> On 9 Nov 2017, at 11:04, Philippe Gerum <r...@xenomai.org> wrote:
>
> On 11/06/2017 10:46 AM, Christoph Muellner wrote:
>> This patch adds an ioctl code to set a GPIO IRQ's CPU affinity
>> to the RTDM user space API.
>>
>> Signed-off-by: Christoph Muellner <christoph.muell...@theobroma-systems.com>
>> ---
>> include/rtdm/uapi/gpio.h | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/include/rtdm/uapi/gpio.h b/include/rtdm/uapi/gpio.h
>> index f846f48b2..e70da2621 100644
>> --- a/include/rtdm/uapi/gpio.h
>> +++ b/include/rtdm/uapi/gpio.h
>> @@ -18,10 +18,16 @@
>> #ifndef _RTDM_UAPI_GPIO_H
>> #define _RTDM_UAPI_GPIO_H
>>
>> +typedef struct {
>> + void* mask;
>
> Asking explicitly for unsigned long * may give a better hint about what
> is expected.
I agree, but then we need a cast when using cpu_set_t in user space, which is
even more ugly.
This is user code, which works atm:
cpu_set_t mask;
CPU_ZERO(&mask);
CPU_SET(4, &mask); //CPU 4 only
rtdm_cpumask_t rtdm_mask;
rtdm_mask.mask = &mask; //assignment of mask
rtdm_mask.size = sizeof(mask);
When making mask a unsigned long*, then the assignment of mask does not work
anymore
without having the compiler complaining about incompatible types.
The reason is, that libc uses the following type hierarchy for cpu_set_t
(bits/sched.h):
typedef unsigned long int __cpu_mask;
typedef struct
{
__cpu_mask __bits[__CPU_SETSIZE / __NCPUBITS];
} cpu_set_t;
So besides casting, only something like this would work:
...
rtdm_mask.mask = &mask.__bits;
...
Making mask a cpu_set_t* is problematic, because this type is only available in
user space and not in kernel.
So I saw two choices: making a wrapper function rtdm_gpio_setirqaff(int fd,
cpu_set_t &mask),
which hides the cast or use void* for the mask. The wrapper function would hide
the cpu_set_t
from the kernel by using #ifndef __KERNEL__ around it.
Do you prefer the wrapper function?
Thanks,
Christoph
>
>> + size_t size;
>> +} rtdm_cpumask_t;
>> +
>> #define GPIO_RTIOC_DIR_OUT _IOW(RTDM_CLASS_GPIO, 0, int)
>> #define GPIO_RTIOC_DIR_IN _IO(RTDM_CLASS_GPIO, 1)
>> #define GPIO_RTIOC_IRQEN _IOW(RTDM_CLASS_GPIO, 2, int) /* GPIO
>> trigger */
>> #define GPIO_RTIOC_IRQDIS _IO(RTDM_CLASS_GPIO, 3)
>> +#define GPIO_RTIOC_IRQAFF _IOW(RTDM_CLASS_GPIO, 4,
>> rtdm_cpumask_t*)
>>
>> #define GPIO_TRIGGER_NONE 0x0 /* unspecified */
>> #define GPIO_TRIGGER_EDGE_RISING 0x1
>>
>
>
> --
> Philippe.
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