[PATCH 7/7] MPIC U3/U4 MSI backend
Michael Ellerman
michael at ellerman.id.au
Tue May 8 12:58:37 EST 2007
MPIC U3/U4 MSI backend. Based on code from Segher, heavily hacked by me.
This only deals with MSI on U3/U4 MPICs, aka. CPC 9x5.
If we find a U3/U4 then we enable this backend, ie. take over the ppc_md
MSI hooks. We might need more elaborate logic in future to decide which
backend is enabled.
We need our own irq_chip so that we can do MSI masking/unmasking on
the device itself. We also need to mask explicitly on shutdown to make
sure we don't get bitten by lazy-disable semantics.
Signed-off-by: Michael Ellerman <michael at ellerman.id.au>
---
arch/powerpc/sysdev/Makefile | 2
arch/powerpc/sysdev/mpic.c | 14 +-
arch/powerpc/sysdev/mpic.h | 11 ++
arch/powerpc/sysdev/mpic_u3msi.c | 186 +++++++++++++++++++++++++++++++++++++++
4 files changed, 206 insertions(+), 7 deletions(-)
Index: msi-new/arch/powerpc/sysdev/Makefile
===================================================================
--- msi-new.orig/arch/powerpc/sysdev/Makefile
+++ msi-new/arch/powerpc/sysdev/Makefile
@@ -2,7 +2,7 @@ ifeq ($(CONFIG_PPC64),y)
EXTRA_CFLAGS += -mno-minimal-toc
endif
-mpic-msi-obj-$(CONFIG_PCI_MSI) += mpic_msi.o
+mpic-msi-obj-$(CONFIG_PCI_MSI) += mpic_msi.o mpic_u3msi.o
obj-$(CONFIG_MPIC) += mpic.o $(mpic-msi-obj-y)
obj-$(CONFIG_PPC_INDIRECT_PCI) += indirect_pci.o
Index: msi-new/arch/powerpc/sysdev/mpic.c
===================================================================
--- msi-new.orig/arch/powerpc/sysdev/mpic.c
+++ msi-new/arch/powerpc/sysdev/mpic.c
@@ -606,7 +606,7 @@ static irqreturn_t mpic_ipi_action(int i
*/
-static void mpic_unmask_irq(unsigned int irq)
+void mpic_unmask_irq(unsigned int irq)
{
unsigned int loops = 100000;
struct mpic *mpic = mpic_from_irq(irq);
@@ -626,7 +626,7 @@ static void mpic_unmask_irq(unsigned int
} while(mpic_irq_read(src, MPIC_INFO(IRQ_VECTOR_PRI)) & MPIC_VECPRI_MASK);
}
-static void mpic_mask_irq(unsigned int irq)
+void mpic_mask_irq(unsigned int irq)
{
unsigned int loops = 100000;
struct mpic *mpic = mpic_from_irq(irq);
@@ -647,7 +647,7 @@ static void mpic_mask_irq(unsigned int i
} while(!(mpic_irq_read(src, MPIC_INFO(IRQ_VECTOR_PRI)) & MPIC_VECPRI_MASK));
}
-static void mpic_end_irq(unsigned int irq)
+void mpic_end_irq(unsigned int irq)
{
struct mpic *mpic = mpic_from_irq(irq);
@@ -780,7 +780,7 @@ static unsigned int mpic_type_to_vecpri(
}
}
-static int mpic_set_irq_type(unsigned int virq, unsigned int flow_type)
+int mpic_set_irq_type(unsigned int virq, unsigned int flow_type)
{
struct mpic *mpic = mpic_from_irq(virq);
unsigned int src = mpic_irq_to_hw(virq);
@@ -1191,8 +1191,10 @@ void __init mpic_init(struct mpic *mpic)
/* Do the HT PIC fixups on U3 broken mpic */
DBG("MPIC flags: %x\n", mpic->flags);
- if ((mpic->flags & MPIC_U3_HT_IRQS) && (mpic->flags & MPIC_PRIMARY))
- mpic_scan_ht_pics(mpic);
+ if ((mpic->flags & MPIC_U3_HT_IRQS) && (mpic->flags & MPIC_PRIMARY)) {
+ mpic_scan_ht_pics(mpic);
+ mpic_u3msi_init(mpic);
+ }
for (i = 0; i < mpic->num_sources; i++) {
/* start with vector = source number, and masked */
Index: msi-new/arch/powerpc/sysdev/mpic.h
===================================================================
--- msi-new.orig/arch/powerpc/sysdev/mpic.h
+++ msi-new/arch/powerpc/sysdev/mpic.h
@@ -16,12 +16,23 @@ extern void mpic_msi_reserve_hwirq(struc
extern int mpic_msi_init_allocator(struct mpic *mpic);
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);
+extern int mpic_u3msi_init(struct mpic *mpic);
#else
static inline void mpic_msi_reserve_hwirq(struct mpic *mpic,
irq_hw_number_t hwirq)
{
return;
}
+
+static inline int mpic_u3msi_init(struct mpic *mpic)
+{
+ return -1;
+}
#endif
+extern int mpic_set_irq_type(unsigned int virq, unsigned int flow_type);
+extern void mpic_end_irq(unsigned int irq);
+extern void mpic_mask_irq(unsigned int irq);
+extern void mpic_unmask_irq(unsigned int irq);
+
#endif /* _POWERPC_SYSDEV_MPIC_H */
Index: msi-new/arch/powerpc/sysdev/mpic_u3msi.c
===================================================================
--- /dev/null
+++ msi-new/arch/powerpc/sysdev/mpic_u3msi.c
@@ -0,0 +1,186 @@
+/*
+ * 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 <linux/msi.h>
+#include <asm/mpic.h>
+#include <asm/prom.h>
+#include <asm/hw_irq.h>
+#include <asm/ppc-pci.h>
+
+#include "mpic.h"
+
+/* A bit ugly, can we get this from the pci_dev somehow? */
+static struct mpic *msi_mpic;
+
+static void mpic_u3msi_mask_irq(unsigned int irq)
+{
+ mask_msi_irq(irq);
+ mpic_mask_irq(irq);
+}
+
+static void mpic_u3msi_unmask_irq(unsigned int irq)
+{
+ mpic_unmask_irq(irq);
+ unmask_msi_irq(irq);
+}
+
+static struct irq_chip mpic_u3msi_chip = {
+ .shutdown = mpic_u3msi_mask_irq,
+ .mask = mpic_u3msi_mask_irq,
+ .unmask = mpic_u3msi_unmask_irq,
+ .eoi = mpic_end_irq,
+ .set_type = mpic_set_irq_type,
+ .typename = "MPIC-U3MSI",
+};
+
+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 = pci_find_ht_capability(bus->self, HT_CAPTYPE_MSI_MAPPING);
+ if (pos)
+ return read_ht_magic_addr(bus->self, pos);
+ }
+
+ return 0;
+}
+
+static int u3msi_msi_check_device(struct pci_dev *pdev, int nvec, int type)
+{
+ if (type == PCI_CAP_ID_MSIX)
+ pr_debug("u3msi: MSI-X untested, trying anyway.\n");
+
+ /* If we can't find a magic address then MSI ain't gonna work */
+ if (find_ht_magic_addr(pdev) == 0) {
+ pr_debug("u3msi: no magic address found for %s\n",
+ pci_name(pdev));
+ return -ENXIO;
+ }
+
+ return 0;
+}
+
+static void u3msi_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);
+ mpic_msi_free_hwirqs(msi_mpic, virq_to_hw(entry->irq), 1);
+ irq_dispose_mapping(entry->irq);
+ }
+
+ return;
+}
+
+static void u3msi_compose_msi_msg(struct pci_dev *pdev, int virq,
+ struct msi_msg *msg)
+{
+ u64 addr;
+
+ addr = find_ht_magic_addr(pdev);
+ msg->address_lo = addr & 0xFFFFFFFF;
+ msg->address_hi = addr >> 32;
+ msg->data = virq_to_hw(virq);
+
+ pr_debug("u3msi: allocated virq 0x%x (hw 0x%lx) at address 0x%lx\n",
+ virq, virq_to_hw(virq), addr);
+}
+
+static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
+{
+ irq_hw_number_t hwirq;
+ int rc;
+ unsigned int virq;
+ struct msi_desc *entry;
+ struct msi_msg msg;
+
+ list_for_each_entry(entry, &pdev->msi_list, list) {
+ hwirq = mpic_msi_alloc_hwirqs(msi_mpic, 1);
+ if (hwirq < 0) {
+ rc = hwirq;
+ pr_debug("u3msi: failed allocating hwirq\n");
+ goto out_free;
+ }
+
+ virq = irq_create_mapping(msi_mpic->irqhost, hwirq);
+ if (virq == NO_IRQ) {
+ pr_debug("u3msi: failed mapping hwirq 0x%lx\n", hwirq);
+ mpic_msi_free_hwirqs(msi_mpic, hwirq, 1);
+ rc = -ENOSPC;
+ goto out_free;
+ }
+
+ set_irq_msi(virq, entry);
+ set_irq_chip(virq, &mpic_u3msi_chip);
+ set_irq_type(virq, IRQ_TYPE_EDGE_RISING);
+
+ u3msi_compose_msi_msg(pdev, virq, &msg);
+ write_msi_msg(virq, &msg);
+
+ hwirq++;
+ }
+
+ return 0;
+
+ out_free:
+ u3msi_teardown_msi_irqs(pdev);
+ return rc;
+}
+
+int mpic_u3msi_init(struct mpic *mpic)
+{
+ int rc;
+
+ rc = mpic_msi_init_allocator(mpic);
+ if (rc) {
+ pr_debug("u3msi: Error allocating bitmap!\n");
+ return rc;
+ }
+
+ pr_debug("u3msi: Registering MPIC U3 MSI callbacks.\n");
+
+ BUG_ON(msi_mpic);
+ msi_mpic = mpic;
+
+ WARN_ON(ppc_md.setup_msi_irqs);
+ ppc_md.setup_msi_irqs = u3msi_setup_msi_irqs;
+ ppc_md.teardown_msi_irqs = u3msi_teardown_msi_irqs;
+ ppc_md.msi_check_device = u3msi_msi_check_device;
+
+ return 0;
+}
More information about the Linuxppc-dev
mailing list