Re: FAILED: patch "[PATCH] riscv: Get rid of CONFIG_PHYS_RAM_BASE in kernel physical" failed to apply to 5.13-stable tree

[Alex Ghiti <alex@ghiti.fr>]

Hi Greg,

Le 9/08/2021 à 12:42, gregkh@linuxfoundation.org a écrit :
> 
> The patch below does not apply to the 5.13-stable tree.

I don't know when stable was cc on this patch, this fixes something 
introduced in 5.14-rc1, so this is not normal it can't be applied.

Sorry for the noise,

Alex

> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
> 
> thanks,
> 
> greg k-h
> 
> ------------------ original commit in Linus's tree ------------------
> 
>  From 6d7f91d914bc90a15ebc426440c26081337ceaa1 Mon Sep 17 00:00:00 2001
> From: Alexandre Ghiti <alex@ghiti.fr>
> Date: Wed, 21 Jul 2021 09:59:35 +0200
> Subject: [PATCH] riscv: Get rid of CONFIG_PHYS_RAM_BASE in kernel physical
>   address conversion
> 
> The usage of CONFIG_PHYS_RAM_BASE for all kernel types was a mistake:
> this value is implementation-specific and this breaks the genericity of
> the RISC-V kernel.
> 
> Fix this by introducing a new variable phys_ram_base that holds this
> value at runtime and use it in the kernel physical address conversion
> macro. Since this value is used only for XIP kernels, evaluate it only if
> CONFIG_XIP_KERNEL is set which in addition optimizes this macro for
> standard kernels at compile-time.
> 
> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
> Tested-by: Emil Renner Berthing <kernel@esmil.dk>
> Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
> Fixes: 44c922572952 ("RISC-V: enable XIP")
> Cc: stable@vger.kernel.org
> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
> 
> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
> index cca8764aed83..b0ca5058e7ae 100644
> --- a/arch/riscv/include/asm/page.h
> +++ b/arch/riscv/include/asm/page.h
> @@ -103,6 +103,7 @@ struct kernel_mapping {
>   };
>   
>   extern struct kernel_mapping kernel_map;
> +extern phys_addr_t phys_ram_base;
>   
>   #ifdef CONFIG_64BIT
>   #define is_kernel_mapping(x)	\
> @@ -113,9 +114,9 @@ extern struct kernel_mapping kernel_map;
>   #define linear_mapping_pa_to_va(x)	((void *)((unsigned long)(x) + kernel_map.va_pa_offset))
>   #define kernel_mapping_pa_to_va(y)	({						\
>   	unsigned long _y = y;								\
> -	(_y >= CONFIG_PHYS_RAM_BASE) ?							\
> -		(void *)((unsigned long)(_y) + kernel_map.va_kernel_pa_offset + XIP_OFFSET) :	\
> -		(void *)((unsigned long)(_y) + kernel_map.va_kernel_xip_pa_offset);		\
> +	(IS_ENABLED(CONFIG_XIP_KERNEL) && _y < phys_ram_base) ?					\
> +		(void *)((unsigned long)(_y) + kernel_map.va_kernel_xip_pa_offset) :		\
> +		(void *)((unsigned long)(_y) + kernel_map.va_kernel_pa_offset + XIP_OFFSET);	\
>   	})
>   #define __pa_to_va_nodebug(x)		linear_mapping_pa_to_va(x)
>   
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index a14bf3910eec..88134cc288d9 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -36,6 +36,9 @@ EXPORT_SYMBOL(kernel_map);
>   #define kernel_map	(*(struct kernel_mapping *)XIP_FIXUP(&kernel_map))
>   #endif
>   
> +phys_addr_t phys_ram_base __ro_after_init;
> +EXPORT_SYMBOL(phys_ram_base);
> +
>   #ifdef CONFIG_XIP_KERNEL
>   extern char _xiprom[], _exiprom[];
>   #endif
> @@ -160,7 +163,7 @@ static void __init setup_bootmem(void)
>   	phys_addr_t vmlinux_end = __pa_symbol(&_end);
>   	phys_addr_t vmlinux_start = __pa_symbol(&_start);
>   	phys_addr_t __maybe_unused max_mapped_addr;
> -	phys_addr_t dram_end;
> +	phys_addr_t phys_ram_end;
>   
>   #ifdef CONFIG_XIP_KERNEL
>   	vmlinux_start = __pa_symbol(&_sdata);
> @@ -181,9 +184,12 @@ static void __init setup_bootmem(void)
>   #endif
>   	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
>   
> -	dram_end = memblock_end_of_DRAM();
>   
> +	phys_ram_end = memblock_end_of_DRAM();
>   #ifndef CONFIG_64BIT
> +#ifndef CONFIG_XIP_KERNEL
> +	phys_ram_base = memblock_start_of_DRAM();
> +#endif
>   	/*
>   	 * memblock allocator is not aware of the fact that last 4K bytes of
>   	 * the addressable memory can not be mapped because of IS_ERR_VALUE
> @@ -194,12 +200,12 @@ static void __init setup_bootmem(void)
>   	 * be done in create_kernel_page_table.
>   	 */
>   	max_mapped_addr = __pa(~(ulong)0);
> -	if (max_mapped_addr == (dram_end - 1))
> +	if (max_mapped_addr == (phys_ram_end - 1))
>   		memblock_set_current_limit(max_mapped_addr - 4096);
>   #endif
>   
> -	min_low_pfn = PFN_UP(memblock_start_of_DRAM());
> -	max_low_pfn = max_pfn = PFN_DOWN(dram_end);
> +	min_low_pfn = PFN_UP(phys_ram_base);
> +	max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
>   
>   	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
>   	set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
> @@ -558,6 +564,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
>   	kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
>   	kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);
>   
> +	phys_ram_base = CONFIG_PHYS_RAM_BASE;
>   	kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE;
>   	kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_sdata);
>   
>