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Date:   Wed, 19 Oct 2022 08:46:39 +0100
Message-ID: <87k04wgsrk.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Huacai Chen <chenhuacai@loongson.cn>
Cc:     Thomas Gleixner <tglx@linutronix.de>, linux-kernel@vger.kernel.org,
        Xuefeng Li <lixuefeng@loongson.cn>,
        Huacai Chen <chenhuacai@gmail.com>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        Jianmin Lv <lvjianmin@loongson.cn>
Subject: Re: [PATCH] irqchip/loongson-htvec: Add ACPI init support
In-Reply-To: <20221017031847.2407930-1-chenhuacai@loongson.cn>
References: <20221017031847.2407930-1-chenhuacai@loongson.cn>
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On Mon, 17 Oct 2022 04:18:47 +0100,
Huacai Chen <chenhuacai@loongson.cn> wrote:
> 
> HTVECINTC stands for "HyperTransport Interrupts" that described in
> Section 14.3 of "Loongson 3A5000 Processor Reference Manual". For more
> information please refer Documentation/loongarch/irq-chip-model.rst.
> 
> Though the extended model is the recommended one, there are still some
> legacy model machines. So we add ACPI init support for HTVECINTC.
> 
> Co-developed-by: Jianmin Lv <lvjianmin@loongson.cn>
> Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> ---
>  arch/loongarch/include/asm/irq.h       |   2 +-
>  drivers/irqchip/Kconfig                |   1 +
>  drivers/irqchip/irq-loongson-htvec.c   | 145 +++++++++++++++++++------
>  drivers/irqchip/irq-loongson-liointc.c |  21 +++-
>  4 files changed, 133 insertions(+), 36 deletions(-)
> 
> diff --git a/arch/loongarch/include/asm/irq.h b/arch/loongarch/include/asm/irq.h
> index d06d4542b634..9d3d36e41afe 100644
> --- a/arch/loongarch/include/asm/irq.h
> +++ b/arch/loongarch/include/asm/irq.h
> @@ -93,7 +93,7 @@ int liointc_acpi_init(struct irq_domain *parent,
>  int eiointc_acpi_init(struct irq_domain *parent,
>  					struct acpi_madt_eio_pic *acpi_eiointc);
>  
> -struct irq_domain *htvec_acpi_init(struct irq_domain *parent,
> +int htvec_acpi_init(struct irq_domain *parent,
>  					struct acpi_madt_ht_pic *acpi_htvec);
>  int pch_lpc_acpi_init(struct irq_domain *parent,
>  					struct acpi_madt_lpc_pic *acpi_pchlpc);
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 7ef9f5e696d3..17396e6e42fc 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -576,6 +576,7 @@ config IRQ_LOONGARCH_CPU
>  	select GENERIC_IRQ_CHIP
>  	select IRQ_DOMAIN
>  	select GENERIC_IRQ_EFFECTIVE_AFF_MASK
> +	select LOONGSON_HTVEC
>  	select LOONGSON_LIOINTC
>  	select LOONGSON_EIOINTC
>  	select LOONGSON_PCH_PIC
> diff --git a/drivers/irqchip/irq-loongson-htvec.c b/drivers/irqchip/irq-loongson-htvec.c
> index 60a335d7e64e..1bb414ec6e78 100644
> --- a/drivers/irqchip/irq-loongson-htvec.c
> +++ b/drivers/irqchip/irq-loongson-htvec.c
> @@ -20,7 +20,6 @@
>  /* Registers */
>  #define HTVEC_EN_OFF		0x20
>  #define HTVEC_MAX_PARENT_IRQ	8
> -
>  #define VEC_COUNT_PER_REG	32
>  #define VEC_REG_IDX(irq_id)	((irq_id) / VEC_COUNT_PER_REG)
>  #define VEC_REG_BIT(irq_id)	((irq_id) % VEC_COUNT_PER_REG)
> @@ -32,6 +31,8 @@ struct htvec {
>  	raw_spinlock_t		htvec_lock;
>  };
>  
> +static struct htvec *htvec_priv;
> +
>  static void htvec_irq_dispatch(struct irq_desc *desc)
>  {
>  	int i;
> @@ -155,64 +156,140 @@ static void htvec_reset(struct htvec *priv)
>  	}
>  }
>  
> -static int htvec_of_init(struct device_node *node,
> -				struct device_node *parent)
> +static int htvec_init(phys_addr_t addr, unsigned long size,
> +		int num_parents, int parent_irq[], struct fwnode_handle *domain_handle)
>  {
> +	int i;
>  	struct htvec *priv;
> -	int err, parent_irq[8], i;
>  
>  	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
>  	if (!priv)
>  		return -ENOMEM;
>  
> +	priv->num_parents = num_parents;
> +	priv->base = ioremap(addr, size);
>  	raw_spin_lock_init(&priv->htvec_lock);
> -	priv->base = of_iomap(node, 0);
> -	if (!priv->base) {
> -		err = -ENOMEM;
> -		goto free_priv;
> -	}
> -
> -	/* Interrupt may come from any of the 8 interrupt lines */
> -	for (i = 0; i < HTVEC_MAX_PARENT_IRQ; i++) {
> -		parent_irq[i] = irq_of_parse_and_map(node, i);
> -		if (parent_irq[i] <= 0)
> -			break;
> -
> -		priv->num_parents++;
> -	}
> -
> -	if (!priv->num_parents) {
> -		pr_err("Failed to get parent irqs\n");
> -		err = -ENODEV;
> -		goto iounmap_base;
> -	}
>  
> -	priv->htvec_domain = irq_domain_create_linear(of_node_to_fwnode(node),
> +	/* Setup IRQ domain */
> +	priv->htvec_domain = irq_domain_create_linear(domain_handle,
>  					(VEC_COUNT_PER_REG * priv->num_parents),
>  					&htvec_domain_ops, priv);
>  	if (!priv->htvec_domain) {
> -		pr_err("Failed to create IRQ domain\n");
> -		err = -ENOMEM;
> -		goto irq_dispose;
> +		pr_err("loongson-htvec: cannot add IRQ domain\n");
> +		goto iounmap_base;
>  	}
>  
>  	htvec_reset(priv);
>  
> -	for (i = 0; i < priv->num_parents; i++)
> +	for (i = 0; i < priv->num_parents; i++) {
>  		irq_set_chained_handler_and_data(parent_irq[i],
>  						 htvec_irq_dispatch, priv);
> +	}
> +
> +	htvec_priv = priv;
>  
>  	return 0;
>  
> -irq_dispose:
> -	for (; i > 0; i--)
> -		irq_dispose_mapping(parent_irq[i - 1]);
>  iounmap_base:
>  	iounmap(priv->base);
> -free_priv:
>  	kfree(priv);
>  
> -	return err;
> +	return -EINVAL;
> +}
> +
> +#ifdef CONFIG_OF
> +
> +static int htvec_of_init(struct device_node *node,
> +				struct device_node *parent)
> +{
> +	int i, err;
> +	int parent_irq[8];
> +	int num_parents = 0;
> +	struct resource res;
> +
> +	if (of_address_to_resource(node, 0, &res))
> +		return -EINVAL;
> +
> +	/* Interrupt may come from any of the 8 interrupt lines */
> +	for (i = 0; i < HTVEC_MAX_PARENT_IRQ; i++) {
> +		parent_irq[i] = irq_of_parse_and_map(node, i);
> +		if (parent_irq[i] <= 0)
> +			break;
> +
> +		num_parents++;
> +	}
> +
> +	err = htvec_init(res.start, resource_size(&res),
> +			num_parents, parent_irq, of_node_to_fwnode(node));
> +	if (err < 0)
> +		return err;
> +
> +	return 0;
>  }
>  
>  IRQCHIP_DECLARE(htvec, "loongson,htvec-1.0", htvec_of_init);
> +
> +#endif
> +
> +#ifdef CONFIG_ACPI
> +static int __init
> +pch_pic_parse_madt(union acpi_subtable_headers *header,
> +		       const unsigned long end)

Please write the function name and the return type on the same
line. Long lines are just fine.

> +{
> +	struct acpi_madt_bio_pic *pchpic_entry = (struct acpi_madt_bio_pic *)header;
> +
> +	return pch_pic_acpi_init(htvec_priv->htvec_domain, pchpic_entry);
> +}
> +
> +static int __init
> +pch_msi_parse_madt(union acpi_subtable_headers *header,
> +		       const unsigned long end)
> +{
> +	struct acpi_madt_msi_pic *pchmsi_entry = (struct acpi_madt_msi_pic *)header;
> +
> +	return pch_msi_acpi_init(htvec_priv->htvec_domain, pchmsi_entry);
> +}
> +
> +static int __init acpi_cascade_irqdomain_init(void)
> +{
> +	acpi_table_parse_madt(ACPI_MADT_TYPE_BIO_PIC,
> +			      pch_pic_parse_madt, 0);
> +	acpi_table_parse_madt(ACPI_MADT_TYPE_MSI_PIC,
> +			      pch_msi_parse_madt, 0);

What if any of these fail? They have a return value for a reason.

> +	return 0;

There is only a single possible return value, which is never checked.

> +}
> +
> +int __init htvec_acpi_init(struct irq_domain *parent,
> +				   struct acpi_madt_ht_pic *acpi_htvec)
> +{
> +	int i, ret;
> +	int num_parents, parent_irq[8];
> +	struct fwnode_handle *domain_handle;
> +
> +	if (!acpi_htvec)
> +		return -EINVAL;
> +
> +	num_parents = HTVEC_MAX_PARENT_IRQ;
> +
> +	domain_handle = irq_domain_alloc_fwnode((phys_addr_t *)acpi_htvec);

NAK. Enough. I already mopped the floor for you during the previous
cycle, I'm not going to do it again. Please see 7e4fd7a1a6fd.

> +	if (!domain_handle) {
> +		pr_err("Unable to allocate domain handle\n");
> +		return -ENOMEM;
> +	}
> +
> +	/* Interrupt may come from any of the 8 interrupt lines */
> +	for (i = 0; i < HTVEC_MAX_PARENT_IRQ; i++)
> +		parent_irq[i] = irq_create_mapping(parent, acpi_htvec->cascade[i]);
> +
> +	ret = htvec_init(acpi_htvec->address, acpi_htvec->size,
> +			num_parents, parent_irq, domain_handle);
> +
> +	if (ret == 0)
> +		acpi_cascade_irqdomain_init();
> +	else
> +		irq_domain_free_fwnode(domain_handle);
> +
> +	return ret;
> +}
> +
> +#endif
> diff --git a/drivers/irqchip/irq-loongson-liointc.c b/drivers/irqchip/irq-loongson-liointc.c
> index 0da8716f8f24..ddf23b1114cb 100644
> --- a/drivers/irqchip/irq-loongson-liointc.c
> +++ b/drivers/irqchip/irq-loongson-liointc.c
> @@ -349,6 +349,22 @@ IRQCHIP_DECLARE(loongson_liointc_2_0, "loongson,liointc-2.0", liointc_of_init);
>  #endif
>  
>  #ifdef CONFIG_ACPI
> +static int __init htintc_parse_madt(union acpi_subtable_headers *header,
> +					const unsigned long end)
> +{
> +	struct acpi_madt_ht_pic *htintc_entry = (struct acpi_madt_ht_pic *)header;
> +	struct irq_domain *parent = irq_find_matching_fwnode(liointc_handle, DOMAIN_BUS_ANY);
> +
> +	return htvec_acpi_init(parent, htintc_entry);
> +}
> +
> +static int __init acpi_cascade_irqdomain_init(void)
> +{
> +	acpi_table_parse_madt(ACPI_MADT_TYPE_HT_PIC,
> +			      htintc_parse_madt, 0);
> +	return 0;

Same comments as above.

> +}
> +
>  int __init liointc_acpi_init(struct irq_domain *parent, struct acpi_madt_lio_pic *acpi_liointc)
>  {
>  	int ret;
> @@ -365,9 +381,12 @@ int __init liointc_acpi_init(struct irq_domain *parent, struct acpi_madt_lio_pic
>  		pr_err("Unable to allocate domain handle\n");
>  		return -ENOMEM;
>  	}
> +
>  	ret = liointc_init(acpi_liointc->address, acpi_liointc->size,
>  			   1, domain_handle, NULL);
> -	if (ret)
> +	if (ret == 0)
> +		acpi_cascade_irqdomain_init();
> +	else
>  		irq_domain_free_fwnode(domain_handle);
>  
>  	return ret;

	M.

-- 
Without deviation from the norm, progress is not possible.