Re: [PATCH] mm/early_ioremap: Print the starting physical address in __early_ioremap()
From: Mike Rapoport
Date: Sun Jan 11 2026 - 04:14:42 EST
On Fri, Jan 09, 2026 at 09:31:51PM +0800, Hou Wenlong wrote:
> The debug WARN() printing occurs after the while loop, so the
> 'phys_addr' reflects the last physical address rather than the actual
> starting physical address, which is not useful for debugging. To
> simplify, the WARN() statement could be moved up before the loop instead
> of introducing a new variable to record the original 'phys_addr' value.
> Additionally, swap the print order of 'slot_virt[slot]' and 'offset', as
> this will enhance output readability.
>
> Signed-off-by: Hou Wenlong <houwenlong.hwl@xxxxxxxxxxxx>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
> ---
> mm/early_ioremap.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/mm/early_ioremap.c b/mm/early_ioremap.c
> index ff35b84a7b50..3fdde074c9da 100644
> --- a/mm/early_ioremap.c
> +++ b/mm/early_ioremap.c
> @@ -139,6 +139,9 @@ __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
> if (WARN_ON(nrpages > NR_FIX_BTMAPS))
> return NULL;
>
> + WARN(early_ioremap_debug, "%s(%pa, %08lx) [%d] => %08lx + %08lx\n",
> + __func__, &phys_addr, size, slot, slot_virt[slot], offset);
> +
> /*
> * Ok, go for it..
> */
> @@ -152,8 +155,6 @@ __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
> --idx;
> --nrpages;
> }
> - WARN(early_ioremap_debug, "%s(%pa, %08lx) [%d] => %08lx + %08lx\n",
> - __func__, &phys_addr, size, slot, offset, slot_virt[slot]);
>
> prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]);
> return prev_map[slot];
> --
> 2.31.1
>
--
Sincerely yours,
Mike.