Re: [dpdk-dev] [PATCH v2 1/3] bus/pci: enable PCI master in command register

["Kinsella, Ray" <mdr@ashroe.eu>]

On 22/04/2021 02:18, Haiyue Wang wrote:
> This adds the support to set 'Bus Master Enable' bit in the PCI command
> register.
> 
> Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
> Tested-by: Qi Zhang <qi.z.zhang@intel.com>
> ---
>  drivers/bus/pci/pci_common.c  | 20 ++++++++++++++++++++
>  drivers/bus/pci/rte_bus_pci.h | 12 ++++++++++++
>  drivers/bus/pci/version.map   |  1 +
>  lib/pci/rte_pci.h             |  4 ++++
>  4 files changed, 37 insertions(+)
> 
> diff --git a/drivers/bus/pci/pci_common.c b/drivers/bus/pci/pci_common.c
> index ee7f96635..b631cb9c7 100644
> --- a/drivers/bus/pci/pci_common.c
> +++ b/drivers/bus/pci/pci_common.c
> @@ -746,6 +746,26 @@ rte_pci_find_ext_capability(struct rte_pci_device *dev, uint32_t cap)
>  	return 0;
>  }
>  
> +int
> +rte_pci_enable_bus_master(struct rte_pci_device *dev)
> +{
> +	uint16_t cmd;
> +
> +	if (rte_pci_read_config(dev, &cmd, sizeof(cmd), RTE_PCI_COMMAND) < 0) {
> +		RTE_LOG(ERR, EAL, "error in reading PCI command register\n");
> +		return -1;
> +	}
> +
> +	cmd |= RTE_PCI_COMMAND_MASTER;
> +
> +	if (rte_pci_write_config(dev, &cmd, sizeof(cmd), RTE_PCI_COMMAND) < 0) {
> +		RTE_LOG(ERR, EAL, "error in writing PCI command register\n");
> +		return -1;
> +	}
> +
> +	return 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 64886b473..83caf477b 100644
> --- a/drivers/bus/pci/rte_bus_pci.h
> +++ b/drivers/bus/pci/rte_bus_pci.h
> @@ -249,6 +249,18 @@ void rte_pci_dump(FILE *f);
>  __rte_experimental
>  off_t rte_pci_find_ext_capability(struct rte_pci_device *dev, uint32_t cap);
>  
> +/**
> + * Enables Bus Master for device's PCI command register.
> + *
> + *  @param dev
> + *    A pointer to rte_pci_device structure.
> + *
> + *  @return
> + *  0 on success, -1 on error in PCI config space read/write.
> + */
> +__rte_experimental
> +int rte_pci_enable_bus_master(struct rte_pci_device *dev);
> +
>  /**
>   * Register a PCI driver.
>   *
> diff --git a/drivers/bus/pci/version.map b/drivers/bus/pci/version.map
> index f33ed0abd..b271e48a8 100644
> --- a/drivers/bus/pci/version.map
> +++ b/drivers/bus/pci/version.map
> @@ -20,5 +20,6 @@ DPDK_21 {
>  EXPERIMENTAL {
>  	global:
>  

Please annotate when the symbol was added.

> +	rte_pci_enable_bus_master;
>  	rte_pci_find_ext_capability;
>  };
> diff --git a/lib/pci/rte_pci.h b/lib/pci/rte_pci.h
> index a8f8e404a..1f33d687f 100644
> --- a/lib/pci/rte_pci.h
> +++ b/lib/pci/rte_pci.h
> @@ -32,6 +32,10 @@ extern "C" {
>  
>  #define RTE_PCI_VENDOR_ID	0x00	/* 16 bits */
>  #define RTE_PCI_DEVICE_ID	0x02	/* 16 bits */
> +#define RTE_PCI_COMMAND		0x04	/* 16 bits */
> +
> +/* PCI Command Register */
> +#define RTE_PCI_COMMAND_MASTER	0x4	/* Bus Master Enable */
>  
>  /* PCI Express capability registers */
>  #define RTE_PCI_EXP_DEVCTL	8	/* Device Control */
>