arm64: mm: Convert to GENERIC_IOREMAP

Add hook for arm64's special operation when ioremap(), then
ioremap_wc/np/cache is converted to use ioremap_prot() from
GENERIC_IOREMAP, update the Copyright and kill the unused
inclusions.

Reviewed-by: Anshuman Khandual <[e-mail]>
Acked-by: Catalin Marinas <[e-mail]>
Signed-off-by: Kefeng Wang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Will Deacon <[e-mail]>

arch/arm64/Kconfig

···
 	select GENERIC_CPU_VULNERABILITIES
 	select GENERIC_EARLY_IOREMAP
 	select GENERIC_IDLE_POLL_SETUP
+	select GENERIC_IOREMAP
 	select GENERIC_IRQ_IPI
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW

arch/arm64/include/asm/io.h

···
 /*
  * I/O memory mapping functions.
  */
-extern void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot);
-extern void iounmap(volatile void __iomem *addr);
-extern void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size);
 
-#define ioremap(addr, size)		__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
-#define ioremap_wc(addr, size)		__ioremap((addr), (size), __pgprot(PROT_NORMAL_NC))
-#define ioremap_np(addr, size)		__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRnE))
+bool ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot);
+#define ioremap_allowed ioremap_allowed
+
+#define _PAGE_IOREMAP PROT_DEVICE_nGnRE
+
+#define ioremap_wc(addr, size)	\
+	ioremap_prot((addr), (size), PROT_NORMAL_NC)
+#define ioremap_np(addr, size)	\
+	ioremap_prot((addr), (size), PROT_DEVICE_nGnRnE)
 
 /*
  * io{read,write}{16,32,64}be() macros
···
 #define iowrite64be(v,p)	({ __iowmb(); __raw_writeq((__force __u64)cpu_to_be64(v), p); })
 
 #include <asm-generic/io.h>
+
+#define ioremap_cache ioremap_cache
+static inline void __iomem *ioremap_cache(phys_addr_t addr, size_t size)
+{
+	if (pfn_is_map_memory(__phys_to_pfn(addr)))
+		return (void __iomem *)__phys_to_virt(addr);
+
+	return ioremap_prot(addr, size, PROT_NORMAL);
+}
 
 /*
  * More restrictive address range checking than the default implementation

arch/arm64/kernel/acpi.c

···
 				prot = __acpi_get_writethrough_mem_attribute();
 		}
 	}
-	return __ioremap(phys, size, prot);
+	return ioremap_prot(phys, size, pgprot_val(prot));
 }
 
 /*

arch/arm64/mm/ioremap.c

···
 // SPDX-License-Identifier: GPL-2.0-only
-/*
- * Based on arch/arm/mm/ioremap.c
- *
- * (C) Copyright 1995 1996 Linus Torvalds
- * Hacked for ARM by Phil Blundell <[e-mail]>
- * Hacked to allow all architectures to build, and various cleanups
- * by Russell King
- * Copyright (C) 2012 ARM Ltd.
- */
 
-#include <linux/export.h>
 #include <linux/mm.h>
-#include <linux/vmalloc.h>
 #include <linux/io.h>
 
-#include <asm/fixmap.h>
-#include <asm/tlbflush.h>
-
-static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
-				      pgprot_t prot, void *caller)
+bool ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot)
 {
-	unsigned long last_addr;
-	unsigned long offset = phys_addr & ~PAGE_MASK;
-	int err;
-	unsigned long addr;
-	struct vm_struct *area;
+	unsigned long last_addr = phys_addr + size - 1;
 
-	/*
-	 * Page align the mapping address and size, taking account of any
-	 * offset.
-	 */
-	phys_addr &= PAGE_MASK;
-	size = PAGE_ALIGN(size + offset);
+	/* Don't allow outside PHYS_MASK */
+	if (last_addr & ~PHYS_MASK)
+		return false;
 
-	/*
-	 * Don't allow wraparound, zero size or outside PHYS_MASK.
-	 */
-	last_addr = phys_addr + size - 1;
-	if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK))
-		return NULL;
-
-	/*
-	 * Don't allow RAM to be mapped.
-	 */
+	/* Don't allow RAM to be mapped. */
 	if (WARN_ON(pfn_is_map_memory(__phys_to_pfn(phys_addr))))
-		return NULL;
+		return false;
 
-	area = get_vm_area_caller(size, VM_IOREMAP, caller);
-	if (!area)
-		return NULL;
-	addr = (unsigned long)area->addr;
-	area->phys_addr = phys_addr;
-
-	err = ioremap_page_range(addr, addr + size, phys_addr, prot);
-	if (err) {
-		vunmap((void *)addr);
-		return NULL;
-	}
-
-	return (void __iomem *)(offset + addr);
+	return true;
 }
-
-void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot)
-{
-	return __ioremap_caller(phys_addr, size, prot,
-				__builtin_return_address(0));
-}
-EXPORT_SYMBOL(__ioremap);
-
-void iounmap(volatile void __iomem *io_addr)
-{
-	unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
-
-	/*
-	 * We could get an address outside vmalloc range in case
-	 * of ioremap_cache() reusing a RAM mapping.
-	 */
-	if (is_vmalloc_addr((void *)addr))
-		vunmap((void *)addr);
-}
-EXPORT_SYMBOL(iounmap);
-
-void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size)
-{
-	/* For normal memory we already have a cacheable mapping. */
-	if (pfn_is_map_memory(__phys_to_pfn(phys_addr)))
-		return (void __iomem *)__phys_to_virt(phys_addr);
-
-	return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL),
-				__builtin_return_address(0));
-}
-EXPORT_SYMBOL(ioremap_cache);
 
 /*
  * Must be called after early_fixmap_init