diff mbox series

[NEXT,1/4] powerpc/pasemi: Add PCI initialisation for Nemo board.

Message ID 4b3d1ee02c7.3de0aa2c@auth.smtp.1and1.co.uk (mailing list archive)
State Changes Requested
Headers show
Series [NEXT,1/4] powerpc/pasemi: Add PCI initialisation for Nemo board. | expand

Commit Message

Darren Stevens Dec. 31, 2017, 10 p.m. UTC 
The A-Eon Amigaone X1000's Nemo motherboard has an AMD SB600
    connected to one of the PCI-e root ports on its PaSemi
    Pwrficient 1628M SoC. Normally the SB600 southbridge would be
    connected to a hidden PCI-e port on the system's northbridge,
    and as a result doesn't fully comply with the PCI-e spec.
    
    Add code to relax the PCI-e detection in both the root port
    and the Linux kernel allowing on board devices to be detected.
    
    Signed-off-by: Darren Stevens <Darren@stevens-zone.net>

---

Comments

kernel test robot Jan. 3, 2018, 12:15 p.m. UTC | #1 
Hi Darren,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on powerpc/next]
[also build test WARNING on v4.15-rc6 next-20180103]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Darren-Stevens/powerpc-pasemi-Add-PCI-initialisation-for-Nemo-board/20180103-091349
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-allmodconfig (attached as .config)
compiler: powerpc64-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=powerpc 

All warnings (new ones prefixed by >>):

   In file included from include/linux/printk.h:7:0,
                    from include/linux/kernel.h:14,
                    from arch/powerpc/platforms/pasemi/pci.c:26:
   arch/powerpc/platforms/pasemi/pci.c: In function 'sb600_set_flag':
>> include/linux/kern_levels.h:5:18: warning: format '%lx' expects argument of type 'long unsigned int', but argument 2 has type 'resource_size_t {aka long long unsigned int}' [-Wformat=]
    #define KERN_SOH "\001"  /* ASCII Start Of Header */
                     ^
   include/linux/kern_levels.h:10:19: note: in expansion of macro 'KERN_SOH'
    #define KERN_CRIT KERN_SOH "2" /* critical conditions */
                      ^~~~~~~~
>> arch/powerpc/platforms/pasemi/pci.c:137:10: note: in expansion of macro 'KERN_CRIT'
      printk(KERN_CRIT "NEMO SB600 IOB base %08lx\n",res.start);
             ^~~~~~~~~
   arch/powerpc/platforms/pasemi/pci.c:137:45: note: format string is defined here
      printk(KERN_CRIT "NEMO SB600 IOB base %08lx\n",res.start);
                                            ~~~~^
                                            %08llx

vim +/KERN_CRIT +137 arch/powerpc/platforms/pasemi/pci.c

  > 26	#include <linux/kernel.h>
    27	#include <linux/pci.h>
    28	
    29	#include <asm/pci-bridge.h>
    30	#include <asm/isa-bridge.h>
    31	#include <asm/machdep.h>
    32	
    33	#include <asm/ppc-pci.h>
    34	
    35	#include "pasemi.h"
    36	
    37	#define PA_PXP_CFA(bus, devfn, off) (((bus) << 20) | ((devfn) << 12) | (off))
    38	
    39	static inline int pa_pxp_offset_valid(u8 bus, u8 devfn, int offset)
    40	{
    41		/* Device 0 Function 0 is special: It's config space spans function 1 as
    42		 * well, so allow larger offset. It's really a two-function device but the
    43		 * second function does not probe.
    44		 */
    45		if (bus == 0 && devfn == 0)
    46			return offset < 8192;
    47		else
    48			return offset < 4096;
    49	}
    50	
    51	static void volatile __iomem *pa_pxp_cfg_addr(struct pci_controller *hose,
    52					       u8 bus, u8 devfn, int offset)
    53	{
    54		return hose->cfg_data + PA_PXP_CFA(bus, devfn, offset);
    55	}
    56	
    57	static inline int is_root_port(int busno, int devfn)
    58	{
    59		return ((busno == 0) && (PCI_FUNC(devfn) < 4) &&
    60			 ((PCI_SLOT(devfn) == 16) || (PCI_SLOT(devfn) == 17)));
    61	}
    62	
    63	static inline int is_5945_reg(int reg)
    64	{
    65		return (((reg >= 0x18) && (reg < 0x34)) ||
    66			((reg >= 0x158) && (reg < 0x178)));
    67	}
    68	
    69	static int workaround_5945(struct pci_bus *bus, unsigned int devfn,
    70				   int offset, int len, u32 *val)
    71	{
    72		struct pci_controller *hose;
    73		void volatile __iomem *addr, *dummy;
    74		int byte;
    75		u32 tmp;
    76	
    77		if (!is_root_port(bus->number, devfn) || !is_5945_reg(offset))
    78			return 0;
    79	
    80		hose = pci_bus_to_host(bus);
    81	
    82		addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset & ~0x3);
    83		byte = offset & 0x3;
    84	
    85		/* Workaround bug 5945: write 0 to a dummy register before reading,
    86		 * and write back what we read. We must read/write the full 32-bit
    87		 * contents so we need to shift and mask by hand.
    88		 */
    89		dummy = pa_pxp_cfg_addr(hose, bus->number, devfn, 0x10);
    90		out_le32(dummy, 0);
    91		tmp = in_le32(addr);
    92		out_le32(addr, tmp);
    93	
    94		switch (len) {
    95		case 1:
    96			*val = (tmp >> (8*byte)) & 0xff;
    97			break;
    98		case 2:
    99			if (byte == 0)
   100				*val = tmp & 0xffff;
   101			else
   102				*val = (tmp >> 16) & 0xffff;
   103			break;
   104		default:
   105			*val = tmp;
   106			break;
   107		}
   108	
   109		return 1;
   110	}
   111	
   112	#ifdef CONFIG_PPC_PASEMI_NEMO
   113	static int sb600_bus = 5;
   114	static void __iomem *iob_mapbase = NULL;
   115	
   116	static void sb600_set_flag(int bus)
   117	{
   118		struct resource res;
   119		struct device_node *dn;
   120		int err;
   121	
   122		if (iob_mapbase == NULL) {
   123			dn = of_find_compatible_node(NULL, "isa", "pasemi,1682m-iob");
   124			if (!dn) {
   125				printk(KERN_CRIT "NEMO SB600 missing iob node\n");
   126				return;
   127			}
   128	
   129			err = of_address_to_resource(dn, 0, &res);
   130			of_node_put(dn);
   131	
   132			if (err) {
   133				printk(KERN_CRIT "NEMO SB600 missing resource\n");
   134				return;
   135			}
   136	
 > 137			printk(KERN_CRIT "NEMO SB600 IOB base %08lx\n",res.start);
   138	
   139			iob_mapbase = ioremap(res.start + 0x100, 0x94);
   140		}
   141	
   142		if (iob_mapbase != NULL) {
   143			if (bus == sb600_bus) {
   144				/*
   145				 * This is the SB600's bus, tell the PCI-e root port
   146				 * to allow non-zero devices to enumerate.
   147				 */
   148				out_le32(iob_mapbase + 4, in_le32(iob_mapbase + 4) | 0x800);
   149			} else {
   150				/*
   151				 * Only scan device 0 on other busses
   152				 */
   153				out_le32(iob_mapbase + 4, in_le32(iob_mapbase + 4) & ~0x800);
   154			}
   155		}
   156	}
   157	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Michael Ellerman May 3, 2018, 1:06 p.m. UTC | #2 
Hi Darren,

Thanks for the patch, sorry it's taken so long to get merged.

Darren Stevens <darren@stevens-zone.net> writes:
>     The A-Eon Amigaone X1000's Nemo motherboard has an AMD SB600
>     connected to one of the PCI-e root ports on its PaSemi
>     Pwrficient 1628M SoC. Normally the SB600 southbridge would be
>     connected to a hidden PCI-e port on the system's northbridge,
>     and as a result doesn't fully comply with the PCI-e spec.
>     
>     Add code to relax the PCI-e detection in both the root port
>     and the Linux kernel allowing on board devices to be detected.
>     
>     Signed-off-by: Darren Stevens <Darren@stevens-zone.net>

This should not be indented.

> diff --git a/arch/powerpc/platforms/pasemi/pasemi.h b/arch/powerpc/platforms/pasemi/pasemi.h
> index 329d2a6..8900dee 100644
> --- a/arch/powerpc/platforms/pasemi/pasemi.h
> +++ b/arch/powerpc/platforms/pasemi/pasemi.h
> @@ -3,6 +3,9 @@
>  #define _PASEMI_PASEMI_H
>  
>  extern unsigned long pas_get_boot_time(void);
> +#ifdef CONFIG_PPC_PASEMI_NEMO
> +extern void nemo_pci_init(void);
> +#endif

We don't need an #ifdef around this thanks.

> diff --git a/arch/powerpc/platforms/pasemi/pci.c b/arch/powerpc/platforms/pasemi/pci.c
> index 5ff6108..cb0ac87 100644
> --- a/arch/powerpc/platforms/pasemi/pci.c
> +++ b/arch/powerpc/platforms/pasemi/pci.c
> @@ -108,6 +109,92 @@ static int workaround_5945(struct pci_bus *bus, unsigned int devfn,
>  	return 1;
>  }
>  
> +#ifdef CONFIG_PPC_PASEMI_NEMO
> +static int sb600_bus = 5;

That's only used once so could just be a #define, or even a literal in
the code.

> +static void __iomem *iob_mapbase = NULL;

That's only used in sb6000_set_flag() so should be in there shouldn't it?

> +static void sb600_set_flag(int bus)
> +{
> +	struct resource res;
> +	struct device_node *dn;
> +	int err;
> +
> +	if (iob_mapbase == NULL) {
> +		dn = of_find_compatible_node(NULL, "isa", "pasemi,1682m-iob");
> +		if (!dn) {
> +			printk(KERN_CRIT "NEMO SB600 missing iob node\n");

I'm not sure CRIT is really necessary, we tend to use ERR, but I don't
mind that much.

But can you use pr_err()/pr_crit() please.

> +			return;
> +		}
> +
> +		err = of_address_to_resource(dn, 0, &res);
> +		of_node_put(dn);
> +
> +		if (err) {
> +			printk(KERN_CRIT "NEMO SB600 missing resource\n");
> +			return;
> +		}
> +
> +		printk(KERN_CRIT "NEMO SB600 IOB base %08lx\n",res.start);

That's INFO or even DEBUG.

> +
> +		iob_mapbase = ioremap(res.start + 0x100, 0x94);

0x94 ?

It's going to map you at least one page anyway.

> +	}
> +
> +	if (iob_mapbase != NULL) {
> +		if (bus == sb600_bus) {
> +			/*
> +			 * This is the SB600's bus, tell the PCI-e root port
> +			 * to allow non-zero devices to enumerate.
> +			 */
> +			out_le32(iob_mapbase + 4, in_le32(iob_mapbase + 4) | 0x800);

Does reg #4 have a name?
Or 0x800 ?

> +		} else {
> +			/*
> +			 * Only scan device 0 on other busses
> +			 */
> +			out_le32(iob_mapbase + 4, in_le32(iob_mapbase + 4) & ~0x800);
> +		}
> +	}
> +}
> +
> +static int nemo_pxp_read_config(struct pci_bus *bus, unsigned int devfn,
> +			      int offset, int len, u32 *val)
> +{
> +	struct pci_controller *hose;

Can we call them host or controller or something in new code?

> +	void volatile __iomem *addr;

Does that need to be volatile?

> +	hose = pci_bus_to_host(bus);
> +	if (!hose)
> +		return PCIBIOS_DEVICE_NOT_FOUND;
> +
> +	if (!pa_pxp_offset_valid(bus->number, devfn, offset))
> +		return PCIBIOS_BAD_REGISTER_NUMBER;
> +
> +	if (workaround_5945(bus, devfn, offset, len, val))
> +		return PCIBIOS_SUCCESSFUL;
> +
> +	addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset);
> +
> +	sb600_set_flag(bus->number);
> +
> +	/*
> +	 * Note: the caller has already checked that offset is
> +	 * suitably aligned and that len is 1, 2 or 4.
> +	 */
> +	switch (len) {
> +	case 1:
> +		*val = in_8(addr);
> +		break;
> +	case 2:
> +		*val = in_le16(addr);
> +		break;
> +	default:
> +		*val = in_le32(addr);
> +		break;
> +	}
> +
> +	return PCIBIOS_SUCCESSFUL;
> +}
> +#endif
> +
>  static int pa_pxp_read_config(struct pci_bus *bus, unsigned int devfn,
>  			      int offset, int len, u32 *val)
>  {
> @@ -178,6 +265,20 @@ static int pa_pxp_write_config(struct pci_bus *bus, unsigned int devfn,
>  	return PCIBIOS_SUCCESSFUL;
>  }
>  
> +#ifdef CONFIG_PPC_PASEMI_NEMO
> +static struct pci_ops nemo_pxp_ops = {
> +	.read = nemo_pxp_read_config,
> +	.write = pa_pxp_write_config,
> +};
> +
> +static void __init setup_nemo_pxp(struct pci_controller *hose)
> +{
> +	hose->ops = &nemo_pxp_ops;
> +	hose->cfg_data = ioremap(0xe0000000, 0x10000000);
> +}

Could these go in one of the ifdef block below? Just to reduce the
number of times we ifdef NEMO.
> @@ -213,6 +343,28 @@ static int __init pas_add_bridge(struct device_node *dev)
>  	return 0;
>  }
>  
> +#ifdef CONFIG_PPC_PASEMI_NEMO
> +void __init nemo_pci_init(void)
> +{
> +	struct device_node *np, *root;
> +
> +	root = of_find_node_by_path("/");
> +	if (!root) {
> +		printk(KERN_CRIT "pas_pci_init: can't find root "
> +			"of device tree\n");

TBH that can't really happen, or if it does we're not going to boot
elsewhere.

So the printk() is probably overkill.

> +		return;
> +	}
> +
> +	pci_set_flags(PCI_SCAN_ALL_PCIE_DEVS);
> +
> +	for (np = NULL; (np = of_get_next_child(root, np)) != NULL;)

Does the pxp node not have a compatible property? (I may have asked that
before).

Normally you'd search by compatible, not name.

If you have to search by name then of_get_child_by_name() should work.

> +		if (np->name && !strcmp(np->name, "pxp") && !nemo_add_bridge(np))
> +			of_node_get(np);

Why are we of_node_get()'ing here?

If nemo_add_bridge() wants to keep a reference it should do that itself.

> +
> +	of_node_put(root);
> +}
> +#endif
> +
>  void __init pas_pci_init(void)
>  {
>  	struct device_node *np, *root;


cheers
Christian Zigotzky July 10, 2018, 5:43 a.m. UTC | #3 
Hi Michael,
Hi All,

kbuild test robot Wed, 03 Jan 2018 04:17:20 -0800 wrote:

Hi Darren,

Thank you for the patch! Perhaps something to improve:

arch/powerpc/platforms/pasemi/pci.c: In function 'sb600_set_flag': >> include/linux/kern_levels.h:5:18: warning: format '%lx' expects argument of >> type 'long unsigned int', but argument 2 has type 'resource_size_t {aka long >> long unsigned int}' [-Wformat=] #define KERN_SOH "\001" /* ASCII Start Of Header */

—-

I was able to fix this small format issue. I replaced the format '%08lx' with '%08llx'.

+ printk(KERN_CRIT "NEMO SB600 IOB base %08llx\n",res.start);

Is this fix OK or is there a better solution?

> On 3. May 2018, at 15:06, Michael Ellerman <mpe@ellerman.id.au> wrote:
> 
>> +
>> +        printk(KERN_CRIT "NEMO SB600 IOB base %08lx\n",res.start);
> 
> That's INFO or even DEBUG.
>> 

Michael,

What do you think about this fix?

+ printk(KERN_INFO "NEMO SB600 IOB base %08llx\n",res.start);

Thanks,
Christian
Michael Ellerman July 10, 2018, 1:50 p.m. UTC | #4 
Christian Zigotzky <chzigotzky@xenosoft.de> writes:

> Hi Michael,
> Hi All,
>
> kbuild test robot Wed, 03 Jan 2018 04:17:20 -0800 wrote:
>
> Hi Darren,
>
> Thank you for the patch! Perhaps something to improve:
>
> arch/powerpc/platforms/pasemi/pci.c: In function 'sb600_set_flag': >> include/linux/kern_levels.h:5:18: warning: format '%lx' expects argument of >> type 'long unsigned int', but argument 2 has type 'resource_size_t {aka long >> long unsigned int}' [-Wformat=] #define KERN_SOH "\001" /* ASCII Start Of Header */
>
> —-
>
> I was able to fix this small format issue. I replaced the format '%08lx' with '%08llx'.
>
> + printk(KERN_CRIT "NEMO SB600 IOB base %08llx\n",res.start);
>
> Is this fix OK or is there a better solution?
>
>> On 3. May 2018, at 15:06, Michael Ellerman <mpe@ellerman.id.au> wrote:
>> 
>>> +
>>> +        printk(KERN_CRIT "NEMO SB600 IOB base %08lx\n",res.start);
>> 
>> That's INFO or even DEBUG.
>>> 
>
> Michael,
>
> What do you think about this fix?
>
> + printk(KERN_INFO "NEMO SB600 IOB base %08llx\n",res.start);

pr_info() would be nice.

But I replied with lots of other comments previously.

None of them were super critical, but it would be nice to get them fixed
before merging if possible.

cheers
Christian Zigotzky July 10, 2018, 5:15 p.m. UTC | #5 
Hello Michael,

Thanks a lot for your reply. OK, first I would like to add 

pr_info("NEMO SB600 IOB base %08llx\n",res.start)

to the Nemo patch. Is this line correct now?

After that I will try to contact Darren because of your other comments.

If I don’t reach Darren then I will try to fix the issues but I think I need your help for fixing them.

Thanks,
Christian

> On 10. Jul 2018, at 15:50, Michael Ellerman wrote:
> 
> pr_info() would be nice.
> 
> But I replied with lots of other comments previously.
> 
> None of them were super critical, but it would be nice to get them fixed
> before merging if possible.
> 
> cheers
Michael Ellerman July 11, 2018, 2:04 p.m. UTC | #6 
Christian Zigotzky <chzigotzky@xenosoft.de> writes:

> Hello Michael,
>
> Thanks a lot for your reply. OK, first I would like to add 
>
> pr_info("NEMO SB600 IOB base %08llx\n",res.start)
>
> to the Nemo patch. Is this line correct now?

Yes I think so.

The type of start is resource_size_t, which can be 32 or 64-bits. But in
this code it should always be 64-bit.

> After that I will try to contact Darren because of your other comments.
>
> If I don’t reach Darren then I will try to fix the issues but I think
> I need your help for fixing them.

Sure.

cheers
diff mbox series

Patch

diff --git a/arch/powerpc/platforms/pasemi/pasemi.h b/arch/powerpc/platforms/pasemi/pasemi.h
index 329d2a6..8900dee 100644
--- a/arch/powerpc/platforms/pasemi/pasemi.h
+++ b/arch/powerpc/platforms/pasemi/pasemi.h
@@ -3,6 +3,9 @@ 
 #define _PASEMI_PASEMI_H
 
 extern unsigned long pas_get_boot_time(void);
+#ifdef CONFIG_PPC_PASEMI_NEMO
+extern void nemo_pci_init(void);
+#endif
 extern void pas_pci_init(void);
 extern void pas_pci_irq_fixup(struct pci_dev *dev);
 extern void pas_pci_dma_dev_setup(struct pci_dev *dev);
diff --git a/arch/powerpc/platforms/pasemi/pci.c b/arch/powerpc/platforms/pasemi/pci.c
index 5ff6108..cb0ac87 100644
--- a/arch/powerpc/platforms/pasemi/pci.c
+++ b/arch/powerpc/platforms/pasemi/pci.c
@@ -27,6 +27,7 @@ 
 #include <linux/pci.h>
 
 #include <asm/pci-bridge.h>
+#include <asm/isa-bridge.h>
 #include <asm/machdep.h>
 
 #include <asm/ppc-pci.h>
@@ -108,6 +109,92 @@  static int workaround_5945(struct pci_bus *bus, unsigned int devfn,
 	return 1;
 }
 
+#ifdef CONFIG_PPC_PASEMI_NEMO
+static int sb600_bus = 5;
+static void __iomem *iob_mapbase = NULL;
+
+static void sb600_set_flag(int bus)
+{
+	struct resource res;
+	struct device_node *dn;
+	int err;
+
+	if (iob_mapbase == NULL) {
+		dn = of_find_compatible_node(NULL, "isa", "pasemi,1682m-iob");
+		if (!dn) {
+			printk(KERN_CRIT "NEMO SB600 missing iob node\n");
+			return;
+		}
+
+		err = of_address_to_resource(dn, 0, &res);
+		of_node_put(dn);
+
+		if (err) {
+			printk(KERN_CRIT "NEMO SB600 missing resource\n");
+			return;
+		}
+
+		printk(KERN_CRIT "NEMO SB600 IOB base %08lx\n",res.start);
+
+		iob_mapbase = ioremap(res.start + 0x100, 0x94);
+	}
+
+	if (iob_mapbase != NULL) {
+		if (bus == sb600_bus) {
+			/*
+			 * This is the SB600's bus, tell the PCI-e root port
+			 * to allow non-zero devices to enumerate.
+			 */
+			out_le32(iob_mapbase + 4, in_le32(iob_mapbase + 4) | 0x800);
+		} else {
+			/*
+			 * Only scan device 0 on other busses
+			 */
+			out_le32(iob_mapbase + 4, in_le32(iob_mapbase + 4) & ~0x800);
+		}
+	}
+}
+
+static int nemo_pxp_read_config(struct pci_bus *bus, unsigned int devfn,
+			      int offset, int len, u32 *val)
+{
+	struct pci_controller *hose;
+	void volatile __iomem *addr;
+
+	hose = pci_bus_to_host(bus);
+	if (!hose)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	if (!pa_pxp_offset_valid(bus->number, devfn, offset))
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+
+	if (workaround_5945(bus, devfn, offset, len, val))
+		return PCIBIOS_SUCCESSFUL;
+
+	addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset);
+
+	sb600_set_flag(bus->number);
+
+	/*
+	 * Note: the caller has already checked that offset is
+	 * suitably aligned and that len is 1, 2 or 4.
+	 */
+	switch (len) {
+	case 1:
+		*val = in_8(addr);
+		break;
+	case 2:
+		*val = in_le16(addr);
+		break;
+	default:
+		*val = in_le32(addr);
+		break;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+#endif
+
 static int pa_pxp_read_config(struct pci_bus *bus, unsigned int devfn,
 			      int offset, int len, u32 *val)
 {
@@ -178,6 +265,20 @@  static int pa_pxp_write_config(struct pci_bus *bus, unsigned int devfn,
 	return PCIBIOS_SUCCESSFUL;
 }
 
+#ifdef CONFIG_PPC_PASEMI_NEMO
+static struct pci_ops nemo_pxp_ops = {
+	.read = nemo_pxp_read_config,
+	.write = pa_pxp_write_config,
+};
+
+static void __init setup_nemo_pxp(struct pci_controller *hose)
+{
+	hose->ops = &nemo_pxp_ops;
+	hose->cfg_data = ioremap(0xe0000000, 0x10000000);
+}
+
+#endif
+
 static struct pci_ops pa_pxp_ops = {
 	.read = pa_pxp_read_config,
 	.write = pa_pxp_write_config,
@@ -189,6 +290,35 @@  static void __init setup_pa_pxp(struct pci_controller *hose)
 	hose->cfg_data = ioremap(0xe0000000, 0x10000000);
 }
 
+#ifdef CONFIG_PPC_PASEMI_NEMO
+static int __init nemo_add_bridge(struct device_node *dev)
+{
+	struct pci_controller *hose;
+
+	pr_debug("Adding PCI host bridge %pOF\n", dev);
+
+	hose = pcibios_alloc_controller(dev);
+	if (!hose)
+		return -ENOMEM;
+
+	hose->first_busno = 0;
+	hose->last_busno = 0xff;
+	hose->controller_ops = pasemi_pci_controller_ops;
+
+	setup_nemo_pxp(hose);
+
+	printk(KERN_INFO "Found PA-PXP PCI host bridge.\n");
+
+	/* Interpret the "ranges" property */
+	pci_process_bridge_OF_ranges(hose, dev, 1);
+
+	/* Scan for an isa bridge. */
+	isa_bridge_find_early(hose);
+
+	return 0;
+}
+#endif
+
 static int __init pas_add_bridge(struct device_node *dev)
 {
 	struct pci_controller *hose;
@@ -213,6 +343,28 @@  static int __init pas_add_bridge(struct device_node *dev)
 	return 0;
 }
 
+#ifdef CONFIG_PPC_PASEMI_NEMO
+void __init nemo_pci_init(void)
+{
+	struct device_node *np, *root;
+
+	root = of_find_node_by_path("/");
+	if (!root) {
+		printk(KERN_CRIT "pas_pci_init: can't find root "
+			"of device tree\n");
+		return;
+	}
+
+	pci_set_flags(PCI_SCAN_ALL_PCIE_DEVS);
+
+	for (np = NULL; (np = of_get_next_child(root, np)) != NULL;)
+		if (np->name && !strcmp(np->name, "pxp") && !nemo_add_bridge(np))
+			of_node_get(np);
+
+	of_node_put(root);
+}
+#endif
+
 void __init pas_pci_init(void)
 {
 	struct device_node *np, *root;