Re: [PATCH v2 11/13] hw/arm/xilinx_zynq: Replace drive_get_next() by drive_get()

["Edgar E. Iglesias" <edgar.iglesias@gmail.com>]

On Wed, Nov 17, 2021 at 05:34:07PM +0100, Markus Armbruster wrote:
> drive_get_next() is basically a bad idea.  It returns the "next" block
> backend of a certain interface type.  "Next" means bus=0,unit=N, where
> subsequent calls count N up from zero, per interface type.
> 
> This lets you define unit numbers implicitly by execution order.  If the
> order changes, or new calls appear "in the middle", unit numbers change.
> ABI break.  Hard to spot in review.
> 
> Machine "xlnx-zcu102" connects backends with drive_get_next() in two
> counting loops, one of them in a helper function.  Change it to use
> drive_get() directly.  This makes the unit numbers explicit in the
> code.


Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>


> 
> Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
> Cc: Alistair Francis <alistair@alistair23.me>
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: qemu-arm@nongnu.org
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  hw/arm/xilinx_zynq.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/hw/arm/xilinx_zynq.c b/hw/arm/xilinx_zynq.c
> index 69c333e91b..50e7268396 100644
> --- a/hw/arm/xilinx_zynq.c
> +++ b/hw/arm/xilinx_zynq.c
> @@ -125,9 +125,10 @@ static void gem_init(NICInfo *nd, uint32_t base, qemu_irq irq)
>      sysbus_connect_irq(s, 0, irq);
>  }
>  
> -static inline void zynq_init_spi_flashes(uint32_t base_addr, qemu_irq irq,
> -                                         bool is_qspi)
> +static inline int zynq_init_spi_flashes(uint32_t base_addr, qemu_irq irq,
> +                                        bool is_qspi, int unit0)
>  {
> +    int unit = unit0;
>      DeviceState *dev;
>      SysBusDevice *busdev;
>      SSIBus *spi;
> @@ -156,7 +157,7 @@ static inline void zynq_init_spi_flashes(uint32_t base_addr, qemu_irq irq,
>          spi = (SSIBus *)qdev_get_child_bus(dev, bus_name);
>  
>          for (j = 0; j < num_ss; ++j) {
> -            DriveInfo *dinfo = drive_get_next(IF_MTD);
> +            DriveInfo *dinfo = drive_get(IF_MTD, 0, unit++);
>              flash_dev = qdev_new("n25q128");
>              if (dinfo) {
>                  qdev_prop_set_drive_err(flash_dev, "drive",
> @@ -170,6 +171,7 @@ static inline void zynq_init_spi_flashes(uint32_t base_addr, qemu_irq irq,
>          }
>      }
>  
> +    return unit;
>  }
>  
>  static void zynq_init(MachineState *machine)
> @@ -247,9 +249,9 @@ static void zynq_init(MachineState *machine)
>          pic[n] = qdev_get_gpio_in(dev, n);
>      }
>  
> -    zynq_init_spi_flashes(0xE0006000, pic[58-IRQ_OFFSET], false);
> -    zynq_init_spi_flashes(0xE0007000, pic[81-IRQ_OFFSET], false);
> -    zynq_init_spi_flashes(0xE000D000, pic[51-IRQ_OFFSET], true);
> +    n = zynq_init_spi_flashes(0xE0006000, pic[58 - IRQ_OFFSET], false, 0);
> +    n = zynq_init_spi_flashes(0xE0007000, pic[81 - IRQ_OFFSET], false, n);
> +    n = zynq_init_spi_flashes(0xE000D000, pic[51 - IRQ_OFFSET], true, n);
>  
>      sysbus_create_simple(TYPE_CHIPIDEA, 0xE0002000, pic[53 - IRQ_OFFSET]);
>      sysbus_create_simple(TYPE_CHIPIDEA, 0xE0003000, pic[76 - IRQ_OFFSET]);
> @@ -298,7 +300,7 @@ static void zynq_init(MachineState *machine)
>          sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, hci_addr);
>          sysbus_connect_irq(SYS_BUS_DEVICE(dev), 0, pic[hci_irq - IRQ_OFFSET]);
>  
> -        di = drive_get_next(IF_SD);
> +        di = drive_get(IF_SD, 0, n);
>          blk = di ? blk_by_legacy_dinfo(di) : NULL;
>          carddev = qdev_new(TYPE_SD_CARD);
>          qdev_prop_set_drive_err(carddev, "drive", blk, &error_fatal);
> -- 
> 2.31.1
>