/*
* Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp.
* Copyright 2006-2007 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.
*
*/
#include <linux/device.h>
#include <linux/irq.h>
#include <linux/msi.h>
#include <asm/rtas.h>
#include <asm/hw_irq.h>
#include <asm/ppc-pci.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
static struct pci_dn *get_pdn(struct pci_dev *pdev)
{
struct device_node *dn;
struct pci_dn *pdn;
dn = pci_device_to_OF_node(pdev);
if (!dn) {
dev_dbg(&pdev->dev, "rtas_msi: No OF device node\n");
return NULL;
}
pdn = PCI_DN(dn);
if (!pdn) {
dev_dbg(&pdev->dev, "rtas_msi: No PCI DN\n");
return NULL;
}
return pdn;
}
/* 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)
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 (rc == 0) /* Success */
rc = rtas_ret[0];
pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d) = (%d)\n",
func, num_irqs, rc);
return rc;
}
static void rtas_disable_msi(struct pci_dev *pdev)
{
struct pci_dn *pdn;
pdn = get_pdn(pdev);
if (!pdn)
return;
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 void rtas_teardown_msi_irqs(struct pci_dev *pdev)
{
struct msi_desc *entry;
list_for_each_entry(entry, &pdev->msi_list, list) {
if (entry->irq == NO_IRQ)
continue;
set_irq_msi(entry->irq, NULL);
irq_dispose_mapping(entry->irq);
}
rtas_disable_msi(pdev);
}
static int check_req_msi(struct pci_dev *pdev, int nvec)
{
struct device_node *dn;
struct pci_dn *pdn;
const u32 *req_msi;
pdn = get_pdn(pdev);
if (!pdn)
return -ENODEV;
dn = pdn->node;
req_msi = of_get_property(dn, "ibm,req#msi", NULL);
if (!req_msi) {
pr_debug("rtas_msi: No ibm,req#msi on %s\n", dn->full_name);
return -ENOENT;
}
if (*req_msi < nvec) {
pr_debug("rtas_msi: ibm,req#msi requests < %d MSIs\n", nvec);
return -ENOSPC;
}
return 0;
}
static int rtas_msi_check_device(struct pci_dev *pdev, int nvec, int type)
{
if (type == PCI_CAP_ID_MSIX)
pr_debug("rtas_msi: MSI-X untested, trying anyway.\n");
return check_req_msi(pdev, nvec);
}
static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
{
struct pci_dn *pdn;
int hwirq, virq, i, rc;
struct msi_desc *entry;
pdn = get_pdn(pdev);
if (!pdn)
return -ENODEV;
/*
* 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.
*/
if (type == PCI_CAP_ID_MSI) {
rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);
if (rc != nvec) {
pr_debug("rtas_msi: trying the old firmware call.\n");
rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec);
}
} else
rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);
if (rc != nvec) {
pr_debug("rtas_msi: rtas_change_msi() failed\n");
/*
* In case of an error it's not clear whether the device is
* left with MSI enabled or not, so we explicitly disable.
*/
goto out_free;
}
i = 0;
list_for_each_entry(entry, &pdev->msi_list, list) {
hwirq = rtas_query_irq_number(pdn, i);
if (hwirq < 0) {
rc = hwirq;
pr_debug("rtas_msi: error (%d) getting hwirq\n", rc);
goto out_free;
}
virq = irq_create_mapping(NULL, hwirq);
if (virq == NO_IRQ) {
pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq);
rc = -ENOSPC;
goto out_free;
}
dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq);
set_irq_msi(virq, entry);
unmask_msi_irq(virq);
}
return 0;
out_free:
rtas_teardown_msi_irqs(pdev);
return rc;
}
static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev)
{
/* No LSI -> leave MSIs (if any) configured */
if (pdev->irq == NO_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)) {
dev_dbg(&pdev->dev, "rtas_msi: no req#msi, 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.setup_msi_irqs);
ppc_md.setup_msi_irqs = rtas_setup_msi_irqs;
ppc_md.teardown_msi_irqs = rtas_teardown_msi_irqs;
ppc_md.msi_check_device = rtas_msi_check_device;
WARN_ON(ppc_md.pci_irq_fixup);
ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup;
return 0;
}
arch_initcall(rtas_msi_init);
