[PATCH v4 5/6] arm64: mm: Convert to GENERIC_IOREMAP

[Kefeng Wang]

Add hook for arm64's special operation when ioremap() and iounmap(),
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 <anshuman.khandual@xxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
 arch/arm64/Kconfig          |  1 +
 arch/arm64/include/asm/io.h | 20 ++++++---
 arch/arm64/kernel/acpi.c    |  2 +-
 arch/arm64/mm/ioremap.c     | 84 +++++--------------------------------
 4 files changed, 26 insertions(+), 81 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1652a9800ebe..ac160aa26126 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -126,6 +126,7 @@ config ARM64
 	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
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index 3995652daf81..02aa5a5e9190 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -163,13 +163,21 @@ extern void __memset_io(volatile void __iomem *, int, size_t);
 /*
  * 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))
+int ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot);
+#define ioremap_allowed ioremap_allowed
+
+int iounmap_allowed(void __iomem *addr);
+#define iounmap_allowed iounmap_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)
+#define ioremap_cache(addr, size) ({							\
+	pfn_is_map_memory(__phys_to_pfn(addr)) ?					\
+	(void __iomem *)__phys_to_virt(addr) : ioremap_prot(addr, size, PROT_NORMAL);	\
+})
 
 /*
  * io{read,write}{16,32,64}be() macros
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index e4dea8db6924..a5a256e3f9fe 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -351,7 +351,7 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
 				prot = __acpi_get_writethrough_mem_attribute();
 		}
 	}
-	return __ioremap(phys, size, prot);
+	return ioremap_prot(phys, size, pgprot_val(prot));
 }
 
 /*
diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c
index b21f91cd830d..4a3f526c6057 100644
--- a/arch/arm64/mm/ioremap.c
+++ b/arch/arm64/mm/ioremap.c
@@ -1,96 +1,32 @@
 // 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 <philb@xxxxxxx>
- * 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)
+int 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;
-
-	/*
-	 * Page align the mapping address and size, taking account of any
-	 * offset.
-	 */
-	phys_addr &= PAGE_MASK;
-	size = PAGE_ALIGN(size + offset);
+	unsigned long last_addr = phys_addr + size - 1;
 
-	/*
-	 * 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 outside PHYS_MASK */
+	if (last_addr & ~PHYS_MASK)
+		return -EINVAL;
 
-	/*
-	 * 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 -EINVAL;
 
-	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);
-}
-
-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));
+	return 0;
 }
-EXPORT_SYMBOL(__ioremap);
 
-void iounmap(volatile void __iomem *io_addr)
+int iounmap_allowed(void __iomem *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));
+	return is_vmalloc_addr(addr) ? 0 : -EINVAL;
 }
-EXPORT_SYMBOL(ioremap_cache);
 
 /*
  * Must be called after early_fixmap_init
-- 
2.35.3