 0xff;
> > +	attrib->threshold_val = (val >> 24) & 0xff;
> > +	attrib->worst_val = (val >> 16) & 0xff;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, offset + 0x08,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	attrib->raw_val = val;
> > +
> > +	return 0;
> > +}
> > +
> > +static int scm_smart_offset_0x00(struct scm_data *scm_data, u32
> > *length)
> > +{
> > +	int rc;
> > +	u64 val;
> > +
> > +	u16 data_identifier;
> > +	u32 data_length;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	data_identifier = val >> 48;
> > +	data_length = val & 0xFFFFFFFF;
> > +
> > +	if (data_identifier != 0x534D) {
> > +		dev_err(&scm_data->dev,
> > +			"Bad data identifier for smart data, expected
> > 'SM', got '%-.*s'\n",
> > +			2, (char *)&data_identifier);
> > +		return -EFAULT;
> > +	}
> > +
> > +	*length = data_length;
> > +	return 0;
> > +}
> > +
> > +static int scm_smart_update(struct scm_data *scm_data)
> > +{
> > +	u32 length, i;
> > +	int rc;
> > +
> > +	mutex_lock(&scm_data->admin_command.lock);
> > +
> > +	rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_SMART);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_execute(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_complete_timeout(scm_data,
> > ADMIN_COMMAND_SMART);
> > +	if (rc < 0) {
> > +		dev_err(&scm_data->dev, "SMART timeout\n");
> > +		goto out;
> > +	}
> > +
> > +	rc = scm_admin_response(scm_data);
> > +	if (rc < 0)
> > +		goto out;
> > +	if (rc != STATUS_SUCCESS) {
> > +		scm_warn_status(scm_data, "Unexpected status from
> > SMART", rc);
> > +		goto out;
> > +	}
> > +
> > +	rc = scm_smart_offset_0x00(scm_data, &length);
> > +	if (rc)
> > +		goto out;
> > +
> > +	length /= 0x10; // Length now contains the number of attributes
> > +
> > +	for (i = 0; i < length; i++)
> > +		read_smart_attrib(scm_data,
> > +				  scm_data->admin_command.data_offset +
> > 0x08 + i * 0x10,
> > +				  &scm_data->smart);
> > +
> > +	rc = scm_admin_response_handled(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = 0;
> > +	goto out;
> > +
> > +out:
> > +	mutex_unlock(&scm_data->admin_command.lock);
> > +	return rc;
> > +}
> > +
> > +static int scm_ndctl_smart(struct scm_data *scm_data, void *buf,
> > +			   unsigned int buf_len)
> > +{
> > +	int rc;
> > +
> > +	if (buf_len != sizeof(scm_data->smart))
> > +		return -EINVAL;
> > +
> > +	rc = scm_smart_update(scm_data);
> > +	if (rc)
> > +		return rc;
> > +
> > +	memcpy(buf, &scm_data->smart, buf_len);
> > +
> > +	return 0;
> > +}
> > +
> > +
> > +static int scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
> > +		     struct nvdimm *nvdimm,
> > +		     unsigned int cmd, void *buf, unsigned int buf_len,
> > int *cmd_rc)
> > +{
> > +	struct scm_data *scm_data = container_of(nd_desc, struct
> > scm_data, bus_desc);
> > +
> > +	switch (cmd) {
> > +	case ND_CMD_SMART:
> > +		*cmd_rc = scm_ndctl_smart(scm_data, buf, buf_len);
> > +		return 0;
> > +
> > +	case ND_CMD_GET_CONFIG_SIZE:
> > +		*cmd_rc = scm_ndctl_config_size(buf);
> > +		return 0;
> > +
> > +	case ND_CMD_GET_CONFIG_DATA:
> > +		*cmd_rc = scm_ndctl_config_read(scm_data, buf);
> > +		return 0;
> > +
> > +	case ND_CMD_SET_CONFIG_DATA:
> > +		*cmd_rc = scm_ndctl_config_write(scm_data, buf);
> > +		return 0;
> > +
> > +	default:
> > +		return -ENOTTY;
> > +	}
> > +}
> > +
> > +static ssize_t serial_show(struct device *dev,
> > +			   struct device_attribute *attr, char *buf)
> > +{
> > +	struct nvdimm *nvdimm = to_nvdimm(dev);
> > +	struct scm_data *scm_data = nvdimm_provider_data(nvdimm);
> > +	const struct ocxl_fn_config *config =
> > ocxl_function_config(scm_data->ocxl_fn);
> > +
> > +	return sprintf(buf, "0x%llx\n", config->serial);
> > +}
> > +static DEVICE_ATTR_RO(serial);
> > +
> > +static struct attribute *scm_dimm_attributes[] = {
> > +	&dev_attr_serial.attr,
> > +	NULL,
> > +};
> > +
> > +static umode_t scm_dimm_attr_visible(struct kobject *kobj,
> > +				     struct attribute *a, int n)
> > +{
> > +	return a->mode;
> > +}
> > +
> > +static const struct attribute_group scm_dimm_attribute_group = {
> > +	.name = "scm",
> > +	.attrs = scm_dimm_attributes,
> > +	.is_visible = scm_dimm_attr_visible,
> > +};
> > +
> > +static const struct attribute_group *scm_dimm_attribute_groups[] =
> > {
> > +	&nvdimm_attribute_group,
> > +	&nd_device_attribute_group,
> > +	&scm_dimm_attribute_group,
> > +	NULL,
> > +};
> > +
> > +/**
> > + * scm_reserve_metadata() - Reserve space for nvdimm metadata
> > + * @scm_data: The SCM device data
> > + * @lpc_mem: The resource representing the LPC memory of the SCM
> > device
> > + */
> > +static int scm_reserve_metadata(struct scm_data *scm_data,
> > +				struct resource *lpc_mem)
> > +{
> > +	scm_data->metadata_addr = devm_memremap(&scm_data->dev,
> > lpc_mem->start,
> > +						SCM_LABEL_AREA_SIZE,
> > MEMREMAP_WB);
> > +	if (IS_ERR(scm_data->metadata_addr))
> > +		return PTR_ERR(scm_data->metadata_addr);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * scm_overwrite() - Overwrite all data on the card
> > + * @scm_data: The SCM device data
> > + * Return: 0 on success
> > + */
> > +int scm_overwrite(struct scm_data *scm_data)
> > +{
> > +	int rc;
> > +
> > +	mutex_lock(&scm_data->ns_command.lock);
> > +
> > +	rc = scm_ns_command_request(scm_data, NS_COMMAND_SECURE_ERASE);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_ns_command_execute(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +	scm_data->overwrite_state = SCM_OVERWRITE_BUSY;
> > +
> > +	return 0;
> > +
> > +out:
> > +	mutex_unlock(&scm_data->ns_command.lock);
> > +	return rc;
> > +}
> > +
> > +/**
> > + * scm_secop_overwrite() - Overwrite all data on the card
> > + * @nvdimm: The nvdimm representation of the SCM device to start
> > the overwrite on
> > + * @key_data: Unused (no security key implementation)
> > + * Return: 0 on success
> > + */
> > +static int scm_secop_overwrite(struct nvdimm *nvdimm,
> > +			       const struct nvdimm_key_data *key_data)
> > +{
> > +	struct scm_data *scm_data = nvdimm_provider_data(nvdimm);
> > +
> > +	return scm_overwrite(scm_data);
> > +}
> > +
> > +/**
> > + * scm_secop_query_overwrite() - Get the current overwrite state
> > + * @nvdimm: The nvdimm representation of the SCM device to start
> > the overwrite on
> > + * Return: 0 if successful or idle, -EBUSY if busy, -EFAULT if
> > failed
> > + */
> > +static int scm_secop_query_overwrite(struct nvdimm *nvdimm)
> > +{
> > +	struct scm_data *scm_data = nvdimm_provider_data(nvdimm);
> > +
> > +	if (scm_data->overwrite_state == SCM_OVERWRITE_BUSY)
> > +		return -EBUSY;
> > +
> > +	if (scm_data->overwrite_state == SCM_OVERWRITE_FAILED)
> > +		return -EFAULT;
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * scm_secop_get_flags() - return the security flags for the SCM
> > device
> > + */
> > +static unsigned long scm_secop_get_flags(struct nvdimm *nvdimm,
> > +		enum nvdimm_passphrase_type ptype)
> > +{
> > +	struct scm_data *scm_data = nvdimm_provider_data(nvdimm);
> > +
> > +	if (scm_data->overwrite_state == SCM_OVERWRITE_BUSY)
> > +		return BIT(NVDIMM_SECURITY_OVERWRITE);
> > +
> > +	return BIT(NVDIMM_SECURITY_DISABLED);
> > +}
> > +
> > +static const struct nvdimm_security_ops sec_ops  = {
> > +	.get_flags = scm_secop_get_flags,
> > +	.overwrite = scm_secop_overwrite,
> > +	.query_overwrite = scm_secop_query_overwrite,
> > +};
> > +
> > +/**
> > + * scm_register_lpc_mem() - Discover persistent memory on a device
> > and register it with the NVDIMM subsystem
> > + * @scm_data: The SCM device data
> > + * Return: 0 on success
> > + */
> > +static int scm_register_lpc_mem(struct scm_data *scm_data)
> > +{
> > +	struct nd_region_desc region_desc;
> > +	struct nd_mapping_desc nd_mapping_desc;
> > +	struct resource *lpc_mem;
> > +	const struct ocxl_afu_config *config;
> > +	const struct ocxl_fn_config *fn_config;
> > +	int rc;
> > +	unsigned long nvdimm_cmd_mask = 0;
> > +	unsigned long nvdimm_flags = 0;
> > +	int target_node;
> > +	char serial[16+1];
> > +
> > +	// Set up the reserved metadata area
> > +	rc = ocxl_afu_map_lpc_mem(scm_data->ocxl_afu);
> > +	if (rc < 0)
> > +		return rc;
> > +
> > +	lpc_mem = ocxl_afu_lpc_mem(scm_data->ocxl_afu);
> > +	if (lpc_mem == NULL)
> > +		return -EINVAL;
> > +
> > +	config = ocxl_afu_config(scm_data->ocxl_afu);
> > +	fn_config = ocxl_function_config(scm_data->ocxl_fn);
> > +
> > +	rc = scm_reserve_metadata(scm_data, lpc_mem);
> > +	if (rc)
> > +		return rc;
> > +
> > +	scm_data->bus_desc.attr_groups = scm_pmem_attribute_groups;
> > +	scm_data->bus_desc.provider_name = "scm";
> > +	scm_data->bus_desc.ndctl = scm_ndctl;
> > +	scm_data->bus_desc.module = THIS_MODULE;
> > +
> > +	scm_data->nvdimm_bus = nvdimm_bus_register(&scm_data->dev,
> > +			       &scm_data->bus_desc);
> > +	if (!scm_data->nvdimm_bus)
> > +		return -EINVAL;
> > +
> > +	scm_data->scm_res.start = (u64)lpc_mem->start +
> > SCM_LABEL_AREA_SIZE;
> > +	scm_data->scm_res.end = (u64)lpc_mem->start + config-
> > >lpc_mem_size - 1;
> > +	scm_data->scm_res.name = "SCM persistent memory";
> > +
> > +	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_SMART, &nvdimm_cmd_mask);
> > +
> > +	set_bit(NDD_ALIASING, &nvdimm_flags);
> > +
> > +	snprintf(serial, sizeof(serial), "%llx", fn_config->serial);
> > +	nd_mapping_desc.nvdimm = __nvdimm_create(scm_data->nvdimm_bus,
> > scm_data,
> > +				 scm_dimm_attribute_groups,
> > +				 nvdimm_flags, nvdimm_cmd_mask,
> > +				 0, NULL, serial, &sec_ops);
> > +	if (!nd_mapping_desc.nvdimm)
> > +		return -ENOMEM;
> > +
> > +	if (nvdimm_bus_check_dimm_count(scm_data->nvdimm_bus, 1))
> > +		return -EINVAL;
> > +
> > +	nd_mapping_desc.start = scm_data->scm_res.start;
> > +	nd_mapping_desc.size = resource_size(&scm_data->scm_res);
> > +	nd_mapping_desc.position = 0;
> > +
> > +	scm_data->nd_set.cookie1 = fn_config->serial + 1; // allow for
> > empty serial
> > +	scm_data->nd_set.cookie2 = fn_config->serial + 1;
> > +
> > +	target_node = of_node_to_nid(scm_data->pdev->dev.of_node);
> > +
> > +	memset(&region_desc, 0, sizeof(region_desc));
> > +	region_desc.res = &scm_data->scm_res;
> > +	region_desc.attr_groups = scm_pmem_region_attribute_groups;
> > +	region_desc.numa_node = NUMA_NO_NODE;
> > +	region_desc.target_node = target_node;
> > +	region_desc.num_mappings = 1;
> > +	region_desc.mapping = &nd_mapping_desc;
> > +	region_desc.nd_set = &scm_data->nd_set;
> > +
> > +	set_bit(ND_REGION_PAGEMAP, &region_desc.flags);
> > +	/*
> > +	 * NB: libnvdimm copies the data from ndr_desc into it's own
> > +	 * structures so passing a stack pointer is fine.
> > +	 */
> > +	scm_data->nd_region = nvdimm_pmem_region_create(scm_data-
> > >nvdimm_bus,
> > +			      &region_desc);
> > +	if (!scm_data->nd_region)
> > +		return -EINVAL;
> > +
> > +	dev_info(&scm_data->dev,
> > +		 "Onlining %lluMB of persistent memory\n",
> > +		 nd_mapping_desc.size / SZ_1M);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * scm_is_memory_available() - Does the controller have memory
> > available?
> > + * @scm_data: a pointer to the SCM device data
> > + * Return: true if the controller has memory available
> > + */
> > +static bool scm_is_memory_available(const struct scm_data
> > *scm_data)
> > +{
> > +	u64 val = 0;
> > +	int rc = scm_chi(scm_data, &val);
> > +
> > +	WARN_ON(rc < 0);
> > +
> > +	return (val & GLOBAL_MMIO_CHI_MA) != 0;
> > +}
> > +
> > +/**
> > + * scm_extract_command_metadata() - Extract command data from MMIO
> > & save it for further use
> > + * @scm_data: a pointer to the SCM device data
> > + * @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 scm_extract_command_metadata(struct scm_data *scm_data,
> > u32 offset,
> > +					struct command_metadata
> > *command_metadata)
> > +{
> > +	int rc;
> > +	u64 tmp;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->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(scm_data->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;
> > +}
> > +
> > +/**
> > + * scm_setup_command_metadata() - Set up the command metadata
> > + * @scm_data: a pointer to the SCM device data
> > + */
> > +static int scm_setup_command_metadata(struct scm_data *scm_data)
> > +{
> > +	int rc;
> > +
> > +	rc = scm_extract_command_metadata(scm_data,
> > GLOBAL_MMIO_ACMA_CREQO,
> > +					  &scm_data->admin_command);
> > +	if (rc)
> > +		return rc;
> > +
> > +	rc = scm_extract_command_metadata(scm_data,
> > GLOBAL_MMIO_NSCMA_CREQO,
> > +					  &scm_data->ns_command);
> > +	if (rc)
> > +		return rc;
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * scm_heartbeat() - Issue a heartbeat command to the controller
> > + * @scm_data: a pointer to the SCM device data
> > + * Return: 0 if the controller responded correctly, negative on
> > error
> > + */
> > +static int scm_heartbeat(struct scm_data *scm_data)
> > +{
> > +	int rc;
> > +
> > +	mutex_lock(&scm_data->admin_command.lock);
> > +
> > +	rc = scm_admin_command_request(scm_data,
> > ADMIN_COMMAND_HEARTBEAT);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_execute(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_complete_timeout(scm_data,
> > ADMIN_COMMAND_HEARTBEAT);
> > +	if (rc < 0) {
> > +		dev_err(&scm_data->dev, "Heartbeat timeout\n");
> > +		goto out;
> > +	}
> > +
> > +	rc = scm_admin_response(scm_data);
> > +	if (rc < 0)
> > +		goto out;
> > +	if (rc != STATUS_SUCCESS)
> > +		scm_warn_status(scm_data, "Unexpected status from
> > heartbeat", rc);
> > +
> > +	rc = scm_admin_response_handled(scm_data);
> > +
> > +	goto out;
> > +
> > +out:
> > +	mutex_unlock(&scm_data->admin_command.lock);
> > +	return rc;
> > +}
> > +
> > +/**
> > + * scm_is_usable() - Is a controller usable?
> > + * @scm_data: a pointer to the SCM device data
> > + * Return: true if the controller is usable
> > + */
> > +static bool scm_is_usable(const struct scm_data *scm_data)
> > +{
> > +	if (!scm_controller_is_ready(scm_data)) {
> > +		dev_err(&scm_data->dev, "SCM controller is not
> > ready.\n");
> > +		return false;
> > +	}
> > +
> > +	if (!scm_is_memory_available(scm_data)) {
> > +		dev_err(&scm_data->dev,
> > +			"SCM controller does not have memory
> > available.\n");
> > +		return false;
> > +	}
> > +
> > +	return true;
> > +}
> > +
> > +/**
> > + * allocate_scm_minor() - Allocate a minor number to use for an
> > SCM device
> > + * @scm_data: The SCM device to associate the minor with
> > + * Return: the allocated minor number
> > + */
> > +static int allocate_scm_minor(struct scm_data *scm_data)
> > +{
> > +	int minor;
> > +
> > +	mutex_lock(&minors_idr_lock);
> > +	minor = idr_alloc(&minors_idr, scm_data, 0, SCM_NUM_MINORS,
> > GFP_KERNEL);
> > +	mutex_unlock(&minors_idr_lock);
> > +	return minor;
> > +}
> > +
> > +static void free_scm_minor(struct scm_data *scm_data)
> > +{
> > +	mutex_lock(&minors_idr_lock);
> > +	idr_remove(&minors_idr, MINOR(scm_data->dev.devt));
> > +	mutex_unlock(&minors_idr_lock);
> > +}
> > +
> > +/**
> > + * free_scm() - Free all members of an SCM struct
> > + * @scm_data: the SCM metadata to clear
> > + */
> > +static void free_scm(struct scm_data *scm_data)
> > +{
> > +	// Disable doorbells
> > +	(void)ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_CHIEC,
> > +				     OCXL_LITTLE_ENDIAN,
> > +				     GLOBAL_MMIO_CHI_ALL);
> > +
> > +	free_scm_minor(scm_data);
> > +
> > +	if (scm_data->irq_addr[1])
> > +		iounmap(scm_data->irq_addr[1]);
> > +
> > +	if (scm_data->irq_addr[0])
> > +		iounmap(scm_data->irq_addr[0]);
> > +
> > +	if (scm_data->cdev.owner)
> > +		cdev_del(&scm_data->cdev);
> > +
> > +	if (scm_data->metadata_addr)
> > +		devm_memunmap(&scm_data->dev, scm_data->metadata_addr);
> > +
> > +	if (scm_data->ocxl_context)
> > +		ocxl_context_free(scm_data->ocxl_context);
> > +
> > +	if (scm_data->ocxl_afu)
> > +		ocxl_afu_put(scm_data->ocxl_afu);
> > +
> > +	if (scm_data->ocxl_fn)
> > +		ocxl_function_close(scm_data->ocxl_fn);
> > +
> > +	kfree(scm_data);
> > +}
> > +
> > +/**
> > + * free_scm_dev - Free an SCM device
> > + * @dev: The device struct
> > + */
> > +static void free_scm_dev(struct device *dev)
> > +{
> > +	struct scm_data *scm_data = container_of(dev, struct scm_data,
> > dev);
> > +
> > +	free_scm(scm_data);
> > +}
> > +
> > +/**
> > + * scm_register - Register an SCM device with the kernel
> > + * @scm_data: the SCM metadata
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int scm_register(struct scm_data *scm_data)
> > +{
> > +	int rc;
> > +	int minor = allocate_scm_minor(scm_data);
> > +
> > +	if (minor < 0)
> > +		return minor;
> > +
> > +	scm_data->dev.release = free_scm_dev;
> > +	rc = dev_set_name(&scm_data->dev, "scm%d", minor);
> > +	if (rc < 0)
> > +		return rc;
> > +
> > +	scm_data->dev.devt = MKDEV(MAJOR(scm_dev), minor);
> > +	scm_data->dev.class = scm_class;
> > +	scm_data->dev.parent = &scm_data->pdev->dev;
> > +
> > +	rc = device_register(&scm_data->dev);
> > +	return rc;
> > +}
> > +
> > +static void scm_put(struct scm_data *scm_data)
> > +{
> > +	put_device(&scm_data->dev);
> > +}
> > +
> > +struct scm_data *scm_get(struct scm_data *scm_data)
> > +{
> > +	return (get_device(&scm_data->dev) == NULL) ? NULL : scm_data;
> > +}
> > +
> > +static struct scm_data *find_and_get_scm(dev_t devno)
> > +{
> > +	struct scm_data *scm_data;
> > +	int minor = MINOR(devno);
> > +	/*
> > +	 * We don't declare an RCU critical section here, as our AFU
> > +	 * is protected by a reference counter on the device. By the
> > time the
> > +	 * minor number of a device is removed from the idr, the ref
> > count of
> > +	 * the device is already at 0, so no user API will access that
> > AFU and
> > +	 * this function can't return it.
> > +	 */
> > +	scm_data = idr_find(&minors_idr, minor);
> > +	if (scm_data)
> > +		scm_get(scm_data);
> > +	return scm_data;
> > +}
> > +
> > +static int scm_file_open(struct inode *inode, struct file *file)
> > +{
> > +	struct scm_data *scm_data;
> > +
> > +	scm_data = find_and_get_scm(inode->i_rdev);
> > +	if (!scm_data)
> > +		return -ENODEV;
> > +
> > +	file->private_data = scm_data;
> > +	return 0;
> > +}
> > +
> > +static int scm_file_release(struct inode *inode, struct file
> > *file)
> > +{
> > +	struct scm_data *scm_data = file->private_data;
> > +
> > +	if (scm_data->ev_ctx) {
> > +		eventfd_ctx_put(scm_data->ev_ctx);
> > +		scm_data->ev_ctx = NULL;
> > +	}
> > +
> > +	scm_put(scm_data);
> > +	return 0;
> > +}
> > +
> > +static int scm_ioctl_buffer_info(struct scm_data *scm_data,
> > +				 struct scm_ioctl_buffer_info __user
> > *uarg)
> > +{
> > +	struct scm_ioctl_buffer_info args;
> > +
> > +	args.admin_command_buffer_size = scm_data-
> > >admin_command.data_size;
> > +	args.near_storage_buffer_size = scm_data->ns_command.data_size;
> > +
> > +	if (copy_to_user(uarg, &args, sizeof(args)))
> > +		return -EFAULT;
> > +
> > +	return 0;
> > +}
> > +
> > +static int scm_error_log_offset_0x00(struct scm_data *scm_data,
> > u16 *length)
> > +{
> > +	int rc;
> > +	u64 val;
> > +
> > +	u16 data_identifier;
> > +	u32 data_length;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	data_identifier = val >> 48;
> > +	data_length = val & 0xFFFF;
> > +
> > +	if (data_identifier != 0x454C) {
> > +		dev_err(&scm_data->dev,
> > +			"Bad data identifier for error log data,
> > expected 'EL', got '%2s' (%#x), data_length=%u\n",
> > +			(char *)&data_identifier,
> > +			(unsigned int)data_identifier, data_length);
> > +		return -EFAULT;
> > +	}
> > +
> > +	*length = data_length;
> > +	return 0;
> > +}
> > +
> > +static int scm_error_log_offset_0x08(struct scm_data *scm_data,
> > +				     u32 *log_identifier, u32
> > *program_ref_code)
> > +{
> > +	int rc;
> > +	u64 val;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	*log_identifier = val >> 32;
> > +	*program_ref_code = val & 0xFFFFFFFF;
> > +
> > +	return 0;
> > +}
> > +
> > +static int scm_read_error_log(struct scm_data *scm_data,
> > +			      struct scm_ioctl_error_log *log, bool
> > buf_is_user)
> > +{
> > +	u64 val;
> > +	u16 user_buf_length;
> > +	u16 buf_length;
> > +	u16 i;
> > +	int rc;
> > +
> > +	if (log->buf_size % 8)
> > +		return -EINVAL;
> > +
> > +	rc = scm_chi(scm_data, &val);
> > +	if (rc)
> > +		goto out;
> > +
> > +	if (!(val & GLOBAL_MMIO_CHI_ELA))
> > +		return -EAGAIN;
> > +
> > +	user_buf_length = log->buf_size;
> > +
> > +	mutex_lock(&scm_data->admin_command.lock);
> > +
> > +	rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_ERRLOG);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_execute(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_complete_timeout(scm_data,
> > ADMIN_COMMAND_ERRLOG);
> > +	if (rc < 0) {
> > +		dev_warn(&scm_data->dev, "Read error log timed out\n");
> > +		goto out;
> > +	}
> > +
> > +	rc = scm_admin_response(scm_data);
> > +	if (rc < 0)
> > +		goto out;
> > +	if (rc != STATUS_SUCCESS) {
> > +		scm_warn_status(scm_data, "Unexpected status from
> > retrieve error log", rc);
> > +		goto out;
> > +	}
> > +
> > +
> > +	rc = scm_error_log_offset_0x00(scm_data, &log->buf_size);
> > +	if (rc)
> > +		goto out;
> > +	// log->buf_size now contains the scm buffer size, not the user
> > size
> > +
> > +	rc = scm_error_log_offset_0x08(scm_data, &log->log_identifier,
> > +				       &log->program_reference_code);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x10,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		goto out;
> > +
> > +	log->error_log_type = val >> 56;
> > +	log->action_flags = (log->error_log_type ==
> > SCM_ERROR_LOG_TYPE_GENERAL) ?
> > +			    (val >> 32) & 0xFFFFFF : 0;
> > +	log->power_on_seconds = val & 0xFFFFFFFF;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x18,
> > +				     OCXL_LITTLE_ENDIAN, &log-
> > >timestamp);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x20,
> > +				     OCXL_HOST_ENDIAN, &log->wwid[0]);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x28,
> > +				     OCXL_HOST_ENDIAN, &log->wwid[1]);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x30,
> > +				     OCXL_HOST_ENDIAN, (u64 *)log-
> > >fw_revision);
> > +	if (rc)
> > +		goto out;
> > +	log->fw_revision[8] = '\0';
> > +
> > +	buf_length = (user_buf_length < log->buf_size) ?
> > +		     user_buf_length : log->buf_size;
> > +	for (i = 0; i < buf_length + 0x48; i += 8) {
> > +		u64 val;
> > +
> > +		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +					     scm_data-
> > >admin_command.data_offset + i,
> > +					     OCXL_HOST_ENDIAN, &val);
> > +		if (rc)
> > +			goto out;
> > +
> > +		if (buf_is_user) {
> > +			if (copy_to_user(&log->buf[i], &val,
> > sizeof(u64))) {
> > +				rc = -EFAULT;
> > +				goto out;
> > +			}
> > +		} else
> > +			log->buf[i] = val;
> > +	}
> > +
> > +	rc = scm_admin_response_handled(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +out:
> > +	mutex_unlock(&scm_data->admin_command.lock);
> > +	return rc;
> > +
> > +}
> > +
> > +static int scm_ioctl_error_log(struct scm_data *scm_data,
> > +			       struct scm_ioctl_error_log __user *uarg)
> > +{
> > +	struct scm_ioctl_error_log args;
> > +	int rc;
> > +
> > +	if (copy_from_user(&args, uarg, sizeof(args)))
> > +		return -EFAULT;
> > +
> > +	rc = scm_read_error_log(scm_data, &args, true);
> > +	if (rc)
> > +		return rc;
> > +
> > +	if (copy_to_user(uarg, &args, sizeof(args)))
> > +		return -EFAULT;
> > +
> > +	return 0;
> > +}
> > +
> > +static int scm_ioctl_controller_dump_data(struct scm_data
> > *scm_data,
> > +	struct scm_ioctl_controller_dump_data __user *uarg)
> > +{
> > +	struct scm_ioctl_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 > scm_data->admin_command.data_size)
> > +		return -EINVAL;
> > +
> > +	mutex_lock(&scm_data->admin_command.lock);
> > +
> > +	rc = scm_admin_command_request(scm_data,
> > ADMIN_COMMAND_CONTROLLER_DUMP);
> > +	if (rc)
> > +		goto out;
> > +
> > +	val = ((u64)args.offset) << 32;
> > +	val |= args.buf_size;
> > +	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > +				      scm_data-
> > >admin_command.request_offset + 0x08,
> > +				      OCXL_LITTLE_ENDIAN, val);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_execute(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_complete_timeout(scm_data,
> > +						ADMIN_COMMAND_CONTROLLE
> > R_DUMP);
> > +	if (rc < 0) {
> > +		dev_warn(&scm_data->dev, "Controller dump timed
> > out\n");
> > +		goto out;
> > +	}
> > +
> > +	rc = scm_admin_response(scm_data);
> > +	if (rc < 0)
> > +		goto out;
> > +	if (rc != STATUS_SUCCESS) {
> > +		scm_warn_status(scm_data,
> > +				"Unexpected status from retrieve error
> > log",
> > +				rc);
> > +		goto out;
> > +	}
> > +
> > +	for (i = 0; i < args.buf_size; i += 8) {
> > +		u64 val;
> > +
> > +		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +					     scm_data-
> > >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 = scm_admin_response_handled(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +out:
> > +	mutex_unlock(&scm_data->admin_command.lock);
> > +	return rc;
> > +}
> > +
> > +int scm_request_controller_dump(struct scm_data *scm_data)
> > +{
> > +	int rc;
> > +	u64 busy = 1;
> > +
> > +	rc = ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_CHIC,
> > +				    OCXL_LITTLE_ENDIAN,
> > +				    GLOBAL_MMIO_CHI_CDA);
> > +
> > +
> > +	rc = ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_HCI,
> > +				    OCXL_LITTLE_ENDIAN,
> > +				    GLOBAL_MMIO_HCI_CONTROLLER_DUMP);
> > +	if (rc)
> > +		return rc;
> > +
> > +	while (busy) {
> > +		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +					     GLOBAL_MMIO_HCI,
> > +					     OCXL_LITTLE_ENDIAN,
> > &busy);
> > +		if (rc)
> > +			return rc;
> > +
> > +		busy &= GLOBAL_MMIO_HCI_CONTROLLER_DUMP;
> > +		cond_resched();
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int scm_ioctl_controller_dump_complete(struct scm_data
> > *scm_data)
> > +{
> > +	int rc;
> > +
> > +	rc = ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_HCI,
> > +				    OCXL_LITTLE_ENDIAN,
> > +				    GLOBAL_MMIO_HCI_CONTROLLER_DUMP_COL
> > LECTED);
> > +
> > +	if (rc)
> > +		return -EFAULT;
> > +
> > +	return 0;
> > +}
> > +
> > +static int scm_controller_stats_offset_0x00(struct scm_data
> > *scm_data,
> > +	u32 *length)
> > +{
> > +	int rc;
> > +	u64 val;
> > +
> > +	u16 data_identifier;
> > +	u32 data_length;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	data_identifier = val >> 48;
> > +	data_length = val & 0xFFFFFFFF;
> > +
> > +	if (data_identifier != 0x4353) {
> > +		dev_err(&scm_data->dev,
> > +			"Bad data identifier for controller stats,
> > expected 'CS', got '%-.*s'\n",
> > +			2, (char *)&data_identifier);
> > +		return -EFAULT;
> > +	}
> > +
> > +	*length = data_length;
> > +	return 0;
> > +}
> > +
> > +static int scm_ioctl_controller_stats(struct scm_data *scm_data,
> > +				      struct scm_ioctl_controller_stats
> > __user *uarg)
> > +{
> > +	struct scm_ioctl_controller_stats args;
> > +	u32 length;
> > +	int rc;
> > +	u64 val;
> > +
> > +	memset(&args, '\0', sizeof(args));
> > +
> > +	mutex_lock(&scm_data->admin_command.lock);
> > +
> > +	rc = scm_admin_command_request(scm_data,
> > ADMIN_COMMAND_CONTROLLER_STATS);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > +				      scm_data-
> > >admin_command.request_offset + 0x08,
> > +				      OCXL_LITTLE_ENDIAN, 0);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_execute(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +
> > +	rc = scm_admin_command_complete_timeout(scm_data,
> > +						ADMIN_COMMAND_CONTROLLE
> > R_STATS);
> > +	if (rc < 0) {
> > +		dev_warn(&scm_data->dev, "Controller stats timed
> > out\n");
> > +		goto out;
> > +	}
> > +
> > +	rc = scm_admin_response(scm_data);
> > +	if (rc < 0)
> > +		goto out;
> > +	if (rc != STATUS_SUCCESS) {
> > +		scm_warn_status(scm_data,
> > +				"Unexpected status from controller
> > stats", rc);
> > +		goto out;
> > +	}
> > +
> > +	rc = scm_controller_stats_offset_0x00(scm_data, &length);
> > +	if (rc)
> > +		goto out;
> > +
> > +	if (length != 0x140)
> > +		scm_warn_status(scm_data,
> > +				"Unexpected length for controller stats
> > data, expected 0x140, got 0x%x",
> > +				length);
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08 + 0x08,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		goto out;
> > +
> > +	args.reset_count = val >> 32;
> > +	args.reset_uptime = val & 0xFFFFFFFF;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08 + 0x10,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		goto out;
> > +
> > +	args.power_on_uptime = val >> 32;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08 + 0x40 + 0x08,
> > +				     OCXL_LITTLE_ENDIAN,
> > &args.host_load_count);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08 + 0x40 + 0x10,
> > +				     OCXL_LITTLE_ENDIAN,
> > &args.host_store_count);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08 + 0x40 + 0x18,
> > +				     OCXL_LITTLE_ENDIAN,
> > &args.media_read_count);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08 + 0x40 + 0x20,
> > +				     OCXL_LITTLE_ENDIAN,
> > &args.media_write_count);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08 + 0x40 + 0x28,
> > +				     OCXL_LITTLE_ENDIAN,
> > &args.cache_hit_count);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08 + 0x40 + 0x30,
> > +				     OCXL_LITTLE_ENDIAN,
> > &args.cache_miss_count);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08 + 0x40 + 0x38,
> > +				     OCXL_LITTLE_ENDIAN,
> > &args.media_read_latency);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08 + 0x40 + 0x40,
> > +				     OCXL_LITTLE_ENDIAN,
> > &args.media_write_latency);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08 + 0x40 + 0x48,
> > +				     OCXL_LITTLE_ENDIAN,
> > &args.cache_read_latency);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +				     scm_data-
> > >admin_command.data_offset + 0x08 + 0x40 + 0x50,
> > +				     OCXL_LITTLE_ENDIAN,
> > &args.cache_write_latency);
> > +	if (rc)
> > +		goto out;
> > +
> > +	if (copy_to_user(uarg, &args, sizeof(args))) {
> > +		rc = -EFAULT;
> > +		goto out;
> > +	}
> > +
> > +	rc = scm_admin_response_handled(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = 0;
> > +	goto out;
> > +
> > +out:
> > +	mutex_unlock(&scm_data->admin_command.lock);
> > +	return rc;
> > +}
> > +
> > +static int scm_ioctl_eventfd(struct scm_data *scm_data,
> > +			     struct scm_ioctl_eventfd __user *uarg)
> > +{
> > +	struct scm_ioctl_eventfd args;
> > +
> > +	if (copy_from_user(&args, uarg, sizeof(args)))
> > +		return -EFAULT;
> > +
> > +	if (scm_data->ev_ctx)
> > +		return -EFAULT;
> > +
> > +	scm_data->ev_ctx = eventfd_ctx_fdget(args.eventfd);
> > +	if (!scm_data->ev_ctx)
> > +		return -EFAULT;
> > +
> > +	return 0;
> > +}
> > +
> > +static int scm_ioctl_event_check(struct scm_data *scm_data, u64
> > __user *uarg)
> > +{
> > +	u64 val = 0;
> > +	int rc;
> > +	u64 chi = 0;
> > +
> > +	rc = scm_chi(scm_data, &chi);
> > +	if (rc < 0)
> > +		return -EFAULT;
> > +
> > +	if (chi & GLOBAL_MMIO_CHI_ELA)
> > +		val |= SCM_IOCTL_EVENT_ERROR_LOG_AVAILABLE;
> > +
> > +	if (chi & GLOBAL_MMIO_CHI_CDA)
> > +		val |= SCM_IOCTL_EVENT_CONTROLLER_DUMP_AVAILABLE;
> > +
> > +	if (chi & GLOBAL_MMIO_CHI_CFFS)
> > +		val |= SCM_IOCTL_EVENT_FIRMWARE_FATAL;
> > +
> > +	if (chi & GLOBAL_MMIO_CHI_CHFS)
> > +		val |= SCM_IOCTL_EVENT_HARDWARE_FATAL;
> > +
> > +	rc = copy_to_user((u64 __user *) uarg, &val, sizeof(val));
> > +
> > +	return rc;
> > +}
> > +
> > +/**
> > + * scm_req_controller_health_perf() - Request controller health &
> > performance data
> > + * @scm_data: the SCM metadata
> > + * Return: 0 on success, negative on failure
> > + */
> > +int scm_req_controller_health_perf(struct scm_data *scm_data)
> > +{
> > +	return ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_HCI,
> > +				      OCXL_LITTLE_ENDIAN,
> > +				      GLOBAL_MMIO_HCI_REQ_HEALTH_PERF);
> > +}
> > +
> > +#ifdef CONFIG_OCXL_SCM_DEBUG
> > +/**
> > + * scm_enable_fwdebug() - Enable FW debug on the controller
> > + * @scm_data: a pointer to the SCM device data
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int scm_enable_fwdebug(const struct scm_data *scm_data)
> > +{
> > +	return ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_HCI,
> > +				      OCXL_LITTLE_ENDIAN,
> > +				      GLOBAL_MMIO_HCI_FW_DEBUG);
> > +}
> > +
> > +/**
> > + * scm_disable_fwdebug() - Disable FW debug on the controller
> > + * @scm_data: a pointer to the SCM device data
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int scm_disable_fwdebug(const struct scm_data *scm_data)
> > +{
> > +	return ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_HCIC,
> > +				      OCXL_LITTLE_ENDIAN,
> > +				      GLOBAL_MMIO_HCI_FW_DEBUG);
> > +}
> > +
> > +static int scm_ioctl_fwdebug(struct scm_data *scm_data,
> > +			     struct scm_ioctl_fwdebug __user *uarg)
> > +{
> > +	struct scm_ioctl_fwdebug args;
> > +	u64 val;
> > +	int i;
> > +	int rc;
> > +
> > +	if (copy_from_user(&args, uarg, sizeof(args)))
> > +		return -EFAULT;
> > +
> > +	// Buffer size must be a multiple of 8
> > +	if ((args.buf_size & 0x07))
> > +		return -EINVAL;
> > +
> > +	if (args.buf_size > scm_data->admin_command.data_size)
> > +		return -EINVAL;
> > +
> > +	mutex_lock(&scm_data->admin_command.lock);
> > +
> > +	rc = scm_enable_fwdebug(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_request(scm_data,
> > ADMIN_COMMAND_FW_DEBUG);
> > +	if (rc)
> > +		goto out;
> > +
> > +	// Write DebugAction & FunctionCode
> > +	val = ((u64)args.debug_action << 56) | ((u64)args.function_code
> > << 40);
> > +
> > +	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > +				      scm_data-
> > >admin_command.request_offset + 0x08,
> > +				      OCXL_LITTLE_ENDIAN, val);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > +				      scm_data-
> > >admin_command.request_offset + 0x10,
> > +				      OCXL_LITTLE_ENDIAN,
> > args.debug_parameter_1);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > +				      scm_data-
> > >admin_command.request_offset + 0x18,
> > +				      OCXL_LITTLE_ENDIAN,
> > args.debug_parameter_2);
> > +	if (rc)
> > +		goto out;
> > +
> > +	for (i = 0x20; i < 0x38; i += 0x08)
> > +		rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > +					      scm_data-
> > >admin_command.request_offset + i,
> > +					      OCXL_LITTLE_ENDIAN, 0);
> > +	if (rc)
> > +		goto out;
> > +
> > +
> > +	// Populate admin command buffer
> > +	if (args.buf_size) {
> > +		for (i = 0; i < args.buf_size; i += sizeof(u64)) {
> > +			u64 val;
> > +
> > +			if (copy_from_user(&val, &args.buf[i],
> > sizeof(u64)))
> > +				return -EFAULT;
> > +
> > +			rc = ocxl_global_mmio_write64(scm_data-
> > >ocxl_afu,
> > +						      scm_data-
> > >admin_command.data_offset + i,
> > +						      OCXL_HOST_ENDIAN,
> > val);
> > +			if (rc)
> > +				goto out;
> > +		}
> > +	}
> > +
> > +	rc = scm_admin_command_execute(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_complete_timeout(scm_data,
> > +						scm_data-
> > >timeouts[ADMIN_COMMAND_FW_DEBUG]);
> > +	if (rc < 0)
> > +		goto out;
> > +
> > +	rc = scm_admin_response(scm_data);
> > +	if (rc < 0)
> > +		goto out;
> > +	if (rc != STATUS_SUCCESS) {
> > +		scm_warn_status(scm_data, "Unexpected status from FW
> > Debug", rc);
> > +		goto out;
> > +	}
> > +
> > +	if (args.buf_size) {
> > +		for (i = 0; i < args.buf_size; i += sizeof(u64)) {
> > +			u64 val;
> > +
> > +			rc = ocxl_global_mmio_read64(scm_data-
> > >ocxl_afu,
> > +						     scm_data-
> > >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;
> > +			}
> > +		}
> > +	}
> > +
> > +	rc = scm_admin_response_handled(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_disable_fwdebug(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +out:
> > +	mutex_unlock(&scm_data->admin_command.lock);
> > +	return rc;
> > +}
> > +
> > +static int scm_ioctl_shutdown(struct scm_data *scm_data)
> > +{
> > +	int rc;
> > +
> > +	mutex_lock(&scm_data->admin_command.lock);
> > +
> > +	rc = scm_admin_command_request(scm_data,
> > ADMIN_COMMAND_SHUTDOWN);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_execute(scm_data);
> > +	if (rc)
> > +		goto out;
> > +
> > +	rc = scm_admin_command_complete_timeout(scm_data,
> > ADMIN_COMMAND_SHUTDOWN);
> > +	if (rc < 0) {
> > +		dev_warn(&scm_data->dev, "Shutdown timed out\n");
> > +		goto out;
> > +	}
> > +
> > +	rc = 0;
> > +	goto out;
> > +
> > +out:
> > +	mutex_unlock(&scm_data->admin_command.lock);
> > +	return rc;
> > +}
> > +
> > +static int scm_ioctl_mmio_write(struct scm_data *scm_data,
> > +				struct scm_ioctl_mmio __user *uarg)
> > +{
> > +	struct scm_ioctl_mmio args;
> > +
> > +	if (copy_from_user(&args, uarg, sizeof(args)))
> > +		return -EFAULT;
> > +
> > +	return ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > args.address,
> > +					OCXL_LITTLE_ENDIAN, args.val);
> > +}
> > +
> > +static int scm_ioctl_mmio_read(struct scm_data *scm_data,
> > +			       struct scm_ioctl_mmio __user *uarg)
> > +{
> > +	struct scm_ioctl_mmio args;
> > +	int rc;
> > +
> > +	if (copy_from_user(&args, uarg, sizeof(args)))
> > +		return -EFAULT;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, args.address,
> > +				     OCXL_LITTLE_ENDIAN, &args.val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	if (copy_to_user(uarg, &args, sizeof(args)))
> > +		return -EFAULT;
> > +
> > +	return 0;
> > +}
> > +#else
> > +static int scm_ioctl_fwdebug(struct scm_data *scm_data,
> > +			     struct scm_ioctl_fwdebug __user *uarg)
> > +{
> > +	return -EPERM;
> > +}
> > +
> > +static int scm_ioctl_shutdown(struct scm_data *scm_data)
> > +{
> > +	return -EPERM;
> > +}
> > +
> > +static int scm_ioctl_mmio_write(struct scm_data *scm_data,
> > +				struct scm_ioctl_mmio __user *uarg)
> > +{
> > +	return -EPERM;
> > +}
> > +
> > +static int scm_ioctl_mmio_read(struct scm_data *scm_data,
> > +			       struct scm_ioctl_mmio __user *uarg)
> > +{
> > +	return -EPERM;
> > +}
> > +#endif
> > +
> > +static long scm_file_ioctl(struct file *file, unsigned int cmd,
> > +			   unsigned long args)
> > +{
> > +	struct scm_data *scm_data = file->private_data;
> > +	int rc = -EINVAL;
> > +
> > +	switch (cmd) {
> > +	case SCM_IOCTL_BUFFER_INFO:
> > +		rc = scm_ioctl_buffer_info(scm_data,
> > +					   (struct
> > scm_ioctl_buffer_info __user *)args);
> > +		break;
> > +
> > +	case SCM_IOCTL_ERROR_LOG:
> > +		rc = scm_ioctl_error_log(scm_data,
> > +					 (struct scm_ioctl_error_log
> > __user *)args);
> > +		break;
> > +
> > +	case SCM_IOCTL_CONTROLLER_DUMP:
> > +		rc = scm_request_controller_dump(scm_data);
> > +		break;
> > +
> > +	case SCM_IOCTL_CONTROLLER_DUMP_DATA:
> > +		rc = scm_ioctl_controller_dump_data(scm_data,
> > +						    (struct
> > scm_ioctl_controller_dump_data __user *)args);
> > +		break;
> > +
> > +	case SCM_IOCTL_CONTROLLER_DUMP_COMPLETE:
> > +		rc = scm_ioctl_controller_dump_complete(scm_data);
> > +		break;
> > +
> > +	case SCM_IOCTL_CONTROLLER_STATS:
> > +		rc = scm_ioctl_controller_stats(scm_data,
> > +						(struct
> > scm_ioctl_controller_stats __user *)args);
> > +		break;
> > +
> > +	case SCM_IOCTL_EVENTFD:
> > +		rc = scm_ioctl_eventfd(scm_data,
> > +				       (struct scm_ioctl_eventfd __user
> > *)args);
> > +		break;
> > +
> > +	case SCM_IOCTL_EVENT_CHECK:
> > +		rc = scm_ioctl_event_check(scm_data, (u64 __user
> > *)args);
> > +		break;
> > +
> > +	case SCM_IOCTL_REQUEST_HEALTH:
> > +		rc = scm_req_controller_health_perf(scm_data);
> > +		break;
> > +
> > +	case SCM_IOCTL_FWDEBUG:
> > +		rc = scm_ioctl_fwdebug(scm_data,
> > +				       (struct scm_ioctl_fwdebug __user
> > *)args);
> > +		break;
> > +
> > +	case SCM_IOCTL_SHUTDOWN:
> > +		rc = scm_ioctl_shutdown(scm_data);
> > +		break;
> > +
> > +	case SCM_IOCTL_MMIO_WRITE:
> > +		rc = scm_ioctl_mmio_write(scm_data,
> > +					  (struct scm_ioctl_mmio __user
> > *)args);
> > +		break;
> > +
> > +	case SCM_IOCTL_MMIO_READ:
> > +		rc = scm_ioctl_mmio_read(scm_data,
> > +					 (struct scm_ioctl_mmio __user
> > *)args);
> > +		break;
> > +
> > +	}
> > +
> > +	return rc;
> > +}
> > +
> > +static const struct file_operations scm_fops = {
> > +	.owner		= THIS_MODULE,
> > +	.open	   = scm_file_open,
> > +	.release	= scm_file_release,
> > +	.unlocked_ioctl = scm_file_ioctl,
> > +	.compat_ioctl   = scm_file_ioctl,
> > +};
> > +
> > +/**
> > + * scm_create_cdev() - Create the chardev in /dev for this scm
> > device
> > + * @scm_data: the SCM metadata
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int scm_create_cdev(struct scm_data *scm_data)
> > +{
> > +	int rc;
> > +
> > +	cdev_init(&scm_data->cdev, &scm_fops);
> > +	rc = cdev_add(&scm_data->cdev, scm_data->dev.devt, 1);
> > +	if (rc) {
> > +		dev_err(&scm_data->dev, "Unable to add afu char device:
> > %d\n", rc);
> > +		return rc;
> > +	}
> > +	return 0;
> > +}
> > +
> > +/**
> > + * scm_remove() - Free an OpenCAPI Storage Class Memory device
> > + * @pdev: the PCI device information struct
> > + */
> > +static void scm_remove(struct pci_dev *pdev)
> > +{
> > +	if (PCI_FUNC(pdev->devfn) == 0) {
> > +		struct scm_function_0 *scm_func_0 =
> > pci_get_drvdata(pdev);
> > +
> > +		if (scm_func_0) {
> > +			ocxl_function_close(scm_func_0->ocxl_fn);
> > +			scm_func_0->ocxl_fn = NULL;
> > +		}
> > +	} else {
> > +		struct scm_data *scm_data = pci_get_drvdata(pdev);
> > +
> > +		if (scm_data) {
> > +			if (scm_data->nvdimm_bus)
> > +				nvdimm_bus_unregister(scm_data-
> > >nvdimm_bus);
> > +
> > +			device_unregister(&scm_data->dev);
> > +		}
> > +	}
> > +}
> > +
> > +/**
> > + * scm_setup_device_metadata() - Retrieve config information from
> > the AFU and save it for future use
> > + * @scm_data: the SCM metadata
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int scm_setup_device_metadata(struct scm_data *scm_data)
> > +{
> > +	u64 val;
> > +	int rc;
> > +	int i;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_CCAP0,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	scm_data->scm_revision = val & 0xFFFF;
> > +	scm_data->read_latency = (val >> 32) & 0xFF;
> > +	scm_data->readiness_timeout = val >> 48;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_CCAP1,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	scm_data->max_controller_dump_size = val & 0xFFFFFFFF;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_FWVER,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	for (i = 0; i < 8; i++)
> > +		scm_data->fw_version[i] = (val >> (i * 8)) & 0xff;
> > +
> > +	scm_data->fw_version[8] = '\0';
> > +
> > +	dev_info(&scm_data->dev,
> > +		 "Firmware version '%s' SCM revision %d:%d\n",
> > scm_data->fw_version,
> > +		 scm_data->scm_revision >> 4, scm_data->scm_revision &
> > 0x0F);
> > +
> > +	return 0;
> > +}
> > +
> > +static const char *scm_decode_error_log_type(u8 error_log_type)
> > +{
> > +	switch (error_log_type) {
> > +	case 0x00:
> > +		return "general";
> > +	case 0x01:
> > +		return "predictive failure";
> > +	case 0x02:
> > +		return "thermal warning";
> > +	case 0x03:
> > +		return "data loss";
> > +	case 0x04:
> > +		return "health & performance";
> > +	default:
> > +		return "unknown";
> > +	}
> > +}
> > +
> > +static void scm_dump_error_log(struct scm_data *scm_data)
> > +{
> > +	struct scm_ioctl_error_log log;
> > +	u32 buf_size;
> > +	u8 *buf;
> > +	int rc;
> > +
> > +	if (scm_data->admin_command.data_size == 0)
> > +		return;
> > +
> > +	buf_size = scm_data->admin_command.data_size - 0x48;
> > +	buf = kzalloc(buf_size, GFP_KERNEL);
> > +	if (!buf)
> > +		return;
> > +
> > +	log.buf = buf;
> > +	log.buf_size = buf_size;
> > +
> > +	rc = scm_read_error_log(scm_data, &log, false);
> > +	if (rc < 0)
> > +		goto out;
> > +
> > +	dev_warn(&scm_data->dev,
> > +		 "SCM Error log: WWID=0x%016llx%016llx LID=0x%x PRC=%x
> > type=0x%x %s, Uptime=%u seconds timestamp=0x%llx\n",
> > +		 log.wwid[0], log.wwid[1],
> > +		 log.log_identifier, log.program_reference_code,
> > +		 log.error_log_type,
> > +		 scm_decode_error_log_type(log.error_log_type),
> > +		 log.power_on_seconds, log.timestamp);
> > +	print_hex_dump(KERN_WARNING, "buf", DUMP_PREFIX_OFFSET, 16, 1,
> > buf,
> > +		       log.buf_size, false);
> > +
> > +out:
> > +	kfree(buf);
> > +}
> > +
> > +static void scm_handle_nscra_doorbell(struct scm_data *scm_data)
> > +{
> > +	int rc;
> > +
> > +	if (scm_data->ns_command.op_code == NS_COMMAND_SECURE_ERASE) {
> > +		u64 success, attempted;
> > +
> > +
> > +		rc = scm_ns_response(scm_data);
> > +		if (rc < 0) {
> > +			scm_data->overwrite_state =
> > SCM_OVERWRITE_FAILED;
> > +			mutex_unlock(&scm_data->ns_command.lock);
> > +			return;
> > +		}
> > +		if (rc != STATUS_SUCCESS)
> > +			scm_warn_status(scm_data, "Unexpected status
> > from overwrite", rc);
> > +
> > +		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +					     scm_data-
> > >ns_command.response_offset +
> > +					     NS_RESPONSE_SECURE_ERASE_A
> > CCESSIBLE_SUCCESS,
> > +					     OCXL_HOST_ENDIAN,
> > &success);
> > +		if (rc) {
> > +			scm_data->overwrite_state =
> > SCM_OVERWRITE_FAILED;
> > +			mutex_unlock(&scm_data->ns_command.lock);
> > +			return;
> > +		}
> > +
> > +		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +					     scm_data-
> > >ns_command.response_offset +
> > +					     NS_RESPONSE_SECURE_ERASE_A
> > CCESSIBLE_ATTEMPTED,
> > +					     OCXL_HOST_ENDIAN,
> > &attempted);
> > +		if (rc) {
> > +			scm_data->overwrite_state =
> > SCM_OVERWRITE_FAILED;
> > +			mutex_unlock(&scm_data->ns_command.lock);
> > +			return;
> > +		}
> > +
> > +		scm_data->overwrite_state = SCM_OVERWRITE_SUCCESS;
> > +		if (success != attempted)
> > +			scm_data->overwrite_state =
> > SCM_OVERWRITE_FAILED;
> > +
> > +		dev_info(&scm_data->dev,
> > +			 "Overwritten %llu/%llu accessible pages",
> > success, attempted);
> > +
> > +		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +					     scm_data-
> > >ns_command.response_offset +
> > +					     NS_RESPONSE_SECURE_ERASE_D
> > EFECTIVE_SUCCESS,
> > +					     OCXL_HOST_ENDIAN,
> > &success);
> > +		if (rc) {
> > +			scm_data->overwrite_state =
> > SCM_OVERWRITE_FAILED;
> > +			mutex_unlock(&scm_data->ns_command.lock);
> > +			return;
> > +		}
> > +
> > +		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > +					     scm_data-
> > >ns_command.response_offset +
> > +					     NS_RESPONSE_SECURE_ERASE_D
> > EFECTIVE_ATTEMPTED,
> > +					     OCXL_HOST_ENDIAN,
> > &attempted);
> > +		if (rc) {
> > +			scm_data->overwrite_state =
> > SCM_OVERWRITE_FAILED;
> > +			mutex_unlock(&scm_data->ns_command.lock);
> > +			return;
> > +		}
> > +
> > +		if (success != attempted)
> > +			scm_data->overwrite_state =
> > SCM_OVERWRITE_FAILED;
> > +
> > +		dev_info(&scm_data->dev,
> > +			 "Overwritten %llu/%llu defective pages",
> > success, attempted);
> > +
> > +		scm_ns_response_handled(scm_data);
> > +
> > +		mutex_unlock(&scm_data->ns_command.lock);
> > +		return;
> > +	}
> > +}
> > +
> > +static irqreturn_t scm_imn0_handler(void *private)
> > +{
> > +	struct scm_data *scm_data = private;
> > +	int rc;
> > +	u64 chi = 0;
> > +
> > +	rc = scm_chi(scm_data, &chi);
> > +	if (rc < 0)
> > +		return IRQ_NONE;
> > +
> > +	if (chi & GLOBAL_MMIO_CHI_NSCRA)
> > +		scm_handle_nscra_doorbell(scm_data);
> > +
> > +	if (chi & GLOBAL_MMIO_CHI_ELA) {
> > +		dev_warn(&scm_data->dev, "Error log is available\n");
> > +
> > +		if (scm_data->ev_ctx)
> > +			eventfd_signal(scm_data->ev_ctx, 1);
> > +	}
> > +
> > +	if (chi & GLOBAL_MMIO_CHI_CDA) {
> > +		dev_warn(&scm_data->dev, "Controller dump is
> > available\n");
> > +
> > +		if (scm_data->ev_ctx)
> > +			eventfd_signal(scm_data->ev_ctx, 1);
> > +	}
> > +
> > +
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +static irqreturn_t scm_imn1_handler(void *private)
> > +{
> > +	struct scm_data *scm_data = private;
> > +	u64 chi = 0;
> > +
> > +	(void)scm_chi(scm_data, &chi);
> > +
> > +	if (chi & (GLOBAL_MMIO_CHI_CFFS | GLOBAL_MMIO_CHI_CHFS)) {
> > +		dev_err(&scm_data->dev,
> > +			"Controller status is fatal, chi=0x%llx, going
> > offline\n", chi);
> > +
> > +		if (scm_data->nvdimm_bus) {
> > +			nvdimm_bus_unregister(scm_data->nvdimm_bus);
> > +			scm_data->nvdimm_bus = NULL;
> > +		}
> > +
> > +		if (scm_data->ev_ctx)
> > +			eventfd_signal(scm_data->ev_ctx, 1);
> > +	}
> > +
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +
> > +/**
> > + * scm_setup_irq() - Set up the IRQs for the SCM device
> > + * @scm_data: the SCM metadata
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int scm_setup_irq(struct scm_data *scm_data)
> > +{
> > +	int rc;
> > +	u64 irq_addr;
> > +
> > +	rc = ocxl_afu_irq_alloc(scm_data->ocxl_context, &scm_data-
> > >irq_id[0]);
> > +	if (rc)
> > +		return rc;
> > +
> > +	rc = ocxl_irq_set_handler(scm_data->ocxl_context, scm_data-
> > >irq_id[0],
> > +				  scm_imn0_handler, NULL, scm_data);
> > +
> > +	irq_addr = ocxl_afu_irq_get_addr(scm_data->ocxl_context,
> > scm_data->irq_id[0]);
> > +	if (!irq_addr)
> > +		return -EFAULT;
> > +
> > +	scm_data->irq_addr[0] = ioremap(irq_addr, PAGE_SIZE);
> > +	if (!scm_data->irq_addr[0])
> > +		return -EINVAL;
> > +
> > +	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_IMA0_OHP,
> > +				      OCXL_LITTLE_ENDIAN,
> > +				      (u64)scm_data->irq_addr[0]);
> > +	if (rc)
> > +		goto out_irq0;
> > +
> > +	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_IMA0_CFP,
> > +				      OCXL_LITTLE_ENDIAN, 0);
> > +	if (rc)
> > +		goto out_irq0;
> > +
> > +	rc = ocxl_afu_irq_alloc(scm_data->ocxl_context, &scm_data-
> > >irq_id[1]);
> > +	if (rc)
> > +		goto out_irq0;
> > +
> > +
> > +	rc = ocxl_irq_set_handler(scm_data->ocxl_context, scm_data-
> > >irq_id[1],
> > +				  scm_imn1_handler, NULL, scm_data);
> > +	if (rc)
> > +		goto out_irq0;
> > +
> > +	irq_addr = ocxl_afu_irq_get_addr(scm_data->ocxl_context,
> > scm_data->irq_id[1]);
> > +	if (!irq_addr)
> > +		goto out_irq0;
> > +
> > +	scm_data->irq_addr[1] = ioremap(irq_addr, PAGE_SIZE);
> > +	if (!scm_data->irq_addr[1])
> > +		goto out_irq0;
> > +
> > +	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_IMA1_OHP,
> > +				      OCXL_LITTLE_ENDIAN,
> > +				      (u64)scm_data->irq_addr[1]);
> > +	if (rc)
> > +		goto out_irq1;
> > +
> > +	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_IMA1_CFP,
> > +				      OCXL_LITTLE_ENDIAN, 0);
> > +	if (rc)
> > +		goto out_irq1;
> > +
> > +	// Enable doorbells
> > +	rc = ocxl_global_mmio_set64(scm_data->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(scm_data->irq_addr[1]);
> > +	scm_data->irq_addr[1] = NULL;
> > +
> > +out_irq0:
> > +	iounmap(scm_data->irq_addr[0]);
> > +	scm_data->irq_addr[0] = NULL;
> > +
> > +	return rc;
> > +}
> > +
> > +/**
> > + * scm_probe_function_0 - Set up function 0 for an OpenCAPI
> > Storage Class Memory device
> > + * This is important as it enables higher than 0 across all other
> > functions,
> > + * which in turn enables higher bandwidth accesses
> > + * @pdev: the PCI device information struct
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int scm_probe_function_0(struct pci_dev *pdev)
> > +{
> > +	struct scm_function_0 *scm_func_0 = NULL;
> > +
> > +	scm_func_0 = kzalloc(sizeof(*scm_func_0), GFP_KERNEL);
> > +	if (!scm_func_0)
> > +		return -ENOMEM;
> > +
> > +	scm_func_0->pdev = pdev;
> > +	scm_func_0->ocxl_fn = ocxl_function_open(pdev);
> > +	if (IS_ERR(scm_func_0->ocxl_fn)) {
> > +		kfree(scm_func_0);
> > +		dev_err(&pdev->dev, "failed to open OCXL function\n");
> > +		return -EFAULT;
> > +	}
> > +
> > +	pci_set_drvdata(pdev, scm_func_0);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * scm_probe - Init an OpenCAPI Storage Class Memory device
> > + * @pdev: the PCI device information struct
> > + * @ent: The entry from scm_pci_tbl
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int scm_probe(struct pci_dev *pdev, const struct
> > pci_device_id *ent)
> > +{
> > +	struct scm_data *scm_data = NULL;
> > +	int elapsed;
> > +	u64 chi;
> > +
> > +	if (PCI_FUNC(pdev->devfn) == 0)
> > +		return scm_probe_function_0(pdev);
> > +	else if (PCI_FUNC(pdev->devfn) != 1)
> > +		return 0;
> > +
> > +	scm_data = kzalloc(sizeof(*scm_data), GFP_KERNEL);
> > +	if (!scm_data)
> > +		goto err;
> > +	scm_data->pdev = pdev;
> > +	mutex_init(&scm_data->admin_command.lock);
> > +	mutex_init(&scm_data->ns_command.lock);
> > +
> > +
> > +	scm_data->timeouts[ADMIN_COMMAND_ERRLOG] = 2000; // ms
> > +	scm_data->timeouts[ADMIN_COMMAND_HEARTBEAT] = 100; // ms
> > +	scm_data->timeouts[ADMIN_COMMAND_SMART] = 100; // ms
> > +	scm_data->timeouts[ADMIN_COMMAND_CONTROLLER_DUMP] = 1000; // ms
> > +	scm_data->timeouts[ADMIN_COMMAND_CONTROLLER_STATS] = 100; // ms
> > +	scm_data->timeouts[ADMIN_COMMAND_SHUTDOWN] = 1000; // ms
> > +	scm_data->timeouts[ADMIN_COMMAND_FW_UPDATE] = 16000; // ms
> > +
> > +	pci_set_drvdata(pdev, scm_data);
> > +
> > +	scm_data->ocxl_fn = ocxl_function_open(pdev);
> > +	if (IS_ERR(scm_data->ocxl_fn)) {
> > +		kfree(scm_data);
> > +		scm_data = NULL;
> > +		pci_set_drvdata(pdev, NULL);
> > +		dev_err(&pdev->dev, "failed to open OCXL function\n");
> > +		goto err;
> > +	}
> > +
> > +	scm_data->ocxl_afu = ocxl_function_fetch_afu(scm_data->ocxl_fn, 
> > 0);
> > +	if (scm_data->ocxl_afu == NULL)
> > +		goto err;
> > +
> > +	ocxl_afu_get(scm_data->ocxl_afu);
> > +
> > +	if (scm_register(scm_data) < 0)
> > +		goto err;
> > +
> > +	if (ocxl_context_alloc(&scm_data->ocxl_context, scm_data-
> > >ocxl_afu, NULL))
> > +		goto err;
> > +
> > +	if (ocxl_context_attach(scm_data->ocxl_context, 0, NULL))
> > +		goto err;
> > +
> > +	if (scm_setup_device_metadata(scm_data))
> > +		goto err;
> > +
> > +	if (scm_setup_irq(scm_data))
> > +		goto err;
> > +
> > +	if (scm_setup_command_metadata(scm_data))
> > +		goto err;
> > +
> > +	if (scm_create_cdev(scm_data))
> > +		goto err;
> > +
> > +	if (scm_sysfs_add(scm_data))
> > +		goto err;
> > +
> > +	if (scm_heartbeat(scm_data))
> > +		goto err;
> > +
> > +	elapsed = 0;
> > +	while (!scm_is_usable(scm_data)) {
> > +		if (elapsed++ > SCM_USABLE_TIMEOUT) {
> > +			dev_warn(&scm_data->dev, "SCM ready
> > timeout.\n");
> > +			goto err;
> > +		}
> > +
> > +		dev_warn(&scm_data->dev,
> > +			 "Waiting for SCM to become usable (%d/%d
> > seconds)\n",
> > +			 elapsed, SCM_USABLE_TIMEOUT);
> > +		msleep(1000);
> > +	}
> > +
> > +	if (scm_register_lpc_mem(scm_data))
> > +		goto err;
> > +
> > +	return 0;
> > +
> > +err:
> > +	if (scm_data &&
> > +		    (scm_chi(scm_data, &chi) == 0) &&
> > +		    (chi & GLOBAL_MMIO_CHI_ELA))
> > +		scm_dump_error_log(scm_data);
> > +
> > +	dev_err(&pdev->dev,
> > +		"Error detected, will not register storage class
> > memory\n");
> > +	return -ENXIO;
> > +}
> > +
> > +struct pci_driver scm_pci_driver = {
> > +	.name = "ocxl-scm",
> > +	.id_table = scm_pci_tbl,
> > +	.probe = scm_probe,
> > +	.remove = scm_remove,
> > +	.shutdown = scm_remove,
> > +};
> > +
> > +static int scm_file_init(void)
> > +{
> > +	int rc;
> > +
> > +	mutex_init(&minors_idr_lock);
> > +	idr_init(&minors_idr);
> > +
> > +	rc = alloc_chrdev_region(&scm_dev, 0, SCM_NUM_MINORS, "scm");
> > +	if (rc) {
> > +		pr_err("Unable to allocate scm major number: %d\n",
> > rc);
> > +		return rc;
> > +	}
> > +
> > +	scm_class = class_create(THIS_MODULE, "scm");
> > +	if (IS_ERR(scm_class)) {
> > +		pr_err("Unable to create scm class\n");
> > +		unregister_chrdev_region(scm_dev, SCM_NUM_MINORS);
> > +		return PTR_ERR(scm_class);
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static void scm_file_exit(void)
> > +{
> > +	class_destroy(scm_class);
> > +	unregister_chrdev_region(scm_dev, SCM_NUM_MINORS);
> > +	idr_destroy(&minors_idr);
> > +}
> > +
> > +static int __init scm_init(void)
> > +{
> > +	int rc = 0;
> > +
> > +	rc = scm_file_init();
> > +	if (rc)
> > +		return rc;
> > +
> > +	rc = pci_register_driver(&scm_pci_driver);
> > +	if (rc) {
> > +		scm_file_exit();
> > +		return rc;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static void scm_exit(void)
> > +{
> > +	pci_unregister_driver(&scm_pci_driver);
> > +	scm_file_exit();
> > +}
> > +
> > +module_init(scm_init);
> > +module_exit(scm_exit);
> > +
> > +MODULE_DESCRIPTION("Storage Class Memory");
> > +MODULE_LICENSE("GPL");
> > diff --git a/drivers/nvdimm/ocxl-scm_internal.c
> > b/drivers/nvdimm/ocxl-scm_internal.c
> > new file mode 100644
> > index 000000000000..e7c247835817
> > --- /dev/null
> > +++ b/drivers/nvdimm/ocxl-scm_internal.c
> > @@ -0,0 +1,232 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +// Copyright 2019 IBM Corp.
> > +
> > +#include <misc/ocxl.h>
> > +#include <linux/delay.h>
> > +#include "ocxl-scm_internal.h"
> > +
> > +int scm_chi(const struct scm_data *scm_data, u64 *chi)
> > +{
> > +	u64 val;
> > +	int rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_CHI,
> > +					 OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	*chi = val;
> > +
> > +	return 0;
> > +}
> > +
> > +bool scm_controller_is_ready(const struct scm_data *scm_data)
> > +{
> > +	u64 val = 0;
> > +	int rc = scm_chi(scm_data, &val);
> > +
> > +	WARN_ON(rc < 0);
> > +
> > +	return (val & GLOBAL_MMIO_CHI_CRDY) != 0;
> > +}
> > +
> > +static int scm_command_request(const struct scm_data *scm_data,
> > +			       struct command_metadata *cmd, u8
> > op_code)
> > +{
> > +	u64 val = op_code;
> > +	int rc;
> > +	u8 i;
> > +
> > +	if (!scm_controller_is_ready(scm_data))
> > +		return -EIO;
> > +
> > +	cmd->op_code = op_code;
> > +	cmd->id++;
> > +
> > +	val |= ((u64)cmd->id) << 16;
> > +
> > +	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu, cmd-
> > >request_offset,
> > +				      OCXL_LITTLE_ENDIAN, val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	for (i = 0x08; i <= 0x38; i += 0x08) {
> > +		rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > +					      cmd->request_offset + i,
> > +					      OCXL_LITTLE_ENDIAN, 0);
> > +		if (rc)
> > +			return rc;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +int scm_admin_command_request(struct scm_data *scm_data, u8
> > op_code)
> > +{
> > +	return scm_command_request(scm_data, &scm_data->admin_command,
> > op_code);
> > +}
> > +
> > +int scm_command_response(const struct scm_data *scm_data,
> > +			 const struct command_metadata *cmd)
> > +{
> > +	u64 val;
> > +	u16 id;
> > +	u8 status;
> > +	int rc = ocxl_global_mmio_read64(scm_data->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(&scm_data->dev,
> > +			 "Expected response for command %d, but
> > received response for command %d instead.\n",
> > +			 cmd->id, id);
> > +	}
> > +
> > +	return status;
> > +}
> > +
> > +int scm_admin_response(const struct scm_data *scm_data)
> > +{
> > +	return scm_command_response(scm_data, &scm_data-
> > >admin_command);
> > +}
> > +
> > +
> > +int scm_admin_command_execute(const struct scm_data *scm_data)
> > +{
> > +	return ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_HCI,
> > +				      OCXL_LITTLE_ENDIAN,
> > GLOBAL_MMIO_HCI_ACRW);
> > +}
> > +
> > +static bool scm_admin_command_complete(const struct scm_data
> > *scm_data)
> > +{
> > +	u64 val = 0;
> > +
> > +	int rc = scm_chi(scm_data, &val);
> > +
> > +	WARN_ON(rc);
> > +
> > +	return (val & GLOBAL_MMIO_CHI_ACRA) != 0;
> > +}
> > +
> > +int scm_admin_command_complete_timeout(const struct scm_data
> > *scm_data,
> > +				       int command)
> > +{
> > +	u32 timeout = scm_data->timeouts[command];
> > +	timeout++;
> > +	timeout /= 32;
> > +	if (!timeout)
> > +		timeout = SCM_DEFAULT_TIMEOUT / 32;
> > +
> > +	while (timeout-- > 0) {
> > +		if (scm_admin_command_complete(scm_data))
> > +			return 0;
> > +		msleep(32);
> > +	}
> > +
> > +	return -EBUSY;
> > +}
> > +
> > +int scm_admin_response_handled(const struct scm_data *scm_data)
> > +{
> > +	return ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_CHIC,
> > +				      OCXL_LITTLE_ENDIAN,
> > GLOBAL_MMIO_CHI_ACRA);
> > +}
> > +
> > +int scm_ns_command_request(struct scm_data *scm_data, u8 op_code)
> > +{
> > +	return scm_command_request(scm_data, &scm_data->ns_command,
> > op_code);
> > +}
> > +
> > +int scm_ns_response(const struct scm_data *scm_data)
> > +{
> > +	return scm_command_response(scm_data, &scm_data->ns_command);
> > +}
> > +
> > +int scm_ns_command_execute(const struct scm_data *scm_data)
> > +{
> > +	return ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_HCI,
> > +				      OCXL_LITTLE_ENDIAN,
> > GLOBAL_MMIO_HCI_NSCRW);
> > +}
> > +
> > +bool scm_ns_command_complete(const struct scm_data *scm_data)
> > +{
> > +	u64 val = 0;
> > +	int rc = scm_chi(scm_data, &val);
> > +
> > +	WARN_ON(rc);
> > +
> > +	return (val & GLOBAL_MMIO_CHI_NSCRA) != 0;
> > +}
> > +
> > +int scm_ns_response_handled(const struct scm_data *scm_data)
> > +{
> > +	return ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_CHIC,
> > +				      OCXL_LITTLE_ENDIAN,
> > GLOBAL_MMIO_CHI_NSCRA);
> > +}
> > +
> > +
> > +void scm_warn_status(const struct scm_data *scm_data, 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(&scm_data->dev, "%s: %s (%x)\n", message, text,
> > status);
> > +}
> > +
> > +void scm_warn_status_fw_update(const struct scm_data *scm_data,
> > +			       const char *message, u8 status)
> > +{
> > +	const char *text;
> > +
> > +	switch (status) {
> > +	case STATUS_FW_UPDATE_BLOCKED:
> > +		text = "Firmware update is blocked, please try again
> > later";
> > +		break;
> > +
> > +	case STATUS_FW_ARG_INVALID:
> > +		text = "Internal error in SCM firmware update
> > mechanism";
> > +		break;
> > +
> > +	case STATUS_FW_INVALID:
> > +		text = "Firmware content is invalid, please verify
> > firmware update file";
> > +		break;
> > +
> > +	default:
> > +		return scm_warn_status(scm_data, message, status);
> > +	}
> > +
> > +	dev_warn(&scm_data->dev, "%s: %s (%x)\n", message, text,
> > status);
> > +}
> > diff --git a/drivers/nvdimm/ocxl-scm_internal.h
> > b/drivers/nvdimm/ocxl-scm_internal.h
> > new file mode 100644
> > index 000000000000..c236d8092c6d
> > --- /dev/null
> > +++ b/drivers/nvdimm/ocxl-scm_internal.h
> > @@ -0,0 +1,331 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +// Copyright 2019 IBM Corp.
> > +
> > +#include <linux/pci.h>
> > +#include <linux/cdev.h>
> > +#include <misc/ocxl.h>
> > +#include <linux/libnvdimm.h>
> > +#include <uapi/linux/ocxl-scm.h>
> > +#include <linux/mm.h>
> > +
> > +#define SCM_DEFAULT_TIMEOUT 100
> > +
> > +#define GLOBAL_MMIO_CHI		0x000
> > +#define GLOBAL_MMIO_CHIC	0x008
> > +#define GLOBAL_MMIO_CHIE	0x010
> > +#define GLOBAL_MMIO_CHIEC	0x018
> > +#define GLOBAL_MMIO_HCI		0x020
> > +#define GLOBAL_MMIO_HCIC	0x028
> > +#define GLOBAL_MMIO_IMA0_OHP	0x040
> > +#define GLOBAL_MMIO_IMA0_CFP	0x048
> > +#define GLOBAL_MMIO_IMA1_OHP	0x050
> > +#define GLOBAL_MMIO_IMA1_CFP	0x058
> > +#define GLOBAL_MMIO_ACMA_CREQO	0x100
> > +#define GLOBAL_MMIO_ACMA_CRSPO	0x104
> > +#define GLOBAL_MMIO_ACMA_CDBO	0x108
> > +#define GLOBAL_MMIO_ACMA_CDBS	0x10c
> > +#define GLOBAL_MMIO_NSCMA_CREQO	0x120
> > +#define GLOBAL_MMIO_NSCMA_CRSPO	0x124
> > +#define GLOBAL_MMIO_NSCMA_CDBO	0x128
> > +#define GLOBAL_MMIO_NSCMA_CDBS	0x12c
> > +#define GLOBAL_MMIO_CSTS	0x140
> > +#define GLOBAL_MMIO_FWVER	0x148
> > +#define GLOBAL_MMIO_CCAP0	0x160
> > +#define GLOBAL_MMIO_CCAP1	0x168
> > +
> > +#define GLOBAL_MMIO_CHI_ACRA	BIT_ULL(0)
> > +#define GLOBAL_MMIO_CHI_NSCRA	BIT_ULL(1)
> > +#define GLOBAL_MMIO_CHI_CRDY	BIT_ULL(4)
> > +#define GLOBAL_MMIO_CHI_CFFS	BIT_ULL(5)
> > +#define GLOBAL_MMIO_CHI_MA	BIT_ULL(6)
> > +#define GLOBAL_MMIO_CHI_ELA	BIT_ULL(7)
> > +#define GLOBAL_MMIO_CHI_CDA	BIT_ULL(8)
> > +#define GLOBAL_MMIO_CHI_CHFS	BIT_ULL(9)
> > +
> > +#define GLOBAL_MMIO_CHI_ALL	(GLOBAL_MMIO_CHI_ACRA | \
> > +				 GLOBAL_MMIO_CHI_NSCRA | \
> > +				 GLOBAL_MMIO_CHI_CRDY | \
> > +				 GLOBAL_MMIO_CHI_CFFS | \
> > +				 GLOBAL_MMIO_CHI_MA | \
> > +				 GLOBAL_MMIO_CHI_ELA | \
> > +				 GLOBAL_MMIO_CHI_CDA | \
> > +				 GLOBAL_MMIO_CHI_CHFS)
> > +
> > +#define GLOBAL_MMIO_HCI_ACRW				BIT_ULL
> > (0)
> > +#define GLOBAL_MMIO_HCI_NSCRW				BIT_ULL
> > (1)
> > +#define GLOBAL_MMIO_HCI_AFU_RESET			BIT_ULL(2)
> > +#define GLOBAL_MMIO_HCI_FW_DEBUG			BIT_ULL(3)
> > +#define GLOBAL_MMIO_HCI_CONTROLLER_DUMP			BIT_ULL
> > (4)
> > +#define GLOBAL_MMIO_HCI_CONTROLLER_DUMP_COLLECTED	BIT_ULL(5)
> > +#define GLOBAL_MMIO_HCI_REQ_HEALTH_PERF			BIT_ULL
> > (6)
> > +
> > +#define ADMIN_COMMAND_HEARTBEAT		0x00u
> > +#define ADMIN_COMMAND_SHUTDOWN		0x01u
> > +#define ADMIN_COMMAND_FW_UPDATE		0x02u
> > +#define ADMIN_COMMAND_FW_DEBUG		0x03u
> > +#define ADMIN_COMMAND_ERRLOG		0x04u
> > +#define ADMIN_COMMAND_SMART		0x05u
> > +#define ADMIN_COMMAND_CONTROLLER_STATS	0x06u
> > +#define ADMIN_COMMAND_CONTROLLER_DUMP	0x07u
> > +#define ADMIN_COMMAND_CMD_CAPS		0x08u
> > +#define ADMIN_COMMAND_MAX		0x08u
> > +
> > +#define NS_COMMAND_SECURE_ERASE	0x20ull
> > +
> > +#define NS_RESPONSE_SECURE_ERASE_ACCESSIBLE_SUCCESS 0x20
> > +#define NS_RESPONSE_SECURE_ERASE_ACCESSIBLE_ATTEMPTED 0x28
> > +#define NS_RESPONSE_SECURE_ERASE_DEFECTIVE_SUCCESS 0x30
> > +#define NS_RESPONSE_SECURE_ERASE_DEFECTIVE_ATTEMPTED 0x38
> > +
> > +
> > +
> > +#define STATUS_SUCCESS		0x00
> > +#define STATUS_MEM_UNAVAILABLE	0x20
> > +#define STATUS_BAD_OPCODE	0x50
> > +#define STATUS_BAD_REQUEST_PARM	0x51
> > +#define STATUS_BAD_DATA_PARM	0x52
> > +#define STATUS_DEBUG_BLOCKED	0x70
> > +#define STATUS_FAIL		0xFF
> > +
> > +#define STATUS_FW_UPDATE_BLOCKED 0x21
> > +#define STATUS_FW_ARG_INVALID	0x51
> > +#define STATUS_FW_INVALID	0x52
> > +
> > +#define SCM_LABEL_AREA_SIZE	(1UL << PA_SECTION_SHIFT)
> > +
> > +struct command_metadata {
> > +	u32 request_offset;
> > +	u32 response_offset;
> > +	u32 data_offset;
> > +	u32 data_size;
> > +	struct mutex lock;
> > +	u16 id;
> > +	u8 op_code;
> > +};
> > +
> > +struct scm_function_0 {
> > +	struct pci_dev *pdev;
> > +	struct ocxl_fn *ocxl_fn;
> > +};
> > +
> > +enum overwrite_state {
> > +	SCM_OVERWRITE_IDLE = 0,
> > +	SCM_OVERWRITE_BUSY,
> > +	SCM_OVERWRITE_SUCCESS,
> > +	SCM_OVERWRITE_FAILED
> > +};
> > +
> > +#define SCM_SMART_ATTR_POWER_ON_HOURS	0x09
> > +#define SCM_SMART_ATTR_TEMPERATURE	0xC2
> > +#define SCM_SMART_ATTR_LIFE_REMAINING	0xCA
> > +
> > +struct scm_smart_attrib {
> > +	__u8 id; /* out, See defines above */
> > +	__u16 attribute_flags;
> > +	__u8 current_val;
> > +	__u8 threshold_val;
> > +	__u8 worst_val;
> > +	__u8 reserved;
> > +	__u64 raw_val;
> > +};
> > +
> > +struct scm_smart_attribs {
> > +	struct scm_smart_attrib power_on_hours;
> > +	struct scm_smart_attrib temperature;
> > +	struct scm_smart_attrib life_remaining;
> > +};
> > +
> > +struct scm_data {
> > +	struct device dev;
> > +	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;
> > +	struct ocxl_afu *ocxl_afu;
> > +	struct ocxl_context *ocxl_context;
> > +	void *metadata_addr;
> > +	struct scm_global_mmio *global_mmio;
> > +	struct command_metadata admin_command;
> > +	struct command_metadata ns_command;
> > +	enum overwrite_state overwrite_state;
> > +	struct resource scm_res;
> > +	struct nd_region *nd_region;
> > +	struct eventfd_ctx *ev_ctx;
> > +	struct scm_smart_attribs smart;
> > +	char fw_version[8+1];
> > +	u32 timeouts[ADMIN_COMMAND_MAX+1];
> > +
> > +	u16 scm_revision; // major/minor
> > +	u16 readiness_timeout; /* The worst case time (in milliseconds)
> > that the host shall
> > +				* wait for the controller to become
> > operational following a reset (CHI.CRDY).
> > +				*/
> > +	u16 read_latency; /* The nominal measure of latency (in
> > nanoseconds)
> > +			   * associated with an unassisted read of a
> > memory block.
> > +			   * This represents the capability of the raw
> > media technology without assistance
> > +			   */
> > +	u32 max_controller_dump_size; // bytes
> > +};
> > +
> > +/**
> > + * Create sysfs entries for an SCM device
> > + * scm_data: The SCM metadata
> > + */
> > +int scm_sysfs_add(struct scm_data *scm_data);
> > +
> > +/**
> > + * Get the value of the CHI register:
> > + * scm_data: The SCM metadata
> > + * chi: returns the CHI value
> > + *
> > + * Returns 0 on success, negative on error
> > + */
> > +int scm_chi(const struct scm_data *scm_data, u64 *chi);
> > +
> > +/**
> > + * scm_controller_is_ready - Is the controller ready?
> > + * @scm_data: a pointer to the SCM device data
> > + * Return true if the controller is ready
> > + */
> > +bool scm_controller_is_ready(const struct scm_data *scm_data);
> > +
> > +/**
> > + * Issue an admin command request
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + * op_code: The op-code for the command
> > + *
> > + * Returns an identifier for the command, or negative on error
> > + */
> > +int scm_admin_command_request(struct scm_data *scm_data, u8
> > op_code);
> > +
> > +/**
> > + * Validate an admin response
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + *
> > + * Returns the status code of the command, or negative on error
> > + */
> > +int scm_admin_response(const struct scm_data *scm_data);
> > +
> > +/**
> > + * Notify the controller to start processing a pending admin
> > command
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + *
> > + * Returns 0 on success, negative on error
> > + */
> > +int scm_admin_command_execute(const struct scm_data *scm_data);
> > +
> > +/**
> > + * Wait for an admin command to finish executing
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + * command: the admin command to wait for completion (determines
> > the timeout)
> > + *
> > + * Returns 0 on success, -EBUSY on timeout
> > + */
> > +int scm_admin_command_complete_timeout(const struct scm_data
> > *scm_data,
> > +				       int command);
> > +
> > +/**
> > + * Notify the controller that the admin response has been handled
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + *
> > + * Returns 0 on success, negative on failure
> > + */
> > +int scm_admin_response_handled(const struct scm_data *scm_data);
> > +
> > +/**
> > + * Issue a near storage command request
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + * op_code: The op-code for the command
> > + *
> > + * Returns an identifier for the command, or negative on error
> > + */
> > +int scm_ns_command_request(struct scm_data *scm_data, u8 op_code);
> > +
> > +/**
> > + * Validate a near storage response
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + *
> > + * Returns the status code of the command, or negative on error
> > + */
> > +int scm_ns_response(const struct scm_data *scm_data);
> > +
> > +/**
> > + * Notify the controller to start processing a pending near
> > storage command
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + *
> > + * Returns 0 on success, negative on error
> > + */
> > +int scm_ns_command_execute(const struct scm_data *scm_data);
> > +
> > +/**
> > + * Is a near storage command executing
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + *
> > + * Returns true if the previous admin command has completed
> > + */
> > +bool scm_ns_command_complete(const struct scm_data *scm_data);
> > +
> > +/**
> > + * Notify the controller that the near storage response has been
> > handled
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + *
> > + * Returns 0 on success, negative on failure
> > + */
> > +int scm_ns_response_handled(const struct scm_data *scm_data);
> > +
> > +/**
> > + * Emit a kernel warning showing a command status.
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + * message: A message to accompany the warning
> > + * status: The command status
> > + */
> > +void scm_warn_status(const struct scm_data *scm_data, const char
> > *message,
> > +		     u8 status);
> > +
> > +/**
> > + * Emit a kernel warning showing a command status.
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + * message: A message to accompany the warning
> > + * status: The command status
> > + */
> > +void scm_warn_status_fw_update(const struct scm_data *scm_data,
> > +			       const char *message, u8 status);
> > +
> > +/**
> > + * Request a controller dump
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + */
> > +int scm_request_controller_dump(struct scm_data *scm_data);
> > +
> > +/**
> > + * Request health & performance data (this will emit error logs
> > with the information)
> > + *
> > + * scm_data: a pointer to the SCM device data
> > + */
> > +int scm_req_controller_health_perf(struct scm_data *scm_data);
> > +
> > +
> > +/**
> > + * scm_overwrite() - Overwrite all data on the card
> > + * @scm_data: The SCM device data
> > + * Return: 0 on success
> > + */
> > +int scm_overwrite(struct scm_data *scm_data);
> > diff --git a/drivers/nvdimm/ocxl-scm_sysfs.c b/drivers/nvdimm/ocxl-
> > scm_sysfs.c
> > new file mode 100644
> > index 000000000000..080bbdeb0e56
> > --- /dev/null
> > +++ b/drivers/nvdimm/ocxl-scm_sysfs.c
> > @@ -0,0 +1,219 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +// Copyright 2018 IBM Corp.
> > +
> > +#include <linux/sysfs.h>
> > +#include <linux/capability.h>
> > +#include <linux/limits.h>
> > +#include <linux/firmware.h>
> > +#include "ocxl-scm_internal.h"
> > +
> > +static ssize_t admin_command_buffer_size_show(struct device
> > *device,
> > +	struct device_attribute *attr,
> > +	char *buf)
> > +{
> > +	struct scm_data *scm_data = container_of(device, struct
> > scm_data, dev);
> > +
> > +	return scnprintf(buf, PAGE_SIZE, "%d\n", scm_data-
> > >admin_command.data_size);
> > +}
> > +
> > +static ssize_t fw_version_show(struct device *device,
> > +			       struct device_attribute *attr, char
> > *buf)
> > +{
> > +	struct scm_data *scm_data = container_of(device, struct
> > scm_data, dev);
> > +
> > +	return scnprintf(buf, PAGE_SIZE, "%s\n", scm_data->fw_version);
> > +}
> > +
> > +#define SCM_FWUPDATE_BLOCK_SIZE	32768
> > +
> > +/**
> > + * scm_update_firmware() - Write a 32kB block of data to firmware
> > + * The block may be less than 32kB if it is the last one
> > + *
> > + * scm_data the SCM device metadata
> > + * offset: the offset of the start of the block
> > + * buf: the block data
> > + * size: the size of the block
> > + */
> > +static ssize_t scm_update_firmware(struct scm_data *scm_data,
> > size_t offset,
> > +				   const char *buf, size_t size)
> > +{
> > +	int rc;
> > +	size_t i;
> > +	u64 val;
> > +
> > +	if (size > SCM_FWUPDATE_BLOCK_SIZE)
> > +		return -EINVAL;
> > +
> > +	rc = scm_admin_command_request(scm_data,
> > ADMIN_COMMAND_FW_UPDATE);
> > +	if (rc)
> > +		return rc;
> > +
> > +	val = (((u64)offset) << 32) | size;
> > +	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > +				      scm_data-
> > >admin_command.request_offset + 8,
> > +				      OCXL_LITTLE_ENDIAN, val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	for (i = 0; i < size; i += 8) {
> > +		val = *(u64 *)(buf + i);
> > +		rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
> > +					      scm_data-
> > >admin_command.data_offset + i,
> > +					      OCXL_HOST_ENDIAN, val);
> > +		if (rc)
> > +			return rc;
> > +	}
> > +
> > +	rc = scm_admin_command_execute(scm_data);
> > +	if (rc)
> > +		return rc;
> > +
> > +	rc = scm_admin_command_complete_timeout(scm_data,
> > +						ADMIN_COMMAND_FW_UPDATE
> > );
> > +	if (rc < 0) {
> > +		dev_err(&scm_data->dev, "Firmware update timeout\n");
> > +		return rc;
> > +	}
> > +
> > +	rc = scm_admin_response(scm_data);
> > +	if (rc < 0)
> > +		return rc;
> > +	if (rc != STATUS_SUCCESS) {
> > +		scm_warn_status_fw_update(scm_data, "FW Update", rc);
> > +		return rc;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +/*
> > + * Parse out a firmware filename from sysfs, retrieve it's
> > contents and write it
> > + * to the SCM device firmware storage
> > + */
> > +static ssize_t fw_update_filename_store(struct device *device,
> > +					struct device_attribute *attr,
> > +					const char *buf, size_t size)
> > +{
> > +	char path[NAME_MAX+1];
> > +	const char *end;
> > +	const struct firmware *firmware = NULL;
> > +	size_t offset;
> > +	int rc;
> > +	struct scm_data *scm_data = container_of(device, struct
> > scm_data, dev);
> > +
> > +	if (!capable(CAP_SYS_ADMIN))
> > +		return -EACCES;
> > +
> > +	end = strnchr(buf, size, '\n');
> > +	if (end == NULL)
> > +		end = buf + strnlen(buf, size);
> > +
> > +	if ((end - buf) > NAME_MAX) {
> > +		dev_err(device, "Firmware filename '%-.*s' too long\n",
> > +			(int)(end - buf), buf);
> > +		return -EIO;
> > +	}
> > +
> > +	memcpy(path, buf, end - buf);
> > +	path[end - buf] = '\0';
> > +
> > +	if (request_firmware(&firmware, path, device)) {
> > +		dev_err(device, "Firmware file %s not found\n", path);
> > +		return -EIO;
> > +	}
> > +
> > +	if (firmware->size % 8) {
> > +		release_firmware(firmware);
> > +		dev_err(device, "Firmware '%s' should be a multiple of
> > 8 bytes", path);
> > +		return -EINVAL;
> > +	}
> > +
> > +	mutex_lock(&scm_data->admin_command.lock);
> > +
> > +	for (offset = 0; offset < firmware->size; offset +=
> > SCM_FWUPDATE_BLOCK_SIZE) {
> > +		size_t remainder = firmware->size - offset;
> > +		size_t block_size;
> > +
> > +		block_size = (remainder > SCM_FWUPDATE_BLOCK_SIZE) ?
> > +			      SCM_FWUPDATE_BLOCK_SIZE : remainder;
> > +		rc = scm_update_firmware(scm_data, offset,
> > +					 firmware->data + offset,
> > block_size);
> > +		if (rc) {
> > +			mutex_unlock(&scm_data->admin_command.lock);
> > +			return -EFAULT;
> > +		}
> > +	}
> > +
> > +	mutex_unlock(&scm_data->admin_command.lock);
> > +
> > +	return size;
> > +}
> > +
> > +/*
> > + * Trigger a controller dump
> > + */
> > +static ssize_t controller_dump_store(struct device *device,
> > +				     struct device_attribute *attr,
> > +				     const char *buf, size_t size)
> > +{
> > +	struct scm_data *scm_data = container_of(device, struct
> > scm_data, dev);
> > +
> > +	scm_request_controller_dump(scm_data);
> > +
> > +	return size;
> > +}
> > +
> > +/*
> > + * Request health & performance data
> > + */
> > +static ssize_t health_request_store(struct device *device,
> > +				    struct device_attribute *attr,
> > +				    const char *buf, size_t size)
> > +{
> > +	struct scm_data *scm_data = container_of(device, struct
> > scm_data, dev);
> > +
> > +	scm_req_controller_health_perf(scm_data);
> > +
> > +	return size;
> > +}
> > +
> > +/*
> > + * Overwrite all media
> > + */
> > +static ssize_t overwrite_store(struct device *device,
> > +			       struct device_attribute *attr,
> > +			       const char *buf, size_t size)
> > +{
> > +	struct scm_data *scm_data = container_of(device, struct
> > scm_data, dev);
> > +
> > +	scm_overwrite(scm_data);
> > +
> > +	return size;
> > +}
> > +
> > +static struct device_attribute scm_attrs[] = {
> > +	__ATTR_RO(admin_command_buffer_size),
> > +	__ATTR_RO(fw_version),
> > +	__ATTR_WO(fw_update_filename),
> > +	__ATTR_WO(controller_dump),
> > +	__ATTR_WO(health_request),
> > +	__ATTR_WO(overwrite),
> > +};
> > +
> > +int scm_sysfs_add(struct scm_data *scm_data)
> > +{
> > +	int i, rc;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(scm_attrs); i++) {
> > +		rc = device_create_file(&scm_data->dev, &scm_attrs[i]);
> > +		if (rc) {
> > +			for (; --i >= 0;)
> > +				device_remove_file(&scm_data->dev,
> > &scm_attrs[i]);
> > +
> > +			return rc;
> > +		}
> > +	}
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(scm_sysfs_add);
> > diff --git a/include/uapi/linux/ocxl-scm.h
> > b/include/uapi/linux/ocxl-scm.h
> > new file mode 100644
> > index 000000000000..6dc7e5196da2
> > --- /dev/null
> > +++ b/include/uapi/linux/ocxl-scm.h
> > @@ -0,0 +1,128 @@
> > +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
> > +/* Copyright 2017 IBM Corp. */
> > +#ifndef _UAPI_OCXL_SCM_H
> > +#define _UAPI_OCXL_SCM_H
> > +
> > +#include <linux/types.h>
> > +#include <linux/ioctl.h>
> > +
> > +enum scm_fwdebug_action {
> > +	SCM_FWDEBUG_READ_CONTROLLER_MEMORY = 0x01,
> > +	SCM_FWDEBUG_WRITE_CONTROLLER_MEMORY = 0x02,
> > +	SCM_FWDEBUG_ENABLE_FUNCTION = 0x03,
> > +	SCM_FWDEBUG_DISABLE_FUNCTION = 0x04,
> > +	SCM_FWDEBUG_GET_PEL = 0x05, // Retrieve Persistent Error Log
> > +};
> > +
> > +struct scm_ioctl_buffer_info {
> > +	__u32	admin_command_buffer_size; // out
> > +	__u32	near_storage_buffer_size; // out
> > +};
> > +
> > +struct scm_ioctl_fwdebug { // All args are inputs
> > +	enum scm_fwdebug_action debug_action;
> > +	__u16 function_code;
> > +	__u16 buf_size; // Size of optional data buffer
> > +	__u64 debug_parameter_1;
> > +	__u64 debug_parameter_2;
> > +	__u8 *buf; // Pointer to optional in/out data buffer
> > +};
> > +
> > +#define SCM_ERROR_LOG_ACTION_RESET	(1 << (32-32))
> > +#define SCM_ERROR_LOG_ACTION_CHKFW	(1 << (53-32))
> > +#define SCM_ERROR_LOG_ACTION_REPLACE	(1 << (54-32))
> > +#define SCM_ERROR_LOG_ACTION_DUMP	(1 << (55-32))
> > +
> > +#define SCM_ERROR_LOG_TYPE_GENERAL		(0x00)
> > +#define SCM_ERROR_LOG_TYPE_PREDICTIVE_FAILURE	(0x01)
> > +#define SCM_ERROR_LOG_TYPE_THERMAL_WARNING	(0x02)
> > +#define SCM_ERROR_LOG_TYPE_DATA_LOSS		(0x03)
> > +#define SCM_ERROR_LOG_TYPE_HEALTH_PERFORMANCE	(0x04)
> > +
> > +struct scm_ioctl_error_log {
> > +	__u32 log_identifier; // out
> > +	__u32 program_reference_code; // out
> > +	__u32 action_flags; //out, recommended course of action
> > +	__u32 power_on_seconds; // out, Number of seconds the
> > controller has been on when the error occurred
> > +	__u64 timestamp; // out, relative time since the current IPL
> > +	__u64 wwid[2]; // out, the NAA formatted WWID associated with
> > the controller
> > +	char  fw_revision[8+1]; // out, firmware revision as null
> > terminated text
> > +	__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 are no more error log
> > entries.
> > +			 */
> > +	__u8  error_log_type;
> > +	__u8  reserved1;
> > +	__u32 reserved2;
> > +	__u64 reserved3[2];
> > +	__u8 *buf; // pointer to output buffer
> > +};
> > +
> > +struct scm_ioctl_controller_dump_data {
> > +	__u8 *buf; // pointer to output buffer
> > +	__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];
> > +};
> > +
> > +struct scm_ioctl_controller_stats {
> > +	__u32 reset_count;
> > +	__u32 reset_uptime; // seconds
> > +	__u32 power_on_uptime; // seconds
> > +	__u64 host_load_count;
> > +	__u64 host_store_count;
> > +	__u64 media_read_count;
> > +	__u64 media_write_count;
> > +	__u64 cache_hit_count;
> > +	__u64 cache_miss_count;
> > +	__u64 media_read_latency; // nanoseconds
> > +	__u64 media_write_latency; // nanoseconds
> > +	__u64 cache_read_latency; // nanoseconds
> > +	__u64 cache_write_latency; // nanoseconds
> > +};
> > +
> > +struct scm_ioctl_mmio {
> > +	__u64 address; // Offset in global MMIO space
> > +	__u64 val; // value to write/was read
> > +};
> > +
> > +struct scm_ioctl_eventfd {
> > +	__s32 eventfd;
> > +	__u32 reserved;
> > +};
> > +
> > +#ifndef BIT_ULL
> > +#define BIT_ULL(nr)	(1ULL << (nr))
> > +#endif
> > +
> > +#define SCM_IOCTL_EVENT_CONTROLLER_DUMP_AVAILABLE	BIT_ULL(0)
> > +#define SCM_IOCTL_EVENT_ERROR_LOG_AVAILABLE		BIT_ULL
> > (1)
> > +#define SCM_IOCTL_EVENT_HARDWARE_FATAL			BIT_ULL
> > (2)
> > +#define SCM_IOCTL_EVENT_FIRMWARE_FATAL			BIT_ULL
> > (3)
> > +
> > +/* ioctl numbers */
> > +#define SCM_MAGIC 0x5C
> > +/* SCM devices */
> > +#define SCM_IOCTL_BUFFER_INFO	_IOR(SCM_MAGIC, 0x00, struct
> > scm_ioctl_buffer_info)
> > +#define SCM_IOCTL_ERROR_LOG	_IOWR(SCM_MAGIC, 0x01, struct
> > scm_ioctl_error_log)
> > +#define SCM_IOCTL_CONTROLLER_DUMP _IO(SCM_MAGIC, 0x02)
> > +#define SCM_IOCTL_CONTROLLER_DUMP_DATA _IOWR(SCM_MAGIC, 0x03,
> > struct scm_ioctl_controller_dump_data)
> > +#define SCM_IOCTL_CONTROLLER_DUMP_COMPLETE _IO(SCM_MAGIC, 0x04)
> > +#define SCM_IOCTL_CONTROLLER_STATS _IO(SCM_MAGIC, 0x05)
> > +#define SCM_IOCTL_EVENTFD	_IOW(SCM_MAGIC, 0x06, struct
> > scm_ioctl_eventfd)
> > +#define SCM_IOCTL_EVENT_CHECK	_IOR(SCM_MAGIC, 0x07, __u64)
> > +#define SCM_IOCTL_REQUEST_HEALTH _IO(SCM_MAGIC, 0x08)
> > +
> > +#define SCM_IOCTL_FWDEBUG	_IOWR(SCM_MAGIC, 0xf0, struct
> > scm_ioctl_fwdebug)
> > +#define SCM_IOCTL_MMIO_WRITE	_IOW(SCM_MAGIC, 0xf1, struct
> > scm_ioctl_mmio)
> > +#define SCM_IOCTL_MMIO_READ	_IOWR(SCM_MAGIC, 0xf2, struct
> > scm_ioctl_mmio)
> > +#define SCM_IOCTL_SHUTDOWN	_IO(SCM_MAGIC, 0xf3)
> > +
> > +#endif /* _UAPI_OCXL_SCM_H */
> > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> > index b39827dbd071..376500f4e3a2 100644
> > --- a/mm/memory_hotplug.c
> > +++ b/mm/memory_hotplug.c
> > @@ -279,7 +279,7 @@ static int check_pfn_span(unsigned long pfn,
> > unsigned long nr_pages,
> >   }
> >   
> >   int check_hotplug_memory_addressable(unsigned long pfn,
> > -					    unsigned long nr_pages)
> > +				     unsigned long nr_pages)
> >   {
> >   	const u64 max_addr = PFN_PHYS(pfn + nr_pages) - 1;
> >   
> > 
-- 
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819
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