LoongArch: Consolidate early_ioremap()/ioremap_prot()

1. Use phys_addr_t instead of u64, which can work for both 32/64 bits.
2. Check whether the input physical address is above TO_PHYS_MASK (and
   return NULL if yes) for the DMW version.

Note: In theory early_ioremap() also need the TO_PHYS_MASK checking, but
the UEFI BIOS pass some DMW virtual addresses.

Cc: stable@vger.kernel.org
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Author: chenhuacai

arch/loongarch/include/asm/io.h

@@ -14,7 +14,7 @@
 #include <asm/pgtable-bits.h>
 #include <asm/string.h>
 
-extern void __init __iomem *early_ioremap(u64 phys_addr, unsigned long size);
+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);
 
 #define early_memremap early_ioremap
@@ -25,6 +25,9 @@ extern void __init early_iounmap(void __iomem *addr, unsigned long size);
 static inline void __iomem *ioremap_prot(phys_addr_t offset, unsigned long size,
 					 pgprot_t prot)
 {
+	if (offset > TO_PHYS_MASK)
+		return NULL;
+
 	switch (pgprot_val(prot) & _CACHE_MASK) {
 	case _CACHE_CC:
 		return (void __iomem *)(unsigned long)(CACHE_BASE + offset);

arch/loongarch/mm/ioremap.c

@@ -6,7 +6,7 @@
 #include <asm/io.h>
 #include <asm-generic/early_ioremap.h>
 
-void __init __iomem *early_ioremap(u64 phys_addr, unsigned long size)
+void __init __iomem *early_ioremap(phys_addr_t phys_addr, unsigned long size)
 {
 	return ((void __iomem *)TO_CACHE(phys_addr));
 }