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PCI/DPC: Save and restore config state

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This patch provides DPC save and restore capabilities.  This is necessary
for the driver to observe DPC events in the event the configuration space
needs to be restored after a reset.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>
This commit is contained in:
Keith Busch 2018-09-20 10:27:08 -06:00 committed by Bjorn Helgaas
parent 874b325111
commit 4f802170a8
3 changed files with 65 additions and 6 deletions
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2
drivers/pci/pci.c
View File

@ -1284,6 +1284,7 @@ int pci_save_state(struct pci_dev *dev)
if (i != 0)
return i;
pci_save_dpc_state(dev);
return pci_save_vc_state(dev);
}
EXPORT_SYMBOL(pci_save_state);
@ -1378,6 +1379,7 @@ void pci_restore_state(struct pci_dev *dev)
pci_restore_ats_state(dev);
pci_restore_vc_state(dev);
pci_restore_rebar_state(dev);
pci_restore_dpc_state(dev);
pci_cleanup_aer_error_status_regs(dev);

8
drivers/pci/pci.h
View File

@ -346,6 +346,14 @@ int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info);
void aer_print_error(struct pci_dev *dev, struct aer_err_info *info);
#endif /* CONFIG_PCIEAER */
#ifdef CONFIG_PCIE_DPC
void pci_save_dpc_state(struct pci_dev *dev);
void pci_restore_dpc_state(struct pci_dev *dev);
#else
static inline void pci_save_dpc_state(struct pci_dev *dev) {}
static inline void pci_restore_dpc_state(struct pci_dev *dev) {}
#endif
#ifdef CONFIG_PCI_ATS
void pci_restore_ats_state(struct pci_dev *dev);
#else

61
drivers/pci/pcie/dpc.c
View File

@ -44,6 +44,58 @@ static const char * const rp_pio_error_string[] = {
"Memory Request Completion Timeout", /* Bit Position 18 */
};
static struct dpc_dev *to_dpc_dev(struct pci_dev *dev)
{
struct device *device;
device = pcie_port_find_device(dev, PCIE_PORT_SERVICE_DPC);
if (!device)
return NULL;
return get_service_data(to_pcie_device(device));
}
void pci_save_dpc_state(struct pci_dev *dev)
{
struct dpc_dev *dpc;
struct pci_cap_saved_state *save_state;
u16 *cap;
if (!pci_is_pcie(dev))
return;
dpc = to_dpc_dev(dev);
if (!dpc)
return;
save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_DPC);
if (!save_state)
return;
cap = (u16 *)&save_state->cap.data[0];
pci_read_config_word(dev, dpc->cap_pos + PCI_EXP_DPC_CTL, cap);
}
void pci_restore_dpc_state(struct pci_dev *dev)
{
struct dpc_dev *dpc;
struct pci_cap_saved_state *save_state;
u16 *cap;
if (!pci_is_pcie(dev))
return;
dpc = to_dpc_dev(dev);
if (!dpc)
return;
save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_DPC);
if (!save_state)
return;
cap = (u16 *)&save_state->cap.data[0];
pci_write_config_word(dev, dpc->cap_pos + PCI_EXP_DPC_CTL, *cap);
}
static int dpc_wait_rp_inactive(struct dpc_dev *dpc)
{
unsigned long timeout = jiffies + HZ;
@ -67,18 +119,13 @@ static int dpc_wait_rp_inactive(struct dpc_dev *dpc)
static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
{
struct dpc_dev *dpc;
struct pcie_device *pciedev;
struct device *devdpc;
u16 cap;
/*
* DPC disables the Link automatically in hardware, so it has
* already been reset by the time we get here.
*/
devdpc = pcie_port_find_device(pdev, PCIE_PORT_SERVICE_DPC);
pciedev = to_pcie_device(devdpc);
dpc = get_service_data(pciedev);
dpc = to_dpc_dev(pdev);
cap = dpc->cap_pos;
/*
@ -259,6 +306,8 @@ static int dpc_probe(struct pcie_device *dev)
FLAG(cap, PCI_EXP_DPC_CAP_POISONED_TLP),
FLAG(cap, PCI_EXP_DPC_CAP_SW_TRIGGER), dpc->rp_log_size,
FLAG(cap, PCI_EXP_DPC_CAP_DL_ACTIVE));
pci_add_ext_cap_save_buffer(pdev, PCI_EXT_CAP_ID_DPC, sizeof(u16));
return status;
}