[PATCH v1 u-boot-marvell 4/5] arm64: mvebu: a37xx: add device-tree fixer for PCIe regions

[Stefan Roese]

On 08.04.20 19:25, Marek Behún wrote:
> In case when ARM Trusted Firmware changes the default address of PCIe
> regions (which can be done for devices with 4 GB RAM to maximize the
> amount of RAM the device can use) we add code that looks at how ATF
> changed the PCIe windows in the CPU Address Decoder and changes given
> device-tree blob accordingly.
> 
> Signed-off-by: Marek Behún <marek.behun at nic.cz>
> ---
>   arch/arm/mach-mvebu/armada3700/cpu.c   | 52 ++++++++++++++++++++++++++
>   arch/arm/mach-mvebu/include/mach/cpu.h |  3 ++
>   2 files changed, 55 insertions(+)
> 
> diff --git a/arch/arm/mach-mvebu/armada3700/cpu.c b/arch/arm/mach-mvebu/armada3700/cpu.c
> index 959a909d8a..17d2d43bab 100644
> --- a/arch/arm/mach-mvebu/armada3700/cpu.c
> +++ b/arch/arm/mach-mvebu/armada3700/cpu.c
> @@ -50,6 +50,8 @@
>   #define A3700_PTE_BLOCK_DEVICE \
>   	(PTE_BLOCK_MEMTYPE(MT_DEVICE_NGNRNE) | PTE_BLOCK_NON_SHARE)
>   
> +#define PCIE_PATH			"/soc/pcie at d0070000"
> +
>   DECLARE_GLOBAL_DATA_PTR;
>   
>   static struct mm_region mvebu_mem_map[MAX_MEM_MAP_REGIONS] = {
> @@ -259,6 +261,56 @@ int a3700_dram_init_banksize(void)
>   	return 0;
>   }
>   
> +static u32 find_pcie_window_base(void)
> +{
> +	int win;
> +
> +	for (win = 0; win < MVEBU_CPU_DEC_WINS; ++win) {
> +		u32 base, tgt;
> +
> +		/* skip disabled windows */
> +		if (get_cpu_dec_win(win, &tgt, &base, NULL))
> +			continue;
> +
> +		if (tgt == MVEBU_CPU_DEC_WIN_CTRL_TGT_PCIE)
> +			return base;
> +	}
> +
> +	return -1;

	return -ENOENT; ?

> +}
> +
> +int a3700_fdt_fix_pcie_regions(void *blob)
> +{
> +	u32 new_ranges[14], base;

Where does this "14" come from? Is this a safe upper margin?

> +	const u32 *ranges;
> +	int node, len;
> +
> +	node = fdt_path_offset(blob, PCIE_PATH);
> +	if (node < 0)
> +		return node;
> +
> +	ranges = fdt_getprop(blob, node, "ranges", &len);
> +	if (!ranges)
> +		return -ENOENT;
> +
> +	if (len != sizeof(new_ranges))
> +		return -EINVAL;
> +
> +	memcpy(new_ranges, ranges, len);
> +
> +	base = find_pcie_window_base();
> +	if (base == -1)
> +		return -ENOENT;

	if (base < 0)
		return base; ?

> +
> +	new_ranges[2] = cpu_to_fdt32(base);
> +	new_ranges[4] = new_ranges[2];
> +
> +	new_ranges[9] = cpu_to_fdt32(base + 0x1000000);
> +	new_ranges[11] = new_ranges[9];
> +
> +	return fdt_setprop_inplace(blob, node, "ranges", new_ranges, len);
> +}
> +
>   void reset_cpu(ulong ignored)
>   {
>   	/*
> diff --git a/arch/arm/mach-mvebu/include/mach/cpu.h b/arch/arm/mach-mvebu/include/mach/cpu.h
> index 2a53329420..1d619c4e49 100644
> --- a/arch/arm/mach-mvebu/include/mach/cpu.h
> +++ b/arch/arm/mach-mvebu/include/mach/cpu.h
> @@ -178,6 +178,9 @@ int a8k_dram_init_banksize(void);
>   int a3700_dram_init(void);
>   int a3700_dram_init_banksize(void);
>   
> +/* A3700 PCIe regions fixer for device tree */
> +int a3700_fdt_fix_pcie_regions(void *blob);
> +
>   /*
>    * get_ref_clk
>    *
> 

Thanks,
Stefan