[PATCHv2 1/3] pci: pci-aardvark: move to MSI handling using generic MSI support

Marc Zyngier marc.zyngier at arm.com
Thu Jan 5 09:17:00 PST 2017


Hi Thomas,

On 23/12/16 09:20, Thomas Petazzoni wrote:
> The MSI support introduced with the initial Aardvark driver was based
> on the msi_controller structure and the of_pci_msi_chip_add() /
> of_pci_find_msi_chip_by_node() API, which are being deprecated in
> favor of the generic MSI support.
> 
> Therefore, this commit updates the Aardvark driver to use the generic
> MSI support.
> 
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> ---
> Changes since v1:
>  - Rebased on top of v4.9
>  - Removed the MSI_FLAG_PCI_MSIX flag since we don't support MSI-X for
>    the moment.
> ---
>  drivers/pci/host/pci-aardvark.c | 172 +++++++++++++++-------------------------
>  1 file changed, 66 insertions(+), 106 deletions(-)
> 
> diff --git a/drivers/pci/host/pci-aardvark.c b/drivers/pci/host/pci-aardvark.c
> index 4fce494..3fdca5d 100644
> --- a/drivers/pci/host/pci-aardvark.c
> +++ b/drivers/pci/host/pci-aardvark.c
> @@ -200,10 +200,12 @@ struct advk_pcie {
>  	struct list_head resources;
>  	struct irq_domain *irq_domain;
>  	struct irq_chip irq_chip;
> -	struct msi_controller msi;
>  	struct irq_domain *msi_domain;
> +	struct irq_domain *msi_inner_domain;
> +	struct irq_chip msi_bottom_irq_chip;
>  	struct irq_chip msi_irq_chip;
> -	DECLARE_BITMAP(msi_irq_in_use, MSI_IRQ_NUM);
> +	struct msi_domain_info msi_domain_info;
> +	DECLARE_BITMAP(msi_used, MSI_IRQ_NUM);
>  	struct mutex msi_used_lock;
>  	u16 msi_msg;
>  	int root_bus_nr;
> @@ -545,94 +547,64 @@ static struct pci_ops advk_pcie_ops = {
>  	.write = advk_pcie_wr_conf,
>  };
>  
> -static int advk_pcie_alloc_msi(struct advk_pcie *pcie)
> +static void advk_msi_irq_compose_msi_msg(struct irq_data *data,
> +					 struct msi_msg *msg)
>  {
> -	int hwirq;
> +	struct advk_pcie *pcie = irq_data_get_irq_chip_data(data);
> +	phys_addr_t msi_msg = virt_to_phys(&pcie->msi_msg);
>  
> -	mutex_lock(&pcie->msi_used_lock);
> -	hwirq = find_first_zero_bit(pcie->msi_irq_in_use, MSI_IRQ_NUM);
> -	if (hwirq >= MSI_IRQ_NUM)
> -		hwirq = -ENOSPC;
> -	else
> -		set_bit(hwirq, pcie->msi_irq_in_use);
> -	mutex_unlock(&pcie->msi_used_lock);
> -
> -	return hwirq;
> +	msg->address_lo = lower_32_bits(msi_msg);
> +	msg->address_hi = upper_32_bits(msi_msg);
> +	msg->data = data->irq;
>  }
>  
> -static void advk_pcie_free_msi(struct advk_pcie *pcie, int hwirq)
> +static int advk_msi_set_affinity(struct irq_data *irq_data,
> +				 const struct cpumask *mask, bool force)
>  {
> -	struct device *dev = &pcie->pdev->dev;
> -
> -	mutex_lock(&pcie->msi_used_lock);
> -	if (!test_bit(hwirq, pcie->msi_irq_in_use))
> -		dev_err(dev, "trying to free unused MSI#%d\n", hwirq);
> -	else
> -		clear_bit(hwirq, pcie->msi_irq_in_use);
> -	mutex_unlock(&pcie->msi_used_lock);
> +	return -EINVAL;
>  }
>  
> -static int advk_pcie_setup_msi_irq(struct msi_controller *chip,
> -				   struct pci_dev *pdev,
> -				   struct msi_desc *desc)
> +static int advk_msi_irq_domain_alloc(struct irq_domain *domain,
> +				     unsigned int virq,
> +				     unsigned int nr_irqs, void *args)
>  {
> -	struct advk_pcie *pcie = pdev->bus->sysdata;
> -	struct msi_msg msg;
> -	int virq, hwirq;
> -	phys_addr_t msi_msg_phys;
> -
> -	/* We support MSI, but not MSI-X */
> -	if (desc->msi_attrib.is_msix)
> -		return -EINVAL;
> -
> -	hwirq = advk_pcie_alloc_msi(pcie);
> -	if (hwirq < 0)
> -		return hwirq;
> +	struct advk_pcie *pcie = domain->host_data;
> +	int hwirq, i;
>  
> -	virq = irq_create_mapping(pcie->msi_domain, hwirq);
> -	if (!virq) {
> -		advk_pcie_free_msi(pcie, hwirq);
> -		return -EINVAL;
> +	mutex_lock(&pcie->msi_used_lock);
> +	hwirq = bitmap_find_next_zero_area(pcie->msi_used, MSI_IRQ_NUM,
> +					   0, nr_irqs, 0);
> +	if (hwirq >= MSI_IRQ_NUM) {
> +		mutex_unlock(&pcie->msi_used_lock);
> +		return -ENOSPC;
>  	}
>  
> -	irq_set_msi_desc(virq, desc);
> -
> -	msi_msg_phys = virt_to_phys(&pcie->msi_msg);
> -
> -	msg.address_lo = lower_32_bits(msi_msg_phys);
> -	msg.address_hi = upper_32_bits(msi_msg_phys);
> -	msg.data = virq;
> -
> -	pci_write_msi_msg(virq, &msg);
> -
> -	return 0;
> -}
> +	bitmap_set(pcie->msi_used, hwirq, nr_irqs);
> +	mutex_unlock(&pcie->msi_used_lock);
>  
> -static void advk_pcie_teardown_msi_irq(struct msi_controller *chip,
> -				       unsigned int irq)
> -{
> -	struct irq_data *d = irq_get_irq_data(irq);
> -	struct msi_desc *msi = irq_data_get_msi_desc(d);
> -	struct advk_pcie *pcie = msi_desc_to_pci_sysdata(msi);
> -	unsigned long hwirq = d->hwirq;
> +	for (i = 0; i < nr_irqs; i++)
> +		irq_domain_set_info(domain, virq + i, hwirq + i,
> +				    &pcie->msi_bottom_irq_chip,
> +				    domain->host_data, handle_simple_irq,
> +				    NULL, NULL);

Given that you do not support multi-MSI, this function should never be
called with nr_irqs != 1. Which means you could loose that loop.

>  
> -	irq_dispose_mapping(irq);
> -	advk_pcie_free_msi(pcie, hwirq);
> +	return hwirq;
>  }
>  
> -static int advk_pcie_msi_map(struct irq_domain *domain,
> -			     unsigned int virq, irq_hw_number_t hw)
> +static void advk_msi_irq_domain_free(struct irq_domain *domain,
> +				     unsigned int virq, unsigned int nr_irqs)
>  {
> +	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
>  	struct advk_pcie *pcie = domain->host_data;
>  
> -	irq_set_chip_and_handler(virq, &pcie->msi_irq_chip,
> -				 handle_simple_irq);
> -
> -	return 0;
> +	mutex_lock(&pcie->msi_used_lock);
> +	bitmap_clear(pcie->msi_used, d->hwirq, nr_irqs);
> +	mutex_unlock(&pcie->msi_used_lock);
>  }
>  
> -static const struct irq_domain_ops advk_pcie_msi_irq_ops = {
> -	.map = advk_pcie_msi_map,
> +static const struct irq_domain_ops advk_msi_domain_ops = {
> +	.alloc = advk_msi_irq_domain_alloc,
> +	.free = advk_msi_irq_domain_free,
>  };
>  
>  static void advk_pcie_irq_mask(struct irq_data *d)
> @@ -680,30 +652,24 @@ static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie)
>  {
>  	struct device *dev = &pcie->pdev->dev;
>  	struct device_node *node = dev->of_node;
> -	struct irq_chip *msi_irq_chip;
> -	struct msi_controller *msi;
> +	struct irq_chip *bottom_ic, *msi_ic;
> +	struct msi_domain_info *msi_di;
>  	phys_addr_t msi_msg_phys;
> -	int ret;
>  
> -	msi_irq_chip = &pcie->msi_irq_chip;
> +	mutex_init(&pcie->msi_used_lock);
>  
> -	msi_irq_chip->name = devm_kasprintf(dev, GFP_KERNEL, "%s-msi",
> -					    dev_name(dev));
> -	if (!msi_irq_chip->name)
> -		return -ENOMEM;
> +	bottom_ic = &pcie->msi_bottom_irq_chip;
>  
> -	msi_irq_chip->irq_enable = pci_msi_unmask_irq;
> -	msi_irq_chip->irq_disable = pci_msi_mask_irq;
> -	msi_irq_chip->irq_mask = pci_msi_mask_irq;
> -	msi_irq_chip->irq_unmask = pci_msi_unmask_irq;
> +	bottom_ic->name = "MSI";
> +	bottom_ic->irq_compose_msi_msg = advk_msi_irq_compose_msi_msg;
> +	bottom_ic->irq_set_affinity = advk_msi_set_affinity;
>  
> -	msi = &pcie->msi;
> +	msi_ic = &pcie->msi_irq_chip;
> +	msi_ic->name = "advk-MSI";
>  
> -	msi->setup_irq = advk_pcie_setup_msi_irq;
> -	msi->teardown_irq = advk_pcie_teardown_msi_irq;
> -	msi->of_node = node;
> -
> -	mutex_init(&pcie->msi_used_lock);
> +	msi_di = &pcie->msi_domain_info;
> +	msi_di->flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS;
> +	msi_di->chip = msi_ic;
>  
>  	msi_msg_phys = virt_to_phys(&pcie->msi_msg);
>  
> @@ -712,16 +678,18 @@ static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie)
>  	advk_writel(pcie, upper_32_bits(msi_msg_phys),
>  		    PCIE_MSI_ADDR_HIGH_REG);
>  
> -	pcie->msi_domain =
> +	pcie->msi_inner_domain =
>  		irq_domain_add_linear(NULL, MSI_IRQ_NUM,
> -				      &advk_pcie_msi_irq_ops, pcie);
> -	if (!pcie->msi_domain)
> +				      &advk_msi_domain_ops, pcie);
> +	if (!pcie->msi_inner_domain)
>  		return -ENOMEM;
>  
> -	ret = of_pci_msi_chip_add(msi);
> -	if (ret < 0) {
> -		irq_domain_remove(pcie->msi_domain);
> -		return ret;
> +	pcie->msi_domain =
> +		pci_msi_create_irq_domain(of_node_to_fwnode(node),
> +					  msi_di, pcie->msi_inner_domain);
> +	if (!pcie->msi_domain) {
> +		irq_domain_remove(pcie->msi_inner_domain);
> +		return -ENOMEM;
>  	}
>  
>  	return 0;
> @@ -729,8 +697,8 @@ static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie)
>  
>  static void advk_pcie_remove_msi_irq_domain(struct advk_pcie *pcie)
>  {
> -	of_pci_msi_chip_remove(&pcie->msi);
>  	irq_domain_remove(pcie->msi_domain);
> +	irq_domain_remove(pcie->msi_inner_domain);
>  }
>  
>  static int advk_pcie_init_irq_domain(struct advk_pcie *pcie)
> @@ -917,8 +885,6 @@ static int advk_pcie_probe(struct platform_device *pdev)
>  	struct advk_pcie *pcie;
>  	struct resource *res;
>  	struct pci_bus *bus, *child;
> -	struct msi_controller *msi;
> -	struct device_node *msi_node;
>  	int ret, irq;
>  
>  	pcie = devm_kzalloc(dev, sizeof(struct advk_pcie), GFP_KERNEL);
> @@ -962,14 +928,8 @@ static int advk_pcie_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> -	msi_node = of_parse_phandle(dev->of_node, "msi-parent", 0);
> -	if (msi_node)
> -		msi = of_pci_find_msi_chip_by_node(msi_node);
> -	else
> -		msi = NULL;
> -
> -	bus = pci_scan_root_bus_msi(dev, 0, &advk_pcie_ops,
> -				    pcie, &pcie->resources, &pcie->msi);
> +	bus = pci_scan_root_bus(dev, 0, &advk_pcie_ops,
> +				pcie, &pcie->resources);
>  	if (!bus) {
>  		advk_pcie_remove_msi_irq_domain(pcie);
>  		advk_pcie_remove_irq_domain(pcie);
> 

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...



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