[PATCH 0/2] Add PCI support on nios2 architecture

[PATCH 0/2] Add PCI support on nios2 architecture

[Ley Foon Tan]

This patchset adding pci support for nios2 architecture.
It requires pci_fixup_irqs() from setup-irq.c.

Ley Foon Tan (2):
  nios2: Add architectural support for PCIe
  PCI: Build setup-irq.o for nios2

 arch/nios2/Kconfig            | 24 +++++++++++++++++++++
 arch/nios2/include/asm/Kbuild |  2 +-
 arch/nios2/include/asm/io.h   | 11 +++++++++-
 arch/nios2/include/asm/pci.h  | 50 +++++++++++++++++++++++++++++++++++++++++++
 arch/nios2/kernel/Makefile    |  1 +
 arch/nios2/kernel/pci.c       | 33 ++++++++++++++++++++++++++++
 drivers/pci/Makefile          |  1 +
 7 files changed, 120 insertions(+), 2 deletions(-)
 create mode 100644 arch/nios2/include/asm/pci.h
 create mode 100644 arch/nios2/kernel/pci.c

-- 
1.8.2.1

[PATCH 1/2] nios2: Add architectural support for PCIe

[Ley Foon Tan]

This patch add pcie support on nios2 platform.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
---
 arch/nios2/Kconfig            | 24 +++++++++++++++++++++
 arch/nios2/include/asm/Kbuild |  2 +-
 arch/nios2/include/asm/io.h   | 11 +++++++++-
 arch/nios2/include/asm/pci.h  | 50 +++++++++++++++++++++++++++++++++++++++++++
 arch/nios2/kernel/Makefile    |  1 +
 arch/nios2/kernel/pci.c       | 33 ++++++++++++++++++++++++++++
 6 files changed, 119 insertions(+), 2 deletions(-)
 create mode 100644 arch/nios2/include/asm/pci.h
 create mode 100644 arch/nios2/kernel/pci.c

diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index 4375554..9e0a291 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -11,6 +11,7 @@ config NIOS2
 	select HAVE_ARCH_KGDB
 	select IRQ_DOMAIN
 	select MODULES_USE_ELF_RELA
+	select MIGHT_HAVE_PCI
 	select OF
 	select OF_EARLY_FLATTREE
 	select SOC_BUS
@@ -194,6 +195,29 @@ config NIOS2_IO_REGION_BASE
 
 endmenu
 
+menu "Bus support"
+config PCI
+	bool "PCI support"
+	select GENERIC_PCI_IOMAP
+	help
+	  This feature enables support for PCIe bus system. If you say Y
+	  here, the kernel will include drivers and infrastructure code
+	  to support PCIe bus devices.
+
+config PCI_DOMAINS
+	def_bool PCI
+
+config PCI_DOMAINS_GENERIC
+	def_bool PCI
+
+config PCI_SYSCALL
+	def_bool PCI
+
+source "drivers/pci/Kconfig"
+source "drivers/pci/pcie/Kconfig"
+
+endmenu
+
 menu "Executable file formats"
 
 source "fs/Kconfig.binfmt"
diff --git a/arch/nios2/include/asm/Kbuild b/arch/nios2/include/asm/Kbuild
index 914864e..8b928ba 100644
--- a/arch/nios2/include/asm/Kbuild
+++ b/arch/nios2/include/asm/Kbuild
@@ -34,8 +34,8 @@ generic-y += mm-arch-hooks.h
 generic-y += mman.h
 generic-y += module.h
 generic-y += msgbuf.h
+generic-y += msi.h
 generic-y += param.h
-generic-y += pci.h
 generic-y += percpu.h
 generic-y += poll.h
 generic-y += posix_types.h
diff --git a/arch/nios2/include/asm/io.h b/arch/nios2/include/asm/io.h
index c5a62da..74ba082 100644
--- a/arch/nios2/include/asm/io.h
+++ b/arch/nios2/include/asm/io.h
@@ -14,7 +14,7 @@
 #include <linux/types.h>
 #include <asm/pgtable-bits.h>
 
-/* PCI is not supported in nios2, set this to 0. */
+/* PCI I/O space is not supported, set this to 0. */
 #define IO_SPACE_LIMIT 0
 
 #define readb_relaxed(addr)	readb(addr)
@@ -45,6 +45,15 @@ static inline void iounmap(void __iomem *addr)
 	__iounmap(addr);
 }
 
+static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
+{
+	return NULL;
+}
+
+static inline void ioport_unmap(void __iomem *p)
+{
+}
+
 #define ioremap_wc ioremap_nocache
 #define ioremap_wt ioremap_nocache
 
diff --git a/arch/nios2/include/asm/pci.h b/arch/nios2/include/asm/pci.h
new file mode 100644
index 0000000..f2cba05
--- /dev/null
+++ b/arch/nios2/include/asm/pci.h
@@ -0,0 +1,50 @@
+/* Copyright Altera Corporation (C) 2015. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef _ASM_NIOS2_PCI_H
+#define _ASM_NIOS2_PCI_H
+
+#ifdef __KERNEL__
+#include <linux/dma-mapping.h>
+
+#include <asm/io.h>
+#include <asm-generic/pci-bridge.h>
+#include <asm-generic/pci-dma-compat.h>
+
+#define PCIBIOS_MIN_IO	0UL
+#define PCIBIOS_MIN_MEM	0UL
+
+/*
+ * Set to 1 if the kernel should re-assign all PCI bus numbers
+ */
+#define pcibios_assign_all_busses()	(pci_has_flag(PCI_REASSIGN_ALL_BUS))
+
+#ifdef CONFIG_PCI
+extern int isa_dma_bridge_buggy;
+#else
+#define isa_dma_bridge_buggy	(0)
+#endif
+
+#ifdef CONFIG_PCI_DOMAINS
+static inline int pci_proc_domain(struct pci_bus *bus)
+{
+	return pci_domain_nr(bus);
+}
+#endif /* CONFIG_PCI_DOMAINS */
+
+#endif /* __KERNEL__ */
+
+#endif
diff --git a/arch/nios2/kernel/Makefile b/arch/nios2/kernel/Makefile
index 1aae257..bb1ef81 100644
--- a/arch/nios2/kernel/Makefile
+++ b/arch/nios2/kernel/Makefile
@@ -10,6 +10,7 @@ obj-y	+= entry.o
 obj-y	+= insnemu.o
 obj-y	+= irq.o
 obj-y	+= nios2_ksyms.o
+obj-y	+= pci.o
 obj-y	+= process.o
 obj-y	+= prom.o
 obj-y	+= ptrace.o
diff --git a/arch/nios2/kernel/pci.c b/arch/nios2/kernel/pci.c
new file mode 100644
index 0000000..d28aed7
--- /dev/null
+++ b/arch/nios2/kernel/pci.c
@@ -0,0 +1,33 @@
+/* Copyright Altera Corporation (C) 2015. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include <linux/pci.h>
+
+/*
+ * Called after each bus is probed, but before its children are examined
+ */
+void pcibios_fixup_bus(struct pci_bus *bus)
+{
+	/* nothing to do, expected to be removed in the future */
+}
+
+/*
+ * We don't have to worry about legacy ISA devices, so nothing to do here
+ */
+resource_size_t pcibios_align_resource(void *data, const struct resource *res,
+				resource_size_t size, resource_size_t align)
+{
+	return res->start;
+}
-- 
1.8.2.1

Re: [PATCH 1/2] nios2: Add architectural support for PCIe

[Arnd Bergmann]

On Tuesday 22 September 2015 15:19:26 Ley Foon Tan wrote:
> +
> +config PCI_SYSCALL
> +	def_bool PCI

IIRC, PCI_SYSCALL is deprecated and you should just leave that
turned off.

In any case, you enable the syscalls here but don't assign a
system call number, so that is rather pointless. I 

I might be missing something though. Bjorn?

> @@ -14,7 +14,7 @@
>  #include <linux/types.h>
>  #include <asm/pgtable-bits.h>
>  
> -/* PCI is not supported in nios2, set this to 0. */
> +/* PCI I/O space is not supported, set this to 0. */
>  #define IO_SPACE_LIMIT 0
>  
>  #define readb_relaxed(addr)	readb(addr)

It might be useful to enable this, just in case someone connects
a PCI host bridge that does support I/O space.

Which host bridge do you use? Are you sure there is no I/O space?
Most of them use a set of translation windows to set up a mapping
between bus address (memory, config and io space) and physical
(mmio) space.

> diff --git a/arch/nios2/include/asm/pci.h b/arch/nios2/include/asm/pci.h
> new file mode 100644
> index 0000000..f2cba05
> --- /dev/null
> +++ b/arch/nios2/include/asm/pci.h

What happens if you use the asm-generic header? If there is something
missing in it, we can try to get it to do the right things.

	Arnd

Re: [PATCH 1/2] nios2: Add architectural support for PCIe

[Ley Foon Tan]

On Tue, Sep 22, 2015 at 4:18 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Tuesday 22 September 2015 15:19:26 Ley Foon Tan wrote:
>> +
>> +config PCI_SYSCALL
>> +     def_bool PCI
>
> IIRC, PCI_SYSCALL is deprecated and you should just leave that
> turned off.
>
> In any case, you enable the syscalls here but don't assign a
> system call number, so that is rather pointless. I
You are right. I can remove it if it is deprecated .
>
> I might be missing something though. Bjorn?
>
>> @@ -14,7 +14,7 @@
>>  #include <linux/types.h>
>>  #include <asm/pgtable-bits.h>
>>
>> -/* PCI is not supported in nios2, set this to 0. */
>> +/* PCI I/O space is not supported, set this to 0. */
>>  #define IO_SPACE_LIMIT 0
>>
>>  #define readb_relaxed(addr)  readb(addr)
>
> It might be useful to enable this, just in case someone connects
> a PCI host bridge that does support I/O space.
>
> Which host bridge do you use? Are you sure there is no I/O space?
> Most of them use a set of translation windows to set up a mapping
> between bus address (memory, config and io space) and physical
> (mmio) space.
I'm using Altera PCIe IP. But, you are right. We should enable this,
because it shouldn't limited to support Altera PCIe only.
BTW, any rule/requirement for the IO_SPACE_LIMIT?
And PCIBIOS_MIN_IO should be non-zero if we enable IO_SPACE_LIMIT?

>
>> diff --git a/arch/nios2/include/asm/pci.h b/arch/nios2/include/asm/pci.h
>> new file mode 100644
>> index 0000000..f2cba05
>> --- /dev/null
>> +++ b/arch/nios2/include/asm/pci.h
>
> What happens if you use the asm-generic header? If there is something
> missing in it, we can try to get it to do the right things.
All the defines in arch/nios2/include/asm/pci.h are required by PCI framework.
It will trigger undefined symbols/define error if without them. Seem
all architectures must provide all these defines.
So, we can consider to add default defines for these in asm-generic.

Regards
Ley Foon

Re: [PATCH 1/2] nios2: Add architectural support for PCIe

[Arnd Bergmann]

On Tuesday 22 September 2015 18:53:50 Ley Foon Tan wrote:
> On Tue, Sep 22, 2015 at 4:18 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> > On Tuesday 22 September 2015 15:19:26 Ley Foon Tan wrote:
> > I might be missing something though. Bjorn?
> >
> >> @@ -14,7 +14,7 @@
> >>  #include <linux/types.h>
> >>  #include <asm/pgtable-bits.h>
> >>
> >> -/* PCI is not supported in nios2, set this to 0. */
> >> +/* PCI I/O space is not supported, set this to 0. */
> >>  #define IO_SPACE_LIMIT 0
> >>
> >>  #define readb_relaxed(addr)  readb(addr)
> >
> > It might be useful to enable this, just in case someone connects
> > a PCI host bridge that does support I/O space.
> >
> > Which host bridge do you use? Are you sure there is no I/O space?
> > Most of them use a set of translation windows to set up a mapping
> > between bus address (memory, config and io space) and physical
> > (mmio) space.
>
> I'm using Altera PCIe IP. But, you are right. We should enable this,
> because it shouldn't limited to support Altera PCIe only.
> BTW, any rule/requirement for the IO_SPACE_LIMIT?

If you want to allow just one PCI host bridge, set it to 0xffff, otherwise
use 0xfffff (for up to 16 bridges)

> And PCIBIOS_MIN_IO should be non-zero if we enable IO_SPACE_LIMIT?

If you define pcibios_align_resource() as an empty function, that can
remain zero as well, it's only meant to stay out of the way of ISA
devices.

> >> diff --git a/arch/nios2/include/asm/pci.h b/arch/nios2/include/asm/pci.h
> >> new file mode 100644
> >> index 0000000..f2cba05
> >> --- /dev/null
> >> +++ b/arch/nios2/include/asm/pci.h
> >
> > What happens if you use the asm-generic header? If there is something
> > missing in it, we can try to get it to do the right things.
> All the defines in arch/nios2/include/asm/pci.h are required by PCI framework.
> It will trigger undefined symbols/define error if without them. Seem
> all architectures must provide all these defines.
> So, we can consider to add default defines for these in asm-generic.

I think that would be good, yes. We probably picked defaults for the
asm-generic version that are enough to build with CONFIG_PCI disabled,
but there are useful defaults for the other case as well.

Most architectures that use the file don't support PCI, so you can just
add stuff inside of #ifdef CONFIG_PCI. For the remaining 13 architectures
(git grep -l generic/pci.h  | wc), see whether there are conflicts first.
The normal way would be to have the arch specific definition come before
the #include, and then do something like

#ifndef pci_proc_domain
#define pci_proc_domain pci_proc_domain
static inline int pci_proc_domain(struct pci_bus *bus)
{
#ifdef CONFIG_PCI_DOMAINS_GENERIC
        return pci_domain_nr(bus);
#else
	return 1;
}
#endif

	Arnd

Re: [PATCH 1/2] nios2: Add architectural support for PCIe

[Ley Foon Tan]

On Tue, Sep 22, 2015 at 7:42 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Tuesday 22 September 2015 18:53:50 Ley Foon Tan wrote:
>> On Tue, Sep 22, 2015 at 4:18 PM, Arnd Bergmann <arnd@arndb.de> wrote:
>> > On Tuesday 22 September 2015 15:19:26 Ley Foon Tan wrote:
>> > I might be missing something though. Bjorn?
>> >
>> >> @@ -14,7 +14,7 @@
>> >>  #include <linux/types.h>
>> >>  #include <asm/pgtable-bits.h>
>> >>
>> >> -/* PCI is not supported in nios2, set this to 0. */
>> >> +/* PCI I/O space is not supported, set this to 0. */
>> >>  #define IO_SPACE_LIMIT 0
>> >>
>> >>  #define readb_relaxed(addr)  readb(addr)
>> >
>> > It might be useful to enable this, just in case someone connects
>> > a PCI host bridge that does support I/O space.
>> >
>> > Which host bridge do you use? Are you sure there is no I/O space?
>> > Most of them use a set of translation windows to set up a mapping
>> > between bus address (memory, config and io space) and physical
>> > (mmio) space.
>>
>> I'm using Altera PCIe IP. But, you are right. We should enable this,
>> because it shouldn't limited to support Altera PCIe only.
>> BTW, any rule/requirement for the IO_SPACE_LIMIT?
>
> If you want to allow just one PCI host bridge, set it to 0xffff, otherwise
> use 0xfffff (for up to 16 bridges)
Okay, will set it to 0xffff.
>
>> And PCIBIOS_MIN_IO should be non-zero if we enable IO_SPACE_LIMIT?
>
> If you define pcibios_align_resource() as an empty function, that can
> remain zero as well, it's only meant to stay out of the way of ISA
> devices.
Okay.
>
>> >> diff --git a/arch/nios2/include/asm/pci.h b/arch/nios2/include/asm/pci.h
>> >> new file mode 100644
>> >> index 0000000..f2cba05
>> >> --- /dev/null
>> >> +++ b/arch/nios2/include/asm/pci.h
>> >
>> > What happens if you use the asm-generic header? If there is something
>> > missing in it, we can try to get it to do the right things.
>> All the defines in arch/nios2/include/asm/pci.h are required by PCI framework.
>> It will trigger undefined symbols/define error if without them. Seem
>> all architectures must provide all these defines.
>> So, we can consider to add default defines for these in asm-generic.
>
> I think that would be good, yes. We probably picked defaults for the
> asm-generic version that are enough to build with CONFIG_PCI disabled,
> but there are useful defaults for the other case as well.
>
> Most architectures that use the file don't support PCI, so you can just
> add stuff inside of #ifdef CONFIG_PCI. For the remaining 13 architectures
> (git grep -l generic/pci.h  | wc), see whether there are conflicts first.
> The normal way would be to have the arch specific definition come before
> the #include, and then do something like
>
> #ifndef pci_proc_domain
> #define pci_proc_domain pci_proc_domain
> static inline int pci_proc_domain(struct pci_bus *bus)
> {
> #ifdef CONFIG_PCI_DOMAINS_GENERIC
>         return pci_domain_nr(bus);
> #else
>         return 1;
> }
> #endif

Okay, will try add them to asm-generic.
Do you prefer to send it as separate patch or can be part of this patchset?
Thanks.

Regards
Ley Foon

Re: [PATCH 1/2] nios2: Add architectural support for PCIe

[Arnd Bergmann]

On Tuesday 29 September 2015 11:12:24 Ley Foon Tan wrote:
> >
> > I think that would be good, yes. We probably picked defaults for the
> > asm-generic version that are enough to build with CONFIG_PCI disabled,
> > but there are useful defaults for the other case as well.
> >
> > Most architectures that use the file don't support PCI, so you can just
> > add stuff inside of #ifdef CONFIG_PCI. For the remaining 13 architectures
> > (git grep -l generic/pci.h  | wc), see whether there are conflicts first.
> > The normal way would be to have the arch specific definition come before
> > the #include, and then do something like
> >
> > #ifndef pci_proc_domain
> > #define pci_proc_domain pci_proc_domain
> > static inline int pci_proc_domain(struct pci_bus *bus)
> > {
> > #ifdef CONFIG_PCI_DOMAINS_GENERIC
> >         return pci_domain_nr(bus);
> > #else
> >         return 1;
> > }
> > #endif
> 
> Okay, will try add them to asm-generic.

Thanks

> Do you prefer to send it as separate patch or can be part of this patchset?

I prefer the patches to be part of this series and merged through together
with them.

	Arnd

Re: [PATCH 1/2] nios2: Add architectural support for PCIe

[Ley Foon Tan]

On Tue, Sep 29, 2015 at 3:37 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Tuesday 29 September 2015 11:12:24 Ley Foon Tan wrote:
>> >
>> > I think that would be good, yes. We probably picked defaults for the
>> > asm-generic version that are enough to build with CONFIG_PCI disabled,
>> > but there are useful defaults for the other case as well.
>> >
>> > Most architectures that use the file don't support PCI, so you can just
>> > add stuff inside of #ifdef CONFIG_PCI. For the remaining 13 architectures
>> > (git grep -l generic/pci.h  | wc), see whether there are conflicts first.
>> > The normal way would be to have the arch specific definition come before
>> > the #include, and then do something like
>> >
>> > #ifndef pci_proc_domain
>> > #define pci_proc_domain pci_proc_domain
>> > static inline int pci_proc_domain(struct pci_bus *bus)
>> > {
>> > #ifdef CONFIG_PCI_DOMAINS_GENERIC
>> >         return pci_domain_nr(bus);
>> > #else
>> >         return 1;
>> > }
>> > #endif
>>
>> Okay, will try add them to asm-generic.
>
> Thanks
>
>> Do you prefer to send it as separate patch or can be part of this patchset?
>
> I prefer the patches to be part of this series and merged through together
> with them.
>
Okay, will send a new version later.

Thanks.

Regards
Ley Foon

[PATCH 2/2] PCI: Build setup-irq.o for nios2

[Ley Foon Tan]

nios2 requires setup-irq.o to provide pci_fixup_irqs() implementation.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
---
 drivers/pci/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 73e4af4..db8efcd 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -39,6 +39,7 @@ obj-$(CONFIG_MIPS) += setup-irq.o
 obj-$(CONFIG_TILE) += setup-irq.o
 obj-$(CONFIG_SPARC_LEON) += setup-irq.o
 obj-$(CONFIG_M68K) += setup-irq.o
+obj-$(CONFIG_NIOS2) += setup-irq.o
 
 #
 # ACPI Related PCI FW Functions
-- 
1.8.2.1