Re: [PATCH v7 16/20] PCI: dwc: Introduce generic controller capabilities interface

[Manivannan Sadhasivam <mani@kernel.org>]

On Sun, Nov 13, 2022 at 10:12:57PM +0300, Serge Semin wrote:
> Since in addition to the already available iATU unrolled mapping we are
> about to add a few more DW PCIe platform-specific capabilities (CDM-check
> and generic clocks/resets resources) let's add a generic interface to set
> and get the flags indicating their availability. The new interface shall
> improve maintainability of the platform-specific code.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Thanks,
Mani

> Reviewed-by: Rob Herring <robh@kernel.org>
> 
> ---
> 
> Note the DW_PCIE_CAP_IATU_UNROLL macro is intentionally set to 1 since
> being added afterwards capability will be more suitable to be identified
> with position 0.
> 
> Changelog v3:
> - This is a new patch created on v3 lap of the series.
> ---
>  drivers/pci/controller/dwc/pcie-designware.c | 11 ++++++-----
>  drivers/pci/controller/dwc/pcie-designware.h | 12 +++++++++++-
>  2 files changed, 17 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index ca830ee794a7..9d78e7ca61e1 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -211,7 +211,7 @@ void dw_pcie_write_dbi2(struct dw_pcie *pci, u32 reg, size_t size, u32 val)
>  static inline void __iomem *dw_pcie_select_atu(struct dw_pcie *pci, u32 dir,
>  					       u32 index)
>  {
> -	if (pci->iatu_unroll_enabled)
> +	if (dw_pcie_cap_is(pci, IATU_UNROLL))
>  		return pci->atu_base + PCIE_ATU_UNROLL_BASE(dir, index);
>  
>  	dw_pcie_writel_dbi(pci, PCIE_ATU_VIEWPORT, dir | index);
> @@ -591,7 +591,7 @@ static void dw_pcie_iatu_detect_regions(struct dw_pcie *pci)
>  	u32 val, min, dir;
>  	u64 max;
>  
> -	if (pci->iatu_unroll_enabled) {
> +	if (dw_pcie_cap_is(pci, IATU_UNROLL)) {
>  		max_region = min((int)pci->atu_size / 512, 256);
>  	} else {
>  		dw_pcie_writel_dbi(pci, PCIE_ATU_VIEWPORT, 0xFF);
> @@ -641,8 +641,9 @@ void dw_pcie_iatu_detect(struct dw_pcie *pci)
>  {
>  	struct platform_device *pdev = to_platform_device(pci->dev);
>  
> -	pci->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pci);
> -	if (pci->iatu_unroll_enabled) {
> +	if (dw_pcie_iatu_unroll_enabled(pci)) {
> +		dw_pcie_cap_set(pci, IATU_UNROLL);
> +
>  		if (!pci->atu_base) {
>  			struct resource *res =
>  				platform_get_resource_byname(pdev, IORESOURCE_MEM, "atu");
> @@ -664,7 +665,7 @@ void dw_pcie_iatu_detect(struct dw_pcie *pci)
>  
>  	dw_pcie_iatu_detect_regions(pci);
>  
> -	dev_info(pci->dev, "iATU unroll: %s\n", pci->iatu_unroll_enabled ?
> +	dev_info(pci->dev, "iATU unroll: %s\n", dw_pcie_cap_is(pci, IATU_UNROLL) ?
>  		"enabled" : "disabled");
>  
>  	dev_info(pci->dev, "iATU regions: %u ob, %u ib, align %uK, limit %lluG\n",
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index 37801bbce854..c6dddacee3b1 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -12,6 +12,7 @@
>  #define _PCIE_DESIGNWARE_H
>  
>  #include <linux/bitfield.h>
> +#include <linux/bitops.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/irq.h>
>  #include <linux/msi.h>
> @@ -43,6 +44,15 @@
>  	(__dw_pcie_ver_cmp(_pci, _ver, ==) && \
>  	 __dw_pcie_ver_cmp(_pci, TYPE_ ## _type, >=))
>  
> +/* DWC PCIe controller capabilities */
> +#define DW_PCIE_CAP_IATU_UNROLL		1
> +
> +#define dw_pcie_cap_is(_pci, _cap) \
> +	test_bit(DW_PCIE_CAP_ ## _cap, &(_pci)->caps)
> +
> +#define dw_pcie_cap_set(_pci, _cap) \
> +	set_bit(DW_PCIE_CAP_ ## _cap, &(_pci)->caps)
> +
>  /* Parameters for the waiting for link up routine */
>  #define LINK_WAIT_MAX_RETRIES		10
>  #define LINK_WAIT_USLEEP_MIN		90000
> @@ -317,10 +327,10 @@ struct dw_pcie {
>  	const struct dw_pcie_ops *ops;
>  	u32			version;
>  	u32			type;
> +	unsigned long		caps;
>  	int			num_lanes;
>  	int			link_gen;
>  	u8			n_fts[2];
> -	bool			iatu_unroll_enabled: 1;
>  };
>  
>  #define to_dw_pcie_from_pp(port) container_of((port), struct dw_pcie, pp)
> -- 
> 2.38.1
> 
> 

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