Re: [PATCH 1/2] xen/arm: Move kernel_uimage_probe definition after kernel_decompress

[Ayan Kumar Halder <ayankuma@amd.com>]

On 31/01/2023 15:13, Michal Orzel wrote:
> In a follow-up patch, we will be calling kernel_decompress function from
> within kernel_uimage_probe to support booting compressed images with
> u-boot header. Therefore, move the kernel_uimage_probe definition after
> kernel_decompress so that the latter is visible to the former.
>
> No functional change intended.
>
> Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com>
> ---
>   xen/arch/arm/kernel.c | 146 +++++++++++++++++++++---------------------
>   1 file changed, 73 insertions(+), 73 deletions(-)
>
> diff --git a/xen/arch/arm/kernel.c b/xen/arch/arm/kernel.c
> index 36081e73f140..068fbf88e492 100644
> --- a/xen/arch/arm/kernel.c
> +++ b/xen/arch/arm/kernel.c
> @@ -186,6 +186,79 @@ static void __init kernel_zimage_load(struct kernel_info *info)
>       iounmap(kernel);
>   }
>   
> +static __init uint32_t output_length(char *image, unsigned long image_len)
> +{
> +    return *(uint32_t *)&image[image_len - 4];
> +}
> +
> +static __init int kernel_decompress(struct bootmodule *mod)
> +{
> +    char *output, *input;
> +    char magic[2];
> +    int rc;
> +    unsigned int kernel_order_out;
> +    paddr_t output_size;
> +    struct page_info *pages;
> +    mfn_t mfn;
> +    int i;
> +    paddr_t addr = mod->start;
> +    paddr_t size = mod->size;
> +
> +    if ( size < 2 )
> +        return -EINVAL;
> +
> +    copy_from_paddr(magic, addr, sizeof(magic));
> +
> +    /* only gzip is supported */
> +    if ( !gzip_check(magic, size) )
> +        return -EINVAL;
> +
> +    input = ioremap_cache(addr, size);
> +    if ( input == NULL )
> +        return -EFAULT;
> +
> +    output_size = output_length(input, size);
> +    kernel_order_out = get_order_from_bytes(output_size);
> +    pages = alloc_domheap_pages(NULL, kernel_order_out, 0);
> +    if ( pages == NULL )
> +    {
> +        iounmap(input);
> +        return -ENOMEM;
> +    }
> +    mfn = page_to_mfn(pages);
> +    output = __vmap(&mfn, 1 << kernel_order_out, 1, 1, PAGE_HYPERVISOR, VMAP_DEFAULT);
> +
> +    rc = perform_gunzip(output, input, size);
> +    clean_dcache_va_range(output, output_size);
> +    iounmap(input);
> +    vunmap(output);
> +
> +    if ( rc )
> +    {
> +        free_domheap_pages(pages, kernel_order_out);
> +        return rc;
> +    }
> +
> +    mod->start = page_to_maddr(pages);
> +    mod->size = output_size;
> +
> +    /*
> +     * Need to free pages after output_size here because they won't be
> +     * freed by discard_initial_modules
> +     */
> +    i = PFN_UP(output_size);
> +    for ( ; i < (1 << kernel_order_out); i++ )
> +        free_domheap_page(pages + i);
> +
> +    /*
> +     * Free the original kernel, update the pointers to the
> +     * decompressed kernel
> +     */
> +    fw_unreserved_regions(addr, addr + size, init_domheap_pages, 0);
> +
> +    return 0;
> +}
> +
>   /*
>    * Uimage CPU Architecture Codes
>    */
> @@ -289,79 +362,6 @@ static int __init kernel_uimage_probe(struct kernel_info *info,
>       return 0;
>   }
>   
> -static __init uint32_t output_length(char *image, unsigned long image_len)
> -{
> -    return *(uint32_t *)&image[image_len - 4];
> -}
> -
> -static __init int kernel_decompress(struct bootmodule *mod)
> -{
> -    char *output, *input;
> -    char magic[2];
> -    int rc;
> -    unsigned int kernel_order_out;
> -    paddr_t output_size;
> -    struct page_info *pages;
> -    mfn_t mfn;
> -    int i;
> -    paddr_t addr = mod->start;
> -    paddr_t size = mod->size;
> -
> -    if ( size < 2 )
> -        return -EINVAL;
> -
> -    copy_from_paddr(magic, addr, sizeof(magic));
> -
> -    /* only gzip is supported */
> -    if ( !gzip_check(magic, size) )
> -        return -EINVAL;
> -
> -    input = ioremap_cache(addr, size);
> -    if ( input == NULL )
> -        return -EFAULT;
> -
> -    output_size = output_length(input, size);
> -    kernel_order_out = get_order_from_bytes(output_size);
> -    pages = alloc_domheap_pages(NULL, kernel_order_out, 0);
> -    if ( pages == NULL )
> -    {
> -        iounmap(input);
> -        return -ENOMEM;
> -    }
> -    mfn = page_to_mfn(pages);
> -    output = __vmap(&mfn, 1 << kernel_order_out, 1, 1, PAGE_HYPERVISOR, VMAP_DEFAULT);
> -
> -    rc = perform_gunzip(output, input, size);
> -    clean_dcache_va_range(output, output_size);
> -    iounmap(input);
> -    vunmap(output);
> -
> -    if ( rc )
> -    {
> -        free_domheap_pages(pages, kernel_order_out);
> -        return rc;
> -    }
> -
> -    mod->start = page_to_maddr(pages);
> -    mod->size = output_size;
> -
> -    /*
> -     * Need to free pages after output_size here because they won't be
> -     * freed by discard_initial_modules
> -     */
> -    i = PFN_UP(output_size);
> -    for ( ; i < (1 << kernel_order_out); i++ )
> -        free_domheap_page(pages + i);
> -
> -    /*
> -     * Free the original kernel, update the pointers to the
> -     * decompressed kernel
> -     */
> -    fw_unreserved_regions(addr, addr + size, init_domheap_pages, 0);
> -
> -    return 0;
> -}
> -
>   #ifdef CONFIG_ARM_64
>   /*
>    * Check if the image is a 64-bit Image.