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Message-ID: <48082184-93ea-8564-5a69-ff00350c0201@ghiti.fr>
Date:   Thu, 22 Sep 2022 09:34:40 +0200
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Subject: Re: [PATCH 2/2] riscv: Move cast inside kernel_mapping_[pv]a_to_[vp]a
Content-Language: en-US
To:     Samuel Holland <samuel@sholland.org>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        linux-riscv@lists.infradead.org
Cc:     Albert Ou <aou@eecs.berkeley.edu>, Guo Ren <guoren@kernel.org>,
        Heiko Stuebner <heiko@sntech.de>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        linux-kernel@vger.kernel.org,
        Alexandre Ghiti <alexandre.ghiti@canonical.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Jisheng Zhang <jszhang@kernel.org>,
        Nick Kossifidis <mick@ics.forth.gr>,
        Qinglin Pan <panqinglin2020@iscas.ac.cn>,
        Tong Tiangen <tongtiangen@huawei.com>
References: <20220922054743.30159-1-samuel@sholland.org>
 <20220922054743.30159-2-samuel@sholland.org>
From:   Alexandre Ghiti <alex@ghiti.fr>
In-Reply-To: <20220922054743.30159-2-samuel@sholland.org>
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Precedence: bulk


On 9/22/22 07:47, Samuel Holland wrote:
> Before commit 44c922572952 ("RISC-V: enable XIP"), these macros cast
> their argument to unsigned long. That commit moved the cast after an
> assignment to an unsigned long variable, rendering it ineffectual.
> Move the cast back, so we can remove the cast at each call site.
>
> Signed-off-by: Samuel Holland <samuel@sholland.org>
> ---
>
>   arch/riscv/errata/thead/errata.c |  4 ++--
>   arch/riscv/include/asm/page.h    | 18 +++++++++---------
>   arch/riscv/mm/init.c             | 16 ++++++++--------
>   3 files changed, 19 insertions(+), 19 deletions(-)
>
> diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
> index 83174f13783e..38c2c6b0f6b8 100644
> --- a/arch/riscv/errata/thead/errata.c
> +++ b/arch/riscv/errata/thead/errata.c
> @@ -76,8 +76,8 @@ void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct al
>   		if (cpu_req_errata & tmp) {
>   			/* On vm-alternatives, the mmu isn't running yet */
>   			if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
> -				memcpy((void *)kernel_mapping_va_to_pa((unsigned long)alt->old_ptr),
> -				       (void *)kernel_mapping_va_to_pa((unsigned long)alt->alt_ptr),
> +				memcpy((void *)kernel_mapping_va_to_pa(alt->old_ptr),
> +				       (void *)kernel_mapping_va_to_pa(alt->alt_ptr),
>   				       alt->alt_len);
>   			else
>   				patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len);
> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
> index ac70b0fd9a9a..9f432c1b5289 100644
> --- a/arch/riscv/include/asm/page.h
> +++ b/arch/riscv/include/asm/page.h
> @@ -123,20 +123,20 @@ extern phys_addr_t phys_ram_base;
>   	((x) >= PAGE_OFFSET && (!IS_ENABLED(CONFIG_64BIT) || (x) < PAGE_OFFSET + KERN_VIRT_SIZE))
>   
>   #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;								\
> -	(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 kernel_mapping_pa_to_va(y)	({					\
> +	unsigned long _y = (unsigned long)(y);					\
> +	(IS_ENABLED(CONFIG_XIP_KERNEL) && _y < phys_ram_base) ?			\
> +		(void *)(_y + kernel_map.va_kernel_xip_pa_offset) :		\
> +		(void *)(_y + kernel_map.va_kernel_pa_offset + XIP_OFFSET);	\
>   	})
>   #define __pa_to_va_nodebug(x)		linear_mapping_pa_to_va(x)
>   
>   #define linear_mapping_va_to_pa(x)	((unsigned long)(x) - kernel_map.va_pa_offset)
>   #define kernel_mapping_va_to_pa(y) ({						\
> -	unsigned long _y = y;							\
> -	(IS_ENABLED(CONFIG_XIP_KERNEL) && _y < kernel_map.virt_addr + XIP_OFFSET) ?	\
> -		((unsigned long)(_y) - kernel_map.va_kernel_xip_pa_offset) :		\
> -		((unsigned long)(_y) - kernel_map.va_kernel_pa_offset - XIP_OFFSET);	\
> +	unsigned long _y = (unsigned long)(y);					\
> +	(IS_ENABLED(CONFIG_XIP_KERNEL) && _y < kernel_map.virt_addr + XIP_OFFSET) ? \
> +		(_y - kernel_map.va_kernel_xip_pa_offset) :			\
> +		(_y - kernel_map.va_kernel_pa_offset - XIP_OFFSET);		\
>   	})
>   
>   #define __va_to_pa_nodebug(x)	({						\
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index b56a0a75533f..7d59516ce6b3 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -927,15 +927,15 @@ static void __init pt_ops_set_early(void)
>    */
>   static void __init pt_ops_set_fixmap(void)
>   {
> -	pt_ops.alloc_pte = kernel_mapping_pa_to_va((uintptr_t)alloc_pte_fixmap);
> -	pt_ops.get_pte_virt = kernel_mapping_pa_to_va((uintptr_t)get_pte_virt_fixmap);
> +	pt_ops.alloc_pte = kernel_mapping_pa_to_va(alloc_pte_fixmap);
> +	pt_ops.get_pte_virt = kernel_mapping_pa_to_va(get_pte_virt_fixmap);
>   #ifndef __PAGETABLE_PMD_FOLDED
> -	pt_ops.alloc_pmd = kernel_mapping_pa_to_va((uintptr_t)alloc_pmd_fixmap);
> -	pt_ops.get_pmd_virt = kernel_mapping_pa_to_va((uintptr_t)get_pmd_virt_fixmap);
> -	pt_ops.alloc_pud = kernel_mapping_pa_to_va((uintptr_t)alloc_pud_fixmap);
> -	pt_ops.get_pud_virt = kernel_mapping_pa_to_va((uintptr_t)get_pud_virt_fixmap);
> -	pt_ops.alloc_p4d = kernel_mapping_pa_to_va((uintptr_t)alloc_p4d_fixmap);
> -	pt_ops.get_p4d_virt = kernel_mapping_pa_to_va((uintptr_t)get_p4d_virt_fixmap);
> +	pt_ops.alloc_pmd = kernel_mapping_pa_to_va(alloc_pmd_fixmap);
> +	pt_ops.get_pmd_virt = kernel_mapping_pa_to_va(get_pmd_virt_fixmap);
> +	pt_ops.alloc_pud = kernel_mapping_pa_to_va(alloc_pud_fixmap);
> +	pt_ops.get_pud_virt = kernel_mapping_pa_to_va(get_pud_virt_fixmap);
> +	pt_ops.alloc_p4d = kernel_mapping_pa_to_va(alloc_p4d_fixmap);
> +	pt_ops.get_p4d_virt = kernel_mapping_pa_to_va(get_p4d_virt_fixmap);
>   #endif
>   }
>   


Indeed, the inner cast was useless:

Reviewed-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>

Thanks,

Alex