Re: [PATCH v2] MSI driver for Freescale 83xx/85xx/86xx cpu

can we do something like:
fsl_pci-$(CONFIG_MSI)           += fsl_msi.o
obj-$(CONFIG_FSL_PCI)           += fsl_pci.o $(fsl_pci-y)

obj-$(CONFIG_PPC_MPC106)	+= grackle.o
obj-$(CONFIG_PPC_DCR_NATIVE)	+= dcr-low.o

+static int fsl_msi_init_allocator(struct fsl_msi *msi_data)
+{
+	int rc, size;
+
+	size = BITS_TO_LONGS(NR_MSI_IRQS) * sizeof(long);

should this be long or u32?

+
+	msi_data->fsl_msi_bitmap = kzalloc(size, GFP_KERNEL);
+
+	if (msi_data->fsl_msi_bitmap == NULL) {
+		pr_debug("%s: ENOMEM allocating allocator bitmap!\n",
+				__func__);
+		return -ENOMEM;
+	}
+
+	rc = fsl_msi_free_dt_hwirqs(msi_data);
+	if (rc)
+		goto out_free;
+
+	return 0;
+out_free:
+	kfree(msi_data->fsl_msi_bitmap);
+
+	msi_data->fsl_msi_bitmap = NULL;
+	return rc;
+
+}
+
+static int fsl_msi_check_device(struct pci_dev *pdev, int nvec, int  
type)
+{
+	if (type == PCI_CAP_ID_MSIX)
+		pr_debug("fslmsi: MSI-X untested, trying anyway.\n");
+
+	return 0;
+}
+
+static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
+{
+	struct msi_desc *entry;
+	struct fsl_msi *msi_data = fsl_msi;
+
+	list_for_each_entry(entry, &pdev->msi_list, list) {
+		if (entry->irq == NO_IRQ)
+			continue;
+		set_irq_msi(entry->irq, NULL);
+		fsl_msi_free_hwirqs(msi_data, virq_to_hw(entry->irq), 1);
+		irq_dispose_mapping(entry->irq);
+	}
+
+	return;
+}
+
+static void fsl_compose_msi_msg(struct pci_dev *pdev, int hwirq,
+				  struct msi_msg *msg)
+{
+	struct fsl_msi *msi_data = fsl_msi;
+
+	msg->address_lo = msi_data->msi_addr_lo;
+	msg->address_hi = msi_data->msi_addr_hi;
+	msg->data = hwirq;
+
+	pr_debug("%s: allocated srs: %d, ibs: %d\n",
+		__func__, hwirq / INT_PER_MSIR, hwirq % INT_PER_MSIR);
+}
+
+static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int  
type)
+{
+	irq_hw_number_t hwirq;
+	int rc;
+	unsigned int virq;
+	struct msi_desc *entry;
+	struct msi_msg msg;
+	struct fsl_msi *msi_data = fsl_msi;
+
+	list_for_each_entry(entry, &pdev->msi_list, list) {
+		hwirq = fsl_msi_alloc_hwirqs(msi_data, 1);
+		if (hwirq < 0) {
+			rc = hwirq;
+			pr_debug("%s: fail allocating msi interrupt\n",
+					__func__);
+			goto out_free;
+		}
+
+		virq = irq_create_mapping(msi_data->irqhost, hwirq);
+
+		if (virq == NO_IRQ) {
+			pr_debug("%s: fail mapping hwirq 0x%lx\n",
+					__func__, hwirq);
+			fsl_msi_free_hwirqs(msi_data, hwirq, 1);
+			rc = -ENOSPC;
+			goto out_free;
+		}
+		set_irq_msi(virq, entry);
+
+		fsl_compose_msi_msg(pdev, hwirq, &msg);
+		write_msi_msg(virq, &msg);
+	}
+	return 0;
+
+out_free:
+	return rc;
+}
+
+void fsl_msi_cascade(unsigned int irq, struct irq_desc *desc)
+{
+	unsigned int cascade_irq;
+	struct fsl_msi *msi_data = fsl_msi;
+	int msir_index = -1;
+	u32 msir_value = 0;
+	u32 intr_index;
+	u32 have_shift = 0;
+
+	spin_lock(&desc->lock);
+	if ((msi_data->feature &  FSL_PIC_IP_MASK) == FSL_PIC_IP_IPIC) {
+		if (desc->chip->mask_ack)
+			desc->chip->mask_ack(irq);
+		else {
+			desc->chip->mask(irq);
+			desc->chip->ack(irq);
+		}
+	}
+
+	if (unlikely(desc->status & IRQ_INPROGRESS))
+		goto unlock;
+
+	msir_index = (int)(desc->handler_data);
+
+	if (msir_index >= NR_MSIR)
+		cascade_irq = NO_IRQ;
+
+	desc->status |= IRQ_INPROGRESS;
+	switch (fsl_msi->feature & FSL_PIC_IP_MASK) {
+	case FSL_PIC_IP_MPIC:
+		msir_value = fsl_msi_read(msi_data->msi_regs,
+			msir_index * 0x10);
+		break;
+	case FSL_PIC_IP_IPIC:
+		msir_value = fsl_msi_read(msi_data->msi_regs, msir_index * 0x4);
+		break;
+	}
+
+	while (msir_value) {
+		intr_index = ffs(msir_value) - 1;
+
+		cascade_irq = irq_linear_revmap(msi_data->irqhost,
+			(msir_index * INT_PER_MSIR + intr_index + have_shift));
+
+		if (cascade_irq != NO_IRQ)
+			generic_handle_irq(cascade_irq);
+		have_shift += (intr_index + 1);
+		msir_value = (msir_value >> (intr_index + 1));
+	}
+	desc->status &= ~IRQ_INPROGRESS;
+
+	switch (msi_data->feature & FSL_PIC_IP_MASK) {
+	case FSL_PIC_IP_MPIC:
+		desc->chip->eoi(irq);
+		break;
+	case FSL_PIC_IP_IPIC:
+		if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
+			desc->chip->unmask(irq);
+		break;
+	}
+unlock:
+	spin_unlock(&desc->lock);
+}
+
+static int __devinit fsl_of_msi_probe(struct of_device *dev,
+				const struct of_device_id *match)
+{
+	struct fsl_msi *msi;
+	struct resource res;
+	int err, i, count;
+	int rc;
+	int virt_msir;
+	const u32 *p;
+	struct fsl_msi_feature *tmp_data;
+
+	printk(KERN_DEBUG "Setting up fsl msi support\n");
+
+	msi = kzalloc(sizeof(struct fsl_msi), GFP_KERNEL);
+	if (!msi) {
+		dev_err(&dev->dev, "No memory for MSI structure\n");
+		err = -ENOMEM;
+		goto error_out;
+	}
+
+	msi->of_node = dev->node;
+
+	msi->irqhost = irq_alloc_host(of_node_get(dev->node),
+				IRQ_HOST_MAP_LINEAR,
+				NR_MSI_IRQS, &fsl_msi_host_ops, 0);
+	if (msi->irqhost == NULL) {
+		dev_err(&dev->dev, "No memory for MSI irqhost\n");
+		of_node_put(dev->node);
+		err = -ENOMEM;
+		goto error_out;
+	}
+
+	/* Get the MSI reg base */
+	err = of_address_to_resource(dev->node, 0, &res);
+	if (err) {
+		dev_err(&dev->dev, "%s resource error!\n",
+				dev->node->full_name);
+		goto error_out;
+	}
+
+	msi->msi_regs = ioremap(res.start, res.end - res.start + 1);
+	if (!msi->msi_regs) {
+		dev_err(&dev->dev, "ioremap problem failed\n");
+		goto error_out;
+	}
+
+	tmp_data = (struct fsl_msi_feature *)match->data;
+
+	msi->feature = tmp_data->fsl_pic_ip;
+
+	msi->irqhost->host_data = msi;
+
+	msi->msi_addr_hi = 0x0;
+	msi->msi_addr_lo = res.start + tmp_data->msiir_offset;
+
+	rc = fsl_msi_init_allocator(msi);
+	if (rc) {
+		dev_err(&dev->dev, "Error allocating MSI bitmap\n");
+		goto error_out;
+	}
+
+	p = of_get_property(dev->node, "interrupts", &count);
+	if (!p) {
+		dev_err(&dev->dev, "no interrupts property found on %s\n",
+				dev->node->full_name);
+		err = -ENODEV;
+		goto error_out;
+	}
+	if (count % 8 != 0) {
+		dev_err(&dev->dev, "Malformed interrupts property on %s\n",
+				dev->node->full_name);
+		err = -EINVAL;
+		goto error_out;
+	}
+
+	count /= sizeof(u32);
+	for (i = 0; i < count / 2; i++) {
+		if (i > NR_MSIR)
+			break;
+		virt_msir = irq_of_parse_and_map(dev->node, i);
+		if (virt_msir != NO_IRQ) {
+			set_irq_data(virt_msir, (void *)i);
+			set_irq_chained_handler(virt_msir, fsl_msi_cascade);
+		}
+	}
+
+	fsl_msi = msi;
+
+	WARN_ON(ppc_md.setup_msi_irqs);
+	ppc_md.setup_msi_irqs = fsl_setup_msi_irqs;
+	ppc_md.teardown_msi_irqs = fsl_teardown_msi_irqs;
+	ppc_md.msi_check_device = fsl_msi_check_device;
+	return 0;
+error_out:
+	kfree(msi);
+	return err;
+}
+
+static const struct fsl_msi_feature mpic_msi_feature =  
{FSL_PIC_IP_MPIC, 0x140};
+static const struct fsl_msi_feature ipic_msi_feature =  
{FSL_PIC_IP_IPIC, 0x38};

make this
{
	.fsl_pic_ip = FSL_PIC_IP_MPIC
	.offset = 0x140
};

for readability.

NR_MSR_REG

+#define INT_PER_MSIR	32

IRQS_PER_MSI_REG

+#define NR_MSI_IRQS	(NR_MSIR * INT_PER_MSIR)
+
+#define FSL_PIC_IP_MASK	0x0000000F
+#define FSL_PIC_IP_MPIC	0x00000001
+#define FSL_PIC_IP_IPIC	0x00000002
+
+struct fsl_msi {
+	/* Device node of the MSI interrupt*/
+	struct device_node *of_node;
+
+	struct irq_host *irqhost;
+
+	unsigned long cascade_irq;
+
+	u32 msi_addr_lo;
+	u32 msi_addr_hi;
+	void __iomem *msi_regs;
+	u32 feature;
+
+	unsigned long *fsl_msi_bitmap;
+	spinlock_t bitmap_lock;
+	const char *name;
+};
+
+struct fsl_msi_feature {
+	u32 fsl_pic_ip;
+	u32 msiir_offset;
+};

move this struct into .c

I'm not convinced this is safe.  we need to be careful to make sure  
the pcsrbar doesn't overlap with any other device.

	return 0;
}

- k