Message-ID: <554B7BF7.8030901@freescale.com>
Date: Thu, 7 May 2015 09:51:35 -0500
From: German Rivera <German.Rivera@freescale.com>
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To: Dan Carpenter <dan.carpenter@oracle.com>
CC: <gregkh@linuxfoundation.org>, <arnd@arndb.de>,
        <devel@driverdev.osuosl.org>, <linux-kernel@vger.kernel.org>,
        <stuart.yoder@freescale.com>, <bhupesh.sharma@freescale.com>,
        <agraf@suse.de>, <bhamciu1@freescale.com>, <nir.erez@freescale.com>,
        <itai.katz@freescale.com>, <scottwood@freescale.com>,
        <R89243@freescale.com>, <richard.schmitt@freescale.com>
Subject: Re: [PATCH v2 1/7] staging: fsl-mc: MC bus IRQ support
References: <1430947708-10521-1-git-send-email-German.Rivera@freescale.com> <1430947708-10521-2-git-send-email-German.Rivera@freescale.com> <20150507130330.GI14154@mwanda>
In-Reply-To: <20150507130330.GI14154@mwanda>
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On 05/07/2015 08:03 AM, Dan Carpenter wrote:
> On Wed, May 06, 2015 at 04:28:22PM -0500, J. German Rivera wrote:
>> +/*
>> + * FIXME: Enable this code when the GIC-ITS MC support patch is merged
>> + */
>> +#ifdef GIC_ITS_MC_SUPPORT
>> +static int mc_bus_msi_prepare(struct irq_domain *domain, struct device *dev,
>> +			      int nvec, msi_alloc_info_t *info)
>> +{
>> +	int error;
>> +	u32 its_dev_id;
>> +	struct dprc_attributes dprc_attr;
>> +	struct fsl_mc_device *mc_bus_dev = to_fsl_mc_device(dev);
>> +
>> +	if (WARN_ON(!(mc_bus_dev->flags & FSL_MC_IS_DPRC)))
>> +		return -EINVAL;
>> +
>> +	error = dprc_get_attributes(mc_bus_dev->mc_io,
>> +				    mc_bus_dev->mc_handle, &dprc_attr);
>> +	if (error < 0) {
>> +		dev_err(&mc_bus_dev->dev,
>> +			"dprc_get_attributes() failed: %d\n",
>> +			error);
>> +		return error;
>> +	}
>> +
>> +	/*
>> +	 * Build the device Id to be passed to the GIC-ITS:
>> +	 *
>> +	 * NOTE: This device id corresponds to the IOMMU stream ID
>> +	 * associated with the DPRC object.
>> +	 */
>> +	its_dev_id = mc_bus_dev->icid;
>> +	if (its_dev_id > STREAM_ID_ICID_MASK) {
>> +		dev_err(&mc_bus_dev->dev,
>> +			"Invalid ICID: %#x\n", its_dev_id);
>> +		return -ERANGE;
>> +	}
>> +
>> +	if (dprc_attr.options & DPRC_CFG_OPT_IOMMU_BYPASS)
>> +		its_dev_id |= STREAM_ID_PL_MASK | STREAM_ID_BMT_MASK;
>> +
>> +	return __its_msi_prepare(domain->parent, its_dev_id, dev, nvec, info);
>> +}
>> +
>> +static void mc_bus_mask_msi_irq(struct irq_data *d)
>> +{
>> +	/* Bus specefic Mask */
>> +	irq_chip_mask_parent(d);
>> +}
>> +
>> +static void mc_bus_unmask_msi_irq(struct irq_data *d)
>> +{
>> +	/* Bus specefic unmask */
>> +	irq_chip_unmask_parent(d);
>> +}
>> +
>> +static void mc_bus_msi_domain_write_msg(struct irq_data *irq_data,
>> +					struct msi_msg *msg)
>> +{
>> +	struct msi_desc *msi_entry = irq_data->msi_desc;
>> +	struct fsl_mc_device *mc_bus_dev = to_fsl_mc_device(msi_entry->dev);
>> +	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
>> +	struct fsl_mc_device_irq *irq_res =
>> +		&mc_bus->irq_resources[msi_entry->msi_attrib.entry_nr];
>> +
>> +	if (irq_res->irq_number == irq_data->irq) {
>> +		/*
>> +		 * write msg->address_hi/lo to irq_resource
>> +		 */
>> +		irq_res->msi_paddr =
>> +			((u64)msg->address_hi << 32) | msg->address_lo;
>> +		irq_res->msi_value = msg->data;
>> +	}
>> +}
>> +
>> +static struct irq_chip mc_bus_msi_irq_chip = {
>> +	.name			= "fsl-mc-bus-msi",
>> +	.irq_unmask		= mc_bus_unmask_msi_irq,
>> +	.irq_mask		= mc_bus_mask_msi_irq,
>> +	.irq_eoi		= irq_chip_eoi_parent,
>> +	.irq_write_msi_msg	= mc_bus_msi_domain_write_msg,
>> +};
>> +
>> +static struct msi_domain_ops mc_bus_msi_ops = {
>> +	.msi_prepare	= mc_bus_msi_prepare,
>> +};
>> +
>> +static struct msi_domain_info mc_bus_msi_domain_info = {
>> +	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
>> +		   MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX),
>> +	.ops	= &mc_bus_msi_ops,
>> +	.chip	= &mc_bus_msi_irq_chip,
>> +};
>> +
>> +static int create_mc_irq_domain(struct platform_device *mc_pdev,
>> +				struct irq_domain **new_irq_domain)
>> +{
>> +	int error;
>> +	struct device_node *its_of_node;
>> +	struct irq_domain *its_domain;
>> +	struct irq_domain *irq_domain;
>> +	struct device_node *mc_of_node = mc_pdev->dev.of_node;
>> +
>> +	its_of_node = of_parse_phandle(mc_of_node, "lpi-parent", 0);
>> +	if (!its_of_node) {
>> +		dev_err(&mc_pdev->dev,
>> +			"lpi-parent phandle missing for %s\n",
>> +			mc_of_node->full_name);
>> +		return -ENOENT;
>> +	}
>> +
>> +	/*
>> +	 * Extract MSI parent node:
>> +	 */
>> +	its_domain = irq_find_host(its_of_node);
>> +	if (!its_domain) {
>> +		dev_err(&mc_pdev->dev, "Unable to find parent domain\n");
>> +		error = -ENOENT;
>> +		goto cleanup_its_of_node;
>> +	}
>> +
>> +	/*
>> +	 * FIXME: Enable this code when the GIC-ITS MC support patch is merged
>> +	 */
>> +#ifdef GIC_ITS_MC_SUPPORT
>
> This #ifdef GIC_ITS_MC_SUPPORT is nested inside another #ifdef
> GIC_ITS_MC_SUPPORT.  Can you just delete all the ifdef code?  It really
> makes reviewing this complicated.
>
I'll remove the nested #ifdef. However, as I explained before, these 
#ifdefs are needed to be able to make the code compile without the 
GIC-ITS support in place. Of course, the code will not be moved out of 
staging with these #ifdefs. There is already an item for this in the 
drivers/staging/fsl-mc/TODO file.

>> +	irq_domain = msi_create_irq_domain(mc_of_node, &mc_bus_msi_domain_info,
>> +					   its_domain->parent);
>> +	if (!irq_domain) {
>> +		dev_err(&mc_pdev->dev, "Failed to allocate msi_domain\n");
>> +		error = -ENOMEM;
>> +		goto cleanup_its_of_node;
>> +	}
>> +
>> +	dev_dbg(&mc_pdev->dev, "Allocated MSI domain\n");
>> +#else
>> +	irq_domain = NULL;
>> +#endif
>> +	*new_irq_domain = irq_domain;
>> +	return 0;
>> +
>> +cleanup_its_of_node:
>> +	of_node_put(its_of_node);
>> +	return error;
>> +}
>> +#endif /* GIC_ITS_MC_SUPPORT */
>
> regards,
> dan carpenter
>
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