On 20/04/2021 19:26, Thierry Reding wrote:
> From: Thierry Reding <treding@xxxxxxxxxx>
>
> Instead of programming all SID overrides during early boot, perform the
> operation on-demand after the SMMU translations have been set up for a
> device. This reuses data from device tree to match memory clients for a
> device and programs the SID specified in device tree, which corresponds
> to the SID used for the SMMU context banks for the device.
>
> Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
> ---
> drivers/memory/tegra/mc.c | 9 +++++
> drivers/memory/tegra/tegra186.c | 72 +++++++++++++++++++++++++++++++++
> include/soc/tegra/mc.h | 3 ++
> 3 files changed, 84 insertions(+)
>
> diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
> index c854639cf30c..bace5ecfe770 100644
> --- a/drivers/memory/tegra/mc.c
> +++ b/drivers/memory/tegra/mc.c
> @@ -97,6 +97,15 @@ struct tegra_mc *devm_tegra_memory_controller_get(struct device *dev)
> }
> EXPORT_SYMBOL_GPL(devm_tegra_memory_controller_get);
>
> +int tegra_mc_probe_device(struct tegra_mc *mc, struct device *dev)
> +{
> + if (mc->soc->ops && mc->soc->ops->probe_device)
> + return mc->soc->ops->probe_device(mc, dev);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(tegra_mc_probe_device);
> +
> static int tegra_mc_block_dma_common(struct tegra_mc *mc,
> const struct tegra_mc_reset *rst)
> {
> diff --git a/drivers/memory/tegra/tegra186.c b/drivers/memory/tegra/tegra186.c
> index 1f87915ccd62..e65eac5764d4 100644
> --- a/drivers/memory/tegra/tegra186.c
> +++ b/drivers/memory/tegra/tegra186.c
> @@ -4,6 +4,7 @@
> */
>
> #include <linux/io.h>
> +#include <linux/iommu.h>
> #include <linux/module.h>
> #include <linux/mod_devicetable.h>
> #include <linux/of_device.h>
> @@ -15,6 +16,10 @@
> #include <dt-bindings/memory/tegra186-mc.h>
> #endif
>
> +#define MC_SID_STREAMID_OVERRIDE_MASK GENMASK(7, 0)
> +#define MC_SID_STREAMID_SECURITY_WRITE_ACCESS_DISABLED BIT(16)
> +#define MC_SID_STREAMID_SECURITY_OVERRIDE BIT(8)
> +
> static void tegra186_mc_program_sid(struct tegra_mc *mc)
> {
> unsigned int i;
> @@ -66,10 +71,77 @@ static int tegra186_mc_resume(struct tegra_mc *mc)
> return 0;
> }
>
> +static void tegra186_mc_client_sid_override(struct tegra_mc *mc,
> + const struct tegra_mc_client *client,
> + unsigned int sid)
> +{
> + u32 value, old;
> +
> + value = readl(mc->regs + client->regs.sid.security);
> + if ((value & MC_SID_STREAMID_SECURITY_OVERRIDE) == 0) {
> + /*
> + * If the secure firmware has locked this down the override
> + * for this memory client, there's nothing we can do here.
> + */
> + if (value & MC_SID_STREAMID_SECURITY_WRITE_ACCESS_DISABLED)
> + return;
> +
> + /*
> + * Otherwise, try to set the override itself. Typically the
> + * secure firmware will never have set this configuration.
> + * Instead, it will either have disabled write access to
> + * this field, or it will already have set an explicit
> + * override itself.
> + */
> + WARN_ON((value & MC_SID_STREAMID_SECURITY_OVERRIDE) == 0);
> +
> + value |= MC_SID_STREAMID_SECURITY_OVERRIDE;
> + writel(value, mc->regs + client->regs.sid.security);
> + }
> +
> + value = readl(mc->regs + client->regs.sid.override);
> + old = value & MC_SID_STREAMID_OVERRIDE_MASK;
> +
> + if (old != sid) {
> + dev_dbg(mc->dev, "overriding SID %x for %s with %x\n", old,
> + client->name, sid);
> + writel(sid, mc->regs + client->regs.sid.override);
> + }
> +}
> +
> +static int tegra186_mc_probe_device(struct tegra_mc *mc, struct device *dev)
> +{
> +#if IS_ENABLED(CONFIG_IOMMU_API)
Is this part really build-time dependent? I don't see here any uses of
IOMMU specific fields, so maybe this should be runtime choice based on
enabled interconnect devices?
> + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
> + struct of_phandle_args args;
> + unsigned int i, index = 0;
> +
> + while (!of_parse_phandle_with_args(dev->of_node, "interconnects", "#interconnect-cells",
> + index, &args)) {
> + if (args.np == mc->dev->of_node && args.args_count != 0) {
> + for (i = 0; i < mc->soc->num_clients; i++) {
> + const struct tegra_mc_client *client = &mc->soc->clients[i];
> +
> + if (client->id == args.args[0]) {
> + u32 sid = fwspec->ids[0] & MC_SID_STREAMID_OVERRIDE_MASK;
> +
> + tegra186_mc_client_sid_override(mc, client, sid);
> + }
> + }
> + }
> +
> + index++;
> + }
> +#endif
> +
> + return 0;
> +}
> +
> const struct tegra_mc_ops tegra186_mc_ops = {
> .probe = tegra186_mc_probe,
> .remove = tegra186_mc_remove,
> .resume = tegra186_mc_resume,
> + .probe_device = tegra186_mc_probe_device,
> };
>
> #if defined(CONFIG_ARCH_TEGRA_186_SOC)
> diff --git a/include/soc/tegra/mc.h b/include/soc/tegra/mc.h
> index 1387747d574b..bbad6330008b 100644
> --- a/include/soc/tegra/mc.h
> +++ b/include/soc/tegra/mc.h
> @@ -176,6 +176,7 @@ struct tegra_mc_ops {
> int (*suspend)(struct tegra_mc *mc);
> int (*resume)(struct tegra_mc *mc);
> irqreturn_t (*handle_irq)(int irq, void *data);
> + int (*probe_device)(struct tegra_mc *mc, struct device *dev);
> };
>
> struct tegra_mc_soc {
> @@ -240,4 +241,6 @@ devm_tegra_memory_controller_get(struct device *dev)
> }
> #endif
>
> +int tegra_mc_probe_device(struct tegra_mc *mc, struct device *dev);
> +
What about !CONFIG_TEGRA_MC? I think arm-smmmu will fail.
> #endif /* __SOC_TEGRA_MC_H__ */
>
Best regards,
Krzysztof
