From d85d65cc297fa85b7b2db3b9025c6341d6986d7e Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 1 Jul 2019 05:29:51 -0400 Subject: pcie: minor cleanups for slot control/status MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Rename function arguments to make intent clearer. Better documentation for slot control logic. Suggested-by: Igor Mammedov Signed-off-by: Michael S. Tsirkin Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Igor Mammedov --- hw/pci/pcie.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'hw/pci') diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c index c605d32..a6beb56 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); -- cgit v1.1