Re: [PATCH v17 11/35] virt: gunyah: Translate gh_rm_hyp_resource into gunyah_resource

[Elliot Berman <quic_eberman@xxxxxxxxxxx>]

On Fri, Apr 05, 2024 at 08:40:40AM +0530, Pavan Kondeti wrote:
> On Thu, Feb 22, 2024 at 03:16:34PM -0800, Elliot Berman wrote:
> > When booting a Gunyah virtual machine, the host VM may gain capabilities
> > to interact with resources for the guest virtual machine. Examples of
> > such resources are vCPUs or message queues. To use those resources, we
> > need to translate the RM response into a gunyah_resource structure which
> > are useful to Linux drivers. Presently, Linux drivers need only to know
> > the type of resource, the capability ID, and an interrupt.
> > 
> > On ARM64 systems, the interrupt reported by Gunyah is the GIC interrupt
> > ID number and always a SPI or extended SPI.
> > 
> > Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
> > ---
> >  arch/arm64/include/asm/gunyah.h | 36 ++++++++++++++++++++++
> >  drivers/virt/gunyah/rsc_mgr.c   | 67 +++++++++++++++++++++++++++++++++++++++++
> >  drivers/virt/gunyah/rsc_mgr.h   |  5 +++
> >  include/linux/gunyah.h          |  2 ++
> >  4 files changed, 110 insertions(+)
> > 
> > diff --git a/arch/arm64/include/asm/gunyah.h b/arch/arm64/include/asm/gunyah.h
> > new file mode 100644
> > index 0000000000000..0cd3debe22b64
> > --- /dev/null
> > +++ b/arch/arm64/include/asm/gunyah.h
> > @@ -0,0 +1,36 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> > + */
> > +#ifndef _ASM_GUNYAH_H
> > +#define _ASM_GUNYAH_H
> > +
> > +#include <linux/irq.h>
> > +#include <linux/irqdomain.h>
> > +
> > +static inline int arch_gunyah_fill_irq_fwspec_params(u32 virq,
> > +						 struct irq_fwspec *fwspec)
> > +{
> > +	/* Assume that Gunyah gave us an SPI or ESPI; defensively check it */
> > +	if (WARN(virq < 32, "Unexpected virq: %d\n", virq)) {
> > +		return -EINVAL;
> > +	} else if (virq <= 1019) {
> > +		fwspec->param_count = 3;
> > +		fwspec->param[0] = 0; /* GIC_SPI */
> > +		fwspec->param[1] = virq - 32; /* virq 32 -> SPI 0 */
> > +		fwspec->param[2] = IRQ_TYPE_EDGE_RISING;
> > +	} else if (WARN(virq < 4096, "Unexpected virq: %d\n", virq)) {
> > +		return -EINVAL;
> > +	} else if (virq < 5120) {
> > +		fwspec->param_count = 3;
> > +		fwspec->param[0] = 2; /* GIC_ESPI */
> > +		fwspec->param[1] = virq - 4096; /* virq 4096 -> ESPI 0 */
> > +		fwspec->param[2] = IRQ_TYPE_EDGE_RISING;
> > +	} else {
> > +		WARN(1, "Unexpected virq: %d\n", virq);
> > +		return -EINVAL;
> > +	}
> > +	return 0;
> > +}
> > +
> 
> __get_intid_range() in gic-v3 driver looks more pleasing. Other than
> that the logic for the translation looks good to me.

Agreed, updated for v18.

static inline int arch_gunyah_fill_irq_fwspec_params(u32 virq,
						 struct irq_fwspec *fwspec)
{
	/* Assume that Gunyah gave us an SPI or ESPI; defensively check it */
	switch (virq) {
	case 32 ... 1019:
		fwspec->param_count = 3;
		fwspec->param[0] = 0; /* GIC_SPI */
		fwspec->param[1] = virq - 32; /* virq 32 -> SPI 0 */
		fwspec->param[2] = IRQ_TYPE_EDGE_RISING;
		break;
	case 4096 ... 5119:
		fwspec->param_count = 3;
		fwspec->param[0] = 2; /* GIC_ESPI */
		fwspec->param[1] = virq - 4096; /* virq 4096 -> ESPI 0 */
		fwspec->param[2] = IRQ_TYPE_EDGE_RISING;
		break;
	default:
		WARN(1, "Unexpected virq: %d\n", virq)
		return -EINVAL;
	}
	return 0;
}