Patchwork [PATCHv3,1/2] ppc64: perform proper max_bus_speed detection

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Submitter Lucas Kannebley Tavares
Date April 11, 2013, 1:13 p.m.
Message ID <1365685994-32603-2-git-send-email-lucaskt@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/235738/
State Changes Requested, archived
Delegated to: Michael Ellerman
Headers show

Comments

Lucas Kannebley Tavares - April 11, 2013, 1:13 p.m.
On pseries machines the detection for max_bus_speed should be done
through an OpenFirmware property. This patch adds a function to perform this
detection and a hook to perform dynamic adding of the function only for
pseries.

Signed-off-by: Lucas Kannebley Tavares <lucaskt@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/machdep.h     |    2 +
 arch/powerpc/kernel/pci-common.c       |    8 +++++
 arch/powerpc/platforms/pseries/pci.c   |   51 ++++++++++++++++++++++++++++++++
 arch/powerpc/platforms/pseries/setup.c |    4 ++
 4 files changed, 65 insertions(+), 0 deletions(-)
Michael Ellerman - April 15, 2013, 5 a.m.
On Thu, Apr 11, 2013 at 10:13:13AM -0300, Lucas Kannebley Tavares wrote:
> On pseries machines the detection for max_bus_speed should be done
> through an OpenFirmware property. This patch adds a function to perform this
> detection and a hook to perform dynamic adding of the function only for
> pseries.

The crucial detail you didn't mention is that pcibios_root_bridge_prepare()
already exists as a weak function in the PCI code and is called from
pci_create_root_bus().

> diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
> index 8bcc9ca..15796b5 100644
> --- a/arch/powerpc/platforms/pseries/setup.c
> +++ b/arch/powerpc/platforms/pseries/setup.c
> @@ -430,6 +430,8 @@ static void pSeries_machine_kexec(struct kimage *image)
>  }
>  #endif
>  
> +int pseries_root_bridge_prepare(struct pci_host_bridge *bridge);
> +

Don't do that, put it in a header where it belongs.

cheers
Michael Ellerman - April 15, 2013, 11:42 a.m.
On Thu, Apr 11, 2013 at 10:13:13AM -0300, Lucas Kannebley Tavares wrote:
> On pseries machines the detection for max_bus_speed should be done
> through an OpenFirmware property. This patch adds a function to perform this
> detection and a hook to perform dynamic adding of the function only for
> pseries.

This fails to build for me on ppc64_defconfig, with:

arch/powerpc/include/asm/machdep.h:111:5: error: 'struct pci_host_bridge' declared inside parameter list [-Werror]


Presumably you tested it using some other defconfig?

cheers
Lucas Kannebley Tavares - April 17, 2013, 12:38 p.m.
On 04/15/2013 02:00 AM, Michael Ellerman wrote:
> On Thu, Apr 11, 2013 at 10:13:13AM -0300, Lucas Kannebley Tavares wrote:
>> On pseries machines the detection for max_bus_speed should be done
>> through an OpenFirmware property. This patch adds a function to perform this
>> detection and a hook to perform dynamic adding of the function only for
>> pseries.
>
> The crucial detail you didn't mention is that pcibios_root_bridge_prepare()
> already exists as a weak function in the PCI code and is called from
> pci_create_root_bus().

Adding this comment.

>
>> diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
>> index 8bcc9ca..15796b5 100644
>> --- a/arch/powerpc/platforms/pseries/setup.c
>> +++ b/arch/powerpc/platforms/pseries/setup.c
>> @@ -430,6 +430,8 @@ static void pSeries_machine_kexec(struct kimage *image)
>>   }
>>   #endif
>>
>> +int pseries_root_bridge_prepare(struct pci_host_bridge *bridge);
>> +
>
> Don't do that, put it in a header where it belongs.
>

And done as well.

> cheers
>
Lucas Kannebley Tavares - April 17, 2013, 12:40 p.m.
On 04/15/2013 08:42 AM, Michael Ellerman wrote:
> On Thu, Apr 11, 2013 at 10:13:13AM -0300, Lucas Kannebley Tavares wrote:
>> On pseries machines the detection for max_bus_speed should be done
>> through an OpenFirmware property. This patch adds a function to perform this
>> detection and a hook to perform dynamic adding of the function only for
>> pseries.
>
> This fails to build for me on ppc64_defconfig, with:
>
> arch/powerpc/include/asm/machdep.h:111:5: error: 'struct pci_host_bridge' declared inside parameter list [-Werror]
>
>
> Presumably you tested it using some other defconfig?
>
> cheers
>

Yes, I tested with another config, I did get warnings, though, so I 
should've fixed that earlier.
Adding a forward declaration to prevent this from even throwing out 
warnings.

Patch

diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 3d6b410..8f558bf 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -107,6 +107,8 @@  struct machdep_calls {
 	void		(*pcibios_fixup)(void);
 	int		(*pci_probe_mode)(struct pci_bus *);
 	void		(*pci_irq_fixup)(struct pci_dev *dev);
+	int		(*pcibios_root_bridge_prepare)(struct pci_host_bridge
+				*bridge);
 
 	/* To setup PHBs when using automatic OF platform driver for PCI */
 	int		(*pci_setup_phb)(struct pci_controller *host);
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index fa12ae4..80986cf 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -844,6 +844,14 @@  int pci_proc_domain(struct pci_bus *bus)
 	return 1;
 }
 
+int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
+{
+	if (ppc_md.pcibios_root_bridge_prepare)
+		return ppc_md.pcibios_root_bridge_prepare(bridge);
+
+	return 0;
+}
+
 /* This header fixup will do the resource fixup for all devices as they are
  * probed, but not for bridge ranges
  */
diff --git a/arch/powerpc/platforms/pseries/pci.c b/arch/powerpc/platforms/pseries/pci.c
index 0b580f4..7f9c956 100644
--- a/arch/powerpc/platforms/pseries/pci.c
+++ b/arch/powerpc/platforms/pseries/pci.c
@@ -108,3 +108,54 @@  static void fixup_winbond_82c105(struct pci_dev* dev)
 }
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_WINBOND, PCI_DEVICE_ID_WINBOND_82C105,
 			 fixup_winbond_82c105);
+
+int pseries_root_bridge_prepare(struct pci_host_bridge *bridge)
+{
+	struct device_node *dn, *pdn;
+	struct pci_bus *bus;
+	const uint32_t *pcie_link_speed_stats;
+
+	bus = bridge->bus;
+
+	dn = pcibios_get_phb_of_node(bus);
+	if (!dn)
+		return 0;
+
+	for (pdn = dn; pdn != NULL; pdn = pdn->parent) {
+		pcie_link_speed_stats = (const uint32_t *) of_get_property(dn,
+			"ibm,pcie-link-speed-stats", NULL);
+		if (pcie_link_speed_stats)
+			break;
+	}
+
+	if (!pcie_link_speed_stats) {
+		pr_err("no ibm,pcie-link-speed-stats property\n");
+		return 0;
+	}
+
+	switch (pcie_link_speed_stats[0]) {
+	case 0x01:
+		bus->max_bus_speed = PCIE_SPEED_2_5GT;
+		break;
+	case 0x02:
+		bus->max_bus_speed = PCIE_SPEED_5_0GT;
+		break;
+	default:
+		bus->max_bus_speed = PCI_SPEED_UNKNOWN;
+		break;
+	}
+
+	switch (pcie_link_speed_stats[1]) {
+	case 0x01:
+		bus->cur_bus_speed = PCIE_SPEED_2_5GT;
+		break;
+	case 0x02:
+		bus->cur_bus_speed = PCIE_SPEED_5_0GT;
+		break;
+	default:
+		bus->cur_bus_speed = PCI_SPEED_UNKNOWN;
+		break;
+	}
+
+	return 0;
+}
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 8bcc9ca..15796b5 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -430,6 +430,8 @@  static void pSeries_machine_kexec(struct kimage *image)
 }
 #endif
 
+int pseries_root_bridge_prepare(struct pci_host_bridge *bridge);
+
 static void __init pSeries_setup_arch(void)
 {
 	panic_timeout = 10;
@@ -466,6 +468,8 @@  static void __init pSeries_setup_arch(void)
 	else
 		ppc_md.enable_pmcs = power4_enable_pmcs;
 
+	ppc_md.pcibios_root_bridge_prepare = pseries_root_bridge_prepare;
+
 	if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
 		long rc;
 		if ((rc = pSeries_enable_reloc_on_exc()) != H_SUCCESS) {