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Message-ID: <20160216085024.3f573f40@arm.com>
Date: Tue, 16 Feb 2016 08:50:24 +0000
From: Marc Zyngier <marc.zyngier@....com>
To: MaJun <majun258@...wei.com>
Cc: <Catalin.Marinas@....com>, <linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>, <Will.Deacon@....com>,
<mark.rutland@....com>, <jason@...edaemon.net>,
<tglx@...utronix.de>, <lizefan@...wei.com>, <huxinwei@...wei.com>,
<dingtianhong@...wei.com>, <liguozhu@...ilicon.com>,
<guohanjun@...wei.com>, <zhaojunhua@...ilicon.com>
Subject: Re: [PATCH v2 4/5] irqchip:create irq domain for each mbigen device
On Tue, 16 Feb 2016 14:37:27 +0800
MaJun <majun258@...wei.com> wrote:
> From: Ma Jun <majun258@...wei.com>
>
> For peripheral devices which connect to mbigen,mbigen is a interrupt
> controller. So, we create irq domain for each mbigen device and add
> mbigen irq domain into irq hierarchy structure.
>
> Signed-off-by: Ma Jun <majun258@...wei.com>
> ---
> drivers/irqchip/irq-mbigen-v1.c | 136 +++++++++++++++++++++++++++++++++++++++
> 1 files changed, 136 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/irqchip/irq-mbigen-v1.c b/drivers/irqchip/irq-mbigen-v1.c
> index 9445658..61e7ad0 100644
> --- a/drivers/irqchip/irq-mbigen-v1.c
> +++ b/drivers/irqchip/irq-mbigen-v1.c
> @@ -16,11 +16,30 @@
> * along with this program. If not, see <http://www.gnu.org/licenses/>.
> */
>
> +#include <linux/interrupt.h>
> +#include <linux/irqchip.h>
> #include <linux/module.h>
> +#include <linux/msi.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
> #include <linux/slab.h>
>
> +/* The maximum IRQ pin number of mbigen chip(start from 0) */
> +#define MAXIMUM_IRQ_PIN_NUM 640
> +
> +/**
> + * In mbigen vector register
> + * bit[31:16]: device id
> + * bit[15:0]: event id value
> + */
> +#define IRQ_EVENT_ID_MASK 0xffff
> +
> +/* offset of vector register in mbigen node */
> +#define REG_MBIGEN_VEC_OFFSET 0x300
> +#define REG_MBIGEN_EXT_VEC_OFFSET 0x320
> +
> /**
> * struct mbigen_device - holds the information of mbigen device.
> *
> @@ -32,10 +51,112 @@ struct mbigen_device {
> void __iomem *base;
> };
>
> +static int get_mbigen_nid(unsigned int offset)
> +{
> + int nid = 0;
> +
> + if (offset < 256)
> + nid = offset / 64;
> + else if (offset < 384)
> + nid = 4;
> + else if (offset < 640)
> + nid = 5;
> +
> + return nid;
> +}
> +
> +static inline unsigned int get_mbigen_vec_reg(irq_hw_number_t hwirq)
> +{
> + unsigned int nid;
> +
> + nid = get_mbigen_nid(hwirq);
> +
> + if (nid < 4)
> + return (nid * 4) + REG_MBIGEN_VEC_OFFSET;
> + else
> + return (nid - 4) * 4 + REG_MBIGEN_EXT_VEC_OFFSET;
> +}
> +
> +static struct irq_chip mbigen_irq_chip = {
> + .name = "mbigen-v1",
> +};
> +
> +static void mbigen_write_msg(struct msi_desc *desc, struct msi_msg *msg)
> +{
> + /* The address of doorbell is encoded in mbigen register by default
> + * So,we don't need to program the doorbell address at here
> + * Besides, the event ID is decided by the hardware pin number,
> + * we can't change it in software.So, we don't need to encode the
> + * event ID in mbigen register.
> + */
Really? What if tomorrow I decide to change the EventID allocation
policy in the ITS driver? Have your HW engineers really baked the
behaviour of the Linux driver into the device?
I'm puzzled.
M.
--
Jazz is not dead. It just smells funny.
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