[PATCH 3/7] LoongArch: Add missing linux/mm.h include in asm/io.h

[George Guo <dongtai.guo@linux.dev>]

From: George Guo <guodongtai@kylinos.cn>

When CONFIG_KFENCE is enabled, the virt_to_phys() and phys_to_virt()
macros in arch/loongarch/include/asm/io.h expand to use offset_in_page()
and page_address(), both of which are declared in <linux/mm.h>.

Without this include, any translation unit that includes <asm/io.h> and
expands these macros with CONFIG_KFENCE=y will fail to build. This was
observed when building kernel/liveupdate/luo_session.c with
CONFIG_KFENCE=y:

  asm/io.h: error: implicit declaration of function 'offset_in_page'
  asm/io.h: error: implicit declaration of function 'page_address'

Add the missing include to fix these build errors.

Fixes: 0ca84aeaee15 ("LoongArch: Make {virt, phys, page, pfn} translation work with KFENCE")
Co-developed-by: Kexin Liu <liukexin@kylinos.cn>
Signed-off-by: Kexin Liu <liukexin@kylinos.cn>
Signed-off-by: George Guo <guodongtai@kylinos.cn>
---
 arch/loongarch/include/asm/io.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/loongarch/include/asm/io.h b/arch/loongarch/include/asm/io.h
index 0130185e0349..7ff4aa72a34a 100644
--- a/arch/loongarch/include/asm/io.h
+++ b/arch/loongarch/include/asm/io.h
@@ -13,6 +13,7 @@
 #include <asm/page.h>
 #include <asm/pgtable-bits.h>
 #include <asm/string.h>
+#include <linux/mm.h>
 
 extern void __init __iomem *early_ioremap(phys_addr_t phys_addr, unsigned long size);
 extern void __init early_iounmap(void __iomem *addr, unsigned long size);
-- 
2.25.1