Re: [PATCH v6 1/2] bus/pci: add function to enable/disable PASID

[Ruifeng Wang <ruifeng.wang@arm.com>]

On 2023/11/6 9:16 AM, Chenbo Xia wrote:
> Sorry I missed all previous versions…
> 
> +ARM guy

Thanks for CCing.

> 
>> On Nov 4, 2023, at 02:29, Abdullah Sevincer <abdullah.sevincer@intel.com> wrote:
>>
>> External email: Use caution opening links or attachments
>>
>>
>> This commit implements an internal api to enable and disable PASID for
>> a device e.g. device driver event/dlb2.
>>
>> For kernels when PASID enabled by default it breaks DLB functionality,
>> hence disabling PASID is required for DLB to function properly.
>>
>> PASID capability is not exposed to users hence offset can not be
>> retrieved by rte_pci_find_ext_capability() api. Therefore, api
>> implemented in this commit accepts an offset for PASID with an enable
>> flag which is used to enable/disable PASID.
>>
>> Signed-off-by: Abdullah Sevincer <abdullah.sevincer@intel.com>
> 
> Is PASID now part of PCIe spec? This APIs should both work for x86/arm?
> Not sure ARM is OK with the naming, previously they are calling it more as
> Sub Stream ID (SSID)

PASID is fine to ARM.
SSID is a term used in SMMU(IOMMU) which PASID is mapped to.

>  >> ---
>> drivers/bus/pci/pci_common.c  |  7 +++++++
>> drivers/bus/pci/rte_bus_pci.h | 13 +++++++++++++
>> drivers/bus/pci/version.map   |  1 +
>> lib/pci/rte_pci.h             |  4 ++++
>> 4 files changed, 25 insertions(+)
>>
>> diff --git a/drivers/bus/pci/pci_common.c b/drivers/bus/pci/pci_common.c
>> index 921d957bf6..5aac2406f1 100644
>> --- a/drivers/bus/pci/pci_common.c
>> +++ b/drivers/bus/pci/pci_common.c
>> @@ -938,6 +938,13 @@ rte_pci_set_bus_master(const struct rte_pci_device *dev, bool enable)
>>         return 0;
>> }
>>
>> +int
>> +rte_pci_pasid_ena_dis(const struct rte_pci_device *dev, off_t offset, bool enable)
>> +{
>> +       uint16_t pasid = enable;
>> +       return rte_pci_write_config(dev, &pasid, sizeof(pasid), offset) < 0 ? -1 : 0;
>> +}
>> +
>> struct rte_pci_bus rte_pci_bus = {
>>         .bus = {
>>                 .scan = rte_pci_scan,
>> diff --git a/drivers/bus/pci/rte_bus_pci.h b/drivers/bus/pci/rte_bus_pci.h
>> index 21e234abf0..d45b7bf2ab 100644
>> --- a/drivers/bus/pci/rte_bus_pci.h
>> +++ b/drivers/bus/pci/rte_bus_pci.h
>> @@ -295,6 +295,19 @@ void rte_pci_ioport_read(struct rte_pci_ioport *p,
>> void rte_pci_ioport_write(struct rte_pci_ioport *p,
>>                 const void *data, size_t len, off_t offset);
>>
>> +/**
>> + * Enable/Disable PASID.
>> + *
>> + * @param dev
>> + *   A pointer to a rte_pci_device structure.
>> + * @param offset
>> + *   Offset of the PASID external capability.
>> + * @param enable
>> + *   Flag to enable or disable PASID.
>> + */
>> +__rte_internal
>> +int rte_pci_pasid_ena_dis(const struct rte_pci_device *dev, off_t offset, bool enable);
>> +
>> #ifdef __cplusplus
>> }
>> #endif
>> diff --git a/drivers/bus/pci/version.map b/drivers/bus/pci/version.map
>> index 74c5b075d5..01e6a09eb6 100644
>> --- a/drivers/bus/pci/version.map
>> +++ b/drivers/bus/pci/version.map
>> @@ -36,6 +36,7 @@ INTERNAL {
>>         global:
>>
>>         rte_pci_get_sysfs_path;
>> +       rte_pci_pasid_ena_dis;
>>         rte_pci_register;
>>         rte_pci_unregister;
>> };
>> diff --git a/lib/pci/rte_pci.h b/lib/pci/rte_pci.h
>> index 69e932d910..d195f01950 100644
>> --- a/lib/pci/rte_pci.h
>> +++ b/lib/pci/rte_pci.h
>> @@ -101,6 +101,10 @@ extern "C" {
>> #define RTE_PCI_EXT_CAP_ID_ACS         0x0d    /* Access Control Services */
>> #define RTE_PCI_EXT_CAP_ID_SRIOV       0x10    /* SR-IOV */
>> #define RTE_PCI_EXT_CAP_ID_PRI         0x13    /* Page Request Interface */
>> +#define RTE_PCI_EXT_CAP_ID_PASID        0x1B    /* Process Address Space ID */
>> +
>> +/* Process Address Space ID */
>> +#define RTE_PCI_PASID_CTRL             0x06    /* PASID control register */
> 
> Align with old definitions will looks better. Using TAB?
> 
> Thanks,
> Chenbo
> 
>>
>> /* Advanced Error Reporting (RTE_PCI_EXT_CAP_ID_ERR) */
>> #define RTE_PCI_ERR_UNCOR_STATUS       0x04    /* Uncorrectable Error Status */
>> --
>> 2.25.1
>>
>