lib/devres.c


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1Overview

The Dell Systems Management Base Driver provides a sysfs interface for
systems management software such as Dell OpenManage to perform system
management interrupts and host control actions (system power cycle or
power off after OS shutdown) on certain Dell systems.

Dell OpenManage requires this driver on the following Dell PowerEdge systems:
300, 1300, 1400, 400SC, 500SC, 1500SC, 1550, 600SC, 1600SC, 650, 1655MC,
700, and 750.  Other Dell software such as the open source libsmbios project
is expected to make use of this driver, and it may include the use of this
driver on other Dell systems.

The Dell libsmbios project aims towards providing access to as much BIOS
information as possible.  See http://linux.dell.com/libsmbios/main/ for
more information about the libsmbios project.


System Management Interrupt

On some Dell systems, systems management software must access certain
management information via a system management interrupt (SMI).  The SMI data
buffer must reside in 32-bit address space, and the physical address of the
buffer is required for the SMI.  The driver maintains the memory required for
the SMI and provides a way for the application to generate the SMI.
The driver creates the following sysfs entries for systems management
software to perform these system management interrupts:

/sys/devices/platform/dcdbas/smi_data
/sys/devices/platform/dcdbas/smi_data_buf_phys_addr
/sys/devices/platform/dcdbas/smi_data_buf_size
/sys/devices/platform/dcdbas/smi_request

Systems management software must perform the following steps to execute
a SMI using this driver:

1) Lock smi_data.
2) Write system management command to smi_data.
3) Write "1" to smi_request to generate a calling interface SMI or
   "2" to generate a raw SMI.
4) Read system management command response from smi_data.
5) Unlock smi_data.


Host Control Action

Dell OpenManage supports a host control feature that allows the administrator
to perform a power cycle or power off of the system after the OS has finished
shutting down.  On some Dell systems, this host control feature requires that
a driver perform a SMI after the OS has finished shutting down.

The driver creates the following sysfs entries for systems management software
to schedule the driver to perform a power cycle or power off host control
action after the system has finished shutting down:

/sys/devices/platform/dcdbas/host_control_action
/sys/devices/platform/dcdbas/host_control_smi_type
/sys/devices/platform/dcdbas/host_control_on_shutdown

Dell OpenManage performs the following steps to execute a power cycle or
power off host control action using this driver:

1) Write host control action to be performed to host_control_action.
2) Write type of SMI that driver needs to perform to host_control_smi_type.
3) Write "1" to host_control_on_shutdown to enable host control action.
4) Initiate OS shutdown.
   (Driver will perform host control SMI when it is notified that the OS
   has finished shutting down.)


Host Control SMI Type

The following table shows the value to write to host_control_smi_type to
perform a power cycle or power off host control action:

PowerEdge System    Host Control SMI Type
----------------    ---------------------
      300             HC_SMITYPE_TYPE1
     1300             HC_SMITYPE_TYPE1
     1400             HC_SMITYPE_TYPE2
      500SC           HC_SMITYPE_TYPE2
     1500SC           HC_SMITYPE_TYPE2
     1550             HC_SMITYPE_TYPE2
      600SC           HC_SMITYPE_TYPE2
     1600SC           HC_SMITYPE_TYPE2
      650             HC_SMITYPE_TYPE2
     1655MC           HC_SMITYPE_TYPE2
      700             HC_SMITYPE_TYPE3
      750             HC_SMITYPE_TYPE3
#include <linux/pci.h>
#include <linux/io.h>
#include <linux/gfp.h>
#include <linux/module.h>

void devm_ioremap_release(struct device *dev, void *res)
{
	iounmap(*(void __iomem **)res);
}

static int devm_ioremap_match(struct device *dev, void *res, void *match_data)
{
	return *(void **)res == match_data;
}

/**
 * devm_ioremap - Managed ioremap()
 * @dev: Generic device to remap IO address for
 * @offset: BUS offset to map
 * @size: Size of map
 *
 * Managed ioremap().  Map is automatically unmapped on driver detach.
 */
void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
			   unsigned long size)
{
	void __iomem **ptr, *addr;

	ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return NULL;

	addr = ioremap(offset, size);
	if (addr) {
		*ptr = addr;
		devres_add(dev, ptr);
	} else
		devres_free(ptr);

	return addr;
}
EXPORT_SYMBOL(devm_ioremap);

/**
 * devm_ioremap_nocache - Managed ioremap_nocache()
 * @dev: Generic device to remap IO address for
 * @offset: BUS offset to map
 * @size: Size of map
 *
 * Managed ioremap_nocache().  Map is automatically unmapped on driver
 * detach.
 */
void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
				   unsigned long size)
{
	void __iomem **ptr, *addr;

	ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return NULL;

	addr = ioremap_nocache(offset, size);
	if (addr) {
		*ptr = addr;
		devres_add(dev, ptr);
	} else
		devres_free(ptr);

	return addr;
}
EXPORT_SYMBOL(devm_ioremap_nocache);

/**
 * devm_iounmap - Managed iounmap()
 * @dev: Generic device to unmap for
 * @addr: Address to unmap
 *
 * Managed iounmap().  @addr must have been mapped using devm_ioremap*().
 */
void devm_iounmap(struct device *dev, void __iomem *addr)
{
	iounmap(addr);
	WARN_ON(devres_destroy(dev, devm_ioremap_release, devm_ioremap_match,
			       (void *)addr));
}
EXPORT_SYMBOL(devm_iounmap);

#ifdef CONFIG_HAS_IOPORT
/*
 * Generic iomap devres
 */
static void devm_ioport_map_release(struct device *dev, void *res)
{
	ioport_unmap(*(void __iomem **)res);
}

static int devm_ioport_map_match(struct device *dev, void *res,
				 void *match_data)
{
	return *(void **)res == match_data;
}

/**
 * devm_ioport_map - Managed ioport_map()
 * @dev: Generic device to map ioport for
 * @port: Port to map
 * @nr: Number of ports to map
 *
 * Managed ioport_map().  Map is automatically unmapped on driver
 * detach.
 */
void __iomem * devm_ioport_map(struct device *dev, unsigned long port,
			       unsigned int nr)
{
	void __iomem **ptr, *addr;

	ptr = devres_alloc(devm_ioport_map_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return NULL;

	addr = ioport_map(port, nr);
	if (addr) {
		*ptr = addr;
		devres_add(dev, ptr);
	} else
		devres_free(ptr);

	return addr;
}
EXPORT_SYMBOL(devm_ioport_map);

/**
 * devm_ioport_unmap - Managed ioport_unmap()
 * @dev: Generic device to unmap for
 * @addr: Address to unmap
 *
 * Managed ioport_unmap().  @addr must have been mapped using
 * devm_ioport_map().
 */
void devm_ioport_unmap(struct device *dev, void __iomem *addr)
{
	ioport_unmap(addr);
	WARN_ON(devres_destroy(dev, devm_ioport_map_release,
			       devm_ioport_map_match, (void *)addr));
}
EXPORT_SYMBOL(devm_ioport_unmap);

#ifdef CONFIG_PCI
/*
 * PCI iomap devres
 */
#define PCIM_IOMAP_MAX	PCI_ROM_RESOURCE

struct pcim_iomap_devres {
	void __iomem *table[PCIM_IOMAP_MAX];
};

static void pcim_iomap_release(struct device *gendev, void *res)
{
	struct pci_dev *dev = container_of(gendev, struct pci_dev, dev);
	struct pcim_iomap_devres *this = res;
	int i;

	for (i = 0; i < PCIM_IOMAP_MAX; i++)
		if (this->table[i])
			pci_iounmap(dev, this->table[i]);
}

/**
 * pcim_iomap_table - access iomap allocation table
 * @pdev: PCI device to access iomap table for
 *
 * Access iomap allocation table for @dev.  If iomap table doesn't
 * exist and @pdev is managed, it will be allocated.  All iomaps
 * recorded in the iomap table are automatically unmapped on driver
 * detach.
 *
 * This function might sleep when the table is first allocated but can
 * be safely called without context and guaranteed to succed once
 * allocated.
 */
void __iomem * const * pcim_iomap_table(struct pci_dev *pdev)
{
	struct pcim_iomap_devres *dr, *new_dr;

	dr = devres_find(&pdev->dev, pcim_iomap_release, NULL, NULL);
	if (dr)
		return dr->table;

	new_dr = devres_alloc(pcim_iomap_release, sizeof(*new_dr), GFP_KERNEL);
	if (!new_dr)
		return NULL;
	dr = devres_get(&pdev->dev, new_dr, NULL, NULL);
	return dr->table;
}
EXPORT_SYMBOL(pcim_iomap_table);

/**
 * pcim_iomap - Managed pcim_iomap()
 * @pdev: PCI device to iomap for
 * @bar: BAR to iomap
 * @maxlen: Maximum length of iomap
 *
 * Managed pci_iomap().  Map is automatically unmapped on driver
 * detach.
 */
void __iomem * pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen)
{
	void __iomem **tbl;

	BUG_ON(bar >= PCIM_IOMAP_MAX);

	tbl = (void __iomem **)pcim_iomap_table(pdev);
	if (!tbl || tbl[bar])	/* duplicate mappings not allowed */
		return NULL;

	tbl[bar] = pci_iomap(pdev, bar, maxlen);
	return tbl[bar];
}
EXPORT_SYMBOL(pcim_iomap);

/**
 * pcim_iounmap - Managed pci_iounmap()
 * @pdev: PCI device to iounmap for
 * @addr: Address to unmap
 *
 * Managed pci_iounmap().  @addr must have been mapped using pcim_iomap().
 */
void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr)
{
	void __iomem **tbl;
	int i;

	pci_iounmap(pdev, addr);

	tbl = (void __iomem **)pcim_iomap_table(pdev);
	BUG_ON(!tbl);

	for (i = 0; i < PCIM_IOMAP_MAX; i++)
		if (tbl[i] == addr) {
			tbl[i] = NULL;
			return;
		}
	WARN_ON(1);
}
EXPORT_SYMBOL(pcim_iounmap);

/**
 * pcim_iomap_regions - Request and iomap PCI BARs
 * @pdev: PCI device to map IO resources for
 * @mask: Mask of BARs to request and iomap
 * @name: Name used when requesting regions
 *
 * Request and iomap regions specified by @mask.
 */
int pcim_iomap_regions(struct pci_dev *pdev, u16 mask, const char *name)
{
	void __iomem * const *iomap;
	int i, rc;

	iomap = pcim_iomap_table(pdev);
	if (!iomap)
		return -ENOMEM;

	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
		unsigned long len;

		if (!(mask & (1 << i)))
			continue;

		rc = -EINVAL;
		len = pci_resource_len(pdev, i);
		if (!len)
			goto err_inval;

		rc = pci_request_region(pdev, i, name);
		if (rc)
			goto err_inval;

		rc = -ENOMEM;
		if (!pcim_iomap(pdev, i, 0))
			goto err_region;
	}

	return 0;

 err_region:
	pci_release_region(pdev, i);
 err_inval:
	while (--i >= 0) {
		if (!(mask & (1 << i)))
			continue;
		pcim_iounmap(pdev, iomap[i]);
		pci_release_region(pdev, i);
	}

	return rc;
}
EXPORT_SYMBOL(pcim_iomap_regions);

/**
 * pcim_iomap_regions_request_all - Request all BARs and iomap specified ones
 * @pdev: PCI device to map IO resources for
 * @mask: Mask of BARs to iomap
 * @name: Name used when requesting regions
 *
 * Request all PCI BARs and iomap regions specified by @mask.
 */
int pcim_iomap_regions_request_all(struct pci_dev *pdev, u16 mask,
				   const char *name)
{
	int request_mask = ((1 << 6) - 1) & ~mask;
	int rc;

	rc = pci_request_selected_regions(pdev, request_mask, name);
	if (rc)
		return rc;

	rc = pcim_iomap_regions(pdev, mask, name);
	if (rc)
		pci_release_selected_regions(pdev, request_mask);
	return rc;
}
EXPORT_SYMBOL(pcim_iomap_regions_request_all);

/**
 * pcim_iounmap_regions - Unmap and release PCI BARs
 * @pdev: PCI device to map IO resources for
 * @mask: Mask of BARs to unmap and release
 *
 * Unmap and release regions specified by @mask.
 */
void pcim_iounmap_regions(struct pci_dev *pdev, u16 mask)
{
	void __iomem * const *iomap;
	int i;

	iomap = pcim_iomap_table(pdev);
	if (!iomap)
		return;

	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
		if (!(mask & (1 << i)))
			continue;

		pcim_iounmap(pdev, iomap[i]);
		pci_release_region(pdev, i);
	}
}
EXPORT_SYMBOL(pcim_iounmap_regions);
#endif
#endif