v4.19.13 snapshot.
diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
new file mode 100644
index 0000000..60d6cc6
--- /dev/null
+++ b/drivers/base/platform-msi.c
@@ -0,0 +1,408 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MSI framework for platform devices
+ *
+ * Copyright (C) 2015 ARM Limited, All Rights Reserved.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#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).
+ */
+static irq_hw_number_t platform_msi_calc_hwirq(struct msi_desc *desc)
+{
+ u32 devid;
+
+ devid = desc->platform.msi_priv_data->devid;
+
+ return (devid << (32 - DEV_ID_SHIFT)) | desc->platform.msi_index;
+}
+
+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);
+}
+#else
+#define platform_msi_set_desc NULL
+#define platform_msi_init NULL
+#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);
+ struct platform_msi_priv_data *priv_data;
+
+ priv_data = desc->platform.msi_priv_data;
+
+ priv_data->write_msg(desc, msg);
+}
+
+static void platform_msi_update_chip_ops(struct msi_domain_info *info)
+{
+ struct irq_chip *chip = info->chip;
+
+ 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;
+}
+
+static void platform_msi_free_descs(struct device *dev, int base, int nvec)
+{
+ struct msi_desc *desc, *tmp;
+
+ list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) {
+ if (desc->platform.msi_index >= base &&
+ desc->platform.msi_index < (base + nvec)) {
+ list_del(&desc->list);
+ free_msi_entry(desc);
+ }
+ }
+}
+
+static int platform_msi_alloc_descs_with_irq(struct device *dev, int virq,
+ int nvec,
+ struct platform_msi_priv_data *data)
+
+{
+ struct msi_desc *desc;
+ int i, base = 0;
+
+ if (!list_empty(dev_to_msi_list(dev))) {
+ desc = list_last_entry(dev_to_msi_list(dev),
+ struct msi_desc, list);
+ base = desc->platform.msi_index + 1;
+ }
+
+ for (i = 0; i < nvec; i++) {
+ desc = alloc_msi_entry(dev, 1, NULL);
+ if (!desc)
+ break;
+
+ desc->platform.msi_priv_data = data;
+ desc->platform.msi_index = base + i;
+ desc->irq = virq ? virq + i : 0;
+
+ list_add_tail(&desc->list, dev_to_msi_list(dev));
+ }
+
+ if (i != nvec) {
+ /* Clean up the mess */
+ platform_msi_free_descs(dev, base, nvec);
+
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int platform_msi_alloc_descs(struct device *dev, int nvec,
+ struct platform_msi_priv_data *data)
+
+{
+ return platform_msi_alloc_descs_with_irq(dev, 0, nvec, data);
+}
+
+/**
+ * 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);
+
+ domain = msi_create_irq_domain(fwnode, info, parent);
+ if (domain)
+ irq_domain_update_bus_token(domain, DOMAIN_BUS_PLATFORM_MSI);
+
+ return domain;
+}
+
+static struct platform_msi_priv_data *
+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;
+ /*
+ * 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 ERR_PTR(-EINVAL);
+
+ if (dev->msi_domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) {
+ dev_err(dev, "Incompatible msi_domain, giving up\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* Already had a helping of MSI? Greed... */
+ if (!list_empty(dev_to_msi_list(dev)))
+ return ERR_PTR(-EBUSY);
+
+ datap = kzalloc(sizeof(*datap), GFP_KERNEL);
+ if (!datap)
+ return ERR_PTR(-ENOMEM);
+
+ datap->devid = ida_simple_get(&platform_msi_devid_ida,
+ 0, 1 << DEV_ID_SHIFT, GFP_KERNEL);
+ if (datap->devid < 0) {
+ int err = datap->devid;
+ kfree(datap);
+ return ERR_PTR(err);
+ }
+
+ datap->write_msg = write_msi_msg;
+ datap->dev = dev;
+
+ return datap;
+}
+
+static void platform_msi_free_priv_data(struct platform_msi_priv_data *data)
+{
+ ida_simple_remove(&platform_msi_devid_ida, data->devid);
+ kfree(data);
+}
+
+/**
+ * platform_msi_domain_alloc_irqs - Allocate MSI 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)
+{
+ struct platform_msi_priv_data *priv_data;
+ int err;
+
+ priv_data = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
+ if (IS_ERR(priv_data))
+ return PTR_ERR(priv_data);
+
+ err = platform_msi_alloc_descs(dev, nvec, priv_data);
+ if (err)
+ goto out_free_priv_data;
+
+ err = msi_domain_alloc_irqs(dev->msi_domain, dev, nvec);
+ if (err)
+ goto out_free_desc;
+
+ return 0;
+
+out_free_desc:
+ platform_msi_free_descs(dev, 0, nvec);
+out_free_priv_data:
+ platform_msi_free_priv_data(priv_data);
+
+ 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)
+{
+ if (!list_empty(dev_to_msi_list(dev))) {
+ struct msi_desc *desc;
+
+ desc = first_msi_entry(dev);
+ platform_msi_free_priv_data(desc->platform.msi_priv_data);
+ }
+
+ msi_domain_free_irqs(dev->msi_domain, dev);
+ platform_msi_free_descs(dev, 0, MAX_DEV_MSIS);
+}
+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
+ *
+ * Returns 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;
+}
+
+/**
+ * platform_msi_create_device_domain - Create a platform-msi domain
+ *
+ * @dev: The device generating the MSIs
+ * @nvec: The number of MSIs that need to be allocated
+ * @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
+ *
+ * Returns an irqdomain for @nvec interrupts
+ */
+struct irq_domain *
+platform_msi_create_device_domain(struct device *dev,
+ unsigned int nvec,
+ irq_write_msi_msg_t write_msi_msg,
+ const struct irq_domain_ops *ops,
+ void *host_data)
+{
+ struct platform_msi_priv_data *data;
+ struct irq_domain *domain;
+ int err;
+
+ data = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
+ if (IS_ERR(data))
+ return NULL;
+
+ data->host_data = host_data;
+ domain = irq_domain_create_hierarchy(dev->msi_domain, 0, nvec,
+ dev->fwnode, ops, data);
+ if (!domain)
+ goto free_priv;
+
+ 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(data);
+ return NULL;
+}
+
+/**
+ * platform_msi_domain_free - Free interrupts associated with a platform-msi
+ * domain
+ *
+ * @domain: The platform-msi domain
+ * @virq: The base irq from which to perform the free operation
+ * @nvec: How many interrupts to free from @virq
+ */
+void platform_msi_domain_free(struct irq_domain *domain, unsigned int virq,
+ unsigned int nvec)
+{
+ struct platform_msi_priv_data *data = domain->host_data;
+ struct msi_desc *desc;
+ for_each_msi_entry(desc, data->dev) {
+ if (WARN_ON(!desc->irq || desc->nvec_used != 1))
+ return;
+ if (!(desc->irq >= virq && desc->irq < (virq + nvec)))
+ continue;
+
+ irq_domain_free_irqs_common(domain, desc->irq, 1);
+ }
+}
+
+/**
+ * platform_msi_domain_alloc - Allocate interrupts associated with
+ * a platform-msi domain
+ *
+ * @domain: The platform-msi domain
+ * @virq: The base irq from which to perform the allocate operation
+ * @nvec: How many interrupts to free 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).
+ */
+int platform_msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs)
+{
+ struct platform_msi_priv_data *data = domain->host_data;
+ int err;
+
+ err = platform_msi_alloc_descs_with_irq(data->dev, virq, nr_irqs, data);
+ if (err)
+ return err;
+
+ err = msi_domain_populate_irqs(domain->parent, data->dev,
+ virq, nr_irqs, &data->arg);
+ if (err)
+ platform_msi_domain_free(domain, virq, nr_irqs);
+
+ return err;
+}