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PCI: Embed ATS info directly into struct pci_dev
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The pci_ats struct is small and will get smaller, so I don't think it's
worth allocating it separately from the pci_dev struct.

Embed the ATS fields directly into struct pci_dev.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
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Bjorn Helgaas committed Aug 13, 2015
1 parent edc90fe commit d544d75
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Showing 4 changed files with 27 additions and 53 deletions.
61 changes: 21 additions & 40 deletions drivers/pci/ats.c
Original file line number Diff line number Diff line change
Expand Up @@ -21,41 +21,22 @@ static void ats_alloc_one(struct pci_dev *dev)
{
int pos;
u16 cap;
struct pci_ats *ats;

pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
if (!pos)
return;

ats = kzalloc(sizeof(*ats), GFP_KERNEL);
if (!ats) {
dev_warn(&dev->dev, "can't allocate space for ATS state\n");
return;
}

ats->pos = pos;
pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap);
ats->qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
dev->ats_cap = pos;
pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CAP, &cap);
dev->ats_qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
PCI_ATS_MAX_QDEP;
dev->ats = ats;
}

static void ats_free_one(struct pci_dev *dev)
{
kfree(dev->ats);
dev->ats = NULL;
}

void pci_ats_init(struct pci_dev *dev)
{
ats_alloc_one(dev);
}

void pci_ats_free(struct pci_dev *dev)
{
ats_free_one(dev);
}

/**
* pci_enable_ats - enable the ATS capability
* @dev: the PCI device
Expand All @@ -67,9 +48,9 @@ int pci_enable_ats(struct pci_dev *dev, int ps)
{
u16 ctrl;

BUG_ON(dev->ats && dev->ats->is_enabled);
BUG_ON(dev->ats_cap && dev->ats_enabled);

if (!dev->ats)
if (!dev->ats_cap)
return -EINVAL;

if (ps < PCI_ATS_MIN_STU)
Expand All @@ -83,17 +64,17 @@ int pci_enable_ats(struct pci_dev *dev, int ps)
if (dev->is_virtfn) {
struct pci_dev *pdev = dev->physfn;

if (pdev->ats->stu != ps)
if (pdev->ats_stu != ps)
return -EINVAL;

atomic_inc(&pdev->ats->ref_cnt); /* count enabled VFs */
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);
dev->ats_stu = ps;
ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU);
}
pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);

dev->ats->is_enabled = 1;
dev->ats_enabled = 1;
return 0;
}
EXPORT_SYMBOL_GPL(pci_enable_ats);
Expand All @@ -106,22 +87,22 @@ void pci_disable_ats(struct pci_dev *dev)
{
u16 ctrl;

BUG_ON(!dev->ats || !dev->ats->is_enabled);
BUG_ON(!dev->ats_cap || !dev->ats_enabled);

if (atomic_read(&dev->ats->ref_cnt))
if (atomic_read(&dev->ats_ref_cnt))
return; /* VFs still enabled */

if (dev->is_virtfn) {
struct pci_dev *pdev = dev->physfn;

atomic_dec(&pdev->ats->ref_cnt);
atomic_dec(&pdev->ats_ref_cnt);
}

pci_read_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, &ctrl);
pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, &ctrl);
ctrl &= ~PCI_ATS_CTRL_ENABLE;
pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);

dev->ats->is_enabled = 0;
dev->ats_enabled = 0;
}
EXPORT_SYMBOL_GPL(pci_disable_ats);

Expand All @@ -136,8 +117,8 @@ void pci_restore_ats_state(struct pci_dev *dev)

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->pos + PCI_ATS_CTRL, ctrl);
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);

Expand All @@ -158,8 +139,8 @@ int pci_ats_queue_depth(struct pci_dev *dev)
if (dev->is_virtfn)
return 0;

if (dev->ats)
return dev->ats->qdep;
if (dev->ats_cap)
return dev->ats_qdep;

return -ENODEV;
}
Expand Down
1 change: 0 additions & 1 deletion drivers/pci/remove.c
Original file line number Diff line number Diff line change
Expand Up @@ -26,7 +26,6 @@ static void pci_stop_dev(struct pci_dev *dev)
dev->is_added = 0;
}

pci_ats_free(dev);
if (dev->bus->self)
pcie_aspm_exit_link_state(dev);
}
Expand Down
10 changes: 1 addition & 9 deletions include/linux/pci-ats.h
Original file line number Diff line number Diff line change
Expand Up @@ -4,14 +4,6 @@
#include <linux/pci.h>

/* Address Translation Service */
struct pci_ats {
int pos; /* capability position */
int stu; /* Smallest Translation Unit */
int qdep; /* Invalidate Queue Depth */
atomic_t ref_cnt; /* number of VFs with ATS enabled */
unsigned int is_enabled:1; /* Enable bit is set */
};

#ifdef CONFIG_PCI_ATS

int pci_enable_ats(struct pci_dev *dev, int ps);
Expand All @@ -26,7 +18,7 @@ int pci_ats_queue_depth(struct pci_dev *dev);
*/
static inline int pci_ats_enabled(struct pci_dev *dev)
{
return dev->ats && dev->ats->is_enabled;
return dev->ats_cap && dev->ats_enabled;
}

#else /* CONFIG_PCI_ATS */
Expand Down
8 changes: 5 additions & 3 deletions include/linux/pci.h
Original file line number Diff line number Diff line change
Expand Up @@ -343,6 +343,7 @@ struct pci_dev {
unsigned int msi_enabled:1;
unsigned int msix_enabled:1;
unsigned int ari_enabled:1; /* ARI forwarding */
unsigned int ats_enabled:1; /* Address Translation Service */
unsigned int is_managed:1;
unsigned int needs_freset:1; /* Dev requires fundamental reset */
unsigned int state_saved:1;
Expand Down Expand Up @@ -375,7 +376,10 @@ struct pci_dev {
struct pci_sriov *sriov; /* SR-IOV capability related */
struct pci_dev *physfn; /* the PF this VF is associated with */
};
struct pci_ats *ats; /* Address Translation Service */
int ats_cap; /* ATS Capability offset */
int ats_stu; /* ATS Smallest Translation Unit */
int ats_qdep; /* ATS Invalidate Queue Depth */
atomic_t ats_ref_cnt; /* number of VFs with ATS enabled */
#endif
phys_addr_t rom; /* Physical address of ROM if it's not from the BAR */
size_t romlen; /* Length of ROM if it's not from the BAR */
Expand Down Expand Up @@ -1297,10 +1301,8 @@ void ht_destroy_irq(unsigned int irq);
#ifdef CONFIG_PCI_ATS
/* Address Translation Service */
void pci_ats_init(struct pci_dev *dev);
void pci_ats_free(struct pci_dev *dev);
#else
static inline void pci_ats_init(struct pci_dev *dev) { }
static inline void pci_ats_free(struct pci_dev *dev) { }
#endif

void pci_cfg_access_lock(struct pci_dev *dev);
Expand Down

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