Merge branch 'pci/enumeration'

- Allow 'isolated PCI functions' (multi-function devices without a function
  0) for LoongArch, similar to s390 and jailhouse (Huacai Chen)

- Mask out unrelated bits in PCIE_LNKCAP_SLS2SPEED() and
  PCIE_LNKCTL2_TLS2SPEED(), which makes them more robust and fixes a
  WARN_ON_ONCE() in pcie_set_target_speed() (Jiwei Sun)

- Read Link Control 2 again when retraining a link after a training failure
  so we try to increase the link speed (Jiwei Sun)

- Allow built-in drivers, not just modular drivers, to use async initial
  probing (Lukas Wunner)

- Support Immediate Readiness even on devices with no PM Capability (Sean
  Christopherson)

* pci/enumeration:
  PCI: Support Immediate Readiness on devices without PM capabilities
  PCI: Allow built-in drivers to use async initial probing
  PCI: Adjust the position of reading the Link Control 2 register
  PCI: Fix link speed calculation on retrain failure
  PCI: Extend isolated function probing to LoongArch
This commit is contained in:
Bjorn Helgaas
2025-07-31 16:11:41 -05:00
6 changed files with 37 additions and 23 deletions

View File

@@ -341,7 +341,6 @@ void pci_bus_add_device(struct pci_dev *dev)
{
struct device_node *dn = dev->dev.of_node;
struct platform_device *pdev;
int retval;
/*
* Can not put in pci_device_add yet because resources
@@ -372,9 +371,7 @@ void pci_bus_add_device(struct pci_dev *dev)
if (!dn || of_device_is_available(dn))
pci_dev_allow_binding(dev);
retval = device_attach(&dev->dev);
if (retval < 0 && retval != -EPROBE_DEFER)
pci_warn(dev, "device attach failed (%d)\n", retval);
device_initial_probe(&dev->dev);
pci_dev_assign_added(dev);
}

View File

@@ -3205,7 +3205,6 @@ void pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev)
void pci_pm_init(struct pci_dev *dev)
{
int pm;
u16 status;
u16 pmc;
device_enable_async_suspend(&dev->dev);
@@ -3266,9 +3265,6 @@ void pci_pm_init(struct pci_dev *dev)
pci_pme_active(dev, false);
}
pci_read_config_word(dev, PCI_STATUS, &status);
if (status & PCI_STATUS_IMM_READY)
dev->imm_ready = 1;
pci_pm_power_up_and_verify_state(dev);
pm_runtime_forbid(&dev->dev);
pm_runtime_set_active(&dev->dev);

View File

@@ -391,12 +391,14 @@ void pci_bus_put(struct pci_bus *bus);
#define PCIE_LNKCAP_SLS2SPEED(lnkcap) \
({ \
((lnkcap) == PCI_EXP_LNKCAP_SLS_64_0GB ? PCIE_SPEED_64_0GT : \
(lnkcap) == PCI_EXP_LNKCAP_SLS_32_0GB ? PCIE_SPEED_32_0GT : \
(lnkcap) == PCI_EXP_LNKCAP_SLS_16_0GB ? PCIE_SPEED_16_0GT : \
(lnkcap) == PCI_EXP_LNKCAP_SLS_8_0GB ? PCIE_SPEED_8_0GT : \
(lnkcap) == PCI_EXP_LNKCAP_SLS_5_0GB ? PCIE_SPEED_5_0GT : \
(lnkcap) == PCI_EXP_LNKCAP_SLS_2_5GB ? PCIE_SPEED_2_5GT : \
u32 lnkcap_sls = (lnkcap) & PCI_EXP_LNKCAP_SLS; \
\
(lnkcap_sls == PCI_EXP_LNKCAP_SLS_64_0GB ? PCIE_SPEED_64_0GT : \
lnkcap_sls == PCI_EXP_LNKCAP_SLS_32_0GB ? PCIE_SPEED_32_0GT : \
lnkcap_sls == PCI_EXP_LNKCAP_SLS_16_0GB ? PCIE_SPEED_16_0GT : \
lnkcap_sls == PCI_EXP_LNKCAP_SLS_8_0GB ? PCIE_SPEED_8_0GT : \
lnkcap_sls == PCI_EXP_LNKCAP_SLS_5_0GB ? PCIE_SPEED_5_0GT : \
lnkcap_sls == PCI_EXP_LNKCAP_SLS_2_5GB ? PCIE_SPEED_2_5GT : \
PCI_SPEED_UNKNOWN); \
})
@@ -411,13 +413,17 @@ void pci_bus_put(struct pci_bus *bus);
PCI_SPEED_UNKNOWN)
#define PCIE_LNKCTL2_TLS2SPEED(lnkctl2) \
((lnkctl2) == PCI_EXP_LNKCTL2_TLS_64_0GT ? PCIE_SPEED_64_0GT : \
(lnkctl2) == PCI_EXP_LNKCTL2_TLS_32_0GT ? PCIE_SPEED_32_0GT : \
(lnkctl2) == PCI_EXP_LNKCTL2_TLS_16_0GT ? PCIE_SPEED_16_0GT : \
(lnkctl2) == PCI_EXP_LNKCTL2_TLS_8_0GT ? PCIE_SPEED_8_0GT : \
(lnkctl2) == PCI_EXP_LNKCTL2_TLS_5_0GT ? PCIE_SPEED_5_0GT : \
(lnkctl2) == PCI_EXP_LNKCTL2_TLS_2_5GT ? PCIE_SPEED_2_5GT : \
PCI_SPEED_UNKNOWN)
({ \
u16 lnkctl2_tls = (lnkctl2) & PCI_EXP_LNKCTL2_TLS; \
\
(lnkctl2_tls == PCI_EXP_LNKCTL2_TLS_64_0GT ? PCIE_SPEED_64_0GT : \
lnkctl2_tls == PCI_EXP_LNKCTL2_TLS_32_0GT ? PCIE_SPEED_32_0GT : \
lnkctl2_tls == PCI_EXP_LNKCTL2_TLS_16_0GT ? PCIE_SPEED_16_0GT : \
lnkctl2_tls == PCI_EXP_LNKCTL2_TLS_8_0GT ? PCIE_SPEED_8_0GT : \
lnkctl2_tls == PCI_EXP_LNKCTL2_TLS_5_0GT ? PCIE_SPEED_5_0GT : \
lnkctl2_tls == PCI_EXP_LNKCTL2_TLS_2_5GT ? PCIE_SPEED_2_5GT : \
PCI_SPEED_UNKNOWN); \
})
/* PCIe speed to Mb/s reduced by encoding overhead */
#define PCIE_SPEED2MBS_ENC(speed) \

View File

@@ -2595,6 +2595,15 @@ void pcie_report_downtraining(struct pci_dev *dev)
__pcie_print_link_status(dev, false);
}
static void pci_imm_ready_init(struct pci_dev *dev)
{
u16 status;
pci_read_config_word(dev, PCI_STATUS, &status);
if (status & PCI_STATUS_IMM_READY)
dev->imm_ready = 1;
}
static void pci_init_capabilities(struct pci_dev *dev)
{
pci_ea_init(dev); /* Enhanced Allocation */
@@ -2604,6 +2613,7 @@ static void pci_init_capabilities(struct pci_dev *dev)
/* Buffers for saving PCIe and PCI-X capabilities */
pci_allocate_cap_save_buffers(dev);
pci_imm_ready_init(dev); /* Immediate Readiness */
pci_pm_init(dev); /* Power Management */
pci_vpd_init(dev); /* Vital Product Data */
pci_configure_ari(dev); /* Alternative Routing-ID Forwarding */

View File

@@ -105,13 +105,13 @@ int pcie_failed_link_retrain(struct pci_dev *dev)
!pcie_cap_has_lnkctl2(dev) || !dev->link_active_reporting)
return ret;
pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &lnkctl2);
pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
if (!(lnksta & PCI_EXP_LNKSTA_DLLLA) && pcie_lbms_seen(dev, lnksta)) {
u16 oldlnkctl2 = lnkctl2;
u16 oldlnkctl2;
pci_info(dev, "broken device, retraining non-functional downstream link at 2.5GT/s\n");
pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &oldlnkctl2);
ret = pcie_set_target_speed(dev, PCIE_SPEED_2_5GT, false);
if (ret) {
pci_info(dev, "retraining failed\n");
@@ -123,6 +123,8 @@ int pcie_failed_link_retrain(struct pci_dev *dev)
pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
}
pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &lnkctl2);
if ((lnksta & PCI_EXP_LNKSTA_DLLLA) &&
(lnkctl2 & PCI_EXP_LNKCTL2_TLS) == PCI_EXP_LNKCTL2_TLS_2_5GT &&
pci_match_id(ids, dev)) {

View File

@@ -37,6 +37,9 @@ static inline bool hypervisor_isolated_pci_functions(void)
if (IS_ENABLED(CONFIG_S390))
return true;
if (IS_ENABLED(CONFIG_LOONGARCH))
return true;
return jailhouse_paravirt();
}