Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030575AbWJCVxj (ORCPT ); Tue, 3 Oct 2006 17:53:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030574AbWJCVxj (ORCPT ); Tue, 3 Oct 2006 17:53:39 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:11937 "EHLO e34.co.us.ibm.com") by vger.kernel.org with ESMTP id S1030575AbWJCVxi (ORCPT ); Tue, 3 Oct 2006 17:53:38 -0400 Subject: Re: [RFC/PATCH 6/7] RTAS MSI implementation From: Jake Moilanen To: Michael Ellerman Cc: linux-kernel@vger.kernel.org, Benjamin Herrenschmidt , linuxppc-dev@ozlabs.org, "Eric W. Biederman" In-Reply-To: <20060928215346.CE92067C6D@ozlabs.org> References: <20060928215346.CE92067C6D@ozlabs.org> Content-Type: text/plain Organization: IBM Date: Tue, 03 Oct 2006 16:53:28 -0500 Message-Id: <1159912408.4997.255.camel@goblue> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7753 Lines: 295 On Fri, 2006-09-29 at 07:53 +1000, Michael Ellerman wrote: > Powerpc MSI support via RTAS. Based on Jake's code. > > Signed-off-by: Michael Ellerman > --- > > arch/powerpc/kernel/Makefile | 1 > arch/powerpc/kernel/msi-rtas.c | 246 +++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 247 insertions(+) > > Index: to-merge/arch/powerpc/kernel/Makefile > =================================================================== > --- to-merge.orig/arch/powerpc/kernel/Makefile > +++ to-merge/arch/powerpc/kernel/Makefile > @@ -69,6 +69,7 @@ pci32-$(CONFIG_PPC32) := pci_32.o > obj-$(CONFIG_PCI) += $(pci64-y) $(pci32-y) > > msiobj-y := msi.o > +msiobj-$(CONFIG_PPC_PSERIES) += msi-rtas.o > obj-$(CONFIG_PCI_MSI) += $(msiobj-y) > > kexec-$(CONFIG_PPC64) := machine_kexec_64.o > Index: to-merge/arch/powerpc/kernel/msi-rtas.c > =================================================================== > --- /dev/null > +++ to-merge/arch/powerpc/kernel/msi-rtas.c > @@ -0,0 +1,246 @@ > +/* > + * Copyright (C) 2006 Jake Moilanen , IBM Corp. > + * Copyright (C) 2006 Michael Ellerman, 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; version 2 of the > + * License. > + * > + */ > + > +#define DEBUG 1 > + > +#include > +#include > +#include > +#include > +#include > + > +static int query_token, change_token; > + > +#define RTAS_QUERY_MSI_FN 0 > +#define RTAS_CHANGE_MSI_FN 1 > +#define RTAS_RESET_MSI_FN 2 > + > + > +/* RTAS Helpers */ > + > +static int rtas_change_msi(struct pci_dn *pdn, u32 function, u32 num_irqs) > +{ > + u32 addr, seq_num, rtas_ret[2]; > + unsigned long buid; > + int rc; > + > + addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); > + buid = pdn->phb->buid; > + > + seq_num = 1; > + do { > + rc = rtas_call(change_token, 6, 3, rtas_ret, addr, > + BUID_HI(buid), BUID_LO(buid), > + function, num_irqs, seq_num); This call is still currently broken in firmware. Hopefully we'll have a resolution soon. > + > + seq_num = rtas_ret[1]; > + } while (rtas_busy_delay(rc)); > + > + if (rc) { > + printk(KERN_WARNING "Error[%d]: getting the number of" > + " MSI interrupts for %s\n", rc, pci_name(pdn->pcidev)); > + return rc; > + } > + > + return rtas_ret[0]; > +} > + > +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) { > + printk(KERN_WARNING "Error[%d]: Querying irq source number " > + "for %s\n", rc, pci_name(pdn->pcidev)); > + return rc; > + } > + > + return rtas_ret[0]; > +} > + > +/* > + * The spec gives firmware the option to enable either MSI or MSI-X, > + * this doesn't wash with the Linux API. For the time beinging, we > + * kludge around that by checking ourselves the right type is enabled. > + */ > +static int check_msi_type(struct pci_dev *pdev, int type) > +{ > + int pos, msi_enabled, msix_enabled; > + u16 reg; > + > + pos = pci_find_capability(pdev, PCI_CAP_ID_MSI); > + if (!pos) > + return -1; > + > + pci_read_config_word(pdev, pos + PCI_MSI_FLAGS, ®); > + > + msi_enabled = msix_enabled = 0; > + > + if (reg & PCI_MSI_FLAGS_ENABLE) > + msi_enabled = 1; > + This is not being set correctly by firmware either. I have them looking into the problem. > + if (reg & PCI_MSIX_FLAGS_ENABLE) > + msix_enabled = 1; > + > + if (type == PCI_CAP_ID_MSI && (msix_enabled || !msi_enabled)) { > + pr_debug("check_msi_type: Expected MSI but got %s.\n", > + msix_enabled ? "MSI-X" : "none"); > + return -1; > + } > + > + if (type == PCI_CAP_ID_MSIX && (msi_enabled || !msix_enabled)) { > + pr_debug("check_msi_type: Expected MSI-X but got %s.\n", > + msi_enabled ? "MSI" : "none"); > + return -1; > + } > + > + return 0; > +} > + > +static void msi_rtas_free(struct pci_dev *pdev, int num, > + struct msix_entry *entries, int type) > +{ > + struct device_node *dn; > + struct pci_dn *pdn; > + int i; > + > + dn = pci_device_to_OF_node(pdev); > + if (!dn) { > + pr_debug("msi_rtas_free: No OF device node for %s\n", > + pci_name(pdev)); > + return; > + } > + > + pdn = PCI_DN(dn); > + if (!pdn) { > + pr_debug("msi_rtas_free: No PCI DN for %s\n", > + pci_name(pdev)); > + return; > + } > + > + for (i = 0; i < num; i++) { > + irq_dispose_mapping(entries[i].vector); > + } > + > + /* XXX can we do anything sane if this fails? */ > + rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0); > +} > + > +static int msi_rtas_check(struct pci_dev *pdev, int num, > + struct msix_entry *entries, int type) > +{ > + struct device_node *dn; > + int i; > + > + dn = pci_device_to_OF_node(pdev); > + > + if (!of_find_property(dn, "ibm,req#msi", NULL)) { > + pr_debug("msi_rtas_check: No ibm,req#msi for %s\n", > + pci_name(pdev)); > + return -1; > + } > + > + /* > + * Firmware gives us no control over which entries are allocated > + * for MSI-X, it seems to assume we want 0 - n. For now just insist > + * that the entries array entry members are 0 - n. > + */ > + for (i = 0; i < num; i++) { > + if (entries[i].entry != i) { > + pr_debug("msi_rtas_check: entries[i].entry != i\n"); > + return -1; > + } > + } > + > + return 0; > +} > + > +static int msi_rtas_alloc(struct pci_dev *pdev, int num, > + struct msix_entry *entries, int type) > +{ > + struct pci_dn *pdn; > + int hwirq, virq, i; > + > + pdn = PCI_DN(pci_device_to_OF_node(pdev)); > + > + /* > + * In the case of an error it's not clear whether the device is left > + * with MSI enabled or not, I think we should explicitly disable. > + */ > + if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, num) != num) > + goto out_free; > + > + if (check_msi_type(pdev, type)) > + goto out_free; > + > + for (i = 0; i < num; i++) { > + hwirq = rtas_query_irq_number(pdn, i); > + if (hwirq < 0) > + goto out_free; > + > + virq = irq_create_mapping(NULL, hwirq); > + > + if (virq == NO_IRQ) { > + pr_debug("msi_rtas_alloc: Failed mapping hwirq %d\n", > + hwirq); > + goto out_free; > + } > + > + entries[i].vector = virq; > + } > + > + return 0; > + > + out_free: > + msi_rtas_free(pdev, num, entries, type); Shouldn't this be: msi_rtas_free(pdev, i,....... Otherwise you'll try freeing unallocated entries. > + return -1; > +} > + > +static struct ppc_msi_ops rtas_msi_ops = { > + .check = msi_rtas_check, > + .alloc = msi_rtas_alloc, > + .free = msi_rtas_free > +}; > + > +static struct ppc_msi_ops *rtas_get_msi_ops(struct pci_dev *pdev) > +{ > + return &rtas_msi_ops; > +} > + > +static int msi_rtas_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_init: Couldn't find RTAS tokens, no " > + "MSI support available.\n"); > + return 0; > + } > + > + pr_debug("rtas_msi_init: Registering RTAS MSI ops.\n"); > + > + ppc_md.get_msi_ops = rtas_get_msi_ops; > + > + return 0; > +} > +__initcall(msi_rtas_init); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/