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>

8 files changed, 39 insertions, 33 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;
 
diff --git a/drivers/char/tpm/tpm_acpi.c b/drivers/char/tpm/tpm_acpi.c
index b9a57fa4b710..565a9478cb94 100644
--- a/drivers/char/tpm/tpm_acpi.c
+++ b/drivers/char/tpm/tpm_acpi.c
@@ -95,7 +95,7 @@ int read_log(struct tpm_bios_log *log)
 
         log->bios_event_log_end = log->bios_event_log + len;
 
-        virt = acpi_os_map_memory(start, len);
+        virt = acpi_os_map_iomem(start, len);
         if (!virt) {
                 kfree(log->bios_event_log);
                 printk("%s: ERROR - Unable to map memory\n", __func__);
@@ -104,6 +104,6 @@ int read_log(struct tpm_bios_log *log)
 
         memcpy_fromio(log->bios_event_log, virt, len);
 
-        acpi_os_unmap_memory(virt, len);
+        acpi_os_unmap_iomem(virt, len);
         return 0;
 }
diff --git a/include/acpi/acpi_io.h b/include/acpi/acpi_io.h
index 2be858018c7f..444671e9c65d 100644
--- a/include/acpi/acpi_io.h
+++ b/include/acpi/acpi_io.h
@@ -9,6 +9,9 @@ static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,
        return ioremap_cache(phys, size);
 }
 
+void __iomem *__init_refok
+acpi_os_map_iomem(acpi_physical_address phys, acpi_size size);
+void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size);
 void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size);
 
 int acpi_os_map_generic_address(struct acpi_generic_address *addr);
diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h
index e70012956db3..cd1f052d55bb 100644
--- a/include/acpi/platform/aclinux.h
+++ b/include/acpi/platform/aclinux.h
@@ -128,8 +128,6 @@
 #define ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_acquire_object
 #define ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_get_thread_id
 #define ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_create_lock
-#define ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_map_memory
-#define ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_unmap_memory
 
 /*
  * OSL interfaces used by debugger/disassembler
@@ -163,10 +161,6 @@
 #define __init
 #endif
 
-#ifndef __iomem
-#define __iomem
-#endif
-
 /* Host-dependent types and defines for user-space ACPICA */
 
 #define ACPI_FLUSH_CPU_CACHE()
diff --git a/include/acpi/platform/aclinuxex.h b/include/acpi/platform/aclinuxex.h
index cce0723d05a9..191e741cfa0e 100644
--- a/include/acpi/platform/aclinuxex.h
+++ b/include/acpi/platform/aclinuxex.h
@@ -102,10 +102,6 @@ static inline acpi_thread_id acpi_os_get_thread_id(void)
                 lock ? AE_OK : AE_NO_MEMORY; \
         })
 
-void __iomem *acpi_os_map_memory(acpi_physical_address where, acpi_size length);
-
-void acpi_os_unmap_memory(void __iomem * logical_address, acpi_size size);
-
 /*
  * OSL interfaces added by Linux
  */