From: marc.zyngier@arm•com (Marc Zyngier)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v7 5/8] genirq/irq: introduce msi_doorbell's structs and related callback
Date: Wed, 20 Apr 2016 10:16:08 +0100 [thread overview]
Message-ID: <571748D8.3030402@arm.com> (raw)
In-Reply-To: <1461085990-2547-6-git-send-email-eric.auger@linaro.org>
On 19/04/16 18:13, Eric Auger wrote:
> The purpose is to be able to retrieve the MSI doorbells of an irqchip.
> This is now needed since on some platforms those doorbells must be
> iommu mapped (in case the MSIs transit through an IOMMU that do not
> bypass those transactions).
>
> The assumption is there is a maximum of one doorbell region per cpu.
> The number of doorbells for the whole irqchip is stored in nb_doorbells.
>
> A doorbell region is characterized by its physical address base, size and
> IOMMU protection flag.
>
> irq_chip msi_doorbell_info callback enables to retrieve the doorbells of
> the irqchip.
>
> Signed-off-by: Eric Auger <eric.auger@linaro•org>
>
> ---
>
> v7: creation
> ---
> include/linux/irq.h | 26 ++++++++++++++++++++++----
> 1 file changed, 22 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index c4de623..fdad8c1 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -312,9 +312,25 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
> return d->hwirq;
> }
>
> -/**
> - * struct irq_chip - hardware interrupt chip descriptor
> - *
> +/* MSI doorbell region */
> +struct irq_chip_msi_doorbell {
> + phys_addr_t base;
> + size_t size;
> + int prot; /* iommu protection flag */
I find this one a bit scary. "int" is a probably not the right type if
it is a set of flags (it should describe both the protection and the
memory attributes - in this case, probably something like Device +
Writeable). You should probably use the same type the IOMMU code uses
(and if it is actually an int, then I'll shut up...).
> +};
> +
> +/*
> + * Describe all the MSI doorbell regions for an irqchip.
> + * A single doorbell region per cpu is assumed.
> + * In case a single doorbell is supported for the whole irqchip,
> + * the region is described in as cpu #0's one
> + */
> +struct irq_chip_msi_doorbell_info {
> + struct irq_chip_msi_doorbell __percpu *percpu_doorbells;
> + int nb_doorbells; /* overall number of doorbells */
> +};
How can size and prot be different from one CPU to another? It really
feels like they should be common. Can I suggest something like this?
struct irq_chip_msi_doorbell_info {
phys_addr_t __percpu *doorbells;
size_t size;
u32 prot;
};
and get rid of struct irq_chip_msi_doorbell altogether?
> +
> +/** * struct irq_chip - hardware interrupt chip descriptor *
> * @name: name for /proc/interrupts
> * @irq_startup: start up the interrupt (defaults to ->enable if NULL)
> * @irq_shutdown: shut down the interrupt (defaults to ->disable if NULL)
> @@ -349,6 +365,7 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
> * @irq_get_irqchip_state: return the internal state of an interrupt
> * @irq_set_irqchip_state: set the internal state of a interrupt
> * @irq_set_vcpu_affinity: optional to target a vCPU in a virtual machine
> + * @msi_doorbell_info: return the MSI doorbell info
> * @ipi_send_single: send a single IPI to destination cpus
> * @ipi_send_mask: send an IPI to destination cpus in cpumask
> * @flags: chip specific flags
> @@ -394,7 +411,8 @@ struct irq_chip {
> int (*irq_set_irqchip_state)(struct irq_data *data, enum irqchip_irq_state which, bool state);
>
> int (*irq_set_vcpu_affinity)(struct irq_data *data, void *vcpu_info);
> -
> + const struct irq_chip_msi_doorbell_info *(*msi_doorbell_info)(
> + struct irq_data *data);
> void (*ipi_send_single)(struct irq_data *data, unsigned int cpu);
> void (*ipi_send_mask)(struct irq_data *data, const struct cpumask *dest);
>
>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2016-04-20 9:16 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-19 17:13 [PATCH v7 0/8] KVM PCIe/MSI passthrough on ARM/ARM64: kernel part 2/3: msi changes Eric Auger
2016-04-19 17:13 ` [PATCH v7 1/8] genirq/msi: Add a new MSI_FLAG_IRQ_REMAPPING flag Eric Auger
2016-04-22 11:02 ` Robin Murphy
2016-04-22 12:25 ` Eric Auger
2016-04-22 15:39 ` Thomas Gleixner
2016-04-19 17:13 ` [PATCH v7 2/8] irqchip/gic-v3-its: ITS advertises MSI_FLAG_IRQ_REMAPPING Eric Auger
2016-04-19 17:13 ` [PATCH v7 3/8] genirq/msi: export msi_get_domain_info Eric Auger
2016-04-19 17:13 ` [PATCH v7 4/8] genirq/msi: msi_compose wrapper Eric Auger
2016-04-19 17:13 ` [PATCH v7 5/8] genirq/irq: introduce msi_doorbell's structs and related callback Eric Auger
2016-04-20 9:16 ` Marc Zyngier [this message]
2016-04-20 9:36 ` Eric Auger
2016-04-19 17:13 ` [PATCH v7 6/8] irqchip/gicv2m: implement msi_doorbell_info callback Eric Auger
2016-04-20 9:27 ` Marc Zyngier
2016-04-20 12:33 ` Eric Auger
2016-04-20 17:56 ` Marc Zyngier
2016-04-20 18:16 ` Eric Auger
2016-04-19 17:13 ` [PATCH v7 7/8] genirq/msi: map/unmap the MSI doorbells on msi_domain_alloc/free_irqs Eric Auger
2016-04-19 18:04 ` kbuild test robot
2016-04-20 7:47 ` Eric Auger
2016-04-26 1:24 ` [lkp] " Ye Xiaolong
2016-04-26 16:43 ` Eric Auger
2016-04-19 17:13 ` [PATCH v7 8/8] genirq/msi: use the MSI doorbell's IOVA when requested Eric Auger
2016-04-20 9:44 ` Marc Zyngier
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