On 30.08.2024 12:15 AM, Unnathi Chalicheemala wrote:
> Bootloader and firmware for SM8650 and older chipsets expect node
> name as "qcom_scm". However, DeviceTree uses node name "scm" and this
> mismatch prevents firmware from correctly identifying waitqueue IRQ
> information. Waitqueue IRQ is used for signaling between secure and
> non-secure worlds.
>
> To resolve this, introduce qcom_scm_get_waitq_irq() that'll get the
> hardware irq number to be used from firmware instead of relying on data
> provided by devicetree, thereby bypassing the DeviceTree node name
> mismatch.
>
> This hardware irq number is converted to a linux irq number using newly
> defined fill_irq_fwspec_params(). This linux irq number is then supplied to
> the threaded_irq call.
>
> Signed-off-by: Unnathi Chalicheemala <quic_uchalich@xxxxxxxxxxx>
> ---
> drivers/firmware/qcom/qcom_scm.c | 59 +++++++++++++++++++++++++++++++-
> drivers/firmware/qcom/qcom_scm.h | 1 +
> 2 files changed, 59 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
> index 00c379a3cceb..ed51fbb1c065 100644
> --- a/drivers/firmware/qcom/qcom_scm.c
> +++ b/drivers/firmware/qcom/qcom_scm.c
> @@ -32,6 +32,14 @@
> #include "qcom_scm.h"
> #include "qcom_tzmem.h"
>
> +#define GIC_SPI_BASE 32
> +#define GIC_MAX_SPI 987 // 1019 - 32
> +#define GIC_ESPI_BASE 4096
> +#define GIC_MAX_ESPI 1024 // 5120 - 4096
Are these going to remain constant on different implementations of the
interrupt controller across different SoCs that use this? Are these
mandated anywhere in the arm spec and/or present across the tree with
parts touching gicv3?
Also, the subtraction comments take some guesswork.. perhaps something like
0..31 etc. would be easier.
The MAX_(E)SPI macros could also just have the hwirq number to make the
if-conditions below simpler
> +
> +#define GIC_IRQ_TYPE_SPI 0
> +#define GIC_IRQ_TYPE_ESPI 2
We can definitely use dt-bindings for this
> +
> static bool download_mode = IS_ENABLED(CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT);
> module_param(download_mode, bool, 0);
>
> @@ -1819,6 +1827,55 @@ bool qcom_scm_is_available(void)
> }
> EXPORT_SYMBOL_GPL(qcom_scm_is_available);
>
> +static int qcom_scm_fill_irq_fwspec_params(struct irq_fwspec *fwspec, u32 virq)
> +{
> + if (WARN(virq < GIC_SPI_BASE, "Unexpected virq: %d\n", virq)) {
> + return -ENXIO;
> + } else if (virq <= (GIC_SPI_BASE + GIC_MAX_SPI)) {
> + fwspec->param_count = 3;
> + fwspec->param[0] = GIC_IRQ_TYPE_SPI;
> + fwspec->param[1] = virq - GIC_SPI_BASE;
> + fwspec->param[2] = IRQ_TYPE_EDGE_RISING;
> + } else if (WARN(virq < GIC_ESPI_BASE, "Unexpected virq: %d\n", virq)) {
> + return -ENXIO;
> + } else if (virq < (GIC_ESPI_BASE + GIC_MAX_ESPI)) {
> + fwspec->param_count = 3;
> + fwspec->param[0] = GIC_IRQ_TYPE_ESPI;
> + fwspec->param[1] = virq - GIC_ESPI_BASE;
> + fwspec->param[2] = IRQ_TYPE_EDGE_RISING;
> + } else {
> + WARN(1, "Unexpected virq: %d\n", virq);
> + return -ENXIO;
> + }
> + return 0;
This could use some prettifying (incl the previous comment):
if (GIC_SPI_BASE <= virq && virq <= GIC_SPI_MAX) {
fwspec->param[0] = GIC_IRQ_TYPE_SPI;
fwspec->param[1] = virq - GIC_SPI_BASE;
} else if (GIC_ESPI_BASE <= virq && virq <= GIC_ESPI_MAX) {
fwspec->param[0] = GIC_IRQ_TYPE_ESPI;
fwspec->param[1] = virq - GIC_ESPI_BASE;
} else {
WARN(1, "Unexpected virq"...
return -ENXIO;
}
fwspec->param[2] = IRQ_TYPE_EDGE_RISING;
fwspec->param_count = 3;
is much easier to follow along in my opinion
> +}
> +
> +static int qcom_scm_get_waitq_irq(void)
> +{
> + int ret;
> + u32 hwirq;
> + struct qcom_scm_desc desc = {
> + .svc = QCOM_SCM_SVC_WAITQ,
> + .cmd = QCOM_SCM_WAITQ_GET_INFO,
> + .owner = ARM_SMCCC_OWNER_SIP
> + };
> + struct qcom_scm_res res;
> + struct irq_fwspec fwspec;
> +
> + ret = qcom_scm_call_atomic(__scm->dev, &desc, &res);
> + if (ret)
> + return ret;
> +
> + fwspec.fwnode = of_node_to_fwnode(__scm->dev->of_node);
> + hwirq = res.result[1] & 0xffff;
GENMASK(15, 0)
> + ret = qcom_scm_fill_irq_fwspec_params(&fwspec, hwirq);
> + if (ret)
> + return ret;
> + ret = irq_create_fwspec_mapping(&fwspec);
> +
> + return ret;
> +}
> +
> static int qcom_scm_assert_valid_wq_ctx(u32 wq_ctx)
> {
> /* FW currently only supports a single wq_ctx (zero).
> @@ -1936,7 +1993,7 @@ static int qcom_scm_probe(struct platform_device *pdev)
> /* Let all above stores be available after this */
> smp_store_release(&__scm, scm);
>
> - irq = platform_get_irq_optional(pdev, 0);
> + irq = qcom_scm_get_waitq_irq();
> if (irq < 0) {
> if (irq != -ENXIO)
Is this smc call left unimplemented on !auto platforms? If it's not
(or it spits out bogus data), we're going to get a WARN splat in the
log..
Additionally, this mechanism ties the trustzone and hypervisor together..
Why isn't this done in gunyah which abstracts these resources? A hypercall
sounds much saner than tying in a third party into the mix
Konrad
