All the mail mirrored from lore.kernel.org
 help / color / mirror / Atom feed
From: Dan Williams <dan.j.williams@intel.com>
To: arnd@arndb.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
	tglx@linutronix.de, ross.zwisler@linux.intel.com,
	akpm@linux-foundation.org
Cc: jgross@suse.com, x86@kernel.org, toshi.kani@hp.com,
	konrad.wilk@oracle.com, benh@kernel.crashing.org,
	mcgrof@suse.com, linux-nvdimm@ml01.01.org,
	linux-kernel@vger.kernel.org, stefan.bader@canonical.com,
	luto@amacapital.net, linux-mm@kvack.org,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	geert@linux-m68k.org, ralf@linux-mips.org, hmh@hmh.eng.br,
	mpe@ellerman.id.au, tj@kernel.org, paulus@samba.org, hch@lst.de
Subject: [PATCH v4 5/6] arch: introduce memremap_cache() and memremap_wt()
Date: Thu, 11 Jun 2015 17:19:41 -0400	[thread overview]
Message-ID: <20150611211941.10271.10513.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
In-Reply-To: <20150611211354.10271.57950.stgit@dwillia2-desk3.amr.corp.intel.com>

Existing users of ioremap_cache() are mapping memory that is known in
advance to not have i/o side effects.  These users are forced to cast
away the __iomem annotation, or otherwise neglect to fix the sparse
errors thrown when dereferencing pointers to this memory.  Provide
memremap_*() as a non __iomem annotated ioremap_*().

The ARCH_HAS_MEMREMAP kconfig symbol is introduced for archs to assert
that it is safe to recast / reuse the return value from ioremap as a
normal pointer to memory.  In other words, archs that mandate specific
accessors for __iomem are not memremap() capable and drivers that care,
like pmem, can add a dependency to disable themselves on these archs.

Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/arm/Kconfig                     |    1 +
 arch/arm64/Kconfig                   |    1 +
 arch/arm64/kernel/efi.c              |    4 ++-
 arch/arm64/kernel/smp_spin_table.c   |   10 ++++----
 arch/frv/Kconfig                     |    1 +
 arch/m68k/Kconfig                    |    1 +
 arch/metag/Kconfig                   |    1 +
 arch/mips/Kconfig                    |    1 +
 arch/powerpc/Kconfig                 |    1 +
 arch/x86/Kconfig                     |    1 +
 arch/x86/kernel/crash_dump_64.c      |    6 ++---
 arch/x86/kernel/kdebugfs.c           |    8 +++----
 arch/x86/kernel/ksysfs.c             |   28 ++++++++++++-----------
 arch/x86/mm/ioremap.c                |   10 +++-----
 arch/xtensa/Kconfig                  |    1 +
 drivers/acpi/apei/einj.c             |    8 +++----
 drivers/acpi/apei/erst.c             |    4 ++-
 drivers/block/Kconfig                |    1 +
 drivers/block/pmem.c                 |    7 +++---
 drivers/firmware/google/memconsole.c |    4 ++-
 include/linux/device.h               |    5 ++++
 include/linux/io.h                   |    4 +++
 kernel/resource.c                    |   41 +++++++++++++++++++++++++++++++++-
 lib/Kconfig                          |    5 +++-
 24 files changed, 107 insertions(+), 47 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 45df48ba0b12..397426f8ca37 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -3,6 +3,7 @@ config ARM
 	default y
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select ARCH_HAS_ELF_RANDOMIZE
+	select ARCH_HAS_MEMREMAP
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAVE_CUSTOM_GPIO_H
 	select ARCH_HAS_GCOV_PROFILE_ALL
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7796af4b1d6f..f07a9a5af61e 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -5,6 +5,7 @@ config ARM64
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_MEMREMAP
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_USE_CMPXCHG_LOCKREF
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index ab21e0d58278..b672ef33f08b 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -289,7 +289,7 @@ static int __init arm64_enable_runtime_services(void)
 	pr_info("Remapping and enabling EFI services.\n");
 
 	mapsize = memmap.map_end - memmap.map;
-	memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
+	memmap.map = memremap_cache((phys_addr_t)memmap.phys_map,
 						   mapsize);
 	if (!memmap.map) {
 		pr_err("Failed to remap EFI memory map\n");
@@ -298,7 +298,7 @@ static int __init arm64_enable_runtime_services(void)
 	memmap.map_end = memmap.map + mapsize;
 	efi.memmap = &memmap;
 
-	efi.systab = (__force void *)ioremap_cache(efi_system_table,
+	efi.systab = memremap_cache(efi_system_table,
 						   sizeof(efi_system_table_t));
 	if (!efi.systab) {
 		pr_err("Failed to remap EFI System Table\n");
diff --git a/arch/arm64/kernel/smp_spin_table.c b/arch/arm64/kernel/smp_spin_table.c
index 14944e5b28da..893c8586e20f 100644
--- a/arch/arm64/kernel/smp_spin_table.c
+++ b/arch/arm64/kernel/smp_spin_table.c
@@ -67,18 +67,18 @@ static int smp_spin_table_cpu_init(struct device_node *dn, unsigned int cpu)
 
 static int smp_spin_table_cpu_prepare(unsigned int cpu)
 {
-	__le64 __iomem *release_addr;
+	__le64 *release_addr;
 
 	if (!cpu_release_addr[cpu])
 		return -ENODEV;
 
 	/*
 	 * The cpu-release-addr may or may not be inside the linear mapping.
-	 * As ioremap_cache will either give us a new mapping or reuse the
+	 * As memremap_cache will either give us a new mapping or reuse the
 	 * existing linear mapping, we can use it to cover both cases. In
 	 * either case the memory will be MT_NORMAL.
 	 */
-	release_addr = ioremap_cache(cpu_release_addr[cpu],
+	release_addr = memremap_cache(cpu_release_addr[cpu],
 				     sizeof(*release_addr));
 	if (!release_addr)
 		return -ENOMEM;
@@ -91,7 +91,7 @@ static int smp_spin_table_cpu_prepare(unsigned int cpu)
 	 * the boot protocol.
 	 */
 	writeq_relaxed(__pa(secondary_holding_pen), release_addr);
-	__flush_dcache_area((__force void *)release_addr,
+	__flush_dcache_area(release_addr,
 			    sizeof(*release_addr));
 
 	/*
@@ -99,7 +99,7 @@ static int smp_spin_table_cpu_prepare(unsigned int cpu)
 	 */
 	sev();
 
-	iounmap(release_addr);
+	memunmap(release_addr);
 
 	return 0;
 }
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index 34aa19352dc1..2373bf183527 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -14,6 +14,7 @@ config FRV
 	select OLD_SIGSUSPEND3
 	select OLD_SIGACTION
 	select HAVE_DEBUG_STACKOVERFLOW
+	select ARCH_HAS_MEMREMAP
 
 config ZONE_DMA
 	bool
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 2dd8f63bfbbb..831b1be8c43d 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -23,6 +23,7 @@ config M68K
 	select MODULES_USE_ELF_RELA
 	select OLD_SIGSUSPEND3
 	select OLD_SIGACTION
+	select ARCH_HAS_MEMREMAP
 
 config RWSEM_GENERIC_SPINLOCK
 	bool
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index 0b389a81c43a..5669fe3eb807 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -24,6 +24,7 @@ config METAG
 	select HAVE_PERF_EVENTS
 	select HAVE_SYSCALL_TRACEPOINTS
 	select HAVE_UNDERSCORE_SYMBOL_PREFIX
+	select ARCH_HAS_MEMREMAP
 	select IRQ_DOMAIN
 	select MODULES_USE_ELF_RELA
 	select OF
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index f5016656494f..9ee35e615c0d 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -58,6 +58,7 @@ config MIPS
 	select SYSCTL_EXCEPTION_TRACE
 	select HAVE_VIRT_CPU_ACCOUNTING_GEN
 	select HAVE_IRQ_TIME_ACCOUNTING
+	select ARCH_HAS_MEMREMAP
 
 menu "Machine selection"
 
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 190cc48abc0c..73c1f8b1f022 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -153,6 +153,7 @@ config PPC
 	select NO_BOOTMEM
 	select HAVE_GENERIC_RCU_GUP
 	select HAVE_PERF_EVENTS_NMI if PPC64
+	select ARCH_HAS_MEMREMAP
 
 config GENERIC_CSUM
 	def_bool CPU_LITTLE_ENDIAN
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 228aa35d7e89..f16caf7eac27 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -27,6 +27,7 @@ config X86
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FAST_MULTIPLIER
 	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_MEMREMAP
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index afa64adb75ee..8e04011665fd 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -31,19 +31,19 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 	if (!csize)
 		return 0;
 
-	vaddr = ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
+	vaddr = memremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
 	if (!vaddr)
 		return -ENOMEM;
 
 	if (userbuf) {
 		if (copy_to_user(buf, vaddr + offset, csize)) {
-			iounmap(vaddr);
+			memunmap(vaddr);
 			return -EFAULT;
 		}
 	} else
 		memcpy(buf, vaddr + offset, csize);
 
 	set_iounmap_nonlazy();
-	iounmap(vaddr);
+	memunmap(vaddr);
 	return csize;
 }
diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c
index dc1404bf8e4b..731b10e2814f 100644
--- a/arch/x86/kernel/kdebugfs.c
+++ b/arch/x86/kernel/kdebugfs.c
@@ -49,7 +49,7 @@ static ssize_t setup_data_read(struct file *file, char __user *user_buf,
 	pa = node->paddr + sizeof(struct setup_data) + pos;
 	pg = pfn_to_page((pa + count - 1) >> PAGE_SHIFT);
 	if (PageHighMem(pg)) {
-		p = ioremap_cache(pa, count);
+		p = memremap_cache(pa, count);
 		if (!p)
 			return -ENXIO;
 	} else
@@ -58,7 +58,7 @@ static ssize_t setup_data_read(struct file *file, char __user *user_buf,
 	remain = copy_to_user(user_buf, p, count);
 
 	if (PageHighMem(pg))
-		iounmap(p);
+		memunmap(p);
 
 	if (remain)
 		return -EFAULT;
@@ -128,7 +128,7 @@ static int __init create_setup_data_nodes(struct dentry *parent)
 
 		pg = pfn_to_page((pa_data+sizeof(*data)-1) >> PAGE_SHIFT);
 		if (PageHighMem(pg)) {
-			data = ioremap_cache(pa_data, sizeof(*data));
+			data = memremap_cache(pa_data, sizeof(*data));
 			if (!data) {
 				kfree(node);
 				error = -ENXIO;
@@ -144,7 +144,7 @@ static int __init create_setup_data_nodes(struct dentry *parent)
 		pa_data = data->next;
 
 		if (PageHighMem(pg))
-			iounmap(data);
+			memunmap(data);
 		if (error)
 			goto err_dir;
 		no++;
diff --git a/arch/x86/kernel/ksysfs.c b/arch/x86/kernel/ksysfs.c
index c2bedaea11f7..2fbc62886eae 100644
--- a/arch/x86/kernel/ksysfs.c
+++ b/arch/x86/kernel/ksysfs.c
@@ -16,8 +16,8 @@
 #include <linux/stat.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
+#include <linux/io.h>
 
-#include <asm/io.h>
 #include <asm/setup.h>
 
 static ssize_t version_show(struct kobject *kobj,
@@ -79,12 +79,12 @@ static int get_setup_data_paddr(int nr, u64 *paddr)
 			*paddr = pa_data;
 			return 0;
 		}
-		data = ioremap_cache(pa_data, sizeof(*data));
+		data = memremap_cache(pa_data, sizeof(*data));
 		if (!data)
 			return -ENOMEM;
 
 		pa_data = data->next;
-		iounmap(data);
+		memunmap(data);
 		i++;
 	}
 	return -EINVAL;
@@ -97,17 +97,17 @@ static int __init get_setup_data_size(int nr, size_t *size)
 	u64 pa_data = boot_params.hdr.setup_data;
 
 	while (pa_data) {
-		data = ioremap_cache(pa_data, sizeof(*data));
+		data = memremap_cache(pa_data, sizeof(*data));
 		if (!data)
 			return -ENOMEM;
 		if (nr == i) {
 			*size = data->len;
-			iounmap(data);
+			memunmap(data);
 			return 0;
 		}
 
 		pa_data = data->next;
-		iounmap(data);
+		memunmap(data);
 		i++;
 	}
 	return -EINVAL;
@@ -127,12 +127,12 @@ static ssize_t type_show(struct kobject *kobj,
 	ret = get_setup_data_paddr(nr, &paddr);
 	if (ret)
 		return ret;
-	data = ioremap_cache(paddr, sizeof(*data));
+	data = memremap_cache(paddr, sizeof(*data));
 	if (!data)
 		return -ENOMEM;
 
 	ret = sprintf(buf, "0x%x\n", data->type);
-	iounmap(data);
+	memunmap(data);
 	return ret;
 }
 
@@ -154,7 +154,7 @@ static ssize_t setup_data_data_read(struct file *fp,
 	ret = get_setup_data_paddr(nr, &paddr);
 	if (ret)
 		return ret;
-	data = ioremap_cache(paddr, sizeof(*data));
+	data = memremap_cache(paddr, sizeof(*data));
 	if (!data)
 		return -ENOMEM;
 
@@ -170,15 +170,15 @@ static ssize_t setup_data_data_read(struct file *fp,
 		goto out;
 
 	ret = count;
-	p = ioremap_cache(paddr + sizeof(*data), data->len);
+	p = memremap_cache(paddr + sizeof(*data), data->len);
 	if (!p) {
 		ret = -ENOMEM;
 		goto out;
 	}
 	memcpy(buf, p + off, count);
-	iounmap(p);
+	memunmap(p);
 out:
-	iounmap(data);
+	memunmap(data);
 	return ret;
 }
 
@@ -250,13 +250,13 @@ static int __init get_setup_data_total_num(u64 pa_data, int *nr)
 	*nr = 0;
 	while (pa_data) {
 		*nr += 1;
-		data = ioremap_cache(pa_data, sizeof(*data));
+		data = memremap_cache(pa_data, sizeof(*data));
 		if (!data) {
 			ret = -ENOMEM;
 			goto out;
 		}
 		pa_data = data->next;
-		iounmap(data);
+		memunmap(data);
 	}
 
 out:
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index cc5ccc415cc0..7f087cb793fa 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -414,12 +414,10 @@ void *xlate_dev_mem_ptr(phys_addr_t phys)
 	if (page_is_ram(start >> PAGE_SHIFT))
 		return __va(phys);
 
-	vaddr = ioremap_cache(start, PAGE_SIZE);
-	/* Only add the offset on success and return NULL if the ioremap() failed: */
+	vaddr = memremap_cache(start, PAGE_SIZE);
 	if (vaddr)
-		vaddr += offset;
-
-	return vaddr;
+		return vaddr + offset;
+	return NULL;
 }
 
 void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
@@ -427,7 +425,7 @@ void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
 	if (page_is_ram(phys >> PAGE_SHIFT))
 		return;
 
-	iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
+	memunmap((void *)((unsigned long)addr & PAGE_MASK));
 }
 
 static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 87be10e8b57a..e601faf87cee 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -3,6 +3,7 @@ config ZONE_DMA
 
 config XTENSA
 	def_bool y
+	select ARCH_HAS_MEMREMAP
 	select ARCH_WANT_FRAME_POINTERS
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select ARCH_WANT_OPTIONAL_GPIOLIB
diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c
index a095d4f858da..2ec9006cfb6c 100644
--- a/drivers/acpi/apei/einj.c
+++ b/drivers/acpi/apei/einj.c
@@ -318,7 +318,7 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
 			    sizeof(*trigger_tab) - 1);
 		goto out;
 	}
-	trigger_tab = ioremap_cache(trigger_paddr, sizeof(*trigger_tab));
+	trigger_tab = memremap_cache(trigger_paddr, sizeof(*trigger_tab));
 	if (!trigger_tab) {
 		pr_err(EINJ_PFX "Failed to map trigger table!\n");
 		goto out_rel_header;
@@ -346,8 +346,8 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
 		       (unsigned long long)trigger_paddr + table_size - 1);
 		goto out_rel_header;
 	}
-	iounmap(trigger_tab);
-	trigger_tab = ioremap_cache(trigger_paddr, table_size);
+	memunmap(trigger_tab);
+	trigger_tab = memremap_cache(trigger_paddr, table_size);
 	if (!trigger_tab) {
 		pr_err(EINJ_PFX "Failed to map trigger table!\n");
 		goto out_rel_entry;
@@ -409,7 +409,7 @@ out_rel_header:
 	release_mem_region(trigger_paddr, sizeof(*trigger_tab));
 out:
 	if (trigger_tab)
-		iounmap(trigger_tab);
+		memunmap(trigger_tab);
 
 	return rc;
 }
diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index 3670bbab57a3..6b95066da51d 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -77,7 +77,7 @@ static struct acpi_table_erst *erst_tab;
 static struct erst_erange {
 	u64 base;
 	u64 size;
-	void __iomem *vaddr;
+	void *vaddr;
 	u32 attr;
 } erst_erange;
 
@@ -1185,7 +1185,7 @@ static int __init erst_init(void)
 		goto err_unmap_reg;
 	}
 	rc = -ENOMEM;
-	erst_erange.vaddr = ioremap_cache(erst_erange.base,
+	erst_erange.vaddr = memremap_cache(erst_erange.base,
 					  erst_erange.size);
 	if (!erst_erange.vaddr)
 		goto err_release_erange;
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index eb1fed5bd516..98418fc330ae 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -406,6 +406,7 @@ config BLK_DEV_RAM_DAX
 
 config BLK_DEV_PMEM
 	tristate "Persistent memory block device support"
+	depends on ARCH_HAS_MEMREMAP
 	help
 	  Saying Y here will allow you to use a contiguous range of reserved
 	  memory as one or more persistent block devices.
diff --git a/drivers/block/pmem.c b/drivers/block/pmem.c
index 095dfaadcaa5..b00b97314b57 100644
--- a/drivers/block/pmem.c
+++ b/drivers/block/pmem.c
@@ -23,6 +23,7 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/slab.h>
+#include <linux/io.h>
 
 #define PMEM_MINORS		16
 
@@ -143,7 +144,7 @@ static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res)
 	 * of the CPU caches in case of a crash.
 	 */
 	err = -ENOMEM;
-	pmem->virt_addr = ioremap_wt(pmem->phys_addr, pmem->size);
+	pmem->virt_addr = memremap_wt(pmem->phys_addr, pmem->size);
 	if (!pmem->virt_addr)
 		goto out_release_region;
 
@@ -179,7 +180,7 @@ static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res)
 out_free_queue:
 	blk_cleanup_queue(pmem->pmem_queue);
 out_unmap:
-	iounmap(pmem->virt_addr);
+	memunmap(pmem->virt_addr);
 out_release_region:
 	release_mem_region(pmem->phys_addr, pmem->size);
 out_free_dev:
@@ -193,7 +194,7 @@ static void pmem_free(struct pmem_device *pmem)
 	del_gendisk(pmem->pmem_disk);
 	put_disk(pmem->pmem_disk);
 	blk_cleanup_queue(pmem->pmem_queue);
-	iounmap(pmem->virt_addr);
+	memunmap(pmem->virt_addr);
 	release_mem_region(pmem->phys_addr, pmem->size);
 	kfree(pmem);
 }
diff --git a/drivers/firmware/google/memconsole.c b/drivers/firmware/google/memconsole.c
index 2f569aaed4c7..877433dc8297 100644
--- a/drivers/firmware/google/memconsole.c
+++ b/drivers/firmware/google/memconsole.c
@@ -52,14 +52,14 @@ static ssize_t memconsole_read(struct file *filp, struct kobject *kobp,
 	char *memconsole;
 	ssize_t ret;
 
-	memconsole = ioremap_cache(memconsole_baseaddr, memconsole_length);
+	memconsole = memremap_cache(memconsole_baseaddr, memconsole_length);
 	if (!memconsole) {
 		pr_err("memconsole: ioremap_cache failed\n");
 		return -ENOMEM;
 	}
 	ret = memory_read_from_buffer(buf, count, &pos, memconsole,
 				      memconsole_length);
-	iounmap(memconsole);
+	memunmap(memconsole);
 	return ret;
 }
 
diff --git a/include/linux/device.h b/include/linux/device.h
index 6558af90c8fe..518f49c5d596 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -638,6 +638,11 @@ extern void devm_free_pages(struct device *dev, unsigned long addr);
 
 void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
 
+static inline void *devm_memremap_resource(struct device *dev, struct resource *res)
+{
+	return (void __force *) devm_ioremap_resource(dev, res);
+}
+
 /* allows to add/remove a custom action to devres stack */
 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
diff --git a/include/linux/io.h b/include/linux/io.h
index 4cd8996cfea0..23ef87d311d5 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -123,4 +123,8 @@ static inline int arch_phys_wc_index(int handle)
 #endif
 #endif
 
+extern void *memremap_cache(resource_size_t offset, size_t size);
+extern void *memremap_wt(resource_size_t offset, size_t size);
+extern void memunmap(void *addr);
+
 #endif /* _LINUX_IO_H */
diff --git a/kernel/resource.c b/kernel/resource.c
index 90552aab5f2d..2f8aca09da52 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -23,7 +23,7 @@
 #include <linux/pfn.h>
 #include <linux/mm.h>
 #include <linux/resource_ext.h>
-#include <asm/io.h>
+#include <linux/io.h>
 
 
 struct resource ioport_resource = {
@@ -528,6 +528,45 @@ int region_is_ram(resource_size_t start, unsigned long size)
 	return ret;
 }
 
+#ifdef CONFIG_ARCH_HAS_MEMREMAP
+/*
+ * memremap() is "ioremap" for cases where it is known that the resource
+ * being mapped does not have i/o side effects and the __iomem
+ * annotation is not applicable.
+ */
+static bool memremap_valid(resource_size_t offset, size_t size)
+{
+	if (region_is_ram(offset, size) != 0) {
+		WARN_ONCE(1, "memremap attempted on ram %pa size: %zu\n",
+				&offset, size);
+		return false;
+	}
+	return true;
+}
+
+void *memremap_cache(resource_size_t offset, size_t size)
+{
+	if (!memremap_valid(offset, size))
+		return NULL;
+	return (void __force *) ioremap_cache(offset, size);
+}
+EXPORT_SYMBOL(memremap_cache);
+
+void *memremap_wt(resource_size_t offset, size_t size)
+{
+	if (!memremap_valid(offset, size))
+		return NULL;
+	return (void __force *) ioremap_wt(offset, size);
+}
+EXPORT_SYMBOL(memremap_wt);
+
+void memunmap(void *addr)
+{
+	iounmap((void __iomem __force *) addr);
+}
+EXPORT_SYMBOL(memunmap);
+#endif /* CONFIG_ARCH_HAS_MEMREMAP */
+
 void __weak arch_remove_reservations(struct resource *avail)
 {
 }
diff --git a/lib/Kconfig b/lib/Kconfig
index 601965a948e8..bc7bc0278921 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -520,6 +520,9 @@ source "lib/fonts/Kconfig"
 #
 
 config ARCH_HAS_SG_CHAIN
-	def_bool n
+	bool
+
+config ARCH_HAS_MEMREMAP
+	bool
 
 endmenu


WARNING: multiple messages have this Message-ID (diff)
From: Dan Williams <dan.j.williams@intel.com>
To: arnd@arndb.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
	tglx@linutronix.de, ross.zwisler@linux.intel.com,
	akpm@linux-foundation.org
Cc: jgross@suse.com, x86@kernel.org, toshi.kani@hp.com,
	konrad.wilk@oracle.com, benh@kernel.crashing.org,
	mcgrof@suse.com, linux-nvdimm@lists.01.org,
	linux-kernel@vger.kernel.org, stefan.bader@canonical.com,
	luto@amacapital.net, linux-mm@kvack.org,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	geert@linux-m68k.org, ralf@linux-mips.org, hmh@hmh.eng.br,
	mpe@ellerman.id.au, tj@kernel.org, paulus@samba.org, hch@lst.de
Subject: [PATCH v4 5/6] arch: introduce memremap_cache() and memremap_wt()
Date: Thu, 11 Jun 2015 17:19:41 -0400	[thread overview]
Message-ID: <20150611211941.10271.10513.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
In-Reply-To: <20150611211354.10271.57950.stgit@dwillia2-desk3.amr.corp.intel.com>

Existing users of ioremap_cache() are mapping memory that is known in
advance to not have i/o side effects.  These users are forced to cast
away the __iomem annotation, or otherwise neglect to fix the sparse
errors thrown when dereferencing pointers to this memory.  Provide
memremap_*() as a non __iomem annotated ioremap_*().

The ARCH_HAS_MEMREMAP kconfig symbol is introduced for archs to assert
that it is safe to recast / reuse the return value from ioremap as a
normal pointer to memory.  In other words, archs that mandate specific
accessors for __iomem are not memremap() capable and drivers that care,
like pmem, can add a dependency to disable themselves on these archs.

Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/arm/Kconfig                     |    1 +
 arch/arm64/Kconfig                   |    1 +
 arch/arm64/kernel/efi.c              |    4 ++-
 arch/arm64/kernel/smp_spin_table.c   |   10 ++++----
 arch/frv/Kconfig                     |    1 +
 arch/m68k/Kconfig                    |    1 +
 arch/metag/Kconfig                   |    1 +
 arch/mips/Kconfig                    |    1 +
 arch/powerpc/Kconfig                 |    1 +
 arch/x86/Kconfig                     |    1 +
 arch/x86/kernel/crash_dump_64.c      |    6 ++---
 arch/x86/kernel/kdebugfs.c           |    8 +++----
 arch/x86/kernel/ksysfs.c             |   28 ++++++++++++-----------
 arch/x86/mm/ioremap.c                |   10 +++-----
 arch/xtensa/Kconfig                  |    1 +
 drivers/acpi/apei/einj.c             |    8 +++----
 drivers/acpi/apei/erst.c             |    4 ++-
 drivers/block/Kconfig                |    1 +
 drivers/block/pmem.c                 |    7 +++---
 drivers/firmware/google/memconsole.c |    4 ++-
 include/linux/device.h               |    5 ++++
 include/linux/io.h                   |    4 +++
 kernel/resource.c                    |   41 +++++++++++++++++++++++++++++++++-
 lib/Kconfig                          |    5 +++-
 24 files changed, 107 insertions(+), 47 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 45df48ba0b12..397426f8ca37 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -3,6 +3,7 @@ config ARM
 	default y
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select ARCH_HAS_ELF_RANDOMIZE
+	select ARCH_HAS_MEMREMAP
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAVE_CUSTOM_GPIO_H
 	select ARCH_HAS_GCOV_PROFILE_ALL
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7796af4b1d6f..f07a9a5af61e 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -5,6 +5,7 @@ config ARM64
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_MEMREMAP
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_USE_CMPXCHG_LOCKREF
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index ab21e0d58278..b672ef33f08b 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -289,7 +289,7 @@ static int __init arm64_enable_runtime_services(void)
 	pr_info("Remapping and enabling EFI services.\n");
 
 	mapsize = memmap.map_end - memmap.map;
-	memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
+	memmap.map = memremap_cache((phys_addr_t)memmap.phys_map,
 						   mapsize);
 	if (!memmap.map) {
 		pr_err("Failed to remap EFI memory map\n");
@@ -298,7 +298,7 @@ static int __init arm64_enable_runtime_services(void)
 	memmap.map_end = memmap.map + mapsize;
 	efi.memmap = &memmap;
 
-	efi.systab = (__force void *)ioremap_cache(efi_system_table,
+	efi.systab = memremap_cache(efi_system_table,
 						   sizeof(efi_system_table_t));
 	if (!efi.systab) {
 		pr_err("Failed to remap EFI System Table\n");
diff --git a/arch/arm64/kernel/smp_spin_table.c b/arch/arm64/kernel/smp_spin_table.c
index 14944e5b28da..893c8586e20f 100644
--- a/arch/arm64/kernel/smp_spin_table.c
+++ b/arch/arm64/kernel/smp_spin_table.c
@@ -67,18 +67,18 @@ static int smp_spin_table_cpu_init(struct device_node *dn, unsigned int cpu)
 
 static int smp_spin_table_cpu_prepare(unsigned int cpu)
 {
-	__le64 __iomem *release_addr;
+	__le64 *release_addr;
 
 	if (!cpu_release_addr[cpu])
 		return -ENODEV;
 
 	/*
 	 * The cpu-release-addr may or may not be inside the linear mapping.
-	 * As ioremap_cache will either give us a new mapping or reuse the
+	 * As memremap_cache will either give us a new mapping or reuse the
 	 * existing linear mapping, we can use it to cover both cases. In
 	 * either case the memory will be MT_NORMAL.
 	 */
-	release_addr = ioremap_cache(cpu_release_addr[cpu],
+	release_addr = memremap_cache(cpu_release_addr[cpu],
 				     sizeof(*release_addr));
 	if (!release_addr)
 		return -ENOMEM;
@@ -91,7 +91,7 @@ static int smp_spin_table_cpu_prepare(unsigned int cpu)
 	 * the boot protocol.
 	 */
 	writeq_relaxed(__pa(secondary_holding_pen), release_addr);
-	__flush_dcache_area((__force void *)release_addr,
+	__flush_dcache_area(release_addr,
 			    sizeof(*release_addr));
 
 	/*
@@ -99,7 +99,7 @@ static int smp_spin_table_cpu_prepare(unsigned int cpu)
 	 */
 	sev();
 
-	iounmap(release_addr);
+	memunmap(release_addr);
 
 	return 0;
 }
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index 34aa19352dc1..2373bf183527 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -14,6 +14,7 @@ config FRV
 	select OLD_SIGSUSPEND3
 	select OLD_SIGACTION
 	select HAVE_DEBUG_STACKOVERFLOW
+	select ARCH_HAS_MEMREMAP
 
 config ZONE_DMA
 	bool
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 2dd8f63bfbbb..831b1be8c43d 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -23,6 +23,7 @@ config M68K
 	select MODULES_USE_ELF_RELA
 	select OLD_SIGSUSPEND3
 	select OLD_SIGACTION
+	select ARCH_HAS_MEMREMAP
 
 config RWSEM_GENERIC_SPINLOCK
 	bool
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index 0b389a81c43a..5669fe3eb807 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -24,6 +24,7 @@ config METAG
 	select HAVE_PERF_EVENTS
 	select HAVE_SYSCALL_TRACEPOINTS
 	select HAVE_UNDERSCORE_SYMBOL_PREFIX
+	select ARCH_HAS_MEMREMAP
 	select IRQ_DOMAIN
 	select MODULES_USE_ELF_RELA
 	select OF
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index f5016656494f..9ee35e615c0d 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -58,6 +58,7 @@ config MIPS
 	select SYSCTL_EXCEPTION_TRACE
 	select HAVE_VIRT_CPU_ACCOUNTING_GEN
 	select HAVE_IRQ_TIME_ACCOUNTING
+	select ARCH_HAS_MEMREMAP
 
 menu "Machine selection"
 
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 190cc48abc0c..73c1f8b1f022 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -153,6 +153,7 @@ config PPC
 	select NO_BOOTMEM
 	select HAVE_GENERIC_RCU_GUP
 	select HAVE_PERF_EVENTS_NMI if PPC64
+	select ARCH_HAS_MEMREMAP
 
 config GENERIC_CSUM
 	def_bool CPU_LITTLE_ENDIAN
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 228aa35d7e89..f16caf7eac27 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -27,6 +27,7 @@ config X86
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FAST_MULTIPLIER
 	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_MEMREMAP
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index afa64adb75ee..8e04011665fd 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -31,19 +31,19 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 	if (!csize)
 		return 0;
 
-	vaddr = ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
+	vaddr = memremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
 	if (!vaddr)
 		return -ENOMEM;
 
 	if (userbuf) {
 		if (copy_to_user(buf, vaddr + offset, csize)) {
-			iounmap(vaddr);
+			memunmap(vaddr);
 			return -EFAULT;
 		}
 	} else
 		memcpy(buf, vaddr + offset, csize);
 
 	set_iounmap_nonlazy();
-	iounmap(vaddr);
+	memunmap(vaddr);
 	return csize;
 }
diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c
index dc1404bf8e4b..731b10e2814f 100644
--- a/arch/x86/kernel/kdebugfs.c
+++ b/arch/x86/kernel/kdebugfs.c
@@ -49,7 +49,7 @@ static ssize_t setup_data_read(struct file *file, char __user *user_buf,
 	pa = node->paddr + sizeof(struct setup_data) + pos;
 	pg = pfn_to_page((pa + count - 1) >> PAGE_SHIFT);
 	if (PageHighMem(pg)) {
-		p = ioremap_cache(pa, count);
+		p = memremap_cache(pa, count);
 		if (!p)
 			return -ENXIO;
 	} else
@@ -58,7 +58,7 @@ static ssize_t setup_data_read(struct file *file, char __user *user_buf,
 	remain = copy_to_user(user_buf, p, count);
 
 	if (PageHighMem(pg))
-		iounmap(p);
+		memunmap(p);
 
 	if (remain)
 		return -EFAULT;
@@ -128,7 +128,7 @@ static int __init create_setup_data_nodes(struct dentry *parent)
 
 		pg = pfn_to_page((pa_data+sizeof(*data)-1) >> PAGE_SHIFT);
 		if (PageHighMem(pg)) {
-			data = ioremap_cache(pa_data, sizeof(*data));
+			data = memremap_cache(pa_data, sizeof(*data));
 			if (!data) {
 				kfree(node);
 				error = -ENXIO;
@@ -144,7 +144,7 @@ static int __init create_setup_data_nodes(struct dentry *parent)
 		pa_data = data->next;
 
 		if (PageHighMem(pg))
-			iounmap(data);
+			memunmap(data);
 		if (error)
 			goto err_dir;
 		no++;
diff --git a/arch/x86/kernel/ksysfs.c b/arch/x86/kernel/ksysfs.c
index c2bedaea11f7..2fbc62886eae 100644
--- a/arch/x86/kernel/ksysfs.c
+++ b/arch/x86/kernel/ksysfs.c
@@ -16,8 +16,8 @@
 #include <linux/stat.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
+#include <linux/io.h>
 
-#include <asm/io.h>
 #include <asm/setup.h>
 
 static ssize_t version_show(struct kobject *kobj,
@@ -79,12 +79,12 @@ static int get_setup_data_paddr(int nr, u64 *paddr)
 			*paddr = pa_data;
 			return 0;
 		}
-		data = ioremap_cache(pa_data, sizeof(*data));
+		data = memremap_cache(pa_data, sizeof(*data));
 		if (!data)
 			return -ENOMEM;
 
 		pa_data = data->next;
-		iounmap(data);
+		memunmap(data);
 		i++;
 	}
 	return -EINVAL;
@@ -97,17 +97,17 @@ static int __init get_setup_data_size(int nr, size_t *size)
 	u64 pa_data = boot_params.hdr.setup_data;
 
 	while (pa_data) {
-		data = ioremap_cache(pa_data, sizeof(*data));
+		data = memremap_cache(pa_data, sizeof(*data));
 		if (!data)
 			return -ENOMEM;
 		if (nr == i) {
 			*size = data->len;
-			iounmap(data);
+			memunmap(data);
 			return 0;
 		}
 
 		pa_data = data->next;
-		iounmap(data);
+		memunmap(data);
 		i++;
 	}
 	return -EINVAL;
@@ -127,12 +127,12 @@ static ssize_t type_show(struct kobject *kobj,
 	ret = get_setup_data_paddr(nr, &paddr);
 	if (ret)
 		return ret;
-	data = ioremap_cache(paddr, sizeof(*data));
+	data = memremap_cache(paddr, sizeof(*data));
 	if (!data)
 		return -ENOMEM;
 
 	ret = sprintf(buf, "0x%x\n", data->type);
-	iounmap(data);
+	memunmap(data);
 	return ret;
 }
 
@@ -154,7 +154,7 @@ static ssize_t setup_data_data_read(struct file *fp,
 	ret = get_setup_data_paddr(nr, &paddr);
 	if (ret)
 		return ret;
-	data = ioremap_cache(paddr, sizeof(*data));
+	data = memremap_cache(paddr, sizeof(*data));
 	if (!data)
 		return -ENOMEM;
 
@@ -170,15 +170,15 @@ static ssize_t setup_data_data_read(struct file *fp,
 		goto out;
 
 	ret = count;
-	p = ioremap_cache(paddr + sizeof(*data), data->len);
+	p = memremap_cache(paddr + sizeof(*data), data->len);
 	if (!p) {
 		ret = -ENOMEM;
 		goto out;
 	}
 	memcpy(buf, p + off, count);
-	iounmap(p);
+	memunmap(p);
 out:
-	iounmap(data);
+	memunmap(data);
 	return ret;
 }
 
@@ -250,13 +250,13 @@ static int __init get_setup_data_total_num(u64 pa_data, int *nr)
 	*nr = 0;
 	while (pa_data) {
 		*nr += 1;
-		data = ioremap_cache(pa_data, sizeof(*data));
+		data = memremap_cache(pa_data, sizeof(*data));
 		if (!data) {
 			ret = -ENOMEM;
 			goto out;
 		}
 		pa_data = data->next;
-		iounmap(data);
+		memunmap(data);
 	}
 
 out:
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index cc5ccc415cc0..7f087cb793fa 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -414,12 +414,10 @@ void *xlate_dev_mem_ptr(phys_addr_t phys)
 	if (page_is_ram(start >> PAGE_SHIFT))
 		return __va(phys);
 
-	vaddr = ioremap_cache(start, PAGE_SIZE);
-	/* Only add the offset on success and return NULL if the ioremap() failed: */
+	vaddr = memremap_cache(start, PAGE_SIZE);
 	if (vaddr)
-		vaddr += offset;
-
-	return vaddr;
+		return vaddr + offset;
+	return NULL;
 }
 
 void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
@@ -427,7 +425,7 @@ void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
 	if (page_is_ram(phys >> PAGE_SHIFT))
 		return;
 
-	iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
+	memunmap((void *)((unsigned long)addr & PAGE_MASK));
 }
 
 static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 87be10e8b57a..e601faf87cee 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -3,6 +3,7 @@ config ZONE_DMA
 
 config XTENSA
 	def_bool y
+	select ARCH_HAS_MEMREMAP
 	select ARCH_WANT_FRAME_POINTERS
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select ARCH_WANT_OPTIONAL_GPIOLIB
diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c
index a095d4f858da..2ec9006cfb6c 100644
--- a/drivers/acpi/apei/einj.c
+++ b/drivers/acpi/apei/einj.c
@@ -318,7 +318,7 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
 			    sizeof(*trigger_tab) - 1);
 		goto out;
 	}
-	trigger_tab = ioremap_cache(trigger_paddr, sizeof(*trigger_tab));
+	trigger_tab = memremap_cache(trigger_paddr, sizeof(*trigger_tab));
 	if (!trigger_tab) {
 		pr_err(EINJ_PFX "Failed to map trigger table!\n");
 		goto out_rel_header;
@@ -346,8 +346,8 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
 		       (unsigned long long)trigger_paddr + table_size - 1);
 		goto out_rel_header;
 	}
-	iounmap(trigger_tab);
-	trigger_tab = ioremap_cache(trigger_paddr, table_size);
+	memunmap(trigger_tab);
+	trigger_tab = memremap_cache(trigger_paddr, table_size);
 	if (!trigger_tab) {
 		pr_err(EINJ_PFX "Failed to map trigger table!\n");
 		goto out_rel_entry;
@@ -409,7 +409,7 @@ out_rel_header:
 	release_mem_region(trigger_paddr, sizeof(*trigger_tab));
 out:
 	if (trigger_tab)
-		iounmap(trigger_tab);
+		memunmap(trigger_tab);
 
 	return rc;
 }
diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index 3670bbab57a3..6b95066da51d 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -77,7 +77,7 @@ static struct acpi_table_erst *erst_tab;
 static struct erst_erange {
 	u64 base;
 	u64 size;
-	void __iomem *vaddr;
+	void *vaddr;
 	u32 attr;
 } erst_erange;
 
@@ -1185,7 +1185,7 @@ static int __init erst_init(void)
 		goto err_unmap_reg;
 	}
 	rc = -ENOMEM;
-	erst_erange.vaddr = ioremap_cache(erst_erange.base,
+	erst_erange.vaddr = memremap_cache(erst_erange.base,
 					  erst_erange.size);
 	if (!erst_erange.vaddr)
 		goto err_release_erange;
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index eb1fed5bd516..98418fc330ae 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -406,6 +406,7 @@ config BLK_DEV_RAM_DAX
 
 config BLK_DEV_PMEM
 	tristate "Persistent memory block device support"
+	depends on ARCH_HAS_MEMREMAP
 	help
 	  Saying Y here will allow you to use a contiguous range of reserved
 	  memory as one or more persistent block devices.
diff --git a/drivers/block/pmem.c b/drivers/block/pmem.c
index 095dfaadcaa5..b00b97314b57 100644
--- a/drivers/block/pmem.c
+++ b/drivers/block/pmem.c
@@ -23,6 +23,7 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/slab.h>
+#include <linux/io.h>
 
 #define PMEM_MINORS		16
 
@@ -143,7 +144,7 @@ static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res)
 	 * of the CPU caches in case of a crash.
 	 */
 	err = -ENOMEM;
-	pmem->virt_addr = ioremap_wt(pmem->phys_addr, pmem->size);
+	pmem->virt_addr = memremap_wt(pmem->phys_addr, pmem->size);
 	if (!pmem->virt_addr)
 		goto out_release_region;
 
@@ -179,7 +180,7 @@ static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res)
 out_free_queue:
 	blk_cleanup_queue(pmem->pmem_queue);
 out_unmap:
-	iounmap(pmem->virt_addr);
+	memunmap(pmem->virt_addr);
 out_release_region:
 	release_mem_region(pmem->phys_addr, pmem->size);
 out_free_dev:
@@ -193,7 +194,7 @@ static void pmem_free(struct pmem_device *pmem)
 	del_gendisk(pmem->pmem_disk);
 	put_disk(pmem->pmem_disk);
 	blk_cleanup_queue(pmem->pmem_queue);
-	iounmap(pmem->virt_addr);
+	memunmap(pmem->virt_addr);
 	release_mem_region(pmem->phys_addr, pmem->size);
 	kfree(pmem);
 }
diff --git a/drivers/firmware/google/memconsole.c b/drivers/firmware/google/memconsole.c
index 2f569aaed4c7..877433dc8297 100644
--- a/drivers/firmware/google/memconsole.c
+++ b/drivers/firmware/google/memconsole.c
@@ -52,14 +52,14 @@ static ssize_t memconsole_read(struct file *filp, struct kobject *kobp,
 	char *memconsole;
 	ssize_t ret;
 
-	memconsole = ioremap_cache(memconsole_baseaddr, memconsole_length);
+	memconsole = memremap_cache(memconsole_baseaddr, memconsole_length);
 	if (!memconsole) {
 		pr_err("memconsole: ioremap_cache failed\n");
 		return -ENOMEM;
 	}
 	ret = memory_read_from_buffer(buf, count, &pos, memconsole,
 				      memconsole_length);
-	iounmap(memconsole);
+	memunmap(memconsole);
 	return ret;
 }
 
diff --git a/include/linux/device.h b/include/linux/device.h
index 6558af90c8fe..518f49c5d596 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -638,6 +638,11 @@ extern void devm_free_pages(struct device *dev, unsigned long addr);
 
 void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
 
+static inline void *devm_memremap_resource(struct device *dev, struct resource *res)
+{
+	return (void __force *) devm_ioremap_resource(dev, res);
+}
+
 /* allows to add/remove a custom action to devres stack */
 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
diff --git a/include/linux/io.h b/include/linux/io.h
index 4cd8996cfea0..23ef87d311d5 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -123,4 +123,8 @@ static inline int arch_phys_wc_index(int handle)
 #endif
 #endif
 
+extern void *memremap_cache(resource_size_t offset, size_t size);
+extern void *memremap_wt(resource_size_t offset, size_t size);
+extern void memunmap(void *addr);
+
 #endif /* _LINUX_IO_H */
diff --git a/kernel/resource.c b/kernel/resource.c
index 90552aab5f2d..2f8aca09da52 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -23,7 +23,7 @@
 #include <linux/pfn.h>
 #include <linux/mm.h>
 #include <linux/resource_ext.h>
-#include <asm/io.h>
+#include <linux/io.h>
 
 
 struct resource ioport_resource = {
@@ -528,6 +528,45 @@ int region_is_ram(resource_size_t start, unsigned long size)
 	return ret;
 }
 
+#ifdef CONFIG_ARCH_HAS_MEMREMAP
+/*
+ * memremap() is "ioremap" for cases where it is known that the resource
+ * being mapped does not have i/o side effects and the __iomem
+ * annotation is not applicable.
+ */
+static bool memremap_valid(resource_size_t offset, size_t size)
+{
+	if (region_is_ram(offset, size) != 0) {
+		WARN_ONCE(1, "memremap attempted on ram %pa size: %zu\n",
+				&offset, size);
+		return false;
+	}
+	return true;
+}
+
+void *memremap_cache(resource_size_t offset, size_t size)
+{
+	if (!memremap_valid(offset, size))
+		return NULL;
+	return (void __force *) ioremap_cache(offset, size);
+}
+EXPORT_SYMBOL(memremap_cache);
+
+void *memremap_wt(resource_size_t offset, size_t size)
+{
+	if (!memremap_valid(offset, size))
+		return NULL;
+	return (void __force *) ioremap_wt(offset, size);
+}
+EXPORT_SYMBOL(memremap_wt);
+
+void memunmap(void *addr)
+{
+	iounmap((void __iomem __force *) addr);
+}
+EXPORT_SYMBOL(memunmap);
+#endif /* CONFIG_ARCH_HAS_MEMREMAP */
+
 void __weak arch_remove_reservations(struct resource *avail)
 {
 }
diff --git a/lib/Kconfig b/lib/Kconfig
index 601965a948e8..bc7bc0278921 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -520,6 +520,9 @@ source "lib/fonts/Kconfig"
 #
 
 config ARCH_HAS_SG_CHAIN
-	def_bool n
+	bool
+
+config ARCH_HAS_MEMREMAP
+	bool
 
 endmenu

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  parent reply	other threads:[~2015-06-11 21:22 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-11 21:19 [-tip PATCH v4 0/6] pmem api, generic ioremap_cache, and memremap Dan Williams
2015-06-11 21:19 ` Dan Williams
2015-06-11 21:19 ` [PATCH v4 1/6] arch: unify ioremap prototypes and macro aliases Dan Williams
2015-06-11 21:19   ` Dan Williams
2015-06-17 11:14   ` Christoph Hellwig
2015-06-17 11:14     ` Christoph Hellwig
2015-06-17 17:35   ` Toshi Kani
2015-06-17 17:35     ` Toshi Kani
2015-06-11 21:19 ` [PATCH v4 2/6] cleanup IORESOURCE_CACHEABLE vs ioremap() Dan Williams
2015-06-11 21:19   ` Dan Williams
2015-06-11 21:19 ` [PATCH v4 3/6] arch/*/asm/io.h: add ioremap_cache() to all architectures Dan Williams
2015-06-11 21:19   ` Dan Williams
2015-06-17 11:27   ` Christoph Hellwig
2015-06-17 11:27     ` Christoph Hellwig
2015-06-11 21:19 ` [PATCH v4 4/6] devm: fix ioremap_cache() usage Dan Williams
2015-06-11 21:19   ` Dan Williams
2015-06-11 21:19 ` Dan Williams [this message]
2015-06-11 21:19   ` [PATCH v4 5/6] arch: introduce memremap_cache() and memremap_wt() Dan Williams
2015-06-19 21:28   ` Toshi Kani
2015-06-19 21:28     ` Toshi Kani
2015-06-11 21:19 ` [PATCH v4 6/6] arch, x86: pmem api for ensuring durability of persistent memory updates Dan Williams
2015-06-11 21:19   ` Dan Williams
2015-06-17 11:31   ` Christoph Hellwig
2015-06-17 11:31     ` Christoph Hellwig
2015-06-17 14:54     ` Dan Williams
2015-06-17 14:54       ` Dan Williams
2015-06-17 15:08       ` Andy Lutomirski
2015-06-17 15:08         ` Andy Lutomirski
2015-06-17 15:07   ` Andy Lutomirski
2015-06-17 15:07     ` Andy Lutomirski
2015-06-17 15:15     ` Thomas Gleixner
2015-06-17 15:15       ` Thomas Gleixner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20150611211941.10271.10513.stgit@dwillia2-desk3.amr.corp.intel.com \
    --to=dan.j.williams@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=andy.shevchenko@gmail.com \
    --cc=arnd@arndb.de \
    --cc=benh@kernel.crashing.org \
    --cc=bp@alien8.de \
    --cc=geert@linux-m68k.org \
    --cc=hch@lst.de \
    --cc=hmh@hmh.eng.br \
    --cc=hpa@zytor.com \
    --cc=jgross@suse.com \
    --cc=konrad.wilk@oracle.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-nvdimm@ml01.01.org \
    --cc=luto@amacapital.net \
    --cc=mcgrof@suse.com \
    --cc=mingo@redhat.com \
    --cc=mpe@ellerman.id.au \
    --cc=paulus@samba.org \
    --cc=ralf@linux-mips.org \
    --cc=ross.zwisler@linux.intel.com \
    --cc=stefan.bader@canonical.com \
    --cc=tglx@linutronix.de \
    --cc=tj@kernel.org \
    --cc=toshi.kani@hp.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.