Re: [PATCH] PCI: mediatek: Use devm_of_pci_get_host_bridge_resources() to parse DT

[Honghui Zhang]

On Wed, 2018-11-07 at 12:03 +0000, Lorenzo Pieralisi wrote:
> On Thu, Oct 18, 2018 at 11:23:34AM +0800, honghui.zhang@xxxxxxxxxxxx wrote:
> > From: Honghui Zhang <honghui.zhang@xxxxxxxxxxxx>
> > 
> > Use the devm_of_pci_get_host_bridge_resources() API in place of the PCI OF
> > DT parser.
> > 
> > Signed-off-by: Honghui Zhang <honghui.zhang@xxxxxxxxxxxx>
> > ---
> >  drivers/pci/controller/pcie-mediatek.c | 109 +++++++++------------------------
> >  1 file changed, 29 insertions(+), 80 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
> > index 2a1f97c..6632d4e 100644
> > --- a/drivers/pci/controller/pcie-mediatek.c
> > +++ b/drivers/pci/controller/pcie-mediatek.c
> > @@ -197,29 +197,20 @@ struct mtk_pcie_port {
> >   * @dev: pointer to PCIe device
> >   * @base: IO mapped register base
> >   * @free_ck: free-run reference clock
> > - * @io: IO resource
> > - * @pio: PIO resource
> >   * @mem: non-prefetchable memory resource
> > - * @busn: bus range
> > - * @offset: IO / Memory offset
> >   * @ports: pointer to PCIe port information
> >   * @soc: pointer to SoC-dependent operations
> > + * @busnr: root bus number
> >   */
> >  struct mtk_pcie {
> >  	struct device *dev;
> >  	void __iomem *base;
> >  	struct clk *free_ck;
> >  
> > -	struct resource io;
> > -	struct resource pio;
> >  	struct resource mem;
> > -	struct resource busn;
> > -	struct {
> > -		resource_size_t mem;
> > -		resource_size_t io;
> > -	} offset;
> >  	struct list_head ports;
> >  	const struct mtk_pcie_soc *soc;
> > +	int busnr;
> 
> If you move the code initializing and probing the pci_host_bridge into
> mtk_pcie_setup() (and rename that function) this variable becomes
> useless. It should be an unsigned int, by the way.

Yes, I can directly assign the busnr to host->busnr in the
mtk_pcie_setup and remove this variable.

Thanks.

> 
> >  };
> >  
> >  static void mtk_pcie_subsys_powerdown(struct mtk_pcie *pcie)
> > @@ -1045,55 +1036,42 @@ static int mtk_pcie_setup(struct mtk_pcie *pcie)
> >  {
> >  	struct device *dev = pcie->dev;
> >  	struct device_node *node = dev->of_node, *child;
> > -	struct of_pci_range_parser parser;
> > -	struct of_pci_range range;
> > -	struct resource res;
> >  	struct mtk_pcie_port *port, *tmp;
> > +	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
> > +	struct list_head *windows = &host->windows;
> > +	struct resource_entry *win, *tmp_win;
> > +	resource_size_t io_base;
> >  	int err;
> >  
> > -	if (of_pci_range_parser_init(&parser, node)) {
> > -		dev_err(dev, "missing \"ranges\" property\n");
> > -		return -EINVAL;
> > -	}
> > +	err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff,
> > +						    windows, &io_base);
> > +	if (err)
> > +		return err;
> >  
> > -	for_each_of_pci_range(&parser, &range) {
> > -		err = of_pci_range_to_resource(&range, node, &res);
> > -		if (err < 0)
> > -			return err;
> > +	err = devm_request_pci_bus_resources(dev, windows);
> > +	if (err < 0)
> > +		return err;
> >  
> > -		switch (res.flags & IORESOURCE_TYPE_BITS) {
> > +	/* Get the I/O and memory ranges from DT */
> > +	resource_list_for_each_entry_safe(win, tmp_win, windows) {
> > +		switch (resource_type(win->res)) {
> >  		case IORESOURCE_IO:
> > -			pcie->offset.io = res.start - range.pci_addr;
> > -
> > -			memcpy(&pcie->pio, &res, sizeof(res));
> > -			pcie->pio.name = node->full_name;
> > -
> > -			pcie->io.start = range.cpu_addr;
> > -			pcie->io.end = range.cpu_addr + range.size - 1;
> > -			pcie->io.flags = IORESOURCE_MEM;
> > -			pcie->io.name = "I/O";
> > -
> > -			memcpy(&res, &pcie->io, sizeof(res));
> > -			break;
> > -
> > +			err = devm_pci_remap_iospace(dev, win->res, io_base);
> > +			if (err) {
> > +				dev_warn(dev, "error %d: failed to map resource %pR\n",
> > +					 err, win->res);
> > +				resource_list_destroy_entry(win);
> > +			}
> 
> Missing a break.

Thanks.
> 
> >  		case IORESOURCE_MEM:
> > -			pcie->offset.mem = res.start - range.pci_addr;
> > -
> > -			memcpy(&pcie->mem, &res, sizeof(res));
> > +			memcpy(&pcie->mem, win->res, sizeof(*win->res));
> >  			pcie->mem.name = "non-prefetchable";
> >  			break;
> > +		case IORESOURCE_BUS:
> > +			pcie->busnr = win->res->start;
> > +			break;
> >  		}
> >  	}
> >  
> > -	err = of_pci_parse_bus_range(node, &pcie->busn);
> > -	if (err < 0) {
> > -		dev_err(dev, "failed to parse bus ranges property: %d\n", err);
> > -		pcie->busn.name = node->name;
> > -		pcie->busn.start = 0;
> > -		pcie->busn.end = 0xff;
> > -		pcie->busn.flags = IORESOURCE_BUS;
> > -	}
> > -
> >  	for_each_available_child_of_node(node, child) {
> >  		int slot;
> >  
> > @@ -1125,28 +1103,6 @@ static int mtk_pcie_setup(struct mtk_pcie *pcie)
> >  	return 0;
> >  }
> >  
> > -static int mtk_pcie_request_resources(struct mtk_pcie *pcie)
> > -{
> > -	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
> > -	struct list_head *windows = &host->windows;
> > -	struct device *dev = pcie->dev;
> > -	int err;
> > -
> > -	pci_add_resource_offset(windows, &pcie->pio, pcie->offset.io);
> > -	pci_add_resource_offset(windows, &pcie->mem, pcie->offset.mem);
> > -	pci_add_resource(windows, &pcie->busn);
> > -
> > -	err = devm_request_pci_bus_resources(dev, windows);
> > -	if (err < 0)
> > -		return err;
> > -
> > -	err = devm_pci_remap_iospace(dev, &pcie->pio, pcie->io.start);
> > -	if (err < 0)
> > -		return err;
> > -
> > -	return 0;
> > -}
> > -
> >  static int mtk_pcie_probe(struct platform_device *pdev)
> >  {
> >  	struct device *dev = &pdev->dev;
> > @@ -1169,11 +1125,7 @@ static int mtk_pcie_probe(struct platform_device *pdev)
> >  	if (err)
> >  		return err;
> >  
> > -	err = mtk_pcie_request_resources(pcie);
> > -	if (err)
> > -		goto put_resources;
> > -
> > -	host->busnr = pcie->busn.start;
> > +	host->busnr = pcie->busnr;
> >  	host->dev.parent = pcie->dev;
> >  	host->ops = pcie->soc->ops;
> >  	host->map_irq = of_irq_parse_and_map_pci;
> > @@ -1181,12 +1133,9 @@ static int mtk_pcie_probe(struct platform_device *pdev)
> >  	host->sysdata = pcie;
> >  
> >  	err = pci_host_probe(host);
> > -	if (err)
> > -		goto put_resources;
> > -
> > -	return 0;
> > +	if (!err)
> > +		return 0;
> >  
> 
> No, leave the error path.
> 
> 	err = pci_host_probe(host);
> 	if (err)
> 		goto put_resources;
> 
> 	return 0;
> put_resources:
> 	...
> 
> it is easier to follow.
> 

OK.
I will revert this snippet in the next version.

Thanks.

> Thanks,
> Lorenzo
> 
> > -put_resources:
> >  	if (!list_empty(&pcie->ports))
> >  		mtk_pcie_put_resources(pcie);
> >  
> > -- 
> > 2.6.4
> >