On 31/07/15 11:15, Ley Foon Tan wrote:

This patch adds Altera PCIe MSI driver. This soft IP supports configurable
number of vectors, which is a dts parameter.

I've reviewed the initial drop of this code; basic courtesy would be to
keep me CCed on the follow-up series.

Use of irq is a bit confusing, as this is a parameter describing the
chaining interrupt. Consider using a different name for this variable.

+			if (irq) {
+				if (test_bit(bit, msi->used))
+					generic_handle_irq(irq);
+				else
+					dev_info(&msi->pdev->dev, "unhandled MSI\n");
+			} else
+				dev_info(&msi->pdev->dev, "unexpected MSI\n");

The whole statement could be rewritten as:

if (irq && test_bit(bit, msi->used))
	generic_handle_irq(irq);
else
	dev_err(...);

In all cases, this is a grave error, so dev_info is not appropriate here.

+
+			/* Clear the bit from status and repeat without reading
+			 * again status register. */
+			clear_bit(bit, &status);

You don't need an atomic operation here, so __clear_bit() should be enough.

+		} while (status);
+	} while (1);
+
+	chained_irq_exit(chip, desc);
+}
+
+static struct irq_chip altera_msi_irq_chip = {
+	.name = "Altera PCIe MSI",
+	.irq_enable = pci_msi_unmask_irq,
+	.irq_disable = pci_msi_mask_irq,
+	.irq_mask = pci_msi_mask_irq,
+	.irq_unmask = pci_msi_unmask_irq,
+};
+
+static struct msi_domain_info altera_msi_domain_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+		     MSI_FLAG_PCI_MSIX),
+	.chip	= &altera_msi_irq_chip,
+};
+
+static void altera_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	u32 mask;
+	struct altera_msi *msi = irq_data_get_irq_chip_data(data);
+	u64 addr = msi->vector_phy + (data->hwirq * sizeof(u32));

Use phys_addr_t.

+
+	msg->address_lo = lower_32_bits(addr);
+	msg->address_hi = upper_32_bits(addr);
+	msg->data = data->hwirq;
+
+	mask = msi_readl(msi, MSI_INTMASK);
+	mask |= 1 << data->hwirq;
+	msi_writel(msi, mask, MSI_INTMASK);

It feels a bit weird to unmask the interrupt when you compose the
message. I'd expect this to be done in the mask/unmask methods.

+	dev_dbg(&msi->pdev->dev, "msi#%d address_lo 0x%x\n", (int)data->hwirq,
+		msg->address_lo);

You may want to print the whole address here.

+}
+
+static int altera_msi_set_affinity(struct irq_data *irq_data,
+				 const struct cpumask *mask, bool force)
+{
+	 return -EINVAL;
+}
+
+static struct irq_chip altera_msi_bottom_irq_chip = {
+	.name			= "Altera MSI",
+	.irq_compose_msi_msg	= altera_compose_msi_msg,
+	.irq_set_affinity	= altera_msi_set_affinity,
+};
+
+static int altera_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				  unsigned int nr_irqs, void *args)
+{
+	struct altera_msi *msi = domain->host_data;
+	int bit;
+
+	mutex_lock(&msi->lock);
+
+	bit = find_first_zero_bit(msi->used, msi->num_of_vectors);
+	if (bit < msi->num_of_vectors)
+		set_bit(bit, msi->used);
+
+	mutex_unlock(&msi->lock);
+
+	if (bit < 0)
+		return bit;

How can "bit" be negative here? find_first_zero_bit returns an unsigned
long... You probably want to change the type of "bit" to reflect that.

+	else if (bit >= msi->num_of_vectors)

Useless "else" anyway.

+		return -ENOSPC;
+
+	irq_domain_set_info(domain, virq, bit, &altera_msi_bottom_irq_chip,
+			    domain->host_data, handle_simple_irq,
+			    NULL, NULL);
+	set_irq_flags(virq, IRQF_VALID);
+
+	return 0;
+}
+
+static void altera_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 altera_msi *msi = irq_data_get_irq_chip_data(d);
+	u32 mask;
+
+	mutex_lock(&msi->lock);
+
+	if (!test_bit(d->hwirq, msi->used))
+		dev_err(&msi->pdev->dev, "trying to free unused MSI#%lu\n",
+		d->hwirq);

Put this statement in { } so that it matches the "else" construct.

+	else {
+		clear_bit(d->hwirq, msi->used);

No need for an atomic operation here, you own the mutex.

+		mask = msi_readl(msi, MSI_INTMASK);
+		mask &= ~(1 << d->hwirq);
+		msi_writel(msi, mask, MSI_INTMASK);
+	}
+
+	mutex_unlock(&msi->lock);
+}
+
+static const struct irq_domain_ops msi_domain_ops = {
+	.alloc	= altera_irq_domain_alloc,
+	.free	= altera_irq_domain_free,
+};
+
+static int altera_allocate_domains(struct altera_msi *msi)
+{
+	msi->inner_domain = irq_domain_add_linear(NULL, msi->num_of_vectors,
+					     &msi_domain_ops, msi);
+	if (!msi->inner_domain) {
+		dev_err(&msi->pdev->dev, "failed to create IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	msi->msi_domain = pci_msi_create_irq_domain(
+				msi->pdev->dev.of_node,

Please put at least one argument to the function on the same line. This
is otherwise very hard to read.

+				&altera_msi_domain_info, msi->inner_domain);
+	if (!msi->msi_domain) {
+		dev_err(&msi->pdev->dev, "failed to create MSI domain\n");
+		irq_domain_remove(msi->inner_domain);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void altera_free_domains(struct altera_msi *msi)
+{
+	irq_domain_remove(msi->msi_domain);
+	irq_domain_remove(msi->inner_domain);
+}
+
+
+static int altera_msi_remove(struct platform_device *pdev)
+{
+	struct altera_msi *msi = platform_get_drvdata(pdev);
+
+	msi_writel(msi, 0, MSI_INTMASK);
+	irq_set_chained_handler(msi->irq, NULL);
+	irq_set_handler_data(msi->irq, NULL);
+
+	altera_free_domains(msi);
+
+	platform_set_drvdata(pdev, NULL);
+	return 0;
+}
+
+int altera_msi_probe(struct platform_device *pdev)

Make this static.

+{
+	struct altera_msi *msi;
+	struct device_node *np = pdev->dev.of_node;
+	struct resource *res;
+	int ret;
+
+	msi = devm_kzalloc(&pdev->dev, sizeof(struct altera_msi),
+		GFP_KERNEL);
+	if (!msi)
+		return -ENOMEM;
+
+	mutex_init(&msi->lock);
+	msi->pdev = pdev;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr");
+	msi->csr_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(msi->csr_base)) {
+		dev_err(&pdev->dev, "get csr resource failed\n");
+		return PTR_ERR(msi->csr_base);
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+			"vector_slave");
+	msi->vector_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(msi->vector_base)) {
+		dev_err(&pdev->dev, "get vector slave resource failed\n");
+		return PTR_ERR(msi->vector_base);
+	}
+
+	msi->vector_phy = res->start;
+
+	if (of_property_read_u32(np, "num-vectors", &msi->num_of_vectors)) {
+		dev_err(&pdev->dev, "failed to parse the number of vectors\n");
+		return -EINVAL;
+	}
+
+	ret = altera_allocate_domains(msi);
+	if (ret)
+		return ret;
+
+	msi->irq = platform_get_irq(pdev, 0);
+	if (msi->irq <= 0) {
+		dev_err(&pdev->dev, "failed to map IRQ: %d\n", msi->irq);
+		ret = -ENODEV;
+		goto err;
+	}
+
+	irq_set_chained_handler(msi->irq, altera_msi_isr);
+	ret = irq_set_handler_data(msi->irq, msi);

Use irq_set_chained_handler_and_data.

+	if (ret) {
+		dev_err(&pdev->dev, "failed to register IRQ handler: %d\n",
+			ret);
+		goto err;
+	}
+
+	platform_set_drvdata(pdev, msi);
+
+	return 0;
+
+err:
+	altera_msi_remove(pdev);
+	return ret;
+}
+
+static const struct of_device_id altera_msi_of_match[] = {
+	{ .compatible = "altr,msi-1.0", NULL },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, altera_msi_of_match);
+
+static struct platform_driver altera_msi_driver = {
+	.driver = {
+		.name = "altera-msi",
+		.owner = THIS_MODULE,

Remove this .owner assignment, the core code deals with it.

+		.of_match_table = altera_msi_of_match,
+	},
+	.probe = altera_msi_probe,
+	.remove = altera_msi_remove,
+};
+
+static int __init altera_msi_init(void)
+{
+	return platform_driver_register(&altera_msi_driver);
+}
+
+subsys_initcall(altera_msi_init);

Hmmm. if you're initializing this as part of the core kernel, it will
never be a module. What is the point of the MODULE_DEVICE_TABLE above?

+
+MODULE_AUTHOR("Ley Foon Tan [off-list ref]");
+MODULE_DESCRIPTION("Altera PCIe MSI support");
+MODULE_LICENSE("GPL v2");

Thanks,

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