[PATCH v3 1/2] PCI: One more parameter to pci_set_pcie_reset_state()
Gavin Shan
gwshan at linux.vnet.ibm.com
Mon Mar 23 14:56:56 AEDT 2015
On Sun, Mar 22, 2015 at 09:34:33PM -0600, Alex Williamson wrote:
>On Mon, 2015-03-23 at 14:02 +1100, Gavin Shan wrote:
>> The patch adds one more parameter ("probe") to pci_set_pcie_reset_state(),
>> which allows to check if one particular PCI device can be resetted by the
>> function. The function will be reused to support PCI device specific methods
>> maintained in pci_dev_reset_methods[] in subsequent patch.
>>
>> Cc: Brian King <brking at us.ibm.com>
>> Cc: Frank Haverkamp <haver at linux.vnet.ibm.com>
>> Cc: Ian Munsie <imunsie at au1.ibm.com>
>> Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
>> ---
>> v3: Fix arguments of pci_set_pcie_reset_state() in cxl driver
>> v2: Reimplemented based on pci_set_pcie_reset_state()
>> ---
>> arch/powerpc/kernel/eeh.c | 14 ++++++++++----
>> drivers/misc/cxl/pci.c | 2 +-
>> drivers/misc/genwqe/card_base.c | 9 +++++++--
>> drivers/pci/pci.c | 15 +++++++++------
>> drivers/scsi/ipr.c | 5 +++--
>> include/linux/pci.h | 5 +++--
>> 6 files changed, 33 insertions(+), 17 deletions(-)
>
>
>Argh, you're trying to make pci_set_pcie_reset_state() compatible with
>pci_dev_specific_reset(), so it can be called via pci_reset_function(),
>but the whole point of the pci_reset_function() interface is to reset a
>*single* function without disturbing anything else. These patches make
>no effort at all to limit the set of affected devices to a single
>function and take great liberties using PCI_ANY_ID for vendors. My take
>on the powerpc version of pcibios_set_pcie_reset_state() is that it's
>effectively a slot reset, so why not hook into the
>pci_reset_hotplug_slot() via the hotplug slot ops? Please also use
>cover letters. Thanks,
>
Yep, that's the point and intention of the patches. pcibios_set_pcie_reset_state()
isn't equal to pci_reset_hotplug_slot(). The later one depends on PCI slot, which
wasn't populated on PowerNV platform yet, but pcibios_set_pcie_reseet_state() doesn't.
The patchset depends on improved pcibios_set_pcie_reset_state(), which can be seen
from following linked. With it, we don't affect any PCI devices as the config space
is saved/restored accordingly before/after reset:
https://patchwork.ozlabs.org/patch/438598/
Sorry that I didn't use cover letter again. I'll have one next time always.
Thanks,
Gavin
>Alex
>
>> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
>> index daa68a1..cd85c18 100644
>> --- a/arch/powerpc/kernel/eeh.c
>> +++ b/arch/powerpc/kernel/eeh.c
>> @@ -726,11 +726,14 @@ static void *eeh_restore_dev_state(void *data, void *userdata)
>> * pcibios_set_pcie_slot_reset - Set PCI-E reset state
>> * @dev: pci device struct
>> * @state: reset state to enter
>> + * @probe: check if the device can take the reset
>> *
>> * Return value:
>> * 0 if success
>> */
>> -int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
>> +int pcibios_set_pcie_reset_state(struct pci_dev *dev,
>> + enum pcie_reset_state state,
>> + int probe)
>> {
>> struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
>> struct eeh_pe *pe = eeh_dev_to_pe(edev);
>> @@ -738,9 +741,12 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat
>> if (!pe) {
>> pr_err("%s: No PE found on PCI device %s\n",
>> __func__, pci_name(dev));
>> - return -EINVAL;
>> + return -ENOTTY;
>> }
>>
>> + if (probe)
>> + return 0;
>> +
>> switch (state) {
>> case pcie_deassert_reset:
>> eeh_ops->reset(pe, EEH_RESET_DEACTIVATE);
>> @@ -762,8 +768,8 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat
>> break;
>> default:
>> eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED);
>> - return -EINVAL;
>> - };
>> + return -ENOTTY;
>> + }
>>
>> return 0;
>> }
>> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
>> index 1ef0164..3a87bfc 100644
>> --- a/drivers/misc/cxl/pci.c
>> +++ b/drivers/misc/cxl/pci.c
>> @@ -789,7 +789,7 @@ int cxl_reset(struct cxl *adapter)
>> /* pcie_warm_reset requests a fundamental pci reset which includes a
>> * PERST assert/deassert. PERST triggers a loading of the image
>> * if "user" or "factory" is selected in sysfs */
>> - if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset))) {
>> + if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset, 0))) {
>> dev_err(&dev->dev, "cxl: pcie_warm_reset failed\n");
>> return rc;
>> }
>> diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c
>> index 4cf8f82..4871f69 100644
>> --- a/drivers/misc/genwqe/card_base.c
>> +++ b/drivers/misc/genwqe/card_base.c
>> @@ -782,17 +782,22 @@ static int genwqe_pci_fundamental_reset(struct pci_dev *pci_dev)
>> {
>> int rc;
>>
>> + /* Probe if the device can take the reset */
>> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 1);
>> + if (rc)
>> + return rc;
>> +
>> /*
>> * lock pci config space access from userspace,
>> * save state and issue PCIe fundamental reset
>> */
>> pci_cfg_access_lock(pci_dev);
>> pci_save_state(pci_dev);
>> - rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset);
>> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 0);
>> if (!rc) {
>> /* keep PCIe reset asserted for 250ms */
>> msleep(250);
>> - pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset);
>> + pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset, 0);
>> /* Wait for 2s to reload flash and train the link */
>> msleep(2000);
>> }
>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>> index 81f06e8..8581a5f 100644
>> --- a/drivers/pci/pci.c
>> +++ b/drivers/pci/pci.c
>> @@ -1558,28 +1558,31 @@ EXPORT_SYMBOL(pci_disable_device);
>> * pcibios_set_pcie_reset_state - set reset state for device dev
>> * @dev: the PCIe device reset
>> * @state: Reset state to enter into
>> - *
>> + * @probe: Check if the device can take the reset
>> *
>> * Sets the PCIe reset state for the device. This is the default
>> * implementation. Architecture implementations can override this.
>> */
>> int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev,
>> - enum pcie_reset_state state)
>> + enum pcie_reset_state state,
>> + int probe)
>> {
>> - return -EINVAL;
>> + return -ENOTTY;
>> }
>>
>> /**
>> * pci_set_pcie_reset_state - set reset state for device dev
>> * @dev: the PCIe device reset
>> * @state: Reset state to enter into
>> - *
>> + * @probe: Check if the device can take the reset
>> *
>> * Sets the PCI reset state for the device.
>> */
>> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
>> +int pci_set_pcie_reset_state(struct pci_dev *dev,
>> + enum pcie_reset_state state,
>> + int probe)
>> {
>> - return pcibios_set_pcie_reset_state(dev, state);
>> + return pcibios_set_pcie_reset_state(dev, state, probe);
>> }
>> EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
>>
>> diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
>> index 9219953..89026f4 100644
>> --- a/drivers/scsi/ipr.c
>> +++ b/drivers/scsi/ipr.c
>> @@ -8317,7 +8317,8 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd)
>> static int ipr_reset_slot_reset_done(struct ipr_cmnd *ipr_cmd)
>> {
>> ENTER;
>> - pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, pcie_deassert_reset);
>> + pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev,
>> + pcie_deassert_reset, 0);
>> ipr_cmd->job_step = ipr_reset_bist_done;
>> ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT);
>> LEAVE;
>> @@ -8339,7 +8340,7 @@ static int ipr_reset_slot_reset(struct ipr_cmnd *ipr_cmd)
>> struct pci_dev *pdev = ioa_cfg->pdev;
>>
>> ENTER;
>> - pci_set_pcie_reset_state(pdev, pcie_warm_reset);
>> + pci_set_pcie_reset_state(pdev, pcie_warm_reset, 0);
>> ipr_cmd->job_step = ipr_reset_slot_reset_done;
>> ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT);
>> LEAVE;
>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>> index 4e1f17d..052ac63 100644
>> --- a/include/linux/pci.h
>> +++ b/include/linux/pci.h
>> @@ -960,7 +960,8 @@ extern unsigned int pcibios_max_latency;
>> void pci_set_master(struct pci_dev *dev);
>> void pci_clear_master(struct pci_dev *dev);
>>
>> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state);
>> +int pci_set_pcie_reset_state(struct pci_dev *dev,
>> + enum pcie_reset_state state, int probe);
>> int pci_set_cacheline_size(struct pci_dev *dev);
>> #define HAVE_PCI_SET_MWI
>> int __must_check pci_set_mwi(struct pci_dev *dev);
>> @@ -1648,7 +1649,7 @@ extern unsigned long pci_hotplug_mem_size;
>> void pcibios_disable_device(struct pci_dev *dev);
>> void pcibios_set_master(struct pci_dev *dev);
>> int pcibios_set_pcie_reset_state(struct pci_dev *dev,
>> - enum pcie_reset_state state);
>> + enum pcie_reset_state state, int probe);
>> int pcibios_add_device(struct pci_dev *dev);
>> void pcibios_release_device(struct pci_dev *dev);
>> void pcibios_penalize_isa_irq(int irq, int active);
>
>
>
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