diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2019-07-01 05:29:51 -0400 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2019-07-01 09:17:30 -0400 |
| commit | d85d65cc297fa85b7b2db3b9025c6341d6986d7e (patch) | |
| tree | 4a70a036596ea38130ec4c99c287dda5cd7901b1 /hw/pci | |
| parent | 110c477c2ede4d06d3a95a2bfda5c4c58d2af516 (diff) | |
pcie: minor cleanups for slot control/status
Rename function arguments to make intent clearer.
Better documentation for slot control logic.
Suggested-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Diffstat (limited to 'hw/pci')
| -rw-r--r-- | hw/pci/pcie.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c index c605d32dd4..a6beb567bd 100644 --- a/hw/pci/pcie.c +++ b/hw/pci/pcie.c @@ -602,7 +602,8 @@ void pcie_cap_slot_get(PCIDevice *dev, uint16_t *slt_ctl, uint16_t *slt_sta) *slt_sta = pci_get_word(exp_cap + PCI_EXP_SLTSTA); } -void pcie_cap_slot_write_config(PCIDevice *dev, uint16_t slt_ctl, uint16_t slt_sta, +void pcie_cap_slot_write_config(PCIDevice *dev, + uint16_t old_slt_ctl, uint16_t old_slt_sta, uint32_t addr, uint32_t val, int len) { uint32_t pos = dev->exp.exp_cap; @@ -625,8 +626,8 @@ void pcie_cap_slot_write_config(PCIDevice *dev, uint16_t slt_ctl, uint16_t slt_s PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | \ PCI_EXP_SLTSTA_CC) - if (val & ~slt_sta & PCIE_SLOT_EVENTS) { - sltsta = (sltsta & ~PCIE_SLOT_EVENTS) | (slt_sta & PCIE_SLOT_EVENTS); + if (val & ~old_slt_sta & PCIE_SLOT_EVENTS) { + sltsta = (sltsta & ~PCIE_SLOT_EVENTS) | (old_slt_sta & PCIE_SLOT_EVENTS); pci_set_word(exp_cap + PCI_EXP_SLTSTA, sltsta); } hotplug_event_clear(dev); @@ -646,13 +647,17 @@ void pcie_cap_slot_write_config(PCIDevice *dev, uint16_t slt_ctl, uint16_t slt_s } /* - * If the slot is polulated, power indicator is off and power + * If the slot is populated, power indicator is off and power * controller is off, it is safe to detach the devices. + * + * Note: don't detach if condition was already true: + * this is a work around for guests that overwrite + * control of powered off slots before powering them on. */ if ((sltsta & PCI_EXP_SLTSTA_PDS) && (val & PCI_EXP_SLTCTL_PCC) && (val & PCI_EXP_SLTCTL_PIC_OFF) == PCI_EXP_SLTCTL_PIC_OFF && - (!(slt_ctl & PCI_EXP_SLTCTL_PCC) || - (slt_ctl & PCI_EXP_SLTCTL_PIC_OFF) != PCI_EXP_SLTCTL_PIC_OFF)) { + (!(old_slt_ctl & PCI_EXP_SLTCTL_PCC) || + (old_slt_ctl & PCI_EXP_SLTCTL_PIC_OFF) != PCI_EXP_SLTCTL_PIC_OFF)) { PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(dev)); pci_for_each_device(sec_bus, pci_bus_num(sec_bus), pcie_unplug_device, NULL); |