| Message ID | 1600028950-10644-1-git-send-email-yangtiezhu@loongson.cn (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [RFC,v2] PCI/portdrv: Only disable Bus Master on kexec reboot and connected PCI devices | expand |
On Mon, Sep 14, 2020 at 04:29:10AM +0800, Tiezhu Yang wrote: > --- a/drivers/pci/pcie/portdrv_pci.c > +++ b/drivers/pci/pcie/portdrv_pci.c > @@ -143,6 +144,28 @@ static void pcie_portdrv_remove(struct pci_dev *dev) > } > > pcie_port_device_remove(dev); > + pci_disable_device(dev); > +} > + > +static void pcie_portdrv_shutdown(struct pci_dev *dev) > +{ > + if (pci_bridge_d3_possible(dev)) { > + pm_runtime_forbid(&dev->dev); > + pm_runtime_get_noresume(&dev->dev); > + pm_runtime_dont_use_autosuspend(&dev->dev); > + } > + > + pcie_port_device_remove(dev); > + > + /* > + * If this is a kexec reboot, turn off Bus Master bit on the > + * device to tell it to not continue to do DMA. Don't touch > + * devices in D3cold or unknown states. > + * If it is not a kexec reboot, firmware will hit the PCI > + * devices with big hammer and stop their DMA any way. > + */ > + if (kexec_in_progress && (dev->current_state <= PCI_D3hot)) > + pci_disable_device(dev); The last portion of this function is already executed afterwards by pci_device_shutdown(). You don't need to duplicate it here: device_shutdown() dev->bus->shutdown() == pci_device_shutdown() drv->shutdown() == pcie_portdrv_shutdown() pci_disable_device() pci_disable_device() Thanks, Lukas
Hi, Tiezhu > ------------------ Original ------------------ > From: "Tiezhu Yang"<yangtiezhu@loongson.cn>; > Date: Mon, Sep 14, 2020 04:29 AM > To: "Bjorn Helgaas"<bhelgaas@google.com>; > Cc: "Konstantin Khlebnikov"<khlebnikov@openvz.org>; "Khalid Aziz"<khalid.aziz@oracle.com>; "Vivek Goyal"<vgoyal@redhat.com>; "Lukas Wunner"<lukas@wunner.de>; "oohall"<oohall@gmail.com>; "rafael.j.wysocki"<rafael.j.wysocki@intel.com>; "Xuefeng Li"<lixuefeng@loongson.cn>; "Huacai Chen"<chenhc@lemote.com>; "Jiaxun Yang"<jiaxun.yang@flygoat.com>; "linux-pci"<linux-pci@vger.kernel.org>; "linux-kernel"<linux-kernel@vger.kernel.org>; > Subject: [RFC PATCH v2] PCI/portdrv: Only disable Bus Master on kexec reboot and connected PCI devices > > > > After commit 745be2e700cd ("PCIe: portdrv: call pci_disable_device > during remove") and commit cc27b735ad3a ("PCI/portdrv: Turn off PCIe > services during shutdown"), it also calls pci_disable_device() during > shutdown, this leads to shutdown or reboot failure occasionally due to > clear PCI_COMMAND_MASTER on the device in do_pci_disable_device(). > > drivers/pci/pci.c > static void do_pci_disable_device(struct pci_dev *dev) > { > u16 pci_command; > > pci_read_config_word(dev, PCI_COMMAND, &pci_command); > if (pci_command & PCI_COMMAND_MASTER) { > pci_command &= ~PCI_COMMAND_MASTER; > pci_write_config_word(dev, PCI_COMMAND, pci_command); > } > > pcibios_disable_device(dev); > } > > When remove "pci_command &= ~PCI_COMMAND_MASTER;", it can work well. > > As Oliver O'Halloran said, no need to call pci_disable_device() when > actually shutting down, but we should call pci_disable_device() before > handing over to the new kernel on kexec reboot, so we can do some > condition checks which are similar with pci_device_shutdown(), this is > done by commit 4fc9bbf98fd6 ("PCI: Disable Bus Master only on kexec > reboot") and commit 6e0eda3c3898 ("PCI: Don't try to disable Bus Master > on disconnected PCI devices"). > > drivers/pci/pci-driver.c > static void pci_device_shutdown(struct device *dev) > { > ... > > /* > * If this is a kexec reboot, turn off Bus Master bit on the > * device to tell it to not continue to do DMA. Don't touch > * devices in D3cold or unknown states. > * If it is not a kexec reboot, firmware will hit the PCI > * devices with big hammer and stop their DMA any way. > */ > if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot)) > pci_clear_master(pci_dev); > } Have you really tried kexec? Why do you think kexec can disable pci device successfully while normal reboot/poweroff cannot? Huacai > > Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> > --- > drivers/pci/pcie/portdrv_core.c | 1 - > drivers/pci/pcie/portdrv_pci.c | 25 ++++++++++++++++++++++++- > 2 files changed, 24 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c > index 50a9522..1991aca 100644 > --- a/drivers/pci/pcie/portdrv_core.c > +++ b/drivers/pci/pcie/portdrv_core.c > @@ -491,7 +491,6 @@ void pcie_port_device_remove(struct pci_dev *dev) > { > device_for_each_child(&dev->dev, NULL, remove_iter); > pci_free_irq_vectors(dev); > - pci_disable_device(dev); > } > > /** > diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c > index 3a3ce40..ce89a9e8 100644 > --- a/drivers/pci/pcie/portdrv_pci.c > +++ b/drivers/pci/pcie/portdrv_pci.c > @@ -15,6 +15,7 @@ > #include <linux/init.h> > #include <linux/aer.h> > #include <linux/dmi.h> > +#include <linux/kexec.h> > > #include "../pci.h" > #include "portdrv.h" > @@ -143,6 +144,28 @@ static void pcie_portdrv_remove(struct pci_dev *dev) > } > > pcie_port_device_remove(dev); > + pci_disable_device(dev); > +} > + > +static void pcie_portdrv_shutdown(struct pci_dev *dev) > +{ > + if (pci_bridge_d3_possible(dev)) { > + pm_runtime_forbid(&dev->dev); > + pm_runtime_get_noresume(&dev->dev); > + pm_runtime_dont_use_autosuspend(&dev->dev); > + } > + > + pcie_port_device_remove(dev); > + > + /* > + * If this is a kexec reboot, turn off Bus Master bit on the > + * device to tell it to not continue to do DMA. Don't touch > + * devices in D3cold or unknown states. > + * If it is not a kexec reboot, firmware will hit the PCI > + * devices with big hammer and stop their DMA any way. > + */ > + if (kexec_in_progress && (dev->current_state <= PCI_D3hot)) > + pci_disable_device(dev); > } > > static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev, > @@ -211,7 +234,7 @@ static void pcie_portdrv_err_resume(struct pci_dev *dev) > > .probe = pcie_portdrv_probe, > .remove = pcie_portdrv_remove, > - .shutdown = pcie_portdrv_remove, > + .shutdown = pcie_portdrv_shutdown, > > .err_handler = &pcie_portdrv_err_handler, > > -- > 1.8.3.1
On 09/14/2020 12:06 PM, Lukas Wunner wrote: > On Mon, Sep 14, 2020 at 04:29:10AM +0800, Tiezhu Yang wrote: >> --- a/drivers/pci/pcie/portdrv_pci.c >> +++ b/drivers/pci/pcie/portdrv_pci.c >> @@ -143,6 +144,28 @@ static void pcie_portdrv_remove(struct pci_dev *dev) >> } >> >> pcie_port_device_remove(dev); >> + pci_disable_device(dev); >> +} >> + >> +static void pcie_portdrv_shutdown(struct pci_dev *dev) >> +{ >> + if (pci_bridge_d3_possible(dev)) { >> + pm_runtime_forbid(&dev->dev); >> + pm_runtime_get_noresume(&dev->dev); >> + pm_runtime_dont_use_autosuspend(&dev->dev); >> + } >> + >> + pcie_port_device_remove(dev); >> + >> + /* >> + * If this is a kexec reboot, turn off Bus Master bit on the >> + * device to tell it to not continue to do DMA. Don't touch >> + * devices in D3cold or unknown states. >> + * If it is not a kexec reboot, firmware will hit the PCI >> + * devices with big hammer and stop their DMA any way. >> + */ >> + if (kexec_in_progress && (dev->current_state <= PCI_D3hot)) >> + pci_disable_device(dev); > The last portion of this function is already executed afterwards by > pci_device_shutdown(). You don't need to duplicate it here: > > device_shutdown() > dev->bus->shutdown() == pci_device_shutdown() > drv->shutdown() == pcie_portdrv_shutdown() > pci_disable_device() > pci_disable_device() pcie_port_device_remove() deletes pci_disable_device(dev) at the beginning of this patch. diff <https://lore.kernel.org/linux-pci/CAAhV-H5-X9OcBe3iRxF8PnKW-0j_10FVqm8cbiqW2-Lv4mTTdQ@mail.gmail.com/T/#iZ2e.:..:1600028950-10644-1-git-send-email-yangtiezhu::40loongson.cn:0drivers:pci:pcie:portdrv_core.c> --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index 50a9522..1991aca 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -491,7 +491,6 @@ void pcie_port_device_remove(struct pci_dev *dev) { device_for_each_child(&dev->dev, NULL, remove_iter); pci_free_irq_vectors(dev); - pci_disable_device(dev); } > > Thanks, > > Lukas
On 09/14/2020 12:31 PM, Huacai Chen wrote: > Hi, Tiezhu > >> ------------------ Original ------------------ >> From: "Tiezhu Yang"<yangtiezhu@loongson.cn>; >> Date: Mon, Sep 14, 2020 04:29 AM >> To: "Bjorn Helgaas"<bhelgaas@google.com>; >> Cc: "Konstantin Khlebnikov"<khlebnikov@openvz.org>; "Khalid Aziz"<khalid.aziz@oracle.com>; "Vivek Goyal"<vgoyal@redhat.com>; "Lukas Wunner"<lukas@wunner.de>; "oohall"<oohall@gmail.com>; "rafael.j.wysocki"<rafael.j.wysocki@intel.com>; "Xuefeng Li"<lixuefeng@loongson.cn>; "Huacai Chen"<chenhc@lemote.com>; "Jiaxun Yang"<jiaxun.yang@flygoat.com>; "linux-pci"<linux-pci@vger.kernel.org>; "linux-kernel"<linux-kernel@vger.kernel.org>; >> Subject: [RFC PATCH v2] PCI/portdrv: Only disable Bus Master on kexec reboot and connected PCI devices >> >> >> >> After commit 745be2e700cd ("PCIe: portdrv: call pci_disable_device >> during remove") and commit cc27b735ad3a ("PCI/portdrv: Turn off PCIe >> services during shutdown"), it also calls pci_disable_device() during >> shutdown, this leads to shutdown or reboot failure occasionally due to >> clear PCI_COMMAND_MASTER on the device in do_pci_disable_device(). >> >> drivers/pci/pci.c >> static void do_pci_disable_device(struct pci_dev *dev) >> { >> u16 pci_command; >> >> pci_read_config_word(dev, PCI_COMMAND, &pci_command); >> if (pci_command & PCI_COMMAND_MASTER) { >> pci_command &= ~PCI_COMMAND_MASTER; >> pci_write_config_word(dev, PCI_COMMAND, pci_command); >> } >> >> pcibios_disable_device(dev); >> } >> >> When remove "pci_command &= ~PCI_COMMAND_MASTER;", it can work well. >> >> As Oliver O'Halloran said, no need to call pci_disable_device() when >> actually shutting down, but we should call pci_disable_device() before >> handing over to the new kernel on kexec reboot, so we can do some >> condition checks which are similar with pci_device_shutdown(), this is >> done by commit 4fc9bbf98fd6 ("PCI: Disable Bus Master only on kexec >> reboot") and commit 6e0eda3c3898 ("PCI: Don't try to disable Bus Master >> on disconnected PCI devices"). >> >> drivers/pci/pci-driver.c >> static void pci_device_shutdown(struct device *dev) >> { >> ... >> >> /* >> * If this is a kexec reboot, turn off Bus Master bit on the >> * device to tell it to not continue to do DMA. Don't touch >> * devices in D3cold or unknown states. >> * If it is not a kexec reboot, firmware will hit the PCI >> * devices with big hammer and stop their DMA any way. >> */ >> if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot)) >> pci_clear_master(pci_dev); >> } > Have you really tried kexec? Why do you think kexec can disable pci > device successfully while normal reboot/poweroff cannot? Yes, I test it on kexec reboot, it works well. > > Huacai >> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> >> --- >> drivers/pci/pcie/portdrv_core.c | 1 - >> drivers/pci/pcie/portdrv_pci.c | 25 ++++++++++++++++++++++++- >> 2 files changed, 24 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c >> index 50a9522..1991aca 100644 >> --- a/drivers/pci/pcie/portdrv_core.c >> +++ b/drivers/pci/pcie/portdrv_core.c >> @@ -491,7 +491,6 @@ void pcie_port_device_remove(struct pci_dev *dev) >> { >> device_for_each_child(&dev->dev, NULL, remove_iter); >> pci_free_irq_vectors(dev); >> - pci_disable_device(dev); >> } >> >> /** >> diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c >> index 3a3ce40..ce89a9e8 100644 >> --- a/drivers/pci/pcie/portdrv_pci.c >> +++ b/drivers/pci/pcie/portdrv_pci.c >> @@ -15,6 +15,7 @@ >> #include <linux/init.h> >> #include <linux/aer.h> >> #include <linux/dmi.h> >> +#include <linux/kexec.h> >> >> #include "../pci.h" >> #include "portdrv.h" >> @@ -143,6 +144,28 @@ static void pcie_portdrv_remove(struct pci_dev *dev) >> } >> >> pcie_port_device_remove(dev); >> + pci_disable_device(dev); >> +} >> + >> +static void pcie_portdrv_shutdown(struct pci_dev *dev) >> +{ >> + if (pci_bridge_d3_possible(dev)) { >> + pm_runtime_forbid(&dev->dev); >> + pm_runtime_get_noresume(&dev->dev); >> + pm_runtime_dont_use_autosuspend(&dev->dev); >> + } >> + >> + pcie_port_device_remove(dev); >> + >> + /* >> + * If this is a kexec reboot, turn off Bus Master bit on the >> + * device to tell it to not continue to do DMA. Don't touch >> + * devices in D3cold or unknown states. >> + * If it is not a kexec reboot, firmware will hit the PCI >> + * devices with big hammer and stop their DMA any way. >> + */ >> + if (kexec_in_progress && (dev->current_state <= PCI_D3hot)) >> + pci_disable_device(dev); >> } >> >> static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev, >> @@ -211,7 +234,7 @@ static void pcie_portdrv_err_resume(struct pci_dev *dev) >> >> .probe = pcie_portdrv_probe, >> .remove = pcie_portdrv_remove, >> - .shutdown = pcie_portdrv_remove, >> + .shutdown = pcie_portdrv_shutdown, >> >> .err_handler = &pcie_portdrv_err_handler, >> >> -- >> 1.8.3.1
On 09/14/2020 02:13 PM, Tiezhu Yang wrote: > On 09/14/2020 12:06 PM, Lukas Wunner wrote: >> On Mon, Sep 14, 2020 at 04:29:10AM +0800, Tiezhu Yang wrote: >>> --- a/drivers/pci/pcie/portdrv_pci.c >>> +++ b/drivers/pci/pcie/portdrv_pci.c >>> @@ -143,6 +144,28 @@ static void pcie_portdrv_remove(struct pci_dev >>> *dev) >>> } >>> pcie_port_device_remove(dev); >>> + pci_disable_device(dev); >>> +} >>> + >>> +static void pcie_portdrv_shutdown(struct pci_dev *dev) >>> +{ >>> + if (pci_bridge_d3_possible(dev)) { >>> + pm_runtime_forbid(&dev->dev); >>> + pm_runtime_get_noresume(&dev->dev); >>> + pm_runtime_dont_use_autosuspend(&dev->dev); >>> + } >>> + >>> + pcie_port_device_remove(dev); >>> + >>> + /* >>> + * If this is a kexec reboot, turn off Bus Master bit on the >>> + * device to tell it to not continue to do DMA. Don't touch >>> + * devices in D3cold or unknown states. >>> + * If it is not a kexec reboot, firmware will hit the PCI >>> + * devices with big hammer and stop their DMA any way. >>> + */ >>> + if (kexec_in_progress && (dev->current_state <= PCI_D3hot)) >>> + pci_disable_device(dev); >> The last portion of this function is already executed afterwards by >> pci_device_shutdown(). You don't need to duplicate it here: >> >> device_shutdown() >> dev->bus->shutdown() == pci_device_shutdown() >> drv->shutdown() == pcie_portdrv_shutdown() >> pci_disable_device() >> pci_disable_device() > > pcie_port_device_remove() deletes pci_disable_device(dev) at the > beginning of this patch. Sorry, I misunderstood your meaning, you are right. > > > diff > <https://lore.kernel.org/linux-pci/CAAhV-H5-X9OcBe3iRxF8PnKW-0j_10FVqm8cbiqW2-Lv4mTTdQ@mail.gmail.com/T/#iZ2e.:..:1600028950-10644-1-git-send-email-yangtiezhu::40loongson.cn:0drivers:pci:pcie:portdrv_core.c> > --git a/drivers/pci/pcie/portdrv_core.c > b/drivers/pci/pcie/portdrv_core.c index 50a9522..1991aca 100644 --- > a/drivers/pci/pcie/portdrv_core.c +++ > b/drivers/pci/pcie/portdrv_core.c @@ -491,7 +491,6 @@ void > pcie_port_device_remove(struct pci_dev *dev) { > device_for_each_child(&dev->dev, NULL, remove_iter); > pci_free_irq_vectors(dev); > - pci_disable_device(dev); } > >> >> Thanks, >> >> Lukas
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index 50a9522..1991aca 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -491,7 +491,6 @@ void pcie_port_device_remove(struct pci_dev *dev) { device_for_each_child(&dev->dev, NULL, remove_iter); pci_free_irq_vectors(dev); - pci_disable_device(dev); } /** diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index 3a3ce40..ce89a9e8 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -15,6 +15,7 @@ #include <linux/init.h> #include <linux/aer.h> #include <linux/dmi.h> +#include <linux/kexec.h> #include "../pci.h" #include "portdrv.h" @@ -143,6 +144,28 @@ static void pcie_portdrv_remove(struct pci_dev *dev) } pcie_port_device_remove(dev); + pci_disable_device(dev); +} + +static void pcie_portdrv_shutdown(struct pci_dev *dev) +{ + if (pci_bridge_d3_possible(dev)) { + pm_runtime_forbid(&dev->dev); + pm_runtime_get_noresume(&dev->dev); + pm_runtime_dont_use_autosuspend(&dev->dev); + } + + pcie_port_device_remove(dev); + + /* + * If this is a kexec reboot, turn off Bus Master bit on the + * device to tell it to not continue to do DMA. Don't touch + * devices in D3cold or unknown states. + * If it is not a kexec reboot, firmware will hit the PCI + * devices with big hammer and stop their DMA any way. + */ + if (kexec_in_progress && (dev->current_state <= PCI_D3hot)) + pci_disable_device(dev); } static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev, @@ -211,7 +234,7 @@ static void pcie_portdrv_err_resume(struct pci_dev *dev) .probe = pcie_portdrv_probe, .remove = pcie_portdrv_remove, - .shutdown = pcie_portdrv_remove, + .shutdown = pcie_portdrv_shutdown, .err_handler = &pcie_portdrv_err_handler,
After commit 745be2e700cd ("PCIe: portdrv: call pci_disable_device during remove") and commit cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during shutdown"), it also calls pci_disable_device() during shutdown, this leads to shutdown or reboot failure occasionally due to clear PCI_COMMAND_MASTER on the device in do_pci_disable_device(). drivers/pci/pci.c static void do_pci_disable_device(struct pci_dev *dev) { u16 pci_command; pci_read_config_word(dev, PCI_COMMAND, &pci_command); if (pci_command & PCI_COMMAND_MASTER) { pci_command &= ~PCI_COMMAND_MASTER; pci_write_config_word(dev, PCI_COMMAND, pci_command); } pcibios_disable_device(dev); } When remove "pci_command &= ~PCI_COMMAND_MASTER;", it can work well. As Oliver O'Halloran said, no need to call pci_disable_device() when actually shutting down, but we should call pci_disable_device() before handing over to the new kernel on kexec reboot, so we can do some condition checks which are similar with pci_device_shutdown(), this is done by commit 4fc9bbf98fd6 ("PCI: Disable Bus Master only on kexec reboot") and commit 6e0eda3c3898 ("PCI: Don't try to disable Bus Master on disconnected PCI devices"). drivers/pci/pci-driver.c static void pci_device_shutdown(struct device *dev) { ... /* * If this is a kexec reboot, turn off Bus Master bit on the * device to tell it to not continue to do DMA. Don't touch * devices in D3cold or unknown states. * If it is not a kexec reboot, firmware will hit the PCI * devices with big hammer and stop their DMA any way. */ if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot)) pci_clear_master(pci_dev); } Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> --- drivers/pci/pcie/portdrv_core.c | 1 - drivers/pci/pcie/portdrv_pci.c | 25 ++++++++++++++++++++++++- 2 files changed, 24 insertions(+), 2 deletions(-)