[PATCH] drivers: mailbox: handle SGI for shared IPI
Tanmay Shah
tanmay.shah at amd.com
Tue May 21 10:48:53 PDT 2024
Hello,
Ping for reviews.
Thanks,
Tanmay
On 5/3/24 9:15 AM, Tanmay Shah wrote:
> At least one IPI is used in TF-A for communication with PMC firmware.
> If this IPI needs to be used by other agents such as RPU then, IPI
> system interrupt can't be generated in mailbox driver. In such case
> TF-A generates SGI to mailbox driver for IPI notification.
>
> Signed-off-by: Tanmay Shah <tanmay.shah at amd.com>
> Signed-off-by: Saeed Nowshadi <saeed.nowshadi at amd.com>
> ---
> drivers/mailbox/zynqmp-ipi-mailbox.c | 159 +++++++++++++++++++++++++--
> 1 file changed, 152 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
> index 1cb553cced90..7c90bac3de21 100644
> --- a/drivers/mailbox/zynqmp-ipi-mailbox.c
> +++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
> @@ -6,9 +6,11 @@
> */
>
> #include <linux/arm-smccc.h>
> +#include <linux/cpuhotplug.h>
> #include <linux/delay.h>
> #include <linux/device.h>
> #include <linux/interrupt.h>
> +#include <linux/irqdomain.h>
> #include <linux/io.h>
> #include <linux/kernel.h>
> #include <linux/mailbox_controller.h>
> @@ -16,6 +18,7 @@
> #include <linux/module.h>
> #include <linux/of.h>
> #include <linux/of_address.h>
> +#include <linux/of_irq.h>
> #include <linux/platform_device.h>
>
> /* IPI agent ID any */
> @@ -59,6 +62,8 @@
> #define DST_BIT_POS 9U
> #define SRC_BITMASK GENMASK(11, 8)
>
> +#define MAX_SGI 16
> +
> /**
> * struct zynqmp_ipi_mchan - Description of a Xilinx ZynqMP IPI mailbox channel
> * @is_opened: indicate if the IPI channel is opened
> @@ -111,6 +116,7 @@ struct zynqmp_ipi_mbox {
> * @irq: IPI agent interrupt ID
> * @method: IPI SMC or HVC is going to be used
> * @local_id: local IPI agent ID
> + * @virq_sgi: IRQ number mapped to SGI
> * @num_mboxes: number of mailboxes of this IPI agent
> * @ipi_mboxes: IPI mailboxes of this IPI agent
> */
> @@ -119,10 +125,13 @@ struct zynqmp_ipi_pdata {
> int irq;
> unsigned int method;
> u32 local_id;
> + int virq_sgi;
> int num_mboxes;
> struct zynqmp_ipi_mbox ipi_mboxes[] __counted_by(num_mboxes);
> };
>
> +static DEFINE_PER_CPU(struct zynqmp_ipi_pdata *, per_cpu_pdata);
> +
> static struct device_driver zynqmp_ipi_mbox_driver = {
> .owner = THIS_MODULE,
> .name = "zynqmp-ipi-mbox",
> @@ -189,6 +198,14 @@ static irqreturn_t zynqmp_ipi_interrupt(int irq, void *data)
> return status;
> }
>
> +static irqreturn_t zynqmp_sgi_interrupt(int irq, void *data)
> +{
> + struct zynqmp_ipi_pdata **pdata_ptr = data;
> + struct zynqmp_ipi_pdata *pdata = *pdata_ptr;
> +
> + return zynqmp_ipi_interrupt(irq, pdata);
> +}
> +
> /**
> * zynqmp_ipi_peek_data - Peek to see if there are any rx messages.
> *
> @@ -748,6 +765,112 @@ static int versal_ipi_setup(struct zynqmp_ipi_mbox *ipi_mbox,
> return 0;
> }
>
> +static int xlnx_mbox_cpuhp_start(unsigned int cpu)
> +{
> + struct zynqmp_ipi_pdata *pdata;
> +
> + pdata = get_cpu_var(per_cpu_pdata);
> + put_cpu_var(per_cpu_pdata);
> + enable_percpu_irq(pdata->virq_sgi, IRQ_TYPE_NONE);
> +
> + return 0;
> +}
> +
> +static int xlnx_mbox_cpuhp_down(unsigned int cpu)
> +{
> + struct zynqmp_ipi_pdata *pdata;
> +
> + pdata = get_cpu_var(per_cpu_pdata);
> + put_cpu_var(per_cpu_pdata);
> + disable_percpu_irq(pdata->virq_sgi);
> +
> + return 0;
> +}
> +
> +static void xlnx_disable_percpu_irq(void *data)
> +{
> + struct zynqmp_ipi_pdata *pdata;
> +
> + pdata = *this_cpu_ptr(&per_cpu_pdata);
> +
> + disable_percpu_irq(pdata->virq_sgi);
> +}
> +
> +static int xlnx_mbox_init_sgi(struct platform_device *pdev,
> + int sgi_num,
> + struct zynqmp_ipi_pdata *pdata)
> +{
> + int ret = 0;
> + int cpu;
> +
> + /*
> + * IRQ related structures are used for the following:
> + * for each SGI interrupt ensure its mapped by GIC IRQ domain
> + * and that each corresponding linux IRQ for the HW IRQ has
> + * a handler for when receiving an interrupt from the remote
> + * processor.
> + */
> + struct irq_domain *domain;
> + struct irq_fwspec sgi_fwspec;
> + struct device_node *interrupt_parent = NULL;
> + struct device *dev = &pdev->dev;
> +
> + /* Find GIC controller to map SGIs. */
> + interrupt_parent = of_irq_find_parent(dev->of_node);
> + if (!interrupt_parent) {
> + dev_err(&pdev->dev, "Failed to find property for Interrupt parent\n");
> + return -EINVAL;
> + }
> +
> + /* Each SGI needs to be associated with GIC's IRQ domain. */
> + domain = irq_find_host(interrupt_parent);
> + of_node_put(interrupt_parent);
> +
> + /* Each mapping needs GIC domain when finding IRQ mapping. */
> + sgi_fwspec.fwnode = domain->fwnode;
> +
> + /*
> + * When irq domain looks at mapping each arg is as follows:
> + * 3 args for: interrupt type (SGI), interrupt # (set later), type
> + */
> + sgi_fwspec.param_count = 1;
> +
> + /* Set SGI's hwirq */
> + sgi_fwspec.param[0] = sgi_num;
> + pdata->virq_sgi = irq_create_fwspec_mapping(&sgi_fwspec);
> +
> + for_each_possible_cpu(cpu)
> + per_cpu(per_cpu_pdata, cpu) = pdata;
> +
> + ret = request_percpu_irq(pdata->virq_sgi, zynqmp_sgi_interrupt, pdev->name,
> + &per_cpu_pdata);
> + WARN_ON(ret);
> + if (ret) {
> + irq_dispose_mapping(pdata->virq_sgi);
> + return ret;
> + }
> +
> + irq_to_desc(pdata->virq_sgi);
> + irq_set_status_flags(pdata->virq_sgi, IRQ_PER_CPU);
> +
> + /* Setup function for the CPU hot-plug cases */
> + cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mailbox/sgi:starting",
> + xlnx_mbox_cpuhp_start, xlnx_mbox_cpuhp_down);
> +
> + return ret;
> +}
> +
> +static void xlnx_mbox_cleanup_sgi(struct zynqmp_ipi_pdata *pdata)
> +{
> + cpuhp_remove_state(CPUHP_AP_ONLINE_DYN);
> +
> + on_each_cpu(xlnx_disable_percpu_irq, NULL, 1);
> +
> + irq_clear_status_flags(pdata->virq_sgi, IRQ_PER_CPU);
> + free_percpu_irq(pdata->virq_sgi, &per_cpu_pdata);
> + irq_dispose_mapping(pdata->virq_sgi);
> +}
> +
> /**
> * zynqmp_ipi_free_mboxes - Free IPI mailboxes devices
> *
> @@ -758,6 +881,9 @@ static void zynqmp_ipi_free_mboxes(struct zynqmp_ipi_pdata *pdata)
> struct zynqmp_ipi_mbox *ipi_mbox;
> int i;
>
> + if (pdata->irq < MAX_SGI)
> + xlnx_mbox_cleanup_sgi(pdata);
> +
> i = pdata->num_mboxes;
> for (; i >= 0; i--) {
> ipi_mbox = &pdata->ipi_mboxes[i];
> @@ -773,7 +899,8 @@ static int zynqmp_ipi_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> struct device_node *nc, *np = pdev->dev.of_node;
> - struct zynqmp_ipi_pdata *pdata;
> + struct zynqmp_ipi_pdata __percpu *pdata;
> + struct of_phandle_args out_irq;
> struct zynqmp_ipi_mbox *mbox;
> int num_mboxes, ret = -EINVAL;
> setup_ipi_fn ipi_fn;
> @@ -821,14 +948,32 @@ static int zynqmp_ipi_probe(struct platform_device *pdev)
> mbox++;
> }
>
> - /* IPI IRQ */
> - ret = platform_get_irq(pdev, 0);
> - if (ret < 0)
> + ret = of_irq_parse_one(dev_of_node(dev), 0, &out_irq);
> + if (ret < 0) {
> + dev_err(dev, "failed to parse interrupts\n");
> goto free_mbox_dev;
> + }
> + ret = out_irq.args[1];
> +
> + /*
> + * If Interrupt number is in SGI range, then request SGI else request
> + * IPI system IRQ.
> + */
> + if (ret < MAX_SGI) {
> + pdata->irq = ret;
> + ret = xlnx_mbox_init_sgi(pdev, pdata->irq, pdata);
> + if (ret)
> + goto free_mbox_dev;
> + } else {
> + ret = platform_get_irq(pdev, 0);
> + if (ret < 0)
> + goto free_mbox_dev;
> +
> + pdata->irq = ret;
> + ret = devm_request_irq(dev, pdata->irq, zynqmp_ipi_interrupt,
> + IRQF_SHARED, dev_name(dev), pdata);
> + }
>
> - pdata->irq = ret;
> - ret = devm_request_irq(dev, pdata->irq, zynqmp_ipi_interrupt,
> - IRQF_SHARED, dev_name(dev), pdata);
> if (ret) {
> dev_err(dev, "IRQ %d is not requested successfully.\n",
> pdata->irq);
>
> base-commit: 9221b2819b8a4196eecf5476d66201be60fbcf29
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