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-rw-r--r--arch/powerpc/platforms/powernv/pci-cxl.c385
1 files changed, 385 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/pci-cxl.c b/arch/powerpc/platforms/powernv/pci-cxl.c
new file mode 100644
index 000000000000..1349a099c74c
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/pci-cxl.c
@@ -0,0 +1,385 @@
+/*
+ * Copyright 2014-2016 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <asm/pci-bridge.h>
+#include <asm/pnv-pci.h>
+#include <asm/opal.h>
+#include <misc/cxl.h>
+
+#include "pci.h"
+
+struct device_node *pnv_pci_get_phb_node(struct pci_dev *dev)
+{
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+
+ return of_node_get(hose->dn);
+}
+EXPORT_SYMBOL(pnv_pci_get_phb_node);
+
+int pnv_phb_to_cxl_mode(struct pci_dev *dev, uint64_t mode)
+{
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+ struct pnv_phb *phb = hose->private_data;
+ struct pnv_ioda_pe *pe;
+ int rc;
+
+ pe = pnv_ioda_get_pe(dev);
+ if (!pe)
+ return -ENODEV;
+
+ pe_info(pe, "Switching PHB to CXL\n");
+
+ rc = opal_pci_set_phb_cxl_mode(phb->opal_id, mode, pe->pe_number);
+ if (rc == OPAL_UNSUPPORTED)
+ dev_err(&dev->dev, "Required cxl mode not supported by firmware - update skiboot\n");
+ else if (rc)
+ dev_err(&dev->dev, "opal_pci_set_phb_cxl_mode failed: %i\n", rc);
+
+ return rc;
+}
+EXPORT_SYMBOL(pnv_phb_to_cxl_mode);
+
+/* Find PHB for cxl dev and allocate MSI hwirqs?
+ * Returns the absolute hardware IRQ number
+ */
+int pnv_cxl_alloc_hwirqs(struct pci_dev *dev, int num)
+{
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+ struct pnv_phb *phb = hose->private_data;
+ int hwirq = msi_bitmap_alloc_hwirqs(&phb->msi_bmp, num);
+
+ if (hwirq < 0) {
+ dev_warn(&dev->dev, "Failed to find a free MSI\n");
+ return -ENOSPC;
+ }
+
+ return phb->msi_base + hwirq;
+}
+EXPORT_SYMBOL(pnv_cxl_alloc_hwirqs);
+
+void pnv_cxl_release_hwirqs(struct pci_dev *dev, int hwirq, int num)
+{
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+ struct pnv_phb *phb = hose->private_data;
+
+ msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq - phb->msi_base, num);
+}
+EXPORT_SYMBOL(pnv_cxl_release_hwirqs);
+
+void pnv_cxl_release_hwirq_ranges(struct cxl_irq_ranges *irqs,
+ struct pci_dev *dev)
+{
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+ struct pnv_phb *phb = hose->private_data;
+ int i, hwirq;
+
+ for (i = 1; i < CXL_IRQ_RANGES; i++) {
+ if (!irqs->range[i])
+ continue;
+ pr_devel("cxl release irq range 0x%x: offset: 0x%lx limit: %ld\n",
+ i, irqs->offset[i],
+ irqs->range[i]);
+ hwirq = irqs->offset[i] - phb->msi_base;
+ msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq,
+ irqs->range[i]);
+ }
+}
+EXPORT_SYMBOL(pnv_cxl_release_hwirq_ranges);
+
+int pnv_cxl_alloc_hwirq_ranges(struct cxl_irq_ranges *irqs,
+ struct pci_dev *dev, int num)
+{
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+ struct pnv_phb *phb = hose->private_data;
+ int i, hwirq, try;
+
+ memset(irqs, 0, sizeof(struct cxl_irq_ranges));
+
+ /* 0 is reserved for the multiplexed PSL DSI interrupt */
+ for (i = 1; i < CXL_IRQ_RANGES && num; i++) {
+ try = num;
+ while (try) {
+ hwirq = msi_bitmap_alloc_hwirqs(&phb->msi_bmp, try);
+ if (hwirq >= 0)
+ break;
+ try /= 2;
+ }
+ if (!try)
+ goto fail;
+
+ irqs->offset[i] = phb->msi_base + hwirq;
+ irqs->range[i] = try;
+ pr_devel("cxl alloc irq range 0x%x: offset: 0x%lx limit: %li\n",
+ i, irqs->offset[i], irqs->range[i]);
+ num -= try;
+ }
+ if (num)
+ goto fail;
+
+ return 0;
+fail:
+ pnv_cxl_release_hwirq_ranges(irqs, dev);
+ return -ENOSPC;
+}
+EXPORT_SYMBOL(pnv_cxl_alloc_hwirq_ranges);
+
+int pnv_cxl_get_irq_count(struct pci_dev *dev)
+{
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+ struct pnv_phb *phb = hose->private_data;
+
+ return phb->msi_bmp.irq_count;
+}
+EXPORT_SYMBOL(pnv_cxl_get_irq_count);
+
+int pnv_cxl_ioda_msi_setup(struct pci_dev *dev, unsigned int hwirq,
+ unsigned int virq)
+{
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+ struct pnv_phb *phb = hose->private_data;
+ unsigned int xive_num = hwirq - phb->msi_base;
+ struct pnv_ioda_pe *pe;
+ int rc;
+
+ if (!(pe = pnv_ioda_get_pe(dev)))
+ return -ENODEV;
+
+ /* Assign XIVE to PE */
+ rc = opal_pci_set_xive_pe(phb->opal_id, pe->pe_number, xive_num);
+ if (rc) {
+ pe_warn(pe, "%s: OPAL error %d setting msi_base 0x%x "
+ "hwirq 0x%x XIVE 0x%x PE\n",
+ pci_name(dev), rc, phb->msi_base, hwirq, xive_num);
+ return -EIO;
+ }
+ pnv_set_msi_irq_chip(phb, virq);
+
+ return 0;
+}
+EXPORT_SYMBOL(pnv_cxl_ioda_msi_setup);
+
+#if IS_MODULE(CONFIG_CXL)
+static inline int get_cxl_module(void)
+{
+ struct module *cxl_module;
+
+ mutex_lock(&module_mutex);
+
+ cxl_module = find_module("cxl");
+ if (cxl_module)
+ __module_get(cxl_module);
+
+ mutex_unlock(&module_mutex);
+
+ if (!cxl_module)
+ return -ENODEV;
+
+ return 0;
+}
+#else
+static inline int get_cxl_module(void) { return 0; }
+#endif
+
+/*
+ * Sets flags and switches the controller ops to enable the cxl kernel api.
+ * Originally the cxl kernel API operated on a virtual PHB, but certain cards
+ * such as the Mellanox CX4 use a peer model instead and for these cards the
+ * cxl kernel api will operate on the real PHB.
+ */
+int pnv_cxl_enable_phb_kernel_api(struct pci_controller *hose, bool enable)
+{
+ struct pnv_phb *phb = hose->private_data;
+ int rc;
+
+ if (!enable) {
+ /*
+ * Once cxl mode is enabled on the PHB, there is currently no
+ * known safe method to disable it again, and trying risks a
+ * checkstop. If we can find a way to safely disable cxl mode
+ * in the future we can revisit this, but for now the only sane
+ * thing to do is to refuse to disable cxl mode:
+ */
+ return -EPERM;
+ }
+
+ /*
+ * Hold a reference to the cxl module since several PHB operations now
+ * depend on it, and it would be insane to allow it to be removed so
+ * long as we are in this mode (and since we can't safely disable this
+ * mode once enabled...).
+ */
+ rc = get_cxl_module();
+ if (rc)
+ return rc;
+
+ phb->flags |= PNV_PHB_FLAG_CXL;
+ hose->controller_ops = pnv_cxl_cx4_ioda_controller_ops;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pnv_cxl_enable_phb_kernel_api);
+
+bool pnv_pci_on_cxl_phb(struct pci_dev *dev)
+{
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+ struct pnv_phb *phb = hose->private_data;
+
+ return !!(phb->flags & PNV_PHB_FLAG_CXL);
+}
+EXPORT_SYMBOL_GPL(pnv_pci_on_cxl_phb);
+
+struct cxl_afu *pnv_cxl_phb_to_afu(struct pci_controller *hose)
+{
+ struct pnv_phb *phb = hose->private_data;
+
+ return (struct cxl_afu *)phb->cxl_afu;
+}
+EXPORT_SYMBOL_GPL(pnv_cxl_phb_to_afu);
+
+void pnv_cxl_phb_set_peer_afu(struct pci_dev *dev, struct cxl_afu *afu)
+{
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+ struct pnv_phb *phb = hose->private_data;
+
+ phb->cxl_afu = afu;
+}
+EXPORT_SYMBOL_GPL(pnv_cxl_phb_set_peer_afu);
+
+/*
+ * In the peer cxl model, the XSL/PSL is physical function 0, and will be used
+ * by other functions on the device for memory access and interrupts. When the
+ * other functions are enabled we explicitly take a reference on the cxl
+ * function since they will use it, and allocate a default context associated
+ * with that function just like the vPHB model of the cxl kernel API.
+ */
+bool pnv_cxl_enable_device_hook(struct pci_dev *dev)
+{
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+ struct pnv_phb *phb = hose->private_data;
+ struct cxl_afu *afu = phb->cxl_afu;
+
+ if (!pnv_pci_enable_device_hook(dev))
+ return false;
+
+
+ /* No special handling for the cxl function, which is always PF 0 */
+ if (PCI_FUNC(dev->devfn) == 0)
+ return true;
+
+ if (!afu) {
+ dev_WARN(&dev->dev, "Attempted to enable function > 0 on CXL PHB without a peer AFU\n");
+ return false;
+ }
+
+ dev_info(&dev->dev, "Enabling function on CXL enabled PHB with peer AFU\n");
+
+ /* Make sure the peer AFU can't go away while this device is active */
+ cxl_afu_get(afu);
+
+ return cxl_pci_associate_default_context(dev, afu);
+}
+
+void pnv_cxl_disable_device(struct pci_dev *dev)
+{
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+ struct pnv_phb *phb = hose->private_data;
+ struct cxl_afu *afu = phb->cxl_afu;
+
+ /* No special handling for cxl function: */
+ if (PCI_FUNC(dev->devfn) == 0)
+ return;
+
+ cxl_pci_disable_device(dev);
+ cxl_afu_put(afu);
+}
+
+/*
+ * This is a special version of pnv_setup_msi_irqs for cards in cxl mode. This
+ * function handles setting up the IVTE entries for the XSL to use.
+ *
+ * We are currently not filling out the MSIX table, since the only currently
+ * supported adapter (CX4) uses a custom MSIX table format in cxl mode and it
+ * is up to their driver to fill that out. In the future we may fill out the
+ * MSIX table (and change the IVTE entries to be an index to the MSIX table)
+ * for adapters implementing the Full MSI-X mode described in the CAIA.
+ */
+int pnv_cxl_cx4_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
+{
+ struct pci_controller *hose = pci_bus_to_host(pdev->bus);
+ struct pnv_phb *phb = hose->private_data;
+ struct msi_desc *entry;
+ struct cxl_context *ctx = NULL;
+ unsigned int virq;
+ int hwirq;
+ int afu_irq = 0;
+ int rc;
+
+ if (WARN_ON(!phb) || !phb->msi_bmp.bitmap)
+ return -ENODEV;
+
+ if (pdev->no_64bit_msi && !phb->msi32_support)
+ return -ENODEV;
+
+ rc = cxl_cx4_setup_msi_irqs(pdev, nvec, type);
+ if (rc)
+ return rc;
+
+ for_each_pci_msi_entry(entry, pdev) {
+ if (!entry->msi_attrib.is_64 && !phb->msi32_support) {
+ pr_warn("%s: Supports only 64-bit MSIs\n",
+ pci_name(pdev));
+ return -ENXIO;
+ }
+
+ hwirq = cxl_next_msi_hwirq(pdev, &ctx, &afu_irq);
+ if (WARN_ON(hwirq <= 0))
+ return (hwirq ? hwirq : -ENOMEM);
+
+ virq = irq_create_mapping(NULL, hwirq);
+ if (virq == NO_IRQ) {
+ pr_warn("%s: Failed to map cxl mode MSI to linux irq\n",
+ pci_name(pdev));
+ return -ENOMEM;
+ }
+
+ rc = pnv_cxl_ioda_msi_setup(pdev, hwirq, virq);
+ if (rc) {
+ pr_warn("%s: Failed to setup cxl mode MSI\n", pci_name(pdev));
+ irq_dispose_mapping(virq);
+ return rc;
+ }
+
+ irq_set_msi_desc(virq, entry);
+ }
+
+ return 0;
+}
+
+void pnv_cxl_cx4_teardown_msi_irqs(struct pci_dev *pdev)
+{
+ struct pci_controller *hose = pci_bus_to_host(pdev->bus);
+ struct pnv_phb *phb = hose->private_data;
+ struct msi_desc *entry;
+ irq_hw_number_t hwirq;
+
+ if (WARN_ON(!phb))
+ return;
+
+ for_each_pci_msi_entry(entry, pdev) {
+ if (entry->irq == NO_IRQ)
+ continue;
+ hwirq = virq_to_hw(entry->irq);
+ irq_set_msi_desc(entry->irq, NULL);
+ irq_dispose_mapping(entry->irq);
+ }
+
+ cxl_cx4_teardown_msi_irqs(pdev);
+}