Message-ID: <2CC2A0A4A178534D93D5159BF3BCB6619C5F94E71E@EAPEX1MAIL1.st.com>
Date:	Mon, 23 Jun 2014 13:26:52 +0800
From:	Mohit KUMAR DCG <Mohit.KUMAR@...com>
To:	Pratyush ANAND <pratyush.anand@...com>,
	Murali Karicheri <m-karicheri2@...com>
Cc:	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
	"Shilimkar, Santosh" <santosh.shilimkar@...com>,
	Russell King <linux@....linux.org.uk>,
	Grant Likely <grant.likely@...aro.org>,
	Rob Herring <robh+dt@...nel.org>,
	Jingoo Han <jg1.han@...sung.com>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Richard Zhu <r65037@...escale.com>,
	"ABRAHAM, KISHON VIJAY" <kishon@...com>,
	Marek Vasut <marex@...x.de>, Arnd Bergmann <arnd@...db.de>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Randy Dunlap <rdunlap@...radead.org>
Subject: RE: [PATCH v2 2/8] PCI: designware: refactor host init code to
 re-use on v3.65 DW pci hw

Hello Murali,

> -----Original Message-----
> From: Pratyush ANAND
> Sent: Monday, June 23, 2014 10:36 AM
> To: Murali Karicheri
> Cc: linux-arm-kernel@...ts.infradead.org; linux-kernel@...r.kernel.org;
> linux-pci@...r.kernel.org; devicetree@...r.kernel.org; linux-
> doc@...r.kernel.org; Shilimkar, Santosh; Russell King; Grant Likely; Rob
> Herring; Mohit KUMAR DCG; Jingoo Han; Bjorn Helgaas; Richard Zhu;
> ABRAHAM, KISHON VIJAY; Marek Vasut; Arnd Bergmann; Pawel Moll; Mark
> Rutland; Ian Campbell; Kumar Gala; Randy Dunlap
> Subject: Re: [PATCH v2 2/8] PCI: designware: refactor host init code to re-use
> on v3.65 DW pci hw
> 
> On Sat, Jun 21, 2014 at 02:47:27AM +0800, Murali Karicheri wrote:
> > On 6/18/2014 3:05 AM, Pratyush Anand wrote:
> > > Hi Murali,
> > >
> > > On Wed, Jun 11, 2014 at 02:51:21AM +0800, Murali Karicheri wrote:
> 
> [...]
> 
> > Pratyush,
> >
> > Thanks for the comments.
> >
> > This is IP specific code and another driver that has this version of
> > the IP will be able to re-use the code. This is also being discussed
> > in another thread from Bjorn and Jingoo.
> 
> Anything which is implemented in application space, will not be same across
> all IP users. For example, you have MSI0_IRQ_ENABLE_SET at offset 0x108 in
> application space.Other vendor may not have this register at the same
> offset. Moreover, other vendors are not even obliged to implement MSI
> Enable signals in same way, so internal bit definition of the register may
> change.
> 
> In summary: Code is only reusable if all register offset and bit definitions are
> same across vendors. In case of DW driver none of the code which are
> accessed using va_app_base should go to common area.
> 

- yes, I completely agree with Pratyush.
As explained earlier also that prior to Synopsys version 3.70 MSI and ATU
code was not standardized and each platform have its specific implementation through
pcie application space logic. So let us follow the convention and not merge any application
specific  code to the DW core code.

Thanks
Mohit

> > Please discuss this in that thread.
> 
> Sorry, I am not following pci mailing list. Doing something else these days. So
> if you can help me with the thread link.
> 
> Regards
> Pratyush
> >
> > >> initialization code. So refactor the msi host controller code into
> > >> a separate function. Other common functions across both hw versions
> > >> are moved to dw_pcie_common_host_init() and called from the newer
> > >> and
> > >> v3.65 hw host initialization code.
> > >>
> > >> Signed-off-by: Murali Karicheri <m-karicheri2@...com>
> > >>
> > >> CC: Santosh Shilimkar <santosh.shilimkar@...com>
> > >> CC: Russell King <linux@....linux.org.uk>
> > >> CC: Grant Likely <grant.likely@...aro.org>
> > >> CC: Rob Herring <robh+dt@...nel.org>
> > >> CC: Mohit Kumar <mohit.kumar@...com>
> > >> CC: Jingoo Han <jg1.han@...sung.com>
> > >> CC: Bjorn Helgaas <bhelgaas@...gle.com>
> > >> CC: Pratyush Anand <pratyush.anand@...com>
> > >> CC: Richard Zhu <r65037@...escale.com>
> > >> CC: Kishon Vijay Abraham I <kishon@...com>
> > >> CC: Marek Vasut <marex@...x.de>
> > >> CC: Arnd Bergmann <arnd@...db.de>
> > >> CC: Pawel Moll <pawel.moll@....com>
> > >> CC: Mark Rutland <mark.rutland@....com>
> > >> CC: Ian Campbell <ijc+devicetree@...lion.org.uk>
> > >> CC: Kumar Gala <galak@...eaurora.org>
> > >> CC: Randy Dunlap <rdunlap@...radead.org>
> > >> CC: Grant Likely <grant.likely@...aro.org>
> > >>
> > >> ---
> > >>   drivers/pci/host/pcie-designware.c |  136
> ++++++++++++++++++++++++++----------
> > >>   1 file changed, 101 insertions(+), 35 deletions(-)
> > >>
> > >> diff --git a/drivers/pci/host/pcie-designware.c
> > >> b/drivers/pci/host/pcie-designware.c
> > >> index e8f5d8d..e4bd19a 100644
> > >> --- a/drivers/pci/host/pcie-designware.c
> > >> +++ b/drivers/pci/host/pcie-designware.c
> > >> @@ -389,13 +389,19 @@ static const struct irq_domain_ops
> msi_domain_ops = {
> > >>   	.map = dw_pcie_msi_map,
> > >>   };
> > >>
> > >> -int __init dw_pcie_host_init(struct pcie_port *pp)
> > >> +/*
> > >> + * dw_pcie_parse_resource() - Function to parse common resources
> > >> + *
> > >> + * @pp: ptr to pcie port
> > >> + *
> > >> + * Parse the range property for MEM, IO and cfg resources, and map
> > >> + * the cfg register space.
> > >> + */
> > > Why do you need this function? If you have some extra resource, you
> > > can ioremap that before you call dw_pcie_host_init.
> >
> > I assume you are referring to dw_pcie_parse_resource(). Keystone PCIe
> > driver needs this to parse the range property for IORESOURCE_MEM and
> > IORESOURCE_IO resources.
> > So refactored this into a function and called from host_init() code
> > for v3.65 and dw_pcie_host_init . But for Keystone PCI driver, no need
> > to ioremap
> > cfg1 and cfg2 as it doesn't have ATU ports. So host_init() code has to
> > be little different.
> > Idea is to have IP specific host_init() and refactor and re-use the
> > common code on both.
> >
> > >
> > >> +int __init dw_pcie_parse_resource(struct pcie_port *pp)
> > >>   {
> > >>   	struct device_node *np = pp->dev->of_node;
> > >>   	struct of_pci_range range;
> > >>   	struct of_pci_range_parser parser;
> > >> -	u32 val;
> > >> -	int i;
> > >>
> > >>   	if (of_pci_range_parser_init(&parser, np)) {
> > >>   		dev_err(pp->dev, "missing ranges property\n"); @@ -431,41
> > >> +437,29 @@ int __init dw_pcie_host_init(struct pcie_port *pp)
> > >>   			pp->config.cfg1_size = resource_size(&pp->cfg)/2;
> > >>   		}
> > >>   	}
> > >> -
> > >> -	if (!pp->dbi_base) {
> > >> -		pp->dbi_base = devm_ioremap(pp->dev, pp->cfg.start,
> > >> -					resource_size(&pp->cfg));
> > >> -		if (!pp->dbi_base) {
> > >> -			dev_err(pp->dev, "error with ioremap\n");
> > >> -			return -ENOMEM;
> > >> -		}
> > >> -	}
> > >> -
> > >> -	pp->cfg0_base = pp->cfg.start;
> > >> -	pp->cfg1_base = pp->cfg.start + pp->config.cfg0_size;
> > >>   	pp->mem_base = pp->mem.start;
> > >>
> > >> -	pp->va_cfg0_base = devm_ioremap(pp->dev, pp->cfg0_base,
> > >> -					pp->config.cfg0_size);
> > >> -	if (!pp->va_cfg0_base) {
> > >> -		dev_err(pp->dev, "error with ioremap in function\n");
> > >> -		return -ENOMEM;
> > >> -	}
> > >> -	pp->va_cfg1_base = devm_ioremap(pp->dev, pp->cfg1_base,
> > >> -					pp->config.cfg1_size);
> > >> -	if (!pp->va_cfg1_base) {
> > >> -		dev_err(pp->dev, "error with ioremap\n");
> > >> -		return -ENOMEM;
> > >> -	}
> > >> +	return 0;
> > >> +}
> > >>
> > >> -	if (of_property_read_u32(np, "num-lanes", &pp->lanes)) {
> > >> -		dev_err(pp->dev, "Failed to parse the number of lanes\n");
> > >> -		return -EINVAL;
> > >> -	}
> > >> +/*
> > >> + * dw_pcie_msi_host_init() - Function to initialize msi host
> > >> +controller
> > >> + *
> > >> + * @pp: ptr to pcie port
> > >> + * @np: device node ptr to msi irq controller
> > >> + * @irq_msi_ops: ptr to MSI irq_domain_ops struct
> > >> + *
> > >> + * Function register irq domain for msi irq controller and create
> > >> +mappings
> > >> + * for MSI irqs.
> > >> + */
> > >
> > > May be you can only do following to support your MSI chip:
> > >
> > > Initialize pp->irq_domain into your add_pcie_port function before
> > > you call dw_pcie_host_init.
> > >
> > > In dw_pcie_host_init,
> > >
> > > if (IS_ENABLED(CONFIG_PCI_MSI) && !pp->irq_domain)
> >
> > How do I pass the keystone specific msi irq_domain_ops? It looks clean
> > the way it is implemented in this patch. Also since MSI host
> > controller and legacy host controller are different, it make sense to
> > add separate host_init for each. Let me know.
> >
> > Regards,
> >
> > Murali
> >
> > >
> > >> +int dw_pcie_msi_host_init(struct pcie_port *pp, struct device_node
> *np,
> > >> +				const struct irq_domain_ops *irq_msi_ops) {
> > >> +	int i;
> > >>
> > >>   	if (IS_ENABLED(CONFIG_PCI_MSI)) {
> > >>   		pp->irq_domain = irq_domain_add_linear(pp->dev-
> >of_node,
> > >> -					MAX_MSI_IRQS, &msi_domain_ops,
> > >> +					MAX_MSI_IRQS, irq_msi_ops,
> > >>   					&dw_pcie_msi_chip);
> > >>   		if (!pp->irq_domain) {
> > >>   			dev_err(pp->dev, "irq domain init failed\n"); @@ -
> 476,6
> > >> +470,29 @@ int __init dw_pcie_host_init(struct pcie_port *pp)
> > >>   			irq_create_mapping(pp->irq_domain, i);
> > >>   	}
> > >>
> > >> +	return 0;
> > >> +}
> > >> +
> > >> +/*
> > >> + * dw_pcie_common_host_init() - common host init function across
> different
> > >> + *				versions of the designware PCI
> controller.
> > >> + * @pp: ptr to pcie port
> > >> + * @hw: ptr to hw_pci structure
> > >> + *
> > >> + * This functions parses common DT properties, call host_init()
> > >> +callback
> > >> + * of the PCI controller driver. Also initialize the common RC
> > >> +configurations
> > >> + * and call common pci core function to intialize the controller driver.
> > >> + */
> > >> +int __init dw_pcie_common_host_init(struct pcie_port *pp, struct
> > >> +hw_pci *hw) {
> > >> +	struct device_node *np = pp->dev->of_node;
> > >> +	u32 val;
> > >> +
> > >> +	if (of_property_read_u32(np, "num-lanes", &pp->lanes)) {
> > >> +		dev_err(pp->dev, "Failed to parse the number of lanes\n");
> > >> +		return -EINVAL;
> > >> +	}
> > >> +
> > >>   	if (pp->ops->host_init)
> > >>   		pp->ops->host_init(pp);
> > >>
> > >> @@ -488,10 +505,10 @@ int __init dw_pcie_host_init(struct pcie_port
> *pp)
> > >>   	val |= PORT_LOGIC_SPEED_CHANGE;
> > >>   	dw_pcie_wr_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4,
> val);
> > >>
> > >> -	dw_pci.nr_controllers = 1;
> > >> -	dw_pci.private_data = (void **)&pp;
> > >> +	hw->nr_controllers = 1;
> > >> +	hw->private_data = (void **)&pp;
> > >>
> > >> -	pci_common_init_dev(pp->dev, &dw_pci);
> > >> +	pci_common_init_dev(pp->dev, hw);
> > >>   	pci_assign_unassigned_resources();
> > >>   #ifdef CONFIG_PCI_DOMAINS
> > >>   	dw_pci.domain++;
> > >> @@ -500,6 +517,55 @@ int __init dw_pcie_host_init(struct pcie_port
> *pp)
> > >>   	return 0;
> > >>   }
> > >>
> > >> +/*
> > >> + * dw_pcie_host_init() - Host init function for new designware h/w
> > >> + *
> > >> + * @pp: ptr to pcie port
> > >> + *
> > >> + * The function parse the PCI resurces for IO, Memory and map the
> > >> +config
> > >> + * space addresses. Also initliaze the MSI irq controller and call
> > >> + * dw_pcie_common_host_init() to initialize the PCI controller.
> > >> + */
> > >> +int __init dw_pcie_host_init(struct pcie_port *pp) {
> > >> +	int ret;
> > >> +
> > >> +	ret = dw_pcie_parse_resource(pp);
> > >> +	if (ret)
> > >> +		return ret;
> > >> +
> > >> +	if (!pp->dbi_base) {
> > >> +		pp->dbi_base = devm_ioremap(pp->dev, pp->cfg.start,
> > >> +					resource_size(&pp->cfg));
> > >> +		if (!pp->dbi_base) {
> > >> +			dev_err(pp->dev, "error with ioremap\n");
> > >> +			return -ENOMEM;
> > >> +		}
> > >> +	}
> > >> +
> > >> +	pp->cfg0_base = pp->cfg.start;
> > >> +	pp->cfg1_base = pp->cfg.start + pp->config.cfg0_size;
> > >> +
> > >> +	pp->va_cfg0_base = devm_ioremap(pp->dev, pp->cfg0_base,
> > >> +					pp->config.cfg0_size);
> > >> +	if (!pp->va_cfg0_base) {
> > >> +		dev_err(pp->dev, "error with ioremap in function\n");
> > >> +		return -ENOMEM;
> > >> +	}
> > >> +	pp->va_cfg1_base = devm_ioremap(pp->dev, pp->cfg1_base,
> > >> +					pp->config.cfg1_size);
> > >> +	if (!pp->va_cfg1_base) {
> > >> +		dev_err(pp->dev, "error with ioremap\n");
> > >> +		return -ENOMEM;
> > >> +	}
> > >> +
> > >> +	ret = dw_pcie_msi_host_init(pp, pp->dev->of_node,
> &msi_domain_ops);
> > >> +	if (ret < 0)
> > >> +		return ret;
> > >> +
> > >> +	return dw_pcie_common_host_init(pp, &dw_pci); }
> > >> +
> > >>   static void dw_pcie_prog_viewport_cfg0(struct pcie_port *pp, u32
> busdev)
> > >>   {
> > >>   	/* Program viewport 0 : OUTBOUND : CFG0 */
> > > Regards
> > > Pratyush
> > >
> > >> --
> > >> 1.7.9.5
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