Commit 05af7bd2 authored by Michael Ellerman's avatar Michael Ellerman Committed by Paul Mackerras
Browse files

[POWERPC] MPIC U3/U4 MSI backend 



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: default avatarMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent a7de7c74

arch/powerpc/sysdev/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -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

arch/powerpc/sysdev/mpic.c

+7 −5
Original line number Diff line number Diff line
@@ -618,7 +618,7 @@ static irqreturn_t mpic_ipi_action(int irq, void *dev_id) 
 */





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);
@@ -638,7 +638,7 @@ static void mpic_unmask_irq(unsigned int irq) 
	} 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);
@@ -659,7 +659,7 @@ static void mpic_mask_irq(unsigned int irq) 
	} 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);
@@ -792,7 +792,7 @@ static unsigned int mpic_type_to_vecpri(struct mpic *mpic, unsigned int type) 
	}

}



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);
@@ -1203,8 +1203,10 @@ 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))

	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 */

arch/powerpc/sysdev/mpic.h

+11 −0
Original line number Diff line number Diff line
@@ -16,12 +16,23 @@ extern void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq); 
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 */

arch/powerpc/sysdev/mpic_u3msi.c

0 → 100644
+186 −0
Original line number Diff line number Diff line 
/*

 * 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;

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE