linux-kernel - Re: [PATCH 2/3] x86/ioremap: use helper to implement xxx_is_setup

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Message-ID: <0dd9802f-ee28-180e-98b2-854c32288a72@amd.com>
Date: Fri, 15 Nov 2024 08:24:08 -0600
From: Tom Lendacky <thomas.lendacky@....com>
To: Baoquan He <bhe@...hat.com>, linux-kernel@...r.kernel.org, bp@...en8.de
Cc: x86@...nel.org
Subject: Re: [PATCH 2/3] x86/ioremap: use helper to implement
 xxx_is_setup_data()

On 11/14/24 19:21, Baoquan He wrote:
> This simplifies codes a lot by removing the duplicated code handling.

You should probably squash this with the first patch.

> 
> And also remove the similar code comment above of them.
> 
> While at it, add __ref to memremap_is_setup_data() to avoid

The __ref shouldn't be needed if you remove the __init from the helper
function.

Thanks,
Tom

> the section mismatch warning:
> 
> WARNING: modpost: vmlinux: section mismatch in reference: arch_memremap_can_ram_remap.cold+0x6 (section: .text.unlikely) -> __memremap_is_setup_data (section: .init.text)
> Signed-off-by: Baoquan He <bhe@...hat.com>
> ---
>  arch/x86/mm/ioremap.c | 119 ++----------------------------------------
>  1 file changed, 3 insertions(+), 116 deletions(-)
> 
> diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
> index 5ef6182db630..5d1b5e4a8756 100644
> --- a/arch/x86/mm/ioremap.c
> +++ b/arch/x86/mm/ioremap.c
> @@ -709,129 +709,16 @@ static bool __init __memremap_is_setup_data(resource_size_t phys_addr,
>  }
>  #undef SD_SIZE
>  
> -/*
> - * Examine the physical address to determine if it is boot data by checking
> - * it against the boot params setup_data chain.
> - */
> -static bool memremap_is_setup_data(resource_size_t phys_addr,
> +static bool __ref memremap_is_setup_data(resource_size_t phys_addr,
>  				   unsigned long size)
>  {
> -	struct setup_indirect *indirect;
> -	struct setup_data *data;
> -	u64 paddr, paddr_next;
> -
> -	paddr = boot_params.hdr.setup_data;
> -	while (paddr) {
> -		unsigned int len;
> -
> -		if (phys_addr == paddr)
> -			return true;
> -
> -		data = memremap(paddr, sizeof(*data),
> -				MEMREMAP_WB | MEMREMAP_DEC);
> -		if (!data) {
> -			pr_warn("failed to memremap setup_data entry\n");
> -			return false;
> -		}
> -
> -		paddr_next = data->next;
> -		len = data->len;
> -
> -		if ((phys_addr > paddr) &&
> -		    (phys_addr < (paddr + sizeof(struct setup_data) + len))) {
> -			memunmap(data);
> -			return true;
> -		}
> -
> -		if (data->type == SETUP_INDIRECT) {
> -			memunmap(data);
> -			data = memremap(paddr, sizeof(*data) + len,
> -					MEMREMAP_WB | MEMREMAP_DEC);
> -			if (!data) {
> -				pr_warn("failed to memremap indirect setup_data\n");
> -				return false;
> -			}
> -
> -			indirect = (struct setup_indirect *)data->data;
> -
> -			if (indirect->type != SETUP_INDIRECT) {
> -				paddr = indirect->addr;
> -				len = indirect->len;
> -			}
> -		}
> -
> -		memunmap(data);
> -
> -		if ((phys_addr > paddr) && (phys_addr < (paddr + len)))
> -			return true;
> -
> -		paddr = paddr_next;
> -	}
> -
> -	return false;
> +	return __memremap_is_setup_data(phys_addr, false);
>  }
>  
> -/*
> - * Examine the physical address to determine if it is boot data by checking
> - * it against the boot params setup_data chain (early boot version).
> - */
>  static bool __init early_memremap_is_setup_data(resource_size_t phys_addr,
>  						unsigned long size)
>  {
> -	struct setup_indirect *indirect;
> -	struct setup_data *data;
> -	u64 paddr, paddr_next;
> -
> -	paddr = boot_params.hdr.setup_data;
> -	while (paddr) {
> -		unsigned int len, size;
> -
> -		if (phys_addr == paddr)
> -			return true;
> -
> -		data = early_memremap_decrypted(paddr, sizeof(*data));
> -		if (!data) {
> -			pr_warn("failed to early memremap setup_data entry\n");
> -			return false;
> -		}
> -
> -		size = sizeof(*data);
> -
> -		paddr_next = data->next;
> -		len = data->len;
> -
> -		if ((phys_addr > paddr) &&
> -		    (phys_addr < (paddr + sizeof(struct setup_data) + len))) {
> -			early_memunmap(data, sizeof(*data));
> -			return true;
> -		}
> -
> -		if (data->type == SETUP_INDIRECT) {
> -			size += len;
> -			early_memunmap(data, sizeof(*data));
> -			data = early_memremap_decrypted(paddr, size);
> -			if (!data) {
> -				pr_warn("failed to early memremap indirect setup_data\n");
> -				return false;
> -			}
> -
> -			indirect = (struct setup_indirect *)data->data;
> -
> -			if (indirect->type != SETUP_INDIRECT) {
> -				paddr = indirect->addr;
> -				len = indirect->len;
> -			}
> -		}
> -
> -		early_memunmap(data, size);
> -
> -		if ((phys_addr > paddr) && (phys_addr < (paddr + len)))
> -			return true;
> -
> -		paddr = paddr_next;
> -	}
> -
> -	return false;
> +	return __memremap_is_setup_data(phys_addr, true);
>  }
>  
>  /*