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c822392280
Some MSI controllers can change address/data pair during the execution of irq_chip::irq_set_affinity() callback. Since the current PCI Endpoint framework cannot support mutable MSI controllers, call irq_domain_is_msi_immutable() API to check if the controller is immutable or not. Also ensure that the MSI domain is a parent MSI domain so that it can allocate address/data pairs. Signed-off-by: Frank Li <Frank.Li@nxp.com> [mani: reworded error message and commit message] Signed-off-by: Manivannan Sadhasivam <mani@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Niklas Cassel <cassel@kernel.org> Link: https://patch.msgid.link/20250710-ep-msi-v21-4-57683fc7fb25@nxp.com
100 lines
2.3 KiB
C
100 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* PCI Endpoint *Controller* (EPC) MSI library
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*
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* Copyright (C) 2025 NXP
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* Author: Frank Li <Frank.Li@nxp.com>
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*/
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#include <linux/device.h>
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#include <linux/export.h>
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#include <linux/irqdomain.h>
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#include <linux/module.h>
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#include <linux/msi.h>
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#include <linux/of_irq.h>
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#include <linux/pci-epc.h>
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#include <linux/pci-epf.h>
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#include <linux/pci-ep-cfs.h>
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#include <linux/pci-ep-msi.h>
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#include <linux/slab.h>
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static void pci_epf_write_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
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{
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struct pci_epc *epc;
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struct pci_epf *epf;
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epc = pci_epc_get(dev_name(msi_desc_to_dev(desc)));
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if (!epc)
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return;
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epf = list_first_entry_or_null(&epc->pci_epf, struct pci_epf, list);
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if (epf && epf->db_msg && desc->msi_index < epf->num_db)
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memcpy(&epf->db_msg[desc->msi_index].msg, msg, sizeof(*msg));
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pci_epc_put(epc);
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}
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int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_db)
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{
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struct pci_epc *epc = epf->epc;
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struct device *dev = &epf->dev;
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struct irq_domain *domain;
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void *msg;
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int ret;
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int i;
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/* TODO: Multi-EPF support */
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if (list_first_entry_or_null(&epc->pci_epf, struct pci_epf, list) != epf) {
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dev_err(dev, "MSI doorbell doesn't support multiple EPF\n");
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return -EINVAL;
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}
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domain = of_msi_map_get_device_domain(epc->dev.parent, 0,
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DOMAIN_BUS_PLATFORM_MSI);
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if (!domain) {
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dev_err(dev, "Can't find MSI domain for EPC\n");
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return -ENODEV;
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}
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if (!irq_domain_is_msi_parent(domain))
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return -ENODEV;
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if (!irq_domain_is_msi_immutable(domain)) {
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dev_err(dev, "Mutable MSI controller not supported\n");
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return -ENODEV;
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}
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dev_set_msi_domain(epc->dev.parent, domain);
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msg = kcalloc(num_db, sizeof(struct pci_epf_doorbell_msg), GFP_KERNEL);
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if (!msg)
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return -ENOMEM;
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epf->num_db = num_db;
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epf->db_msg = msg;
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ret = platform_device_msi_init_and_alloc_irqs(epc->dev.parent, num_db,
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pci_epf_write_msi_msg);
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if (ret) {
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dev_err(dev, "Failed to allocate MSI\n");
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kfree(msg);
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return ret;
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}
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for (i = 0; i < num_db; i++)
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epf->db_msg[i].virq = msi_get_virq(epc->dev.parent, i);
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return ret;
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}
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EXPORT_SYMBOL_GPL(pci_epf_alloc_doorbell);
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void pci_epf_free_doorbell(struct pci_epf *epf)
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{
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platform_device_msi_free_irqs_all(epf->epc->dev.parent);
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kfree(epf->db_msg);
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epf->db_msg = NULL;
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epf->num_db = 0;
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}
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EXPORT_SYMBOL_GPL(pci_epf_free_doorbell);
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