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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/platforms/pseries/msi.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/platforms/pseries/msi.c')
-rw-r--r-- | arch/powerpc/platforms/pseries/msi.c | 701 |
1 files changed, 701 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c new file mode 100644 index 000000000..a3a71d37c --- /dev/null +++ b/arch/powerpc/platforms/pseries/msi.c @@ -0,0 +1,701 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp. + * Copyright 2006-2007 Michael Ellerman, IBM Corp. + */ + +#include <linux/crash_dump.h> +#include <linux/device.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/msi.h> + +#include <asm/rtas.h> +#include <asm/hw_irq.h> +#include <asm/ppc-pci.h> +#include <asm/machdep.h> +#include <asm/xive.h> + +#include "pseries.h" + +static int query_token, change_token; + +#define RTAS_QUERY_FN 0 +#define RTAS_CHANGE_FN 1 +#define RTAS_RESET_FN 2 +#define RTAS_CHANGE_MSI_FN 3 +#define RTAS_CHANGE_MSIX_FN 4 +#define RTAS_CHANGE_32MSI_FN 5 + +/* RTAS Helpers */ + +static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs) +{ + u32 addr, seq_num, rtas_ret[3]; + unsigned long buid; + int rc; + + addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); + buid = pdn->phb->buid; + + seq_num = 1; + do { + if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN || + func == RTAS_CHANGE_32MSI_FN) + rc = rtas_call(change_token, 6, 4, rtas_ret, addr, + BUID_HI(buid), BUID_LO(buid), + func, num_irqs, seq_num); + else + rc = rtas_call(change_token, 6, 3, rtas_ret, addr, + BUID_HI(buid), BUID_LO(buid), + func, num_irqs, seq_num); + + seq_num = rtas_ret[1]; + } while (rtas_busy_delay(rc)); + + /* + * If the RTAS call succeeded, return the number of irqs allocated. + * If not, make sure we return a negative error code. + */ + if (rc == 0) + rc = rtas_ret[0]; + else if (rc > 0) + rc = -rc; + + pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n", + func, num_irqs, rtas_ret[0], rc); + + return rc; +} + +static void rtas_disable_msi(struct pci_dev *pdev) +{ + struct pci_dn *pdn; + + pdn = pci_get_pdn(pdev); + if (!pdn) + return; + + /* + * disabling MSI with the explicit interface also disables MSI-X + */ + if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0) != 0) { + /* + * may have failed because explicit interface is not + * present + */ + if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) { + pr_debug("rtas_msi: Setting MSIs to 0 failed!\n"); + } + } +} + +static int rtas_query_irq_number(struct pci_dn *pdn, int offset) +{ + u32 addr, rtas_ret[2]; + unsigned long buid; + int rc; + + addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); + buid = pdn->phb->buid; + + do { + rc = rtas_call(query_token, 4, 3, rtas_ret, addr, + BUID_HI(buid), BUID_LO(buid), offset); + } while (rtas_busy_delay(rc)); + + if (rc) { + pr_debug("rtas_msi: error (%d) querying source number\n", rc); + return rc; + } + + return rtas_ret[0]; +} + +static int check_req(struct pci_dev *pdev, int nvec, char *prop_name) +{ + struct device_node *dn; + const __be32 *p; + u32 req_msi; + + dn = pci_device_to_OF_node(pdev); + + p = of_get_property(dn, prop_name, NULL); + if (!p) { + pr_debug("rtas_msi: No %s on %pOF\n", prop_name, dn); + return -ENOENT; + } + + req_msi = be32_to_cpup(p); + if (req_msi < nvec) { + pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec); + + if (req_msi == 0) /* Be paranoid */ + return -ENOSPC; + + return req_msi; + } + + return 0; +} + +static int check_req_msi(struct pci_dev *pdev, int nvec) +{ + return check_req(pdev, nvec, "ibm,req#msi"); +} + +static int check_req_msix(struct pci_dev *pdev, int nvec) +{ + return check_req(pdev, nvec, "ibm,req#msi-x"); +} + +/* Quota calculation */ + +static struct device_node *__find_pe_total_msi(struct device_node *node, int *total) +{ + struct device_node *dn; + const __be32 *p; + + dn = of_node_get(node); + while (dn) { + p = of_get_property(dn, "ibm,pe-total-#msi", NULL); + if (p) { + pr_debug("rtas_msi: found prop on dn %pOF\n", + dn); + *total = be32_to_cpup(p); + return dn; + } + + dn = of_get_next_parent(dn); + } + + return NULL; +} + +static struct device_node *find_pe_total_msi(struct pci_dev *dev, int *total) +{ + return __find_pe_total_msi(pci_device_to_OF_node(dev), total); +} + +static struct device_node *find_pe_dn(struct pci_dev *dev, int *total) +{ + struct device_node *dn; + struct eeh_dev *edev; + + /* Found our PE and assume 8 at that point. */ + + dn = pci_device_to_OF_node(dev); + if (!dn) + return NULL; + + /* Get the top level device in the PE */ + edev = pdn_to_eeh_dev(PCI_DN(dn)); + if (edev->pe) + edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, + entry); + dn = pci_device_to_OF_node(edev->pdev); + if (!dn) + return NULL; + + /* We actually want the parent */ + dn = of_get_parent(dn); + if (!dn) + return NULL; + + /* Hardcode of 8 for old firmwares */ + *total = 8; + pr_debug("rtas_msi: using PE dn %pOF\n", dn); + + return dn; +} + +struct msi_counts { + struct device_node *requestor; + int num_devices; + int request; + int quota; + int spare; + int over_quota; +}; + +static void *count_non_bridge_devices(struct device_node *dn, void *data) +{ + struct msi_counts *counts = data; + const __be32 *p; + u32 class; + + pr_debug("rtas_msi: counting %pOF\n", dn); + + p = of_get_property(dn, "class-code", NULL); + class = p ? be32_to_cpup(p) : 0; + + if ((class >> 8) != PCI_CLASS_BRIDGE_PCI) + counts->num_devices++; + + return NULL; +} + +static void *count_spare_msis(struct device_node *dn, void *data) +{ + struct msi_counts *counts = data; + const __be32 *p; + int req; + + if (dn == counts->requestor) + req = counts->request; + else { + /* We don't know if a driver will try to use MSI or MSI-X, + * so we just have to punt and use the larger of the two. */ + req = 0; + p = of_get_property(dn, "ibm,req#msi", NULL); + if (p) + req = be32_to_cpup(p); + + p = of_get_property(dn, "ibm,req#msi-x", NULL); + if (p) + req = max(req, (int)be32_to_cpup(p)); + } + + if (req < counts->quota) + counts->spare += counts->quota - req; + else if (req > counts->quota) + counts->over_quota++; + + return NULL; +} + +static int msi_quota_for_device(struct pci_dev *dev, int request) +{ + struct device_node *pe_dn; + struct msi_counts counts; + int total; + + pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev), + request); + + pe_dn = find_pe_total_msi(dev, &total); + if (!pe_dn) + pe_dn = find_pe_dn(dev, &total); + + if (!pe_dn) { + pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev)); + goto out; + } + + pr_debug("rtas_msi: found PE %pOF\n", pe_dn); + + memset(&counts, 0, sizeof(struct msi_counts)); + + /* Work out how many devices we have below this PE */ + pci_traverse_device_nodes(pe_dn, count_non_bridge_devices, &counts); + + if (counts.num_devices == 0) { + pr_err("rtas_msi: found 0 devices under PE for %s\n", + pci_name(dev)); + goto out; + } + + counts.quota = total / counts.num_devices; + if (request <= counts.quota) + goto out; + + /* else, we have some more calculating to do */ + counts.requestor = pci_device_to_OF_node(dev); + counts.request = request; + pci_traverse_device_nodes(pe_dn, count_spare_msis, &counts); + + /* If the quota isn't an integer multiple of the total, we can + * use the remainder as spare MSIs for anyone that wants them. */ + counts.spare += total % counts.num_devices; + + /* Divide any spare by the number of over-quota requestors */ + if (counts.over_quota) + counts.quota += counts.spare / counts.over_quota; + + /* And finally clamp the request to the possibly adjusted quota */ + request = min(counts.quota, request); + + pr_debug("rtas_msi: request clamped to quota %d\n", request); +out: + of_node_put(pe_dn); + + return request; +} + +static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev) +{ + u32 addr_hi, addr_lo; + + /* + * We should only get in here for IODA1 configs. This is based on the + * fact that we using RTAS for MSIs, we don't have the 32 bit MSI RTAS + * support, and we are in a PCIe Gen2 slot. + */ + dev_info(&pdev->dev, + "rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n"); + pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi); + addr_lo = 0xffff0000 | ((addr_hi >> (48 - 32)) << 4); + pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo); + pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0); +} + +static int rtas_prepare_msi_irqs(struct pci_dev *pdev, int nvec_in, int type, + msi_alloc_info_t *arg) +{ + struct pci_dn *pdn; + int quota, rc; + int nvec = nvec_in; + int use_32bit_msi_hack = 0; + + if (type == PCI_CAP_ID_MSIX) + rc = check_req_msix(pdev, nvec); + else + rc = check_req_msi(pdev, nvec); + + if (rc) + return rc; + + quota = msi_quota_for_device(pdev, nvec); + + if (quota && quota < nvec) + return quota; + + /* + * Firmware currently refuse any non power of two allocation + * so we round up if the quota will allow it. + */ + if (type == PCI_CAP_ID_MSIX) { + int m = roundup_pow_of_two(nvec); + quota = msi_quota_for_device(pdev, m); + + if (quota >= m) + nvec = m; + } + + pdn = pci_get_pdn(pdev); + + /* + * Try the new more explicit firmware interface, if that fails fall + * back to the old interface. The old interface is known to never + * return MSI-Xs. + */ +again: + if (type == PCI_CAP_ID_MSI) { + if (pdev->no_64bit_msi) { + rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec); + if (rc < 0) { + /* + * We only want to run the 32 bit MSI hack below if + * the max bus speed is Gen2 speed + */ + if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT) + return rc; + + use_32bit_msi_hack = 1; + } + } else + rc = -1; + + if (rc < 0) + rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec); + + if (rc < 0) { + pr_debug("rtas_msi: trying the old firmware call.\n"); + rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec); + } + + if (use_32bit_msi_hack && rc > 0) + rtas_hack_32bit_msi_gen2(pdev); + } else + rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec); + + if (rc != nvec) { + if (nvec != nvec_in) { + nvec = nvec_in; + goto again; + } + pr_debug("rtas_msi: rtas_change_msi() failed\n"); + return rc; + } + + return 0; +} + +static int pseries_msi_ops_prepare(struct irq_domain *domain, struct device *dev, + int nvec, msi_alloc_info_t *arg) +{ + struct pci_dev *pdev = to_pci_dev(dev); + int type = pdev->msix_enabled ? PCI_CAP_ID_MSIX : PCI_CAP_ID_MSI; + + return rtas_prepare_msi_irqs(pdev, nvec, type, arg); +} + +/* + * ->msi_free() is called before irq_domain_free_irqs_top() when the + * handler data is still available. Use that to clear the XIVE + * controller data. + */ +static void pseries_msi_ops_msi_free(struct irq_domain *domain, + struct msi_domain_info *info, + unsigned int irq) +{ + if (xive_enabled()) + xive_irq_free_data(irq); +} + +/* + * RTAS can not disable one MSI at a time. It's all or nothing. Do it + * at the end after all IRQs have been freed. + */ +static void pseries_msi_domain_free_irqs(struct irq_domain *domain, + struct device *dev) +{ + if (WARN_ON_ONCE(!dev_is_pci(dev))) + return; + + __msi_domain_free_irqs(domain, dev); + + rtas_disable_msi(to_pci_dev(dev)); +} + +static struct msi_domain_ops pseries_pci_msi_domain_ops = { + .msi_prepare = pseries_msi_ops_prepare, + .msi_free = pseries_msi_ops_msi_free, + .domain_free_irqs = pseries_msi_domain_free_irqs, +}; + +static void pseries_msi_shutdown(struct irq_data *d) +{ + d = d->parent_data; + if (d->chip->irq_shutdown) + d->chip->irq_shutdown(d); +} + +static void pseries_msi_mask(struct irq_data *d) +{ + pci_msi_mask_irq(d); + irq_chip_mask_parent(d); +} + +static void pseries_msi_unmask(struct irq_data *d) +{ + pci_msi_unmask_irq(d); + irq_chip_unmask_parent(d); +} + +static void pseries_msi_write_msg(struct irq_data *data, struct msi_msg *msg) +{ + struct msi_desc *entry = irq_data_get_msi_desc(data); + + /* + * Do not update the MSIx vector table. It's not strictly necessary + * because the table is initialized by the underlying hypervisor, PowerVM + * or QEMU/KVM. However, if the MSIx vector entry is cleared, any further + * activation will fail. This can happen in some drivers (eg. IPR) which + * deactivate an IRQ used for testing MSI support. + */ + entry->msg = *msg; +} + +static struct irq_chip pseries_pci_msi_irq_chip = { + .name = "pSeries-PCI-MSI", + .irq_shutdown = pseries_msi_shutdown, + .irq_mask = pseries_msi_mask, + .irq_unmask = pseries_msi_unmask, + .irq_eoi = irq_chip_eoi_parent, + .irq_write_msi_msg = pseries_msi_write_msg, +}; + + +/* + * Set MSI_FLAG_MSIX_CONTIGUOUS as there is no way to express to + * firmware to request a discontiguous or non-zero based range of + * MSI-X entries. Core code will reject such setup attempts. + */ +static struct msi_domain_info pseries_msi_domain_info = { + .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | + MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX | + MSI_FLAG_MSIX_CONTIGUOUS), + .ops = &pseries_pci_msi_domain_ops, + .chip = &pseries_pci_msi_irq_chip, +}; + +static void pseries_msi_compose_msg(struct irq_data *data, struct msi_msg *msg) +{ + __pci_read_msi_msg(irq_data_get_msi_desc(data), msg); +} + +static struct irq_chip pseries_msi_irq_chip = { + .name = "pSeries-MSI", + .irq_shutdown = pseries_msi_shutdown, + .irq_mask = irq_chip_mask_parent, + .irq_unmask = irq_chip_unmask_parent, + .irq_eoi = irq_chip_eoi_parent, + .irq_set_affinity = irq_chip_set_affinity_parent, + .irq_compose_msi_msg = pseries_msi_compose_msg, +}; + +static int pseries_irq_parent_domain_alloc(struct irq_domain *domain, unsigned int virq, + irq_hw_number_t hwirq) +{ + struct irq_fwspec parent_fwspec; + int ret; + + parent_fwspec.fwnode = domain->parent->fwnode; + parent_fwspec.param_count = 2; + parent_fwspec.param[0] = hwirq; + parent_fwspec.param[1] = IRQ_TYPE_EDGE_RISING; + + ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec); + if (ret) + return ret; + + return 0; +} + +static int pseries_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *arg) +{ + struct pci_controller *phb = domain->host_data; + msi_alloc_info_t *info = arg; + struct msi_desc *desc = info->desc; + struct pci_dev *pdev = msi_desc_to_pci_dev(desc); + int hwirq; + int i, ret; + + hwirq = rtas_query_irq_number(pci_get_pdn(pdev), desc->msi_index); + if (hwirq < 0) { + dev_err(&pdev->dev, "Failed to query HW IRQ: %d\n", hwirq); + return hwirq; + } + + dev_dbg(&pdev->dev, "%s bridge %pOF %d/%x #%d\n", __func__, + phb->dn, virq, hwirq, nr_irqs); + + for (i = 0; i < nr_irqs; i++) { + ret = pseries_irq_parent_domain_alloc(domain, virq + i, hwirq + i); + if (ret) + goto out; + + irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i, + &pseries_msi_irq_chip, domain->host_data); + } + + return 0; + +out: + /* TODO: handle RTAS cleanup in ->msi_finish() ? */ + irq_domain_free_irqs_parent(domain, virq, i - 1); + return ret; +} + +static void pseries_irq_domain_free(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs) +{ + struct irq_data *d = irq_domain_get_irq_data(domain, virq); + struct pci_controller *phb = irq_data_get_irq_chip_data(d); + + pr_debug("%s bridge %pOF %d #%d\n", __func__, phb->dn, virq, nr_irqs); + + /* XIVE domain data is cleared through ->msi_free() */ +} + +static const struct irq_domain_ops pseries_irq_domain_ops = { + .alloc = pseries_irq_domain_alloc, + .free = pseries_irq_domain_free, +}; + +static int __pseries_msi_allocate_domains(struct pci_controller *phb, + unsigned int count) +{ + struct irq_domain *parent = irq_get_default_host(); + + phb->fwnode = irq_domain_alloc_named_id_fwnode("pSeries-MSI", + phb->global_number); + if (!phb->fwnode) + return -ENOMEM; + + phb->dev_domain = irq_domain_create_hierarchy(parent, 0, count, + phb->fwnode, + &pseries_irq_domain_ops, phb); + if (!phb->dev_domain) { + pr_err("PCI: failed to create IRQ domain bridge %pOF (domain %d)\n", + phb->dn, phb->global_number); + irq_domain_free_fwnode(phb->fwnode); + return -ENOMEM; + } + + phb->msi_domain = pci_msi_create_irq_domain(of_node_to_fwnode(phb->dn), + &pseries_msi_domain_info, + phb->dev_domain); + if (!phb->msi_domain) { + pr_err("PCI: failed to create MSI IRQ domain bridge %pOF (domain %d)\n", + phb->dn, phb->global_number); + irq_domain_free_fwnode(phb->fwnode); + irq_domain_remove(phb->dev_domain); + return -ENOMEM; + } + + return 0; +} + +int pseries_msi_allocate_domains(struct pci_controller *phb) +{ + int count; + + if (!__find_pe_total_msi(phb->dn, &count)) { + pr_err("PCI: failed to find MSIs for bridge %pOF (domain %d)\n", + phb->dn, phb->global_number); + return -ENOSPC; + } + + return __pseries_msi_allocate_domains(phb, count); +} + +void pseries_msi_free_domains(struct pci_controller *phb) +{ + if (phb->msi_domain) + irq_domain_remove(phb->msi_domain); + if (phb->dev_domain) + irq_domain_remove(phb->dev_domain); + if (phb->fwnode) + irq_domain_free_fwnode(phb->fwnode); +} + +static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev) +{ + /* No LSI -> leave MSIs (if any) configured */ + if (!pdev->irq) { + dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n"); + return; + } + + /* No MSI -> MSIs can't have been assigned by fw, leave LSI */ + if (check_req_msi(pdev, 1) && check_req_msix(pdev, 1)) { + dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n"); + return; + } + + dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n"); + rtas_disable_msi(pdev); +} + +static int rtas_msi_init(void) +{ + query_token = rtas_token("ibm,query-interrupt-source-number"); + change_token = rtas_token("ibm,change-msi"); + + if ((query_token == RTAS_UNKNOWN_SERVICE) || + (change_token == RTAS_UNKNOWN_SERVICE)) { + pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n"); + return -1; + } + + pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n"); + + WARN_ON(ppc_md.pci_irq_fixup); + ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup; + + return 0; +} +machine_arch_initcall(pseries, rtas_msi_init); |