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Diffstat (limited to 'drivers/cdx/cdx_msi.c')
-rw-r--r--drivers/cdx/cdx_msi.c192
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/cdx/cdx_msi.c b/drivers/cdx/cdx_msi.c
new file mode 100644
index 0000000000..e55f1716cf
--- /dev/null
+++ b/drivers/cdx/cdx_msi.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD CDX bus driver MSI support
+ *
+ * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
+ */
+
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/msi.h>
+#include <linux/cdx/cdx_bus.h>
+
+#include "cdx.h"
+
+static void cdx_msi_write_msg(struct irq_data *irq_data, struct msi_msg *msg)
+{
+ struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
+ struct cdx_device *cdx_dev = to_cdx_device(msi_desc->dev);
+
+ /* We would not operate on msg here rather we wait for irq_bus_sync_unlock()
+ * to be called from preemptible task context.
+ */
+ msi_desc->msg = *msg;
+ cdx_dev->msi_write_pending = true;
+}
+
+static void cdx_msi_write_irq_lock(struct irq_data *irq_data)
+{
+ struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
+ struct cdx_device *cdx_dev = to_cdx_device(msi_desc->dev);
+
+ mutex_lock(&cdx_dev->irqchip_lock);
+}
+
+static void cdx_msi_write_irq_unlock(struct irq_data *irq_data)
+{
+ struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
+ struct cdx_device *cdx_dev = to_cdx_device(msi_desc->dev);
+ struct cdx_controller *cdx = cdx_dev->cdx;
+ struct cdx_device_config dev_config;
+
+ if (!cdx_dev->msi_write_pending) {
+ mutex_unlock(&cdx_dev->irqchip_lock);
+ return;
+ }
+
+ cdx_dev->msi_write_pending = false;
+ mutex_unlock(&cdx_dev->irqchip_lock);
+
+ dev_config.msi.msi_index = msi_desc->msi_index;
+ dev_config.msi.data = msi_desc->msg.data;
+ dev_config.msi.addr = ((u64)(msi_desc->msg.address_hi) << 32) | msi_desc->msg.address_lo;
+
+ /*
+ * dev_configure() is a controller callback which can interact with
+ * Firmware or other entities, and can sleep, so invoke this function
+ * outside of the mutex held region.
+ */
+ dev_config.type = CDX_DEV_MSI_CONF;
+ if (cdx->ops->dev_configure)
+ cdx->ops->dev_configure(cdx, cdx_dev->bus_num, cdx_dev->dev_num, &dev_config);
+}
+
+int cdx_enable_msi(struct cdx_device *cdx_dev)
+{
+ struct cdx_controller *cdx = cdx_dev->cdx;
+ struct cdx_device_config dev_config;
+
+ dev_config.type = CDX_DEV_MSI_ENABLE;
+ dev_config.msi_enable = true;
+ if (cdx->ops->dev_configure) {
+ return cdx->ops->dev_configure(cdx, cdx_dev->bus_num, cdx_dev->dev_num,
+ &dev_config);
+ }
+
+ return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL_GPL(cdx_enable_msi);
+
+void cdx_disable_msi(struct cdx_device *cdx_dev)
+{
+ struct cdx_controller *cdx = cdx_dev->cdx;
+ struct cdx_device_config dev_config;
+
+ dev_config.type = CDX_DEV_MSI_ENABLE;
+ dev_config.msi_enable = false;
+ if (cdx->ops->dev_configure)
+ cdx->ops->dev_configure(cdx, cdx_dev->bus_num, cdx_dev->dev_num, &dev_config);
+}
+EXPORT_SYMBOL_GPL(cdx_disable_msi);
+
+static struct irq_chip cdx_msi_irq_chip = {
+ .name = "CDX-MSI",
+ .irq_mask = irq_chip_mask_parent,
+ .irq_unmask = irq_chip_unmask_parent,
+ .irq_eoi = irq_chip_eoi_parent,
+ .irq_set_affinity = msi_domain_set_affinity,
+ .irq_write_msi_msg = cdx_msi_write_msg,
+ .irq_bus_lock = cdx_msi_write_irq_lock,
+ .irq_bus_sync_unlock = cdx_msi_write_irq_unlock
+};
+
+/* Convert an msi_desc to a unique identifier within the domain. */
+static irq_hw_number_t cdx_domain_calc_hwirq(struct cdx_device *dev,
+ struct msi_desc *desc)
+{
+ return ((irq_hw_number_t)dev->msi_dev_id << 10) | desc->msi_index;
+}
+
+static void cdx_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
+{
+ arg->desc = desc;
+ arg->hwirq = cdx_domain_calc_hwirq(to_cdx_device(desc->dev), desc);
+}
+
+static int cdx_msi_prepare(struct irq_domain *msi_domain,
+ struct device *dev,
+ int nvec, msi_alloc_info_t *info)
+{
+ struct cdx_device *cdx_dev = to_cdx_device(dev);
+ struct device *parent = cdx_dev->cdx->dev;
+ struct msi_domain_info *msi_info;
+ u32 dev_id;
+ int ret;
+
+ /* Retrieve device ID from requestor ID using parent device */
+ ret = of_map_id(parent->of_node, cdx_dev->msi_dev_id, "msi-map", "msi-map-mask",
+ NULL, &dev_id);
+ if (ret) {
+ dev_err(dev, "of_map_id failed for MSI: %d\n", ret);
+ return ret;
+ }
+
+#ifdef GENERIC_MSI_DOMAIN_OPS
+ /* Set the device Id to be passed to the GIC-ITS */
+ info->scratchpad[0].ul = dev_id;
+#endif
+
+ msi_info = msi_get_domain_info(msi_domain->parent);
+
+ return msi_info->ops->msi_prepare(msi_domain->parent, dev, nvec, info);
+}
+
+static struct msi_domain_ops cdx_msi_ops = {
+ .msi_prepare = cdx_msi_prepare,
+ .set_desc = cdx_msi_set_desc
+};
+
+static struct msi_domain_info cdx_msi_domain_info = {
+ .ops = &cdx_msi_ops,
+ .chip = &cdx_msi_irq_chip,
+ .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+ MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS | MSI_FLAG_FREE_MSI_DESCS
+};
+
+struct irq_domain *cdx_msi_domain_init(struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct fwnode_handle *fwnode_handle;
+ struct irq_domain *cdx_msi_domain;
+ struct device_node *parent_node;
+ struct irq_domain *parent;
+
+ fwnode_handle = of_node_to_fwnode(np);
+
+ parent_node = of_parse_phandle(np, "msi-map", 1);
+ if (!parent_node) {
+ dev_err(dev, "msi-map not present on cdx controller\n");
+ return NULL;
+ }
+
+ parent = irq_find_matching_fwnode(of_node_to_fwnode(parent_node), DOMAIN_BUS_NEXUS);
+ if (!parent || !msi_get_domain_info(parent)) {
+ dev_err(dev, "unable to locate ITS domain\n");
+ return NULL;
+ }
+
+ cdx_msi_domain = msi_create_irq_domain(fwnode_handle, &cdx_msi_domain_info, parent);
+ if (!cdx_msi_domain) {
+ dev_err(dev, "unable to create CDX-MSI domain\n");
+ return NULL;
+ }
+
+ dev_dbg(dev, "CDX-MSI domain created\n");
+
+ return cdx_msi_domain;
+}
+EXPORT_SYMBOL_NS_GPL(cdx_msi_domain_init, CDX_BUS_CONTROLLER);