On Sun, Aug 11, 2024 at 08:00:05AM GMT, Christophe JAILLET wrote:
> Le 11/08/2024 à 07:16, Inochi Amaoto a écrit :
> > Sophgo CV18XX/SG200X use DW AXI CORE with a multiplexer for remapping
> > its request lines. The multiplexer supports at most 8 request lines.
> >
> > Add driver for Sophgo CV18XX/SG200X DMA multiplexer.
> >
> > Signed-off-by: Inochi Amaoto <inochiama@xxxxxxxxxxx>
> > ---
>
> Hi,
>
> ...
>
> > +static void *cv1800_dmamux_route_allocate(struct of_phandle_args *dma_spec,
> > + struct of_dma *ofdma)
> > +{
> > + struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
> > + struct cv1800_dmamux_data *dmamux = platform_get_drvdata(pdev);
> > + struct cv1800_dmamux_map *map;
> > + struct llist_node *node;
> > + unsigned long flags;
> > + unsigned int chid, devid, cpuid;
> > + int ret;
> > +
> > + if (dma_spec->args_count != DMAMUX_NCELLS) {
> > + dev_err(&pdev->dev, "invalid number of dma mux args\n");
> > + return ERR_PTR(-EINVAL);
> > + }
> > +
> > + devid = dma_spec->args[0];
> > + cpuid = dma_spec->args[1];
> > + dma_spec->args_count = 1;
> > +
> > + if (devid > MAX_DMA_MAPPING_ID) {
> > + dev_err(&pdev->dev, "invalid device id: %u\n", devid);
> > + return ERR_PTR(-EINVAL);
> > + }
> > +
> > + if (cpuid > MAX_DMA_CPU_ID) {
> > + dev_err(&pdev->dev, "invalid cpu id: %u\n", cpuid);
> > + return ERR_PTR(-EINVAL);
> > + }
> > +
> > + dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
> > + if (!dma_spec->np) {
> > + dev_err(&pdev->dev, "can't get dma master\n");
> > + return ERR_PTR(-EINVAL);
> > + }
> > +
> > + spin_lock_irqsave(&dmamux->lock, flags);
> > +
> > + if (test_bit(devid, dmamux->mapped_peripherals)) {
> > + llist_for_each_entry(map, dmamux->reserve_maps.first, node) {
> > + if (map->peripheral == devid && map->cpu == cpuid)
> > + goto found;
> > + }
> > +
> > + ret = -EINVAL;
> > + goto failed;
> > + } else {
> > + node = llist_del_first(&dmamux->free_maps);
> > + if (!node) {
> > + ret = -ENODEV;
> > + goto failed;
> > + }
> > +
> > + map = llist_entry(node, struct cv1800_dmamux_map, node);
> > + llist_add(&map->node, &dmamux->reserve_maps);
> > + set_bit(devid, dmamux->mapped_peripherals);
> > + }
> > +
> > +found:
> > + chid = map->channel;
> > + map->peripheral = devid;
> > + map->cpu = cpuid;
> > +
> > + regmap_set_bits(dmamux->regmap,
> > + DMAMUX_CH_REG(chid),
> > + DMAMUX_CH_SET(chid, devid));
> > +
> > + regmap_update_bits(dmamux->regmap, CV1800_SDMA_DMA_INT_MUX,
> > + DMAMUX_INT_CH_MASK(chid, cpuid),
> > + DMAMUX_INT_CH_BIT(chid, cpuid));
> > +
> > + spin_unlock_irqrestore(&dmamux->lock, flags);
> > +
> > + dma_spec->args[0] = chid;
> > +
> > + dev_dbg(&pdev->dev, "register channel %u for req %u (cpu %u)\n",
> > + chid, devid, cpuid);
> > +
> > + return map;
> > +
> > +failed:
> > + spin_unlock_irqrestore(&dmamux->lock, flags);
> > + of_node_put(dma_spec->np);
> > + dev_err(&pdev->dev, "errno %d\n", ret);
> > + return ERR_PTR(ret);
> > +
>
> Nitpick: Unneeded empty new line.
>
> > +}
> > +
> > +static int cv1800_dmamux_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct device_node *mux_node = dev->of_node;
> > + struct cv1800_dmamux_data *data;
> > + struct cv1800_dmamux_map *tmp;
> > + struct device *parent = dev->parent;
> > + struct regmap *regmap = NULL;
> > + unsigned int i;
> > +
> > + if (!parent)
> > + return -ENODEV;
> > +
> > + regmap = device_node_to_regmap(parent->of_node);
> > + if (IS_ERR(regmap))
> > + return PTR_ERR(regmap);
> > +
> > + data = devm_kmalloc(dev, sizeof(*data), GFP_KERNEL);
> > + if (!data)
> > + return -ENOMEM;
> > +
> > + spin_lock_init(&data->lock);
> > + init_llist_head(&data->free_maps);
>
> Why init free_maps and not reserve_maps?
> 'data' is not zeroed, so it should be needed, IMHO.
>
> Same for mapped_peripherals. It is not initialized.
>
> I think that using devm_kzalloc() above is needed. (and
> init_llist_head(&data->free_maps) could then be removed, if you want)
>
> Just my 2c.
>
Thanks, I missed these two field. Although I got no error
when testing, it is necessary to fix this.
I think devm_kzalloc can only zero "mapped_peripherals".
It will be good to add missing init_llist_head for
"reserve_maps".
Regards,
Inochi
> > +
> > + for (i = 0; i <= MAX_DMA_CH_ID; i++) {
> > + tmp = devm_kmalloc(dev, sizeof(*tmp), GFP_KERNEL);
> > + if (!tmp) {
> > + /* It is OK for not allocating all channel */
> > + dev_warn(dev, "can not allocate channel %u\n", i);
> > + continue;
> > + }
> > +
> > + init_llist_node(&tmp->node);
> > + tmp->channel = i;
> > + llist_add(&tmp->node, &data->free_maps);
> > + }
> > +
> > + /* if no channel is allocated, the probe must fail */
> > + if (llist_empty(&data->free_maps))
> > + return -ENOMEM;
> > +
> > + data->regmap = regmap;
> > + data->dmarouter.dev = dev;
> > + data->dmarouter.route_free = cv1800_dmamux_free;
> > +
> > + platform_set_drvdata(pdev, data);
> > +
> > + return of_dma_router_register(mux_node,
> > + cv1800_dmamux_route_allocate,
> > + &data->dmarouter);
> > +}
>
> ...
>
> CJ
>
>
>
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