Re: [PATCH v8 04/14] powerpc/vas: Alloc and setup IRQ and trigger port address

[Cédric Le Goater]

On 3/19/20 7:14 AM, Haren Myneni wrote:
> 
> Alloc IRQ and get trigger port address for each VAS instance. Kernel
> register this IRQ per VAS instance and sets this port for each send
> window. NX interrupts the kernel when it sees page fault.
> 
> Signed-off-by: Haren Myneni <ha...@linux.ibm.com>
> ---
>  arch/powerpc/platforms/powernv/vas.c | 34 ++++++++++++++++++++++++++++------
>  arch/powerpc/platforms/powernv/vas.h |  2 ++
>  2 files changed, 30 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/vas.c 
> b/arch/powerpc/platforms/powernv/vas.c
> index ed9cc6d..168ab68 100644
> --- a/arch/powerpc/platforms/powernv/vas.c
> +++ b/arch/powerpc/platforms/powernv/vas.c
> @@ -15,6 +15,7 @@
>  #include <linux/of_address.h>
>  #include <linux/of.h>
>  #include <asm/prom.h>
> +#include <asm/xive.h>
>  
>  #include "vas.h"
>  
> @@ -25,10 +26,12 @@
>  
>  static int init_vas_instance(struct platform_device *pdev)
>  {
> -     int rc, cpu, vasid;
> -     struct resource *res;
> -     struct vas_instance *vinst;
>       struct device_node *dn = pdev->dev.of_node;
> +     struct vas_instance *vinst;
> +     uint32_t chipid, irq;
> +     struct resource *res;
> +     int rc, cpu, vasid;
> +     uint64_t port;
>  
>       rc = of_property_read_u32(dn, "ibm,vas-id", &vasid);
>       if (rc) {
> @@ -36,6 +39,12 @@ static int init_vas_instance(struct platform_device *pdev)
>               return -ENODEV;
>       }
>  
> +     rc = of_property_read_u32(dn, "ibm,chip-id", &chipid);
> +     if (rc) {
> +             pr_err("No ibm,chip-id property for %s?\n", pdev->name);
> +             return -ENODEV;
> +     }
> +
>       if (pdev->num_resources != 4) {
>               pr_err("Unexpected DT configuration for [%s, %d]\n",
>                               pdev->name, vasid);
> @@ -69,9 +78,22 @@ static int init_vas_instance(struct platform_device *pdev)
>  
>       vinst->paste_win_id_shift = 63 - res->end;
>  
> -     pr_devel("Initialized instance [%s, %d], paste_base 0x%llx, "
> -                     "paste_win_id_shift 0x%llx\n", pdev->name, vasid,
> -                     vinst->paste_base_addr, vinst->paste_win_id_shift);
> +     rc = xive_native_alloc_get_irq_info(chipid, &irq, &port);
> +     if (rc)
> +             return rc;
> +
> +     vinst->virq = irq_create_mapping(NULL, irq);
> +     if (!vinst->virq) {
> +             pr_err("Inst%d: Unable to map global irq %d\n",
> +                             vinst->vas_id, irq);
> +             return -EINVAL;
> +     }
> +
> +     vinst->irq_port = port;


I would prefer something like this : 

        hwirq = xive_native_alloc_irq_on_chip(chip_id);

        vinst->virq = irq_create_mapping(NULL, hwirq);
        if (!vinst->virq) {
                ...
        }

        {
                struct irq_data *d = irq_get_irq_data(vinst->virq);
                struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);

                vinst->irq_port = xd->trig_page;
        }


and dump xive_native_alloc_get_irq_info().

C.


> +     pr_devel("Initialized instance [%s, %d] paste_base 0x%llx 
> paste_win_id_shift 0x%llx IRQ %d Port 0x%llx\n",
> +                     pdev->name, vasid, vinst->paste_base_addr,
> +                     vinst->paste_win_id_shift, vinst->virq,
> +                     vinst->irq_port);
>  
>       for_each_possible_cpu(cpu) {
>               if (cpu_to_chip_id(cpu) == of_get_ibm_chip_id(dn))
> diff --git a/arch/powerpc/platforms/powernv/vas.h 
> b/arch/powerpc/platforms/powernv/vas.h
> index 5574aec..598608b 100644
> --- a/arch/powerpc/platforms/powernv/vas.h
> +++ b/arch/powerpc/platforms/powernv/vas.h
> @@ -313,6 +313,8 @@ struct vas_instance {
>       u64 paste_base_addr;
>       u64 paste_win_id_shift;
>  
> +     u64 irq_port;
> +     int virq;
>       struct mutex mutex;
>       struct vas_window *rxwin[VAS_COP_TYPE_MAX];
>       struct vas_window *windows[VAS_WINDOWS_PER_CHIP];
>