[PATCH 5/7] MPIC MSI backend
Michael Ellerman
michael at ellerman.id.au
Thu Jan 11 22:25:21 EST 2007
MPIC MSI backend. Based on code from Segher, heavily hacked by me.
Renamed to mpic_htmsi, as it only deals with MSI over Hypertransport.
We properly discover the HT magic address by reading the config space.
Now we have an irq allocator we can support > 1 MSI, and we don't reuse
the LSI.
Tested, succesfully getting MSIs from the tg3 via HT/PCI-X on a JS21
running SLOF. Successive insmod/rmmods working too.
Signed-off-by: Michael Ellerman <michael at ellerman.id.au>
---
arch/powerpc/sysdev/Makefile | 2
arch/powerpc/sysdev/mpic.h | 7 +
arch/powerpc/sysdev/mpic_htmsi.c | 191 +++++++++++++++++++++++++++++++++++++++
3 files changed, 199 insertions(+), 1 deletion(-)
Index: msi/arch/powerpc/sysdev/Makefile
===================================================================
--- msi.orig/arch/powerpc/sysdev/Makefile
+++ msi/arch/powerpc/sysdev/Makefile
@@ -3,7 +3,7 @@ EXTRA_CFLAGS += -mno-minimal-toc
endif
mpic-obj-y := mpic.o
-mpic-obj-$(CONFIG_PCI_MSI) += mpic_msi.o
+mpic-obj-$(CONFIG_PCI_MSI) += mpic_msi.o mpic_htmsi.o
obj-$(CONFIG_MPIC) += $(mpic-obj-y)
obj-$(CONFIG_PPC_INDIRECT_PCI) += indirect_pci.o
Index: msi/arch/powerpc/sysdev/mpic.h
===================================================================
--- msi.orig/arch/powerpc/sysdev/mpic.h
+++ msi/arch/powerpc/sysdev/mpic.h
@@ -15,11 +15,18 @@
#include <asm/msi.h>
#ifdef CONFIG_PCI_MSI
+extern int mpic_htmsi_init(struct mpic *mpic);
+
extern int mpic_msi_init_allocator(struct mpic *mpic);
extern void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq);
extern irq_hw_number_t mpic_msi_alloc_hwirqs(struct mpic *mpic, int num);
extern void mpic_msi_free_hwirqs(struct mpic *mpic, int offset, int num);
#else
+static inline int mpic_htmsi_init(struct mpic *mpic)
+{
+ return -1;
+}
+
static inline void mpic_msi_reserve_hwirq(struct mpic *mpic,
irq_hw_number_t hwirq)
{
Index: msi/arch/powerpc/sysdev/mpic_htmsi.c
===================================================================
--- /dev/null
+++ msi/arch/powerpc/sysdev/mpic_htmsi.c
@@ -0,0 +1,191 @@
+/*
+ * Copyright 2006, Segher Boessenkool, IBM Corporation.
+ * Copyright 2006-2007, Michael Ellerman, IBM Corporation.
+ *
+ * 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/irq.h>
+#include <linux/bootmem.h>
+#include <asm/msi.h>
+#include <asm/mpic.h>
+#include <asm/prom.h>
+#include <asm/hw_irq.h>
+#include <asm/ppc-pci.h>
+
+#include "mpic.h"
+
+/* XXX Do we ever need > 1 of these? void * msi_ops.data perhaps ? */
+static struct mpic *msi_mpic;
+
+static unsigned int find_ht_msi_capability(struct pci_dev *pdev)
+{
+ unsigned int pos = pci_find_capability(pdev, PCI_CAP_ID_HT);
+ u8 subcap, ttl = 48;
+
+ while (pos && ttl--) {
+ pci_read_config_byte(pdev, pos + 3, &subcap);
+ if ((subcap & 0xF8) == HT_CAPTYPE_MSI_MAPPING)
+ return pos;
+ pos = pci_find_next_capability(pdev, pos, PCI_CAP_ID_HT);
+ }
+
+ return 0;
+}
+
+static u64 read_ht_magic_addr(struct pci_dev *pdev, unsigned int pos)
+{
+ u8 flags;
+ u32 tmp;
+ u64 addr;
+
+ pci_read_config_byte(pdev, pos + HT_MSI_FLAGS, &flags);
+
+ if (flags & HT_MSI_FLAGS_FIXED)
+ return HT_MSI_FIXED_ADDR;
+
+ pci_read_config_dword(pdev, pos + HT_MSI_ADDR_LO, &tmp);
+ addr = tmp & HT_MSI_ADDR_LO_MASK;
+ pci_read_config_dword(pdev, pos + HT_MSI_ADDR_HI, &tmp);
+ addr = addr | ((u64)tmp << 32);
+
+ return addr;
+}
+
+static u64 find_ht_magic_addr(struct pci_dev *pdev)
+{
+ struct pci_bus *bus;
+ unsigned int pos;
+
+ for (bus = pdev->bus; bus; bus = bus->parent) {
+ pos = find_ht_msi_capability(bus->self);
+ if (pos)
+ return read_ht_magic_addr(bus->self, pos);
+ }
+
+ return 0;
+}
+
+static int htmsi_check(struct pci_dev *pdev, int num,
+ struct msix_entry *entries, int type)
+{
+ if (type == PCI_CAP_ID_MSIX) {
+ msi_debug("MSI-X unsupported for %s\n", pci_name(pdev));
+ return 1;
+ }
+
+ /* If we can't find a magic address then MSI ain't gonna work */
+ if (find_ht_magic_addr(pdev) == 0) {
+ msi_debug("no magic address found for %s\n", pci_name(pdev));
+ return 1;
+ }
+
+ return 0;
+}
+
+static void htmsi_free(struct pci_dev *pdev, int num,
+ struct msix_entry *entries, int type)
+{
+ irq_hw_number_t hwirq;
+ int i;
+
+ hwirq = irq_map[entries[0].vector].hwirq;
+
+ for (i = 0; i < num; i++) {
+ irq_dispose_mapping(entries[i].vector);
+ entries[i].vector = NO_IRQ;
+ }
+
+ msi_debug("freeing %d hwirqs for msi at offset 0x%lx\n", num, hwirq);
+ mpic_msi_free_hwirqs(msi_mpic, hwirq, num);
+
+ return;
+}
+
+static int htmsi_alloc(struct pci_dev *pdev, int num,
+ struct msix_entry *entries, int type)
+{
+ int i;
+ irq_hw_number_t hwirq;
+ unsigned int virq;
+
+ hwirq = mpic_msi_alloc_hwirqs(msi_mpic, num);
+ if (hwirq < 0) {
+ msi_debug("failed allocating %d hwirqs for %s\n", num,
+ pci_name(pdev));
+ return -1;
+ }
+
+ for (i = 0; i < num; i++) {
+ /* FIXME should we save the existing type */
+ set_irq_type(hwirq, IRQ_TYPE_EDGE_RISING);
+
+ virq = irq_create_mapping(msi_mpic->irqhost, hwirq);
+ if (virq == NO_IRQ) {
+ msi_debug("failed mapping hwirq 0x%lx for %s\n", hwirq,
+ pci_name(pdev));
+ goto out_free;
+ }
+
+ entries[i].vector = virq;
+ hwirq++;
+ }
+
+ return 0;
+
+ out_free:
+ htmsi_free(pdev, num, entries, type);
+ return -1;
+}
+
+static int htmsi_setup_msi_msg(struct pci_dev *pdev,
+ struct msix_entry *entry, struct msi_msg *msg, int type)
+{
+ u64 addr;
+
+ addr = find_ht_magic_addr(pdev);
+ msg->address_lo = addr & 0xFFFFFFFF;
+ msg->address_hi = addr >> 32;
+ msg->data = irq_map[entry->vector].hwirq;
+
+ msi_debug("allocated irq %d at 0x%lx for %s\n", entry->vector,
+ addr, pci_name(pdev));
+
+ return 0;
+}
+
+static struct ppc_msi_ops mpic_htmsi_ops = {
+ .check = htmsi_check,
+ .alloc = htmsi_alloc,
+ .free = htmsi_free,
+ .enable = msi_raw_enable,
+ .disable = msi_raw_disable,
+ .setup_msi_msg = htmsi_setup_msi_msg,
+};
+
+static struct ppc_msi_ops *htmsi_get_msi_ops(struct pci_dev *pdev)
+{
+ return &mpic_htmsi_ops;
+}
+
+int mpic_htmsi_init(struct mpic *mpic)
+{
+ int rc;
+
+ rc = mpic_msi_init_allocator(mpic);
+ if (rc) {
+ pr_debug("mpic_htmsi_init: Error allocating bitmap!\n");
+ return rc;
+ }
+
+ msi_mpic = mpic;
+
+ pr_debug("mpic_htmsi_init: Registering MPIC MSI ops.\n");
+ ppc_md.get_msi_ops = htmsi_get_msi_ops;
+
+ return 0;
+}
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