Hi Fabrizio,
On Thu, 20 Feb 2025 at 16:01, Fabrizio Castro
<fabrizio.castro.jz@xxxxxxxxxxx> wrote:
> On the Renesas RZ/V2H(P) family of SoCs, DMAC IPs are connected
> to the Interrupt Control Unit (ICU).
> For DMA transfers, a request number and an ack number must be
> registered with the ICU, which means that the DMAC driver has
> to be able to instruct the ICU driver with the registration of
> such ids.
>
> Export rzv2h_icu_register_dma_req_ack() so that the DMA driver
> can register both ids in one go.
>
> Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@xxxxxxxxxxx>
> Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
> v3->v4:
> * No change.
> v2->v3:
> * Replaced rzv2h_icu_register_dma_req_ack with
> rzv2h_icu_register_dma_req_ack() in changelog.
> * Added dummy for rzv2h_icu_register_dma_req_ack().
> * Added Rb Thomas.
Thanks for the update!
> --- a/drivers/irqchip/irq-renesas-rzv2h.c
> +++ b/drivers/irqchip/irq-renesas-rzv2h.c
> @@ -94,6 +110,45 @@ struct rzv2h_icu_priv {
> raw_spinlock_t lock;
> };
>
> +void rzv2h_icu_register_dma_req_ack(struct platform_device *icu_dev, u8 dmac_index, u8 dmac_channel,
> + u16 req_no, u8 ack_no)
> +{
> + struct rzv2h_icu_priv *priv = platform_get_drvdata(icu_dev);
> + u32 icu_dmackselk, dmaack, dmaack_mask;
> + u32 icu_dmksely, dmareq, dmareq_mask;
> + u8 k, field_no;
> + u8 y, upper;
> +
> + if (req_no >= RZV2H_ICU_DMAC_REQ_NO_MIN_FIX_OUTPUT)
> + req_no = RZV2H_ICU_DMAC_REQ_NO_DEFAULT;
What is the purpose of this check?
The hardware register field size is 10 bits, so I think it is better
to just limit it to 0x3ff.
Checking for RZV2H_ICU_DMAC_REQ_NO_MIN_FIX_OUTPUT means you will have to
update this check when a new SoC supports higher values than 0x1b5.
> +
> + if (ack_no >= RZV2H_ICU_DMAC_ACK_NO_MIN_FIX_OUTPUT)
> + ack_no = RZV2H_ICU_DMAC_ACK_NO_DEFAULT;
What is the purpose of this check?
There are only 23 DMACKSELk registers, so using
RZV2H_ICU_DMAC_ACK_NO_DEFAULT = 0x7f will write beyond the last
register below. And drivers/dma/sh/rz-dmac.c does call this
function with req_no = RZV2H_ICU_DMAC_REQ_NO_DEFAULT and ack_no =
RZV2H_ICU_DMAC_ACK_NO_DEFAULT...
> +
> + y = dmac_channel / 2;
> + upper = dmac_channel % 2;
> +
> + dmareq = ICU_DMAC_PREP_DMAREQ(req_no, upper);
> + dmareq_mask = ICU_DMAC_DMAREQ_MASK(upper);
> +
> + k = ack_no / 4;
> + field_no = ack_no % 4;
> +
> + dmaack_mask = ICU_DMAC_DACK_SEL_MASK(field_no);
> + dmaack = ICU_DMAC_PREP_DACK_SEL(ack_no, field_no);
> +
> + guard(raw_spinlock_irqsave)(&priv->lock);
> +
> + icu_dmksely = readl(priv->base + ICU_DMkSELy(dmac_index, y));
> + icu_dmksely = (icu_dmksely & ~dmareq_mask) | dmareq;
> + writel(icu_dmksely, priv->base + ICU_DMkSELy(dmac_index, y));
> +
> + icu_dmackselk = readl(priv->base + ICU_DMACKSELk(k));
> + icu_dmackselk = (icu_dmackselk & ~dmaack_mask) | dmaack;
> + writel(icu_dmackselk, priv->base + ICU_DMACKSELk(k));
> +}
> +EXPORT_SYMBOL_GPL(rzv2h_icu_register_dma_req_ack);
> +
> static inline struct rzv2h_icu_priv *irq_data_to_priv(struct irq_data *data)
> {
> return data->domain->host_data;
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
