[RFC PATCH 2/2] arm: pcibios: move to generic PCI domains

Karicheri, Muralidharan m-karicheri2 at ti.com
Sun Nov 2 18:36:34 PST 2014


>-----Original Message-----
>From: Jingoo Han [mailto:jg1.han at samsung.com]
>Sent: Sunday, November 02, 2014 8:18 PM
>To: 'Lorenzo Pieralisi'
>Cc: linux-arm-kernel at lists.infradead.org; linux-pci at vger.kernel.org; liviu.dudau at arm.com;
>'Arnd Bergmann'; 'Phil Edworthy'; 'Jason Gunthorpe'; 'Bjorn Helgaas'; 'Russell King'; 'Mohit
>Kumar'; 'Richard Zhu'; 'Lucas Stach'; KISHON VIJAY ABRAHAM; Karicheri, Muralidharan;
>'Jingoo Han'
>Subject: Re: [RFC PATCH 2/2] arm: pcibios: move to generic PCI domains
>
>On Thursday, October 30, 2014 8:45 PM, Lorenzo Pieralisi wrote:
>>
>> Most if not all ARM PCI host controller device drivers either ignore
>> the domain field in the pci_sys_data structure or just increment it
>> every time a host controller is probed, using it as a domain counter.
>>
>> Therefore, instead of relying on pci_sys_data to stash the domain
>> number in a standard location, ARM pcibios code can be moved to the
>> newly introduced generic PCI domains code, implemented in commits:
>>
>> commit 41e5c0f81d3e676d671d96a0a1fafb27abfbd9
>> ("of/pci: Add pci_get_new_domain_nr() and of_get_pci_domain_nr()")
>>
>> commit 670ba0c8883b576d0aec28bd7a838358a4be1
>> ("PCI: Add generic domain handling")
>>
>> In order to assign a domain number dynamically, the ARM pcibios
>> defines the function, called by core PCI code:
>>
>> void pci_bus_assign_domain_nr(...)
>>
>> that relies on a DT property to define the domain number or falls back
>> to a counter; its usage replaces the current domain assignment code in
>> PCI host controllers present in the kernel.
>>
>> Cc: Arnd Bergmann <arnd at arndb.de>
>> Cc: Phil Edworthy <phil.edworthy at renesas.com>
>> Cc: Jason Gunthorpe <jgunthorpe at obsidianresearch.com>
>> Cc: Jingoo Han <jg1.han at samsung.com>
>> Cc: Bjorn Helgaas <bhelgaas at google.com>
>> Cc: Russell King <linux at arm.linux.org.uk>
>> Cc: Mohit Kumar <mohit.kumar at st.com>
>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
>
>(+CC Richard Zhu, Lucas Stach, Kishon Vijay Abraham I, Murali Karicheri)
>
>Acked-by: Jingoo Han <jg1.han at samsung.com>
>
>For a long time, I have wanted the patch like this. Personally, I want to increase the build
>coverage and keep the same binary regardless of config options as possible; thus, I don't
>like #ifdef guards such as '#ifdef CONFIG_PCI_DOMAINS'. When I submitted the first patch
>for 'pcie-designware.c', I was not able to find a way to remove '#ifdef
>CONFIG_PCI_DOMAINS' from 'pcie-designware.c'.
>
>This patch looks good and I think that this patch will not make the problem. However, I
>didn't test this patch with Exynos platform, due to some reasons. So, I hope that other
>engineers test this patch on other SoC platforms related to designware PCIe.
>
>To Mohit Kumar (ST SPEAR13XX), Richard Zhu/Lucas Stach (IMX6)
>    Kishon Vijay Abraham I (TI DRA7XX), Murali Karicheri (TI KEYSTONE)
>
Jingoo,
I will be able to try this sometime after 11/9 as I am on travel.

Regards,
Murali

>Would you test this patch and share the result?
>It would be very helpful. Thank you.
>
>Best regards,
>Jingoo Han
>
>> ---
>>  arch/arm/Kconfig                   |  3 +++
>>  arch/arm/include/asm/mach/pci.h    |  3 ---
>>  arch/arm/include/asm/pci.h         |  7 -------
>>  arch/arm/kernel/bios32.c           | 26 +++++++++++++++++++++++---
>>  drivers/pci/host/pci-mvebu.c       | 10 ++--------
>>  drivers/pci/host/pcie-designware.c |  3 ---
>>  drivers/pci/host/pcie-rcar.c       |  3 ---
>>  7 files changed, 28 insertions(+), 27 deletions(-)
>>
>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index
>> 89c4b5c..29544f0 100644
>> --- a/arch/arm/Kconfig
>> +++ b/arch/arm/Kconfig
>> @@ -1292,6 +1292,9 @@ config PCI_DOMAINS
>>  	bool
>>  	depends on PCI
>>
>> +config PCI_DOMAINS_GENERIC
>> +	def_bool PCI_DOMAINS
>> +
>>  config PCI_NANOENGINE
>>  	bool "BSE nanoEngine PCI support"
>>  	depends on SA1100_NANOENGINE
>> diff --git a/arch/arm/include/asm/mach/pci.h
>> b/arch/arm/include/asm/mach/pci.h index 7fc4278..f19f627 100644
>> --- a/arch/arm/include/asm/mach/pci.h
>> +++ b/arch/arm/include/asm/mach/pci.h
>> @@ -44,9 +44,6 @@ struct hw_pci {
>>   * Per-controller structure
>>   */
>>  struct pci_sys_data {
>> -#ifdef CONFIG_PCI_DOMAINS
>> -	int		domain;
>> -#endif
>>  	struct list_head node;
>>  	int		busnr;		/* primary bus number			*/
>>  	u64		mem_offset;	/* bus->cpu memory mapping offset	*/
>> diff --git a/arch/arm/include/asm/pci.h b/arch/arm/include/asm/pci.h
>> index 7e95d85..585dc33 100644
>> --- a/arch/arm/include/asm/pci.h
>> +++ b/arch/arm/include/asm/pci.h
>> @@ -18,13 +18,6 @@ static inline int pcibios_assign_all_busses(void)
>> }
>>
>>  #ifdef CONFIG_PCI_DOMAINS
>> -static inline int pci_domain_nr(struct pci_bus *bus) -{
>> -	struct pci_sys_data *root = bus->sysdata;
>> -
>> -	return root->domain;
>> -}
>> -
>>  static inline int pci_proc_domain(struct pci_bus *bus)  {
>>  	return pci_domain_nr(bus);
>> diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c index
>> 17a26c1..d8c2b4e 100644
>> --- a/arch/arm/kernel/bios32.c
>> +++ b/arch/arm/kernel/bios32.c
>> @@ -11,6 +11,8 @@
>>  #include <linux/slab.h>
>>  #include <linux/init.h>
>>  #include <linux/io.h>
>> +#include <linux/of.h>
>> +#include <linux/of_pci.h>
>>
>>  #include <asm/mach-types.h>
>>  #include <asm/mach/map.h>
>> @@ -468,9 +470,6 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci
>*hw,
>>  		if (!sys)
>>  			panic("PCI: unable to allocate sys data!");
>>
>> -#ifdef CONFIG_PCI_DOMAINS
>> -		sys->domain  = hw->domain;
>> -#endif
>>  		sys->busnr   = busnr;
>>  		sys->swizzle = hw->swizzle;
>>  		sys->map_irq = hw->map_irq;
>> @@ -511,6 +510,27 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci
>*hw,
>>  	}
>>  }
>>
>> +#ifdef CONFIG_PCI_DOMAINS_GENERIC
>> +static bool dt_domain_found;
>> +
>> +void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device
>> +*parent) {
>> +	int domain = of_get_pci_domain_nr(parent->of_node);
>> +
>> +	if (domain >= 0) {
>> +		dt_domain_found = true;
>> +	} else if (dt_domain_found == true) {
>> +		dev_err(parent, "Node %s is missing \"linux,pci-domain\" property in DT\n",
>> +			parent->of_node->full_name);
>> +		return;
>> +	} else {
>> +		domain = pci_get_new_domain_nr();
>> +	}
>> +
>> +	bus->domain_nr = domain;
>> +}
>> +#endif
>> +
>>  void pci_common_init_dev(struct device *parent, struct hw_pci *hw)  {
>>  	struct pci_sys_data *sys;
>> diff --git a/drivers/pci/host/pci-mvebu.c
>> b/drivers/pci/host/pci-mvebu.c index b1315e1..2b4c1f2 100644
>> --- a/drivers/pci/host/pci-mvebu.c
>> +++ b/drivers/pci/host/pci-mvebu.c
>> @@ -722,17 +722,11 @@ static int mvebu_pcie_setup(int nr, struct
>> pci_sys_data *sys)  {
>>  	struct mvebu_pcie *pcie = sys_to_pcie(sys);
>>  	int i;
>> -	int domain = 0;
>>
>> -#ifdef CONFIG_PCI_DOMAINS
>> -	domain = sys->domain;
>> -#endif
>> -
>> -	snprintf(pcie->mem_name, sizeof(pcie->mem_name), "PCI MEM %04x",
>> -		 domain);
>> +	snprintf(pcie->mem_name, sizeof(pcie->mem_name), "PCI MEM %04x",
>> +nr);
>>  	pcie->mem.name = pcie->mem_name;
>>
>> -	snprintf(pcie->io_name, sizeof(pcie->io_name), "PCI I/O %04x", domain);
>> +	snprintf(pcie->io_name, sizeof(pcie->io_name), "PCI I/O %04x", nr);
>>  	pcie->realio.name = pcie->io_name;
>>
>>  	if (request_resource(&iomem_resource, &pcie->mem)) diff --git
>> a/drivers/pci/host/pcie-designware.c
>> b/drivers/pci/host/pcie-designware.c
>> index dfed00a..6790b87 100644
>> --- a/drivers/pci/host/pcie-designware.c
>> +++ b/drivers/pci/host/pcie-designware.c
>> @@ -502,9 +502,6 @@ int __init dw_pcie_host_init(struct pcie_port *pp)
>>  	dw_pci.private_data = (void **)&pp;
>>
>>  	pci_common_init_dev(pp->dev, &dw_pci); -#ifdef CONFIG_PCI_DOMAINS
>> -	dw_pci.domain++;
>> -#endif
>>
>>  	return 0;
>>  }
>> diff --git a/drivers/pci/host/pcie-rcar.c
>> b/drivers/pci/host/pcie-rcar.c index 61158e0..b6b859e 100644
>> --- a/drivers/pci/host/pcie-rcar.c
>> +++ b/drivers/pci/host/pcie-rcar.c
>> @@ -404,9 +404,6 @@ static void rcar_pcie_enable(struct rcar_pcie *pcie)
>>  	rcar_pci.private_data = (void **)&pcie;
>>
>>  	pci_common_init_dev(&pdev->dev, &rcar_pci); -#ifdef
>> CONFIG_PCI_DOMAINS
>> -	rcar_pci.domain++;
>> -#endif
>>  }
>>
>>  static int phy_wait_for_ack(struct rcar_pcie *pcie)
>> --
>> 2.1.2




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