Re: [PATCH 3/3] platform/x86: Intel PMT Crashlog capability driver

Hans de Goede
2020-09-14T13:41:46Z

Hi,

On 9/11/20 9:45 PM, David E. Box wrote:
> From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
>
> Add support for the Intel Platform Monitoring Technology crashlog
> interface. This interface provides a few sysfs values to allow for
> controlling the crashlog telemetry interface as well as a character driver
> to allow for mapping the crashlog memory region so that it can be accessed
> after a crashlog has been recorded.
>
> This driver is meant to only support the server version of the crashlog
> which is identified as crash_type 1 with a version of zero. Currently no
> other types are supported.
>
> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> ---
> .../ABI/testing/sysfs-class-pmt_crashlog | 66 ++
> drivers/platform/x86/Kconfig | 10 +
> drivers/platform/x86/Makefile | 1 +
> drivers/platform/x86/intel_pmt_crashlog.c | 588 ++++++++++++++++++
> 4 files changed, 665 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-class-pmt_crashlog
> create mode 100644 drivers/platform/x86/intel_pmt_crashlog.c
>
> diff --git a/Documentation/ABI/testing/sysfs-class-pmt_crashlog b/Documentation/ABI/testing/sysfs-class-pmt_crashlog
> new file mode 100644
> index 000000000000..40fb4ff437a6
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-class-pmt_crashlog
> @@ -0,0 +1,66 @@
> +What: /sys/class/pmt_crashlog/
> +Date: September 2020
> +KernelVersion: 5.10
> +Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> +Description:
> + The pmt_crashlog/ class directory contains information
> + for devices that expose crashlog capabilities using the Intel
> + Platform Monitoring Technology (PTM).
> +
> +What: /sys/class/pmt_crashlog/crashlogX
> +Date: September 2020
> +KernelVersion: 5.10
> +Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> +Description:
> + The crashlogX directory contains files for configuring an
> + instance of a PMT crashlog device that can perform crash data
> + recoring. Each crashlogX device has an associated
> + /dev/crashlogX device node. This node can be opened and mapped
> + to access the resulting crashlog data. The register layout for
> + the log can be determined from an XML file of specified guid
> + for the parent device.
> +
> +What: /sys/class/pmt_crashlog/crashlogX/guid
> +Date: September 2020
> +KernelVersion: 5.10
> +Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> +Description:
> + (RO) The guid for this crashlog device. The guid identifies the
> + version of the XML file for the parent device that should be
> + used to determine the register layout.
> +
> +What: /sys/class/pmt_crashlog/crashlogX/size
> +Date: September 2020
> +KernelVersion: 5.10
> +Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> +Description:
> + (RO) The length of the result buffer in bytes that corresponds
> + to the mapping size for the /dev/crashlogX device node.
> +
> +What: /sys/class/pmt_crashlog/crashlogX/offset
> +Date: September 2020
> +KernelVersion: 5.10
> +Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> +Description:
> + (RO) The offset of the buffer in bytes that corresponds
> + to the mapping for the /dev/crashlogX device node.
> +
> +What: /sys/class/pmt_crashlog/crashlogX/enable
> +Date: September 2020
> +KernelVersion: 5.10
> +Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> +Description:
> + (RW) Boolean value controlling if the crashlog functionality
> + is enabled for the /dev/crashlogX device node.
> +
> +What: /sys/class/pmt_crashlog/crashlogX/trigger
> +Date: September 2020
> +KernelVersion: 5.10
> +Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> +Description:
> + (RW) Boolean value controlling the triggering of the
> + /dev/crashlogX device node. When read it provides data on if
> + the crashlog has been triggered. When written to it can be
> + used to either clear the current trigger by writing false, or
> + to trigger a new event if the trigger is not currently set.
> +

Both the pmt_crashlog and the attributes suggest that this is highly
Intel PMT specific. /sys/class/foo interfaces are generally speaking
meant to be generic interfaces.

If this was defining a generic, vendor and implementation agnostic interface for
configuring / accessing crashlogs, then using a class would be fine, but that
is not the case, so I believe that this should not implement / register a class.

Since the devices are instantiated through MFD there already is a
static sysfs-path which can be used to find the device in sysfs:
/sys/bus/platform/device/pmt_crashlog

So you can register the sysfs attributes directly under the platform_device
and then userspace can easily find them, so there really is no need to
use a class here.

> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 48335b02014f..50c3234e4f72 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -1360,6 +1360,16 @@ config INTEL_PMC_CORE
> - LTR Ignore
> - MPHY/PLL gating status (Sunrisepoint PCH only)
>
> +config INTEL_PMT_CRASHLOG
> + tristate "Intel Platform Monitoring Technology (PMT) Crashlog driver"
> + help
> + The Intel Platform Monitoring Technology (PMT) crashlog driver provides
> + access to hardware crashlog capabilities on devices that support the
> + feature.
> +
> + For more information, see
> + <file:Documentation/ABI/testing/sysfs-class-intel_pmt_crashlog>
> +
> config INTEL_PMT_TELEMETRY
> tristate "Intel Platform Monitoring Technology (PMT) Telemetry driver"
> help
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index ca942e70de8d..1b8b2502d460 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -140,6 +140,7 @@ obj-$(CONFIG_INTEL_MFLD_THERMAL) += intel_mid_thermal.o
> obj-$(CONFIG_INTEL_MID_POWER_BUTTON) += intel_mid_powerbtn.o
> obj-$(CONFIG_INTEL_MRFLD_PWRBTN) += intel_mrfld_pwrbtn.o
> obj-$(CONFIG_INTEL_PMC_CORE) += intel_pmc_core.o intel_pmc_core_pltdrv.o
> +obj-$(CONFIG_INTEL_PMT_CRASHLOG) += intel_pmt_crashlog.o
> obj-$(CONFIG_INTEL_PMT_TELEMETRY) += intel_pmt_telemetry.o
> obj-$(CONFIG_INTEL_PUNIT_IPC) += intel_punit_ipc.o
> obj-$(CONFIG_INTEL_SCU_IPC) += intel_scu_ipc.o
> diff --git a/drivers/platform/x86/intel_pmt_crashlog.c b/drivers/platform/x86/intel_pmt_crashlog.c
> new file mode 100644
> index 000000000000..31d43708055c
> --- /dev/null
> +++ b/drivers/platform/x86/intel_pmt_crashlog.c
> @@ -0,0 +1,588 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Intel Platform Monitoring Technology Crashlog driver
> + *
> + * Copyright (c) 2020, Intel Corporation.
> + * All Rights Reserved.
> + *
> + * Authors: "Alexander Duyck" <alexander.h.duyck@linux.intel.com>
> + */
> +
> +#include <linux/cdev.h>
> +#include <linux/idr.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +
> +#define DRV_NAME "pmt_crashlog"
> +
> +/* Crashlog access types */
> +#define ACCESS_FUTURE 1
> +#define ACCESS_BARID 2
> +#define ACCESS_LOCAL 3
> +
> +/* Crashlog discovery header types */
> +#define CRASH_TYPE_OOBMSM 1
> +
> +/* Control Flags */
> +#define CRASHLOG_FLAG_DISABLE BIT(27)
> +#define CRASHLOG_FLAG_CLEAR BIT(28)
> +#define CRASHLOG_FLAG_EXECUTE BIT(29)
> +#define CRASHLOG_FLAG_COMPLETE BIT(31)
> +#define CRASHLOG_FLAG_MASK GENMASK(31, 28)
> +
> +/* Common Header */
> +#define CONTROL_OFFSET 0x0
> +#define GUID_OFFSET 0x4
> +#define BASE_OFFSET 0x8
> +#define SIZE_OFFSET 0xC
> +#define GET_ACCESS(v) ((v) & GENMASK(3, 0))
> +#define GET_TYPE(v) (((v) & GENMASK(7, 4)) >> 4)
> +#define GET_VERSION(v) (((v) & GENMASK(19, 16)) >> 16)
> +
> +#define GET_ADDRESS(v) ((v) & GENMASK(31, 3))
> +#define GET_BIR(v) ((v) & GENMASK(2, 0))
> +
> +static DEFINE_IDA(crashlog_devid_ida);
> +
> +struct crashlog_header {
> + u32 base_offset;
> + u32 size;
> + u32 guid;
> + u8 bir;
> + u8 access_type;
> + u8 crash_type;
> + u8 version;
> +};
> +
> +struct pmt_crashlog_priv;
> +
> +struct crashlog_entry {
> + struct pmt_crashlog_priv *priv;
> + struct crashlog_header header;
> + struct resource *header_res;
> + void __iomem *disc_table;
> + unsigned long crashlog_data;
> + size_t crashlog_data_size;
> + struct cdev cdev;
> + dev_t devt;
> + int devid;
> + struct ida *ida;
> +};
> +
> +struct pmt_crashlog_priv {
> + struct device *dev;
> + struct pci_dev *parent;
> + struct crashlog_entry *entry;
> + int num_entries;
> +};
> +
> +/*
> + * I/O
> + */
> +static bool pmt_crashlog_complete(struct crashlog_entry *entry)
> +{
> + u32 control = readl(entry->disc_table + CONTROL_OFFSET);
> +
> + /* return current value of the crashlog complete flag */
> + return !!(control & CRASHLOG_FLAG_COMPLETE);
> +}
> +
> +static bool pmt_crashlog_disabled(struct crashlog_entry *entry)
> +{
> + u32 control = readl(entry->disc_table + CONTROL_OFFSET);
> +
> + /* return current value of the crashlog disabled flag */
> + return !!(control & CRASHLOG_FLAG_DISABLE);
> +}
> +
> +static void pmt_crashlog_set_disable(struct crashlog_entry *entry, bool disable)
> +{
> + u32 control = readl(entry->disc_table + CONTROL_OFFSET);
> +
> + /* clear control bits */
> + control &= ~(CRASHLOG_FLAG_MASK | CRASHLOG_FLAG_DISABLE);
> + if (disable)
> + control |= CRASHLOG_FLAG_DISABLE;
> +
> + writel(control, entry->disc_table + CONTROL_OFFSET);
> +}
> +
> +static void pmt_crashlog_set_clear(struct crashlog_entry *entry)
> +{
> + u32 control = readl(entry->disc_table + CONTROL_OFFSET);
> +
> + /* clear control bits */
> + control &= ~CRASHLOG_FLAG_MASK;
> + control |= CRASHLOG_FLAG_CLEAR;
> +
> + writel(control, entry->disc_table + CONTROL_OFFSET);
> +}
> +
> +static void pmt_crashlog_set_execute(struct crashlog_entry *entry)
> +{
> + u32 control = readl(entry->disc_table + CONTROL_OFFSET);
> +
> + /* clear control bits */
> + control &= ~CRASHLOG_FLAG_MASK;
> + control |= CRASHLOG_FLAG_EXECUTE;
> +
> + writel(control, entry->disc_table + CONTROL_OFFSET);
> +}

These 3 pmt_crashlog_set_* functions are all triggered through
sysfs writes and they all do read-modify-write of the control-register,
so this is racy. You need to add a mutex to protect the r-m-w sequences.

> +
> +/*
> + * devfs
> + */
> +static int pmt_crashlog_open(struct inode *inode, struct file *filp)
> +{
> + struct crashlog_entry *entry;
> + struct pci_driver *pci_drv;
> + struct pmt_crashlog_priv *priv;
> +
> + if (!capable(CAP_SYS_ADMIN))
> + return -EPERM;
> +
> + entry = container_of(inode->i_cdev, struct crashlog_entry, cdev);
> + priv = entry->priv;
> + pci_drv = pci_dev_driver(priv->parent);
> +
> + if (!pci_drv)
> + return -ENODEV;
> +
> + filp->private_data = entry;
> + get_device(&priv->parent->dev);
> +
> + if (!try_module_get(pci_drv->driver.owner)) {
> + put_device(&priv->parent->dev);
> + return -ENODEV;
> + }
> +
> + return 0;
> +}
> +
> +static int pmt_crashlog_release(struct inode *inode, struct file *filp)
> +{
> + struct crashlog_entry *entry = filp->private_data;
> + struct pmt_crashlog_priv *priv;
> + struct pci_driver *pci_drv;
> +
> + priv = entry->priv;
> + pci_drv = pci_dev_driver(priv->parent);
> +
> + put_device(&priv->parent->dev);
> + module_put(pci_drv->driver.owner);
> +
> + return 0;
> +}
> +
> +static int
> +pmt_crashlog_mmap(struct file *filp, struct vm_area_struct *vma)
> +{
> + struct crashlog_entry *entry = filp->private_data;
> + struct pmt_crashlog_priv *priv;
> + unsigned long phys = entry->crashlog_data;
> + unsigned long pfn = PFN_DOWN(phys);
> + unsigned long vsize = vma->vm_end - vma->vm_start;
> + unsigned long psize;
> +
> + if ((vma->vm_flags & VM_WRITE) ||
> + (vma->vm_flags & VM_MAYWRITE))
> + return -EPERM;
> +
> + priv = entry->priv;
> +
> + if (!entry->crashlog_data_size) {
> + dev_err(priv->dev, "Crashlog data not accessible\n");
> + return -EAGAIN;
> + }
> +
> + psize = (PFN_UP(entry->crashlog_data + entry->crashlog_data_size) - pfn) *
> + PAGE_SIZE;
> + if (vsize > psize) {
> + dev_err(priv->dev, "Requested mmap size is too large\n");
> + return -EINVAL;
> + }
> +
> + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
> + if (io_remap_pfn_range(vma, vma->vm_start, pfn,
> + vsize, vma->vm_page_prot))
> + return -EAGAIN;
> +
> + return 0;
> +}
> +
> +static const struct file_operations pmt_crashlog_fops = {
> + .owner = THIS_MODULE,
> + .open = pmt_crashlog_open,
> + .mmap = pmt_crashlog_mmap,

mmap but no read, I guess read may be emulated through mmap,
is that the case ?

I can see sysadmins wanting to be able to do a simple cat
on this file to get the logs (including headers), so if
the kernel-core does not emulate read in this case, you
should really add read support I guess.

Also how big are these files ? sysfs also supports binary
files, so unless these files are huge / this is really
performance critical it may make more sense to just add
a binary sysfs attr for this and get rid of the whole chardev
all together.

> + .release = pmt_crashlog_release,
> +};
> +
> +/*
> + * sysfs
> + */
> +static ssize_t
> +guid_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct crashlog_entry *entry;
> +
> + entry = dev_get_drvdata(dev);
> +
> + return sprintf(buf, "0x%x\n", entry->header.guid);
> +}
> +static DEVICE_ATTR_RO(guid);
> +
> +static ssize_t size_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct crashlog_entry *entry;
> +
> + entry = dev_get_drvdata(dev);
> +
> + return sprintf(buf, "%lu\n", entry->crashlog_data_size);
> +}
> +static DEVICE_ATTR_RO(size);
> +
> +static ssize_t
> +offset_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct crashlog_entry *entry;
> +
> + entry = dev_get_drvdata(dev);
> +
> + return sprintf(buf, "%lu\n", offset_in_page(entry->crashlog_data));
> +}
> +static DEVICE_ATTR_RO(offset);
> +
> +static ssize_t
> +enable_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct crashlog_entry *entry;
> + int enabled;
> +
> + entry = dev_get_drvdata(dev);
> + enabled = !pmt_crashlog_disabled(entry);
> +
> + return sprintf(buf, "%d\n", enabled);
> +}
> +
> +static ssize_t
> +enable_store(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct crashlog_entry *entry;
> + bool enabled;
> + int result;
> +
> + entry = dev_get_drvdata(dev);
> +
> + result = kstrtobool(buf, &enabled);
> + if (result)
> + return result;
> +
> + pmt_crashlog_set_disable(entry, !enabled);
> +
> + return strnlen(buf, count);
> +}
> +static DEVICE_ATTR_RW(enable);
> +
> +static ssize_t
> +trigger_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct crashlog_entry *entry;
> + int trigger;
> +
> + entry = dev_get_drvdata(dev);
> + trigger = pmt_crashlog_complete(entry);
> +
> + return sprintf(buf, "%d\n", trigger);
> +}
> +
> +static ssize_t
> +trigger_store(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct crashlog_entry *entry;
> + bool trigger;
> + int result;
> +
> + entry = dev_get_drvdata(dev);
> +
> + result = kstrtobool(buf, &trigger);
> + if (result)
> + return result;
> +
> + if (trigger) {
> + /* we cannot trigger a new crash if one is still pending */
> + if (pmt_crashlog_complete(entry))
> + return -EEXIST;
> +
> + /* if device is currently disabled, return busy */
> + if (pmt_crashlog_disabled(entry))
> + return -EBUSY;
> +
> + pmt_crashlog_set_execute(entry);
> + } else {
> + pmt_crashlog_set_clear(entry);
> + }
> +
> + return strnlen(buf, count);
> +}
> +static DEVICE_ATTR_RW(trigger);
> +
> +static struct attribute *pmt_crashlog_attrs[] = {
> + &dev_attr_guid.attr,
> + &dev_attr_size.attr,
> + &dev_attr_offset.attr,
> + &dev_attr_enable.attr,
> + &dev_attr_trigger.attr,
> + NULL
> +};
> +ATTRIBUTE_GROUPS(pmt_crashlog);
> +
> +static struct class pmt_crashlog_class = {
> + .name = "pmt_crashlog",
> + .owner = THIS_MODULE,
> + .dev_groups = pmt_crashlog_groups,
> +};
> +
> +/*
> + * initialization
> + */
> +static int pmt_crashlog_make_dev(struct pmt_crashlog_priv *priv,
> + struct crashlog_entry *entry)
> +{
> + struct device *dev;
> + int ret;
> +
> + ret = alloc_chrdev_region(&entry->devt, 0, 1, DRV_NAME);
> + if (ret < 0) {
> + dev_err(priv->dev, "alloc_chrdev_region err: %d\n", ret);
> + return ret;
> + }
> +
> + /* Create a character device for Samplers */
> + cdev_init(&entry->cdev, &pmt_crashlog_fops);
> +
> + ret = cdev_add(&entry->cdev, entry->devt, 1);
> + if (ret) {
> + dev_err(priv->dev, "Could not add char dev\n");
> + return ret;
> + }
> +
> + dev = device_create(&pmt_crashlog_class, &priv->parent->dev, entry->devt,
> + entry, "%s%d", "crashlog", entry->devid);
> +
> + if (IS_ERR(dev)) {
> + dev_err(priv->dev, "Could not create device node\n");
> + cdev_del(&entry->cdev);
> + }
> +
> + return PTR_ERR_OR_ZERO(dev);
> +}
> +
> +static void
> +pmt_crashlog_populate_header(void __iomem *disc_offset,
> + struct crashlog_header *header)
> +{
> + u32 discovery_header = readl(disc_offset);
> +
> + header->access_type = GET_ACCESS(discovery_header);
> + header->crash_type = GET_TYPE(discovery_header);
> + header->version = GET_VERSION(discovery_header);
> + header->guid = readl(disc_offset + GUID_OFFSET);
> + header->base_offset = readl(disc_offset + BASE_OFFSET);
> +
> + /*
> + * For non-local access types the lower 3 bits of base offset
> + * contains the index of the base address register where the
> + * crashlogetry can be found.
> + */
> + header->bir = GET_BIR(header->base_offset);
> + header->base_offset ^= header->bir;
> +
> + /* Size is measured in DWORDs */
> + header->size = readl(disc_offset + SIZE_OFFSET);
> +}
> +
> +static int pmt_crashlog_add_entry(struct pmt_crashlog_priv *priv,
> + struct crashlog_entry *entry)
> +{
> + struct resource *res = entry->header_res;
> + int ret;
> +
> + pmt_crashlog_populate_header(entry->disc_table, &entry->header);
> +
> + /* Local access and BARID only for now */
> + switch (entry->header.access_type) {
> + case ACCESS_LOCAL:
> + dev_info(priv->dev, "access_type: LOCAL\n");
> + if (entry->header.bir) {
> + dev_err(priv->dev,
> + "Unsupported BAR index %d for access type %d\n",
> + entry->header.bir, entry->header.access_type);
> + return -EINVAL;
> + }
> +
> + entry->crashlog_data = res->start + resource_size(res) +
> + entry->header.base_offset;
> + break;
> +
> + case ACCESS_BARID:
> + dev_info(priv->dev, "access_type: BARID\n");
> + entry->crashlog_data =
> + priv->parent->resource[entry->header.bir].start +
> + entry->header.base_offset;
> + break;
> +
> + default:
> + dev_err(priv->dev, "Unsupported access type %d\n",
> + entry->header.access_type);
> + return -EINVAL;
> + }
> +
> + dev_info(priv->dev, "crashlod_data address: 0x%lx\n", entry->crashlog_data);
> +
> + entry->crashlog_data_size = entry->header.size * 4;
> +
> + if (entry->header.crash_type != CRASH_TYPE_OOBMSM) {
> + dev_err(priv->dev, "Unsupported crashlog header type %d\n",
> + entry->header.crash_type);
> + return -EINVAL;
> + }
> +
> + if (entry->header.version != 0) {
> + dev_err(priv->dev, "Unsupported version value %d\n",
> + entry->header.version);
> + return -EINVAL;
> + }
> +
> + entry->ida = &crashlog_devid_ida;
> +
> + entry->devid = ida_simple_get(entry->ida, 0, 0, GFP_KERNEL);
> + if (entry->devid < 0)
> + return entry->devid;
> +
> + ret = pmt_crashlog_make_dev(priv, entry);
> + if (ret) {
> + ida_simple_remove(entry->ida, entry->devid);
> + return ret;
> + }

Hmm wait, you are making one chardev per log entry ? Then just using
binary sysfs attributes seems to make even more sense to me.

> +
> + return 0;
> +}
> +
> +static void pmt_crashlog_remove_entries(struct pmt_crashlog_priv *priv)
> +{
> + int i;
> +
> + for (i = 0; i < priv->num_entries; i++) {
> + device_destroy(&pmt_crashlog_class, priv->entry[i].devt);
> + cdev_del(&priv->entry[i].cdev);
> +
> + unregister_chrdev_region(priv->entry[i].devt, 1);
> + ida_simple_remove(priv->entry[i].ida, priv->entry[i].devid);
> + }
> +}
> +static int pmt_crashlog_probe(struct platform_device *pdev)
> +{
> + struct pmt_crashlog_priv *priv;
> + struct crashlog_entry *entry;
> + int i;
> +
> + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, priv);
> + priv->dev = &pdev->dev;
> + priv->parent = to_pci_dev(priv->dev->parent);
> +
> + priv->entry = devm_kcalloc(&pdev->dev, pdev->num_resources,
> + sizeof(*(priv->entry)), GFP_KERNEL);
> +
> + for (i = 0, entry = priv->entry; i < pdev->num_resources;
> + i++, entry++) {
> + int ret;
> +
> + entry->header_res = platform_get_resource(pdev, IORESOURCE_MEM,
> + i);
> + if (!entry->header_res) {
> + pmt_crashlog_remove_entries(priv);
> + return -ENODEV;
> + }
> +
> + dev_info(&pdev->dev, "%d res start: 0x%llx, end 0x%llx\n", i,
> + entry->header_res->start, entry->header_res->end);
> +
> + entry->disc_table = devm_platform_ioremap_resource(pdev, i);
> + if (IS_ERR(entry->disc_table)) {
> + pmt_crashlog_remove_entries(priv);
> + return PTR_ERR(entry->disc_table);
> + }
> +
> + ret = pmt_crashlog_add_entry(priv, entry);
> + if (ret) {
> + pmt_crashlog_remove_entries(priv);
> + return ret;
> + }
> +
> + entry->priv = priv;
> + priv->num_entries++;
> + }
> +
> + return 0;
> +}
> +
> +static int pmt_crashlog_remove(struct platform_device *pdev)
> +{
> + struct pmt_crashlog_priv *priv;
> +
> + priv = (struct pmt_crashlog_priv *)platform_get_drvdata(pdev);
> +
> + pmt_crashlog_remove_entries(priv);
> +
> + return 0;
> +}
> +
> +static struct platform_driver pmt_crashlog_driver = {
> + .driver = {
> + .name = DRV_NAME,
> + },
> + .probe = pmt_crashlog_probe,
> + .remove = pmt_crashlog_remove,
> +};
> +
> +static int __init pmt_crashlog_init(void)
> +{
> + int ret = class_register(&pmt_crashlog_class);
> +
> + if (ret)
> + return ret;
> +
> + ret = platform_driver_register(&pmt_crashlog_driver);
> + if (ret) {
> + class_unregister(&pmt_crashlog_class);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static void __exit pmt_crashlog_exit(void)
> +{
> + platform_driver_unregister(&pmt_crashlog_driver);
> + class_unregister(&pmt_crashlog_class);
> + ida_destroy(&crashlog_devid_ida);
> +}
> +
> +module_init(pmt_crashlog_init);
> +module_exit(pmt_crashlog_exit);
> +
> +MODULE_AUTHOR("Alexander Duyck <alexander.h.duyck@linux.intel.com>");
> +MODULE_DESCRIPTION("Intel PMT Crashlog driver");
> +MODULE_ALIAS("platform:" DRV_NAME);
> +MODULE_LICENSE("GPL v2");
>

Regards,

Hans