Re: [PATCH v3 1/3] x86/ioremap: introduce helper to implement xxx_is_setup_data()

[Baoquan He]

On 12/07/24 at 05:04pm, Borislav Petkov wrote:
> On Sat, Nov 23, 2024 at 07:42:19PM +0800, Baoquan He wrote:
> > Functions memremap_is_setup_data() and early_memremap_is_setup_data()
> > share completely the same process and handling, except of the
> > different memremap/unmap invocations.
> > 
> > So add helper __memremap_is_setup_data() to extract the common part,
> > parameter 'early' is used to decide what kind of memremap/unmap
> > APIs are called. This simplifies codes a lot by removing the duplicated
> > codes, and also removes the similar code comment above them.
> > 
> > And '__ref' is added to __memremap_is_setup_data() to suppress below
> > section mismatch warning:
> > 
> > ARNING: modpost: vmlinux: section mismatch in reference: __memremap_is_setup_data+0x5f (section: .text) ->
> > early_memunmap (section: .init.text)
> > 
> > Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
> > ---
> >  arch/x86/mm/ioremap.c | 104 ++++++++++++++----------------------------
> >  1 file changed, 35 insertions(+), 69 deletions(-)
> 
> Some touchups ontop:
> 
> diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
> index aaf40a712b04..fe44e8180bdd 100644
> --- a/arch/x86/mm/ioremap.c
> +++ b/arch/x86/mm/ioremap.c

Thanks for optimizing these.

> @@ -632,9 +632,9 @@ static bool memremap_is_efi_data(resource_size_t phys_addr,
>   * Examine the physical address to determine if it is boot data by checking
>   * it against the boot params setup_data chain.
>   */
> -static bool __ref __memremap_is_setup_data(resource_size_t phys_addr,
> -						bool early)
> +static bool __ref __memremap_is_setup_data(resource_size_t phys_addr, bool early)
>  {
> +	unsigned int setup_data_sz = sizeof(struct setup_data);
>  	struct setup_indirect *indirect;
>  	struct setup_data *data;
>  	u64 paddr, paddr_next;
> @@ -647,24 +647,23 @@ static bool __ref __memremap_is_setup_data(resource_size_t phys_addr,
>  			return true;
>  
>  		if (early)
> -			data = early_memremap_decrypted(paddr, sizeof(*data));
> +			data = early_memremap_decrypted(paddr, setup_data_sz);
>  		else
> -			data = memremap(paddr, sizeof(*data),
> -					MEMREMAP_WB | MEMREMAP_DEC);
> +			data = memremap(paddr, setup_data_sz, MEMREMAP_WB | MEMREMAP_DEC);
>  		if (!data) {
> -			pr_warn("failed to memremap setup_data entry\n");
> +			pr_warn("failed to remap setup_data entry\n");
>  			return false;
>  		}
>  
> -		size = sizeof(*data);
> +		size = setup_data_sz;
>  
>  		paddr_next = data->next;
>  		len = data->len;
>  
>  		if ((phys_addr > paddr) &&
> -		    (phys_addr < (paddr + sizeof(*data) + len))) {
> +		    (phys_addr < (paddr + setup_data_sz + len))) {
>  			if (early)
> -				early_memunmap(data, sizeof(*data));
> +				early_memunmap(data, setup_data_sz);
>  			else
>  				memunmap(data);
>  			return true;
> @@ -673,15 +672,14 @@ static bool __ref __memremap_is_setup_data(resource_size_t phys_addr,
>  		if (data->type == SETUP_INDIRECT) {
>  			size += len;
>  			if (early) {
> -				early_memunmap(data, sizeof(*data));
> +				early_memunmap(data, setup_data_sz);
>  				data = early_memremap_decrypted(paddr, size);
>  			} else {
>  				memunmap(data);
> -				data = memremap(paddr, size,
> -						MEMREMAP_WB | MEMREMAP_DEC);
> +				data = memremap(paddr, size, MEMREMAP_WB | MEMREMAP_DEC);
>  			}
>  			if (!data) {
> -				pr_warn("failed to memremap indirect setup_data\n");
> +				pr_warn("failed to remap indirect setup_data\n");
>  				return false;
>  			}
>  
> 
> -- 
> Regards/Gruss,
>     Boris.
> 
> https://people.kernel.org/tglx/notes-about-netiquette
>