[PATCH 1/6] dm: pci: add option to map virtual system memory base address

[Stefan Roese]

On 06.07.21 16:22, Daniel Schwierzeck wrote:
> On MIPS the DRAM start address respectively CONFIG_SYS_SDRAM_BASE
> is still used as a virtual, CPU-mapped address instead of being used
> as physical address. Converting all MIPS boards and generic MIPS code
> to fix that is not trivial. Due to the approaching deadline for
> PCI DM conversion, this workaround is required for MIPS boards with
> PCI support until the CONFIG_SYS_SDRAM_BASE issue could be solved.
> 
> Add a compile-time option to let the PCI uclass core optionally map
> the DRAM address to a physical address when adding the PCI region
> of type PCI_REGION_SYS_MEMORY.
> 
> Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>
> ---
> 
>   drivers/pci/Kconfig      | 13 +++++++++++++
>   drivers/pci/pci-uclass.c |  9 ++++++---
>   2 files changed, 19 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
> index b2b7b253f8..02c34077e2 100644
> --- a/drivers/pci/Kconfig
> +++ b/drivers/pci/Kconfig
> @@ -54,6 +54,19 @@ config PCI_REGION_MULTI_ENTRY
>   	  region type. This helps to add support for SoC's like OcteonTX/TX2
>   	  where every peripheral is on the PCI bus.
>   
> +config PCI_MAP_SYSTEM_MEMORY
> +	bool "Map local system memory from a virtual base address"
> +	depends on PCI || DM_PCI
> +	depends on MIPS
> +	default n

AFAIK, "default n" is not needed as it's the "default" setting.

Apart from this:

Reviewed-by: Stefan Roese <sr at denx.de>

Thanks,
Stefan

> +	help
> +	  Say Y if base address of system memory is being used as a virtual address
> +	  instead of a physical address (e.g. on MIPS). The PCI core will then remap
> +	  the virtual memory base address to a physical address when adding the PCI
> +	  region of type PCI_REGION_SYS_MEMORY.
> +	  This should only be required on MIPS where CONFIG_SYS_SDRAM_BASE is still
> +	  being used as virtual address.
> +
>   config PCI_SRIOV
>   	bool "Enable Single Root I/O Virtualization support for PCI"
>   	depends on PCI || DM_PCI
> diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
> index 22a033e632..1e2ed5426e 100644
> --- a/drivers/pci/pci-uclass.c
> +++ b/drivers/pci/pci-uclass.c
> @@ -998,10 +998,13 @@ static void decode_regions(struct pci_controller *hose, ofnode parent_node,
>   
>   	for (i = 0; i < CONFIG_NR_DRAM_BANKS; ++i) {
>   		if (bd->bi_dram[i].size) {
> +			phys_addr_t start = bd->bi_dram[i].start;
> +
> +			if (IS_ENABLED(CONFIG_PCI_MAP_SYSTEM_MEMORY))
> +				start = virt_to_phys((void *)(uintptr_t)bd->bi_dram[i].start);
> +
>   			pci_set_region(hose->regions + hose->region_count++,
> -				       bd->bi_dram[i].start,
> -				       bd->bi_dram[i].start,
> -				       bd->bi_dram[i].size,
> +				       start, start, bd->bi_dram[i].size,
>   				       PCI_REGION_MEM | PCI_REGION_SYS_MEMORY);
>   		}
>   	}
> 


Viele Grüße,
Stefan

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