Re: [dpdk-dev] [PATCH 2/8] app/testpmd: use PCI memory resource access APIs

[Li, Xiaoyun]

Hi

> -----Original Message-----
> From: Xia, Chenbo <chenbo....@intel.com>
> Sent: Friday, September 10, 2021 10:24
> To: dev@dpdk.org
> Cc: Li, Xiaoyun <xiaoyun...@intel.com>
> Subject: [PATCH 2/8] app/testpmd: use PCI memory resource access APIs
> 
> Currently testpmd uses struct rte_pci_device to access PCI memory resource.
> Since this structure will be internal later, this patch replaces use of
> rte_pci_device with new PCI memory resource access APIs to read/write BAR 0.
> 
> Signed-off-by: Chenbo Xia <chenbo....@intel.com>
> ---
>  app/test-pmd/config.c  | 38 +++++++++++-----------------------
>  app/test-pmd/testpmd.h | 46 +++++++++++++++++++++---------------------
>  2 files changed, 35 insertions(+), 49 deletions(-)
> 
<snip>
> 
> @@ -1081,7 +1063,9 @@ port_reg_bit_set(portid_t port_id, uint32_t reg_off,
> uint8_t bit_pos,
>                       (int) bit_v);
>               return;
>       }
> -     reg_v = port_id_pci_reg_read(port_id, reg_off);
> +     if (port_id_pci_reg_read(port_id, reg_off, &reg_v))
> +             return;
> +
>       if (bit_v == 0)
>               reg_v &= ~(1 << bit_pos);
>       else
> @@ -1123,7 +1107,9 @@ port_reg_bit_field_set(portid_t port_id, uint32_t
> reg_off,
>                               (unsigned)max_v, (unsigned)max_v);
>               return;
>       }
> -     reg_v = port_id_pci_reg_read(port_id, reg_off);
> +     if (port_id_pci_reg_read(port_id, reg_off, &reg_v))
> +             return;
> +
>       reg_v &= ~(max_v << l_bit); /* Keep unchanged bits */
>       reg_v |= (value << l_bit); /* Set changed bits */
>       port_id_pci_reg_write(port_id, reg_off, reg_v); diff --git a/app/test-

In your implementation, port_id_pci_reg_write() can fail. Then the following 
display shouldn't be called.
So change this function to have return value and check it before use it will be 
better.

> pmd/testpmd.h b/app/test-pmd/testpmd.h index 16a3598e48..7922807a6e
> 100644
> --- a/app/test-pmd/testpmd.h
> +++ b/app/test-pmd/testpmd.h
<snip>
>  static inline void
> -port_pci_reg_write(struct rte_port *port, uint32_t reg_off, uint32_t reg_v)
> +port_id_pci_reg_write(portid_t pt_id, uint32_t reg_off, uint32_t reg_v)
>  {
> -     const struct rte_pci_device *pci_dev;
> +     struct rte_port *port = &ports[(pt_id)];
> +     char name[RTE_ETH_NAME_MAX_LEN];
>       const struct rte_bus *bus;
> -     void *reg_addr;
> 
>       if (!port->dev_info.device) {
>               fprintf(stderr, "Invalid device\n");
> @@ -721,19 +721,19 @@ port_pci_reg_write(struct rte_port *port, uint32_t
> reg_off, uint32_t reg_v)
> 
>       bus = rte_bus_find_by_device(port->dev_info.device);
>       if (bus && !strcmp(bus->name, "pci")) {
> -             pci_dev = RTE_DEV_TO_PCI(port->dev_info.device);
> +             rte_eth_dev_get_name_by_port(pt_id, name);
>       } else {
>               fprintf(stderr, "Not a PCI device\n");
>               return;
>       }
> 
> -     reg_addr = ((char *)pci_dev->mem_resource[0].addr + reg_off);
> -     *((volatile uint32_t *)reg_addr) = rte_cpu_to_le_32(reg_v);
> +     reg_v = rte_cpu_to_le_32(reg_v);
> +     if (rte_pci_mem_wr32(name, 0, &reg_v, reg_off)) {
> +             fprintf(stderr, "Failed to write register\n");
> +             return;
> +     }
>  }
> 
> -#define port_id_pci_reg_write(pt_id, reg_off, reg_value) \
> -     port_pci_reg_write(&ports[(pt_id)], (reg_off), (reg_value))
> -
>  static inline void
>  get_start_cycles(uint64_t *start_tsc)
>  {
> --
> 2.17.1