1 files changed, 51 insertions, 304 deletions

diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
index f37ad34c80ec..0e60dd650b5e 100644
--- a/drivers/base/platform-msi.c
+++ b/drivers/base/platform-msi.c
@@ -4,349 +4,96 @@
  *
  * Copyright (C) 2015 ARM Limited, All Rights Reserved.
  * Author: Marc Zyngier <marc.zyngier@arm.com>
+ * Copyright (C) 2022 Linutronix GmbH
  */
 
 #include <linux/device.h>
-#include <linux/idr.h>
-#include <linux/irq.h>
 #include <linux/irqdomain.h>
 #include <linux/msi.h>
-#include <linux/slab.h>
 
-#define DEV_ID_SHIFT	21
-#define MAX_DEV_MSIS	(1 << (32 - DEV_ID_SHIFT))
-
-/*
- * Internal data structure containing a (made up, but unique) devid
- * and the callback to write the MSI message.
- */
-struct platform_msi_priv_data {
-	struct device			*dev;
-	void				*host_data;
-	msi_alloc_info_t		arg;
-	irq_write_msi_msg_t		write_msg;
-	int				devid;
-};
-
-/* The devid allocator */
-static DEFINE_IDA(platform_msi_devid_ida);
-
-#ifdef GENERIC_MSI_DOMAIN_OPS
 /*
- * Convert an msi_desc to a globaly unique identifier (per-device
- * devid + msi_desc position in the msi_list).
+ * This indirection can go when platform_device_msi_init_and_alloc_irqs()
+ * is switched to a proper irq_chip::irq_write_msi_msg() callback. Keep it
+ * simple for now.
  */
-static irq_hw_number_t platform_msi_calc_hwirq(struct msi_desc *desc)
+static void platform_msi_write_msi_msg(struct irq_data *d, struct msi_msg *msg)
 {
-	u32 devid = desc->dev->msi.data->platform_data->devid;
+	irq_write_msi_msg_t cb = d->chip_data;
 
-	return (devid << (32 - DEV_ID_SHIFT)) | desc->msi_index;
+	cb(irq_data_get_msi_desc(d), msg);
 }
 
 static void platform_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
 {
 	arg->desc = desc;
-	arg->hwirq = platform_msi_calc_hwirq(desc);
-}
-
-static int platform_msi_init(struct irq_domain *domain,
-			     struct msi_domain_info *info,
-			     unsigned int virq, irq_hw_number_t hwirq,
-			     msi_alloc_info_t *arg)
-{
-	return irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
-					     info->chip, info->chip_data);
-}
-
-static void platform_msi_set_proxy_dev(msi_alloc_info_t *arg)
-{
-	arg->flags |= MSI_ALLOC_FLAGS_PROXY_DEVICE;
+	arg->hwirq = desc->msi_index;
 }
-#else
-#define platform_msi_set_desc		NULL
-#define platform_msi_init		NULL
-#define platform_msi_set_proxy_dev(x)	do {} while(0)
-#endif
 
-static void platform_msi_update_dom_ops(struct msi_domain_info *info)
-{
-	struct msi_domain_ops *ops = info->ops;
-
-	BUG_ON(!ops);
-
-	if (ops->msi_init == NULL)
-		ops->msi_init = platform_msi_init;
-	if (ops->set_desc == NULL)
-		ops->set_desc = platform_msi_set_desc;
-}
-
-static void platform_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
-{
-	struct msi_desc *desc = irq_data_get_msi_desc(data);
+static const struct msi_domain_template platform_msi_template = {
+	.chip = {
+		.name			= "pMSI",
+		.irq_mask		= irq_chip_mask_parent,
+		.irq_unmask		= irq_chip_unmask_parent,
+		.irq_write_msi_msg	= platform_msi_write_msi_msg,
+		/* The rest is filled in by the platform MSI parent */
+	},
 
-	desc->dev->msi.data->platform_data->write_msg(desc, msg);
-}
-
-static void platform_msi_update_chip_ops(struct msi_domain_info *info)
-{
-	struct irq_chip *chip = info->chip;
+	.ops = {
+		.set_desc		= platform_msi_set_desc,
+	},
 
-	BUG_ON(!chip);
-	if (!chip->irq_mask)
-		chip->irq_mask = irq_chip_mask_parent;
-	if (!chip->irq_unmask)
-		chip->irq_unmask = irq_chip_unmask_parent;
-	if (!chip->irq_eoi)
-		chip->irq_eoi = irq_chip_eoi_parent;
-	if (!chip->irq_set_affinity)
-		chip->irq_set_affinity = msi_domain_set_affinity;
-	if (!chip->irq_write_msi_msg)
-		chip->irq_write_msi_msg = platform_msi_write_msg;
-	if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE) &&
-		    !(chip->flags & IRQCHIP_SUPPORTS_LEVEL_MSI)))
-		info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
-}
-
-/**
- * platform_msi_create_irq_domain - Create a platform MSI interrupt domain
- * @fwnode:		Optional fwnode of the interrupt controller
- * @info:	MSI domain info
- * @parent:	Parent irq domain
- *
- * Updates the domain and chip ops and creates a platform MSI
- * interrupt domain.
- *
- * Returns:
- * A domain pointer or NULL in case of failure.
- */
-struct irq_domain *platform_msi_create_irq_domain(struct fwnode_handle *fwnode,
-						  struct msi_domain_info *info,
-						  struct irq_domain *parent)
-{
-	struct irq_domain *domain;
-
-	if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
-		platform_msi_update_dom_ops(info);
-	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
-		platform_msi_update_chip_ops(info);
-	info->flags |= MSI_FLAG_DEV_SYSFS | MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS |
-		       MSI_FLAG_FREE_MSI_DESCS;
-
-	domain = msi_create_irq_domain(fwnode, info, parent);
-	if (domain)
-		irq_domain_update_bus_token(domain, DOMAIN_BUS_PLATFORM_MSI);
-
-	return domain;
-}
-EXPORT_SYMBOL_GPL(platform_msi_create_irq_domain);
-
-static int platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec,
-					irq_write_msi_msg_t write_msi_msg)
-{
-	struct platform_msi_priv_data *datap;
-	int err;
-
-	/*
-	 * Limit the number of interrupts to 2048 per device. Should we
-	 * need to bump this up, DEV_ID_SHIFT should be adjusted
-	 * accordingly (which would impact the max number of MSI
-	 * capable devices).
-	 */
-	if (!dev->msi.domain || !write_msi_msg || !nvec || nvec > MAX_DEV_MSIS)
-		return -EINVAL;
-
-	if (dev->msi.domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) {
-		dev_err(dev, "Incompatible msi_domain, giving up\n");
-		return -EINVAL;
-	}
-
-	err = msi_setup_device_data(dev);
-	if (err)
-		return err;
-
-	/* Already initialized? */
-	if (dev->msi.data->platform_data)
-		return -EBUSY;
-
-	datap = kzalloc(sizeof(*datap), GFP_KERNEL);
-	if (!datap)
-		return -ENOMEM;
-
-	datap->devid = ida_simple_get(&platform_msi_devid_ida,
-				      0, 1 << DEV_ID_SHIFT, GFP_KERNEL);
-	if (datap->devid < 0) {
-		err = datap->devid;
-		kfree(datap);
-		return err;
-	}
-
-	datap->write_msg = write_msi_msg;
-	datap->dev = dev;
-	dev->msi.data->platform_data = datap;
-	return 0;
-}
-
-static void platform_msi_free_priv_data(struct device *dev)
-{
-	struct platform_msi_priv_data *data = dev->msi.data->platform_data;
-
-	dev->msi.data->platform_data = NULL;
-	ida_simple_remove(&platform_msi_devid_ida, data->devid);
-	kfree(data);
-}
+	.info = {
+		.bus_token		= DOMAIN_BUS_DEVICE_MSI,
+	},
+};
 
 /**
- * platform_msi_domain_alloc_irqs - Allocate MSI interrupts for @dev
+ * platform_device_msi_init_and_alloc_irqs - Initialize platform device MSI
+ *					     and allocate interrupts for @dev
  * @dev:		The device for which to allocate interrupts
  * @nvec:		The number of interrupts to allocate
  * @write_msi_msg:	Callback to write an interrupt message for @dev
  *
  * Returns:
  * Zero for success, or an error code in case of failure
- */
-int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec,
-				   irq_write_msi_msg_t write_msi_msg)
-{
-	int err;
-
-	err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
-	if (err)
-		return err;
-
-	err = msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, nvec - 1);
-	if (err)
-		platform_msi_free_priv_data(dev);
-
-	return err;
-}
-EXPORT_SYMBOL_GPL(platform_msi_domain_alloc_irqs);
-
-/**
- * platform_msi_domain_free_irqs - Free MSI interrupts for @dev
- * @dev:	The device for which to free interrupts
- */
-void platform_msi_domain_free_irqs(struct device *dev)
-{
-	msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN);
-	platform_msi_free_priv_data(dev);
-}
-EXPORT_SYMBOL_GPL(platform_msi_domain_free_irqs);
-
-/**
- * platform_msi_get_host_data - Query the private data associated with
- *                              a platform-msi domain
- * @domain:	The platform-msi domain
- *
- * Return: The private data provided when calling
- * platform_msi_create_device_domain().
- */
-void *platform_msi_get_host_data(struct irq_domain *domain)
-{
-	struct platform_msi_priv_data *data = domain->host_data;
-
-	return data->host_data;
-}
-
-static struct lock_class_key platform_device_msi_lock_class;
-
-/**
- * __platform_msi_create_device_domain - Create a platform-msi device domain
- *
- * @dev:		The device generating the MSIs
- * @nvec:		The number of MSIs that need to be allocated
- * @is_tree:		flag to indicate tree hierarchy
- * @write_msi_msg:	Callback to write an interrupt message for @dev
- * @ops:		The hierarchy domain operations to use
- * @host_data:		Private data associated to this domain
  *
- * Return: An irqdomain for @nvec interrupts on success, NULL in case of error.
+ * This creates a MSI domain on @dev which has @dev->msi.domain as
+ * parent. The parent domain sets up the new domain. The domain has
+ * a fixed size of @nvec. The domain is managed by devres and will
+ * be removed when the device is removed.
  *
- * This is for interrupt domains which stack on a platform-msi domain
- * created by platform_msi_create_irq_domain(). @dev->msi.domain points to
- * that platform-msi domain which is the parent for the new domain.
+ * Note: For migration purposes this falls back to the original platform_msi code
+ *	 up to the point where all platforms have been converted to the MSI
+ *	 parent model.
  */
-struct irq_domain *
-__platform_msi_create_device_domain(struct device *dev,
-				    unsigned int nvec,
-				    bool is_tree,
-				    irq_write_msi_msg_t write_msi_msg,
-				    const struct irq_domain_ops *ops,
-				    void *host_data)
+int platform_device_msi_init_and_alloc_irqs(struct device *dev, unsigned int nvec,
+					    irq_write_msi_msg_t write_msi_msg)
 {
-	struct platform_msi_priv_data *data;
-	struct irq_domain *domain;
-	int err;
+	struct irq_domain *domain = dev->msi.domain;
 
-	err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
-	if (err)
-		return NULL;
+	if (!domain || !write_msi_msg)
+		return -EINVAL;
 
 	/*
-	 * Use a separate lock class for the MSI descriptor mutex on
-	 * platform MSI device domains because the descriptor mutex nests
-	 * into the domain mutex. See alloc/free below.
+	 * @write_msi_msg is stored in the resulting msi_domain_info::data.
+	 * The underlying domain creation mechanism will assign that
+	 * callback to the resulting irq chip.
 	 */
-	lockdep_set_class(&dev->msi.data->mutex, &platform_device_msi_lock_class);
-
-	data = dev->msi.data->platform_data;
-	data->host_data = host_data;
-	domain = irq_domain_create_hierarchy(dev->msi.domain, 0,
-					     is_tree ? 0 : nvec,
-					     dev->fwnode, ops, data);
-	if (!domain)
-		goto free_priv;
+	if (!msi_create_device_irq_domain(dev, MSI_DEFAULT_DOMAIN,
+					  &platform_msi_template,
+					  nvec, NULL, write_msi_msg))
+		return -ENODEV;
 
-	platform_msi_set_proxy_dev(&data->arg);
-	err = msi_domain_prepare_irqs(domain->parent, dev, nvec, &data->arg);
-	if (err)
-		goto free_domain;
-
-	return domain;
-
-free_domain:
-	irq_domain_remove(domain);
-free_priv:
-	platform_msi_free_priv_data(dev);
-	return NULL;
+	return msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, nvec - 1);
 }
+EXPORT_SYMBOL_GPL(platform_device_msi_init_and_alloc_irqs);
 
 /**
- * platform_msi_device_domain_free - Free interrupts associated with a platform-msi
- *				     device domain
- *
- * @domain:	The platform-msi device domain
- * @virq:	The base irq from which to perform the free operation
- * @nr_irqs:	How many interrupts to free from @virq
- */
-void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int virq,
-				     unsigned int nr_irqs)
-{
-	struct platform_msi_priv_data *data = domain->host_data;
-
-	msi_lock_descs(data->dev);
-	msi_domain_depopulate_descs(data->dev, virq, nr_irqs);
-	irq_domain_free_irqs_common(domain, virq, nr_irqs);
-	msi_free_msi_descs_range(data->dev, virq, virq + nr_irqs - 1);
-	msi_unlock_descs(data->dev);
-}
-
-/**
- * platform_msi_device_domain_alloc - Allocate interrupts associated with
- *				      a platform-msi device domain
- *
- * @domain:	The platform-msi device domain
- * @virq:	The base irq from which to perform the allocate operation
- * @nr_irqs:	How many interrupts to allocate from @virq
- *
- * Return 0 on success, or an error code on failure. Must be called
- * with irq_domain_mutex held (which can only be done as part of a
- * top-level interrupt allocation).
+ * platform_device_msi_free_irqs_all - Free all interrupts for @dev
+ * @dev:	The device for which to free interrupts
  */
-int platform_msi_device_domain_alloc(struct irq_domain *domain, unsigned int virq,
-				     unsigned int nr_irqs)
+void platform_device_msi_free_irqs_all(struct device *dev)
 {
-	struct platform_msi_priv_data *data = domain->host_data;
-	struct device *dev = data->dev;
-
-	return msi_domain_populate_irqs(domain->parent, dev, virq, nr_irqs, &data->arg);
+	msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN);
 }
+EXPORT_SYMBOL_GPL(platform_device_msi_free_irqs_all);