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linux/drivers/pci/ats.c
Kuppuswamy Sathyanarayanan 8c938ddc6d PCI/ATS: Add pci_ats_page_aligned() interface 
Return the Page Aligned Request bit in the ATS Capability Register.

As per PCIe spec r4.0, sec 10.5.1.2, if the Page Aligned Request bit is
set, it indicates the Untranslated Addresses generated by the device are
always aligned to a 4096 byte boundary.

An IOMMU that can only translate page-aligned addresses can only be used
with devices that always produce aligned Untranslated Addresses. This
interface will be used by drivers for such IOMMUs to determine whether
devices can use the ATS service.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Suggested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2019-02-26 11:08:07 +01:00

454 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* PCI Express I/O Virtualization (IOV) support
* Address Translation Service 1.0
* Page Request Interface added by Joerg Roedel <joerg.roedel@amd.com>
* PASID support added by Joerg Roedel <joerg.roedel@amd.com>
*
* Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
* Copyright (C) 2011 Advanced Micro Devices,
*/
#include <linux/export.h>
#include <linux/pci-ats.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include "pci.h"
void pci_ats_init(struct pci_dev *dev)
{
int pos;
if (pci_ats_disabled())
return;
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
if (!pos)
return;
dev->ats_cap = pos;
}
/**
* pci_enable_ats - enable the ATS capability
* @dev: the PCI device
* @ps: the IOMMU page shift
*
* Returns 0 on success, or negative on failure.
*/
int pci_enable_ats(struct pci_dev *dev, int ps)
{
u16 ctrl;
struct pci_dev *pdev;
if (!dev->ats_cap)
return -EINVAL;
if (WARN_ON(dev->ats_enabled))
return -EBUSY;
if (ps < PCI_ATS_MIN_STU)
return -EINVAL;
/*
* Note that enabling ATS on a VF fails unless it's already enabled
* with the same STU on the PF.
*/
ctrl = PCI_ATS_CTRL_ENABLE;
if (dev->is_virtfn) {
pdev = pci_physfn(dev);
if (pdev->ats_stu != ps)
return -EINVAL;
atomic_inc(&pdev->ats_ref_cnt); /* count enabled VFs */
} else {
dev->ats_stu = ps;
ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU);
}
pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
dev->ats_enabled = 1;
return 0;
}
EXPORT_SYMBOL_GPL(pci_enable_ats);
/**
* pci_disable_ats - disable the ATS capability
* @dev: the PCI device
*/
void pci_disable_ats(struct pci_dev *dev)
{
struct pci_dev *pdev;
u16 ctrl;
if (WARN_ON(!dev->ats_enabled))
return;
if (atomic_read(&dev->ats_ref_cnt))
return; /* VFs still enabled */
if (dev->is_virtfn) {
pdev = pci_physfn(dev);
atomic_dec(&pdev->ats_ref_cnt);
}
pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, &ctrl);
ctrl &= ~PCI_ATS_CTRL_ENABLE;
pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
dev->ats_enabled = 0;
}
EXPORT_SYMBOL_GPL(pci_disable_ats);
void pci_restore_ats_state(struct pci_dev *dev)
{
u16 ctrl;
if (!dev->ats_enabled)
return;
ctrl = PCI_ATS_CTRL_ENABLE;
if (!dev->is_virtfn)
ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU);
pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
}
EXPORT_SYMBOL_GPL(pci_restore_ats_state);
/**
* pci_ats_queue_depth - query the ATS Invalidate Queue Depth
* @dev: the PCI device
*
* Returns the queue depth on success, or negative on failure.
*
* The ATS spec uses 0 in the Invalidate Queue Depth field to
* indicate that the function can accept 32 Invalidate Request.
* But here we use the `real' values (i.e. 1~32) for the Queue
* Depth; and 0 indicates the function shares the Queue with
* other functions (doesn't exclusively own a Queue).
*/
int pci_ats_queue_depth(struct pci_dev *dev)
{
u16 cap;
if (!dev->ats_cap)
return -EINVAL;
if (dev->is_virtfn)
return 0;
pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CAP, &cap);
return PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) : PCI_ATS_MAX_QDEP;
}
EXPORT_SYMBOL_GPL(pci_ats_queue_depth);
/**
* pci_ats_page_aligned - Return Page Aligned Request bit status.
* @pdev: the PCI device
*
* Returns 1, if the Untranslated Addresses generated by the device
* are always aligned or 0 otherwise.
*
* Per PCIe spec r4.0, sec 10.5.1.2, if the Page Aligned Request bit
* is set, it indicates the Untranslated Addresses generated by the
* device are always aligned to a 4096 byte boundary.
*/
int pci_ats_page_aligned(struct pci_dev *pdev)
{
u16 cap;
if (!pdev->ats_cap)
return 0;
pci_read_config_word(pdev, pdev->ats_cap + PCI_ATS_CAP, &cap);
if (cap & PCI_ATS_CAP_PAGE_ALIGNED)
return 1;
return 0;
}
EXPORT_SYMBOL_GPL(pci_ats_page_aligned);
#ifdef CONFIG_PCI_PRI
/**
* pci_enable_pri - Enable PRI capability
* @ pdev: PCI device structure
*
* Returns 0 on success, negative value on error
*/
int pci_enable_pri(struct pci_dev *pdev, u32 reqs)
{
u16 control, status;
u32 max_requests;
int pos;
if (WARN_ON(pdev->pri_enabled))
return -EBUSY;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
if (!pos)
return -EINVAL;
pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status);
if (!(status & PCI_PRI_STATUS_STOPPED))
return -EBUSY;
pci_read_config_dword(pdev, pos + PCI_PRI_MAX_REQ, &max_requests);
reqs = min(max_requests, reqs);
pdev->pri_reqs_alloc = reqs;
pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
control = PCI_PRI_CTRL_ENABLE;
pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
pdev->pri_enabled = 1;
return 0;
}
EXPORT_SYMBOL_GPL(pci_enable_pri);
/**
* pci_disable_pri - Disable PRI capability
* @pdev: PCI device structure
*
* Only clears the enabled-bit, regardless of its former value
*/
void pci_disable_pri(struct pci_dev *pdev)
{
u16 control;
int pos;
if (WARN_ON(!pdev->pri_enabled))
return;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
if (!pos)
return;
pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
control &= ~PCI_PRI_CTRL_ENABLE;
pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
pdev->pri_enabled = 0;
}
EXPORT_SYMBOL_GPL(pci_disable_pri);
/**
* pci_restore_pri_state - Restore PRI
* @pdev: PCI device structure
*/
void pci_restore_pri_state(struct pci_dev *pdev)
{
u16 control = PCI_PRI_CTRL_ENABLE;
u32 reqs = pdev->pri_reqs_alloc;
int pos;
if (!pdev->pri_enabled)
return;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
if (!pos)
return;
pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
}
EXPORT_SYMBOL_GPL(pci_restore_pri_state);
/**
* pci_reset_pri - Resets device's PRI state
* @pdev: PCI device structure
*
* The PRI capability must be disabled before this function is called.
* Returns 0 on success, negative value on error.
*/
int pci_reset_pri(struct pci_dev *pdev)
{
u16 control;
int pos;
if (WARN_ON(pdev->pri_enabled))
return -EBUSY;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
if (!pos)
return -EINVAL;
control = PCI_PRI_CTRL_RESET;
pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
return 0;
}
EXPORT_SYMBOL_GPL(pci_reset_pri);
#endif /* CONFIG_PCI_PRI */
#ifdef CONFIG_PCI_PASID
/**
* pci_enable_pasid - Enable the PASID capability
* @pdev: PCI device structure
* @features: Features to enable
*
* Returns 0 on success, negative value on error. This function checks
* whether the features are actually supported by the device and returns
* an error if not.
*/
int pci_enable_pasid(struct pci_dev *pdev, int features)
{
u16 control, supported;
int pos;
if (WARN_ON(pdev->pasid_enabled))
return -EBUSY;
if (!pdev->eetlp_prefix_path)
return -EINVAL;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
if (!pos)
return -EINVAL;
pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
/* User wants to enable anything unsupported? */
if ((supported & features) != features)
return -EINVAL;
control = PCI_PASID_CTRL_ENABLE | features;
pdev->pasid_features = features;
pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
pdev->pasid_enabled = 1;
return 0;
}
EXPORT_SYMBOL_GPL(pci_enable_pasid);
/**
* pci_disable_pasid - Disable the PASID capability
* @pdev: PCI device structure
*/
void pci_disable_pasid(struct pci_dev *pdev)
{
u16 control = 0;
int pos;
if (WARN_ON(!pdev->pasid_enabled))
return;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
if (!pos)
return;
pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
pdev->pasid_enabled = 0;
}
EXPORT_SYMBOL_GPL(pci_disable_pasid);
/**
* pci_restore_pasid_state - Restore PASID capabilities
* @pdev: PCI device structure
*/
void pci_restore_pasid_state(struct pci_dev *pdev)
{
u16 control;
int pos;
if (!pdev->pasid_enabled)
return;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
if (!pos)
return;
control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features;
pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
}
EXPORT_SYMBOL_GPL(pci_restore_pasid_state);
/**
* pci_pasid_features - Check which PASID features are supported
* @pdev: PCI device structure
*
* Returns a negative value when no PASI capability is present.
* Otherwise is returns a bitmask with supported features. Current
* features reported are:
* PCI_PASID_CAP_EXEC - Execute permission supported
* PCI_PASID_CAP_PRIV - Privileged mode supported
*/
int pci_pasid_features(struct pci_dev *pdev)
{
u16 supported;
int pos;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
if (!pos)
return -EINVAL;
pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
return supported;
}
EXPORT_SYMBOL_GPL(pci_pasid_features);
/**
* pci_prg_resp_pasid_required - Return PRG Response PASID Required bit
* status.
* @pdev: PCI device structure
*
* Returns 1 if PASID is required in PRG Response Message, 0 otherwise.
*
* Even though the PRG response PASID status is read from PRI Status
* Register, since this API will mainly be used by PASID users, this
* function is defined within #ifdef CONFIG_PCI_PASID instead of
* CONFIG_PCI_PRI.
*/
int pci_prg_resp_pasid_required(struct pci_dev *pdev)
{
u16 status;
int pos;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
if (!pos)
return 0;
pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status);
if (status & PCI_PRI_STATUS_PASID)
return 1;
return 0;
}
EXPORT_SYMBOL_GPL(pci_prg_resp_pasid_required);
#define PASID_NUMBER_SHIFT 8
#define PASID_NUMBER_MASK (0x1f << PASID_NUMBER_SHIFT)
/**
* pci_max_pasid - Get maximum number of PASIDs supported by device
* @pdev: PCI device structure
*
* Returns negative value when PASID capability is not present.
* Otherwise it returns the numer of supported PASIDs.
*/
int pci_max_pasids(struct pci_dev *pdev)
{
u16 supported;
int pos;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
if (!pos)
return -EINVAL;
pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
supported = (supported & PASID_NUMBER_MASK) >> PASID_NUMBER_SHIFT;
return (1 << supported);
}
EXPORT_SYMBOL_GPL(pci_max_pasids);
#endif /* CONFIG_PCI_PASID */
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