ACPI: Clean up acpi_os_map/unmap_memory() to eliminate __iomem.

ACPICA doesn't include protections around address space checking, Linux
build tests always complain increased sparse warnings around ACPICA
internal acpi_os_map/unmap_memory() invocations.  This patch tries to fix
this issue permanently.

There are 2 choices left for us to solve this issue:
 1. Add __iomem address space awareness into ACPICA.
 2. Remove sparse checker of __iomem from ACPICA source code.

This patch chooses solution 2, because:
 1.  Most of the acpi_os_map/unmap_memory() invocations are used for ACPICA.
     table mappings, which in fact are not IO addresses.
 2.  The only IO addresses usage is for "system memory space" mapping code in:
      drivers/acpi/acpica/exregion.c
      drivers/acpi/acpica/evrgnini.c
      drivers/acpi/acpica/exregion.c
    The mapped address is accessed in the handler of "system memory space"
    - acpi_ex_system_memory_space_handler().  This function in fact can be
    changed to invoke acpi_os_read/write_memory() so that __iomem can
    always be type-casted in the OSL layer.

According to the above investigation, we drew the following conclusion:
It is not a good idea to introduce __iomem address space awareness into
ACPICA mostly in order to protect non-IO addresses.

We can simply remove __iomem for acpi_os_map/unmap_memory() to remove
__iomem checker for ACPICA code. Then we need to enforce external usages
to invoke other APIs that are aware of __iomem address space.
The external usages are:
 drivers/acpi/apei/einj.c
 drivers/acpi/acpi_extlog.c
 drivers/char/tpm/tpm_acpi.c
 drivers/acpi/nvs.c

This patch thus performs cleanups in this way:
 1. Add acpi_os_map/unmap_iomem() to be invoked by non-ACPICA code.
 2. Remove __iomem from acpi_os_map/unmap_memory().

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

4 files changed, 34 insertions, 21 deletions

diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
index c4a5d87ede7e..185334114d71 100644
--- a/drivers/acpi/acpi_extlog.c
+++ b/drivers/acpi/acpi_extlog.c
@@ -220,13 +220,13 @@ static int __init extlog_init(void)
 		goto err;
 	}
 
-	extlog_l1_hdr = acpi_os_map_memory(l1_dirbase, l1_hdr_size);
+	extlog_l1_hdr = acpi_os_map_iomem(l1_dirbase, l1_hdr_size);
 	l1_head = (struct extlog_l1_head *)extlog_l1_hdr;
 	l1_size = l1_head->total_len;
 	l1_percpu_entry = l1_head->entries;
 	elog_base = l1_head->elog_base;
 	elog_size = l1_head->elog_len;
-	acpi_os_unmap_memory(extlog_l1_hdr, l1_hdr_size);
+	acpi_os_unmap_iomem(extlog_l1_hdr, l1_hdr_size);
 	release_mem_region(l1_dirbase, l1_hdr_size);
 
 	/* remap L1 header again based on completed information */
@@ -237,7 +237,7 @@ static int __init extlog_init(void)
 			(unsigned long long)l1_dirbase + l1_size);
 		goto err;
 	}
-	extlog_l1_addr = acpi_os_map_memory(l1_dirbase, l1_size);
+	extlog_l1_addr = acpi_os_map_iomem(l1_dirbase, l1_size);
 	l1_entry_base = (u64 *)((u8 *)extlog_l1_addr + l1_hdr_size);
 
 	/* remap elog table */
@@ -248,7 +248,7 @@ static int __init extlog_init(void)
 			(unsigned long long)elog_base + elog_size);
 		goto err_release_l1_dir;
 	}
-	elog_addr = acpi_os_map_memory(elog_base, elog_size);
+	elog_addr = acpi_os_map_iomem(elog_base, elog_size);
 
 	rc = -ENOMEM;
 	/* allocate buffer to save elog record */
@@ -270,11 +270,11 @@ static int __init extlog_init(void)
 
 err_release_elog:
 	if (elog_addr)
-		acpi_os_unmap_memory(elog_addr, elog_size);
+		acpi_os_unmap_iomem(elog_addr, elog_size);
 	release_mem_region(elog_base, elog_size);
 err_release_l1_dir:
 	if (extlog_l1_addr)
-		acpi_os_unmap_memory(extlog_l1_addr, l1_size);
+		acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
 	release_mem_region(l1_dirbase, l1_size);
 err:
 	pr_warn(FW_BUG "Extended error log disabled because of problems parsing f/w tables\n");
@@ -287,9 +287,9 @@ static void __exit extlog_exit(void)
 	mce_unregister_decode_chain(&extlog_mce_dec);
 	((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN;
 	if (extlog_l1_addr)
-		acpi_os_unmap_memory(extlog_l1_addr, l1_size);
+		acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
 	if (elog_addr)
-		acpi_os_unmap_memory(elog_addr, elog_size);
+		acpi_os_unmap_iomem(elog_addr, elog_size);
 	release_mem_region(elog_base, elog_size);
 	release_mem_region(l1_dirbase, l1_size);
 	kfree(elog_buf);
diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c
index 1be6f5564485..a095d4f858da 100644
--- a/drivers/acpi/apei/einj.c
+++ b/drivers/acpi/apei/einj.c
@@ -202,7 +202,7 @@ static void check_vendor_extension(u64 paddr,
 
 	if (!offset)
 		return;
-	v = acpi_os_map_memory(paddr + offset, sizeof(*v));
+	v = acpi_os_map_iomem(paddr + offset, sizeof(*v));
 	if (!v)
 		return;
 	sbdf = v->pcie_sbdf;
@@ -210,7 +210,7 @@ static void check_vendor_extension(u64 paddr,
 		sbdf >> 24, (sbdf >> 16) & 0xff,
 		(sbdf >> 11) & 0x1f, (sbdf >> 8) & 0x7,
 		 v->vendor_id, v->device_id, v->rev_id);
-	acpi_os_unmap_memory(v, sizeof(*v));
+	acpi_os_unmap_iomem(v, sizeof(*v));
 }
 
 static void *einj_get_parameter_address(void)
@@ -236,7 +236,7 @@ static void *einj_get_parameter_address(void)
 	if (pa_v5) {
 		struct set_error_type_with_address *v5param;
 
-		v5param = acpi_os_map_memory(pa_v5, sizeof(*v5param));
+		v5param = acpi_os_map_iomem(pa_v5, sizeof(*v5param));
 		if (v5param) {
 			acpi5 = 1;
 			check_vendor_extension(pa_v5, v5param);
@@ -246,11 +246,11 @@ static void *einj_get_parameter_address(void)
 	if (param_extension && pa_v4) {
 		struct einj_parameter *v4param;
 
-		v4param = acpi_os_map_memory(pa_v4, sizeof(*v4param));
+		v4param = acpi_os_map_iomem(pa_v4, sizeof(*v4param));
 		if (!v4param)
 			return NULL;
 		if (v4param->reserved1 || v4param->reserved2) {
-			acpi_os_unmap_memory(v4param, sizeof(*v4param));
+			acpi_os_unmap_iomem(v4param, sizeof(*v4param));
 			return NULL;
 		}
 		return v4param;
@@ -794,7 +794,7 @@ err_unmap:
 			sizeof(struct set_error_type_with_address) :
 			sizeof(struct einj_parameter);
 
-		acpi_os_unmap_memory(einj_param, size);
+		acpi_os_unmap_iomem(einj_param, size);
 	}
 	apei_exec_post_unmap_gars(&ctx);
 err_release:
@@ -816,7 +816,7 @@ static void __exit einj_exit(void)
 			sizeof(struct set_error_type_with_address) :
 			sizeof(struct einj_parameter);
 
-		acpi_os_unmap_memory(einj_param, size);
+		acpi_os_unmap_iomem(einj_param, size);
 	}
 	einj_exec_ctx_init(&ctx);
 	apei_exec_post_unmap_gars(&ctx);
diff --git a/drivers/acpi/nvs.c b/drivers/acpi/nvs.c
index de4fe03873c5..85287b8fe3aa 100644
--- a/drivers/acpi/nvs.c
+++ b/drivers/acpi/nvs.c
@@ -139,8 +139,8 @@ void suspend_nvs_free(void)
 					iounmap(entry->kaddr);
 					entry->unmap = false;
 				} else {
-					acpi_os_unmap_memory(entry->kaddr,
-							     entry->size);
+					acpi_os_unmap_iomem(entry->kaddr,
+							    entry->size);
 				}
 				entry->kaddr = NULL;
 			}
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 9aeae41e22fb..147bc1b91b42 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -355,7 +355,7 @@ static void acpi_unmap(acpi_physical_address pg_off, void __iomem *vaddr)
 }
 
 void __iomem *__init_refok
-acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
+acpi_os_map_iomem(acpi_physical_address phys, acpi_size size)
 {
 	struct acpi_ioremap *map;
 	void __iomem *virt;
@@ -401,10 +401,17 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
 
 	list_add_tail_rcu(&map->list, &acpi_ioremaps);
 
- out:
+out:
 	mutex_unlock(&acpi_ioremap_lock);
 	return map->virt + (phys - map->phys);
 }
+EXPORT_SYMBOL_GPL(acpi_os_map_iomem);
+
+void *__init_refok
+acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
+{
+	return (void *)acpi_os_map_iomem(phys, size);
+}
 EXPORT_SYMBOL_GPL(acpi_os_map_memory);
 
 static void acpi_os_drop_map_ref(struct acpi_ioremap *map)
@@ -422,7 +429,7 @@ static void acpi_os_map_cleanup(struct acpi_ioremap *map)
 	}
 }
 
-void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
+void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size)
 {
 	struct acpi_ioremap *map;
 
@@ -443,6 +450,12 @@ void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
 
 	acpi_os_map_cleanup(map);
 }
+EXPORT_SYMBOL_GPL(acpi_os_unmap_iomem);
+
+void __ref acpi_os_unmap_memory(void *virt, acpi_size size)
+{
+	return acpi_os_unmap_iomem((void __iomem *)virt, size);
+}
 EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);
 
 void __init early_acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
@@ -464,7 +477,7 @@ int acpi_os_map_generic_address(struct acpi_generic_address *gas)
 	if (!addr || !gas->bit_width)
 		return -EINVAL;
 
-	virt = acpi_os_map_memory(addr, gas->bit_width / 8);
+	virt = acpi_os_map_iomem(addr, gas->bit_width / 8);
 	if (!virt)
 		return -EIO;