x86/boot/e820: Simplify e820_reserve_resources()

Remove unnecessary duplications of "e820_table->entries[i]." via a local
variable, plus pass in 'entry' to the type_to_*() functions which further
improves the readability of the code - and other small tweaks.

No change in functionality.

Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index cdf224992c27910730e4594905a3a7557218f3c9..511402d88795f494c62d0cbe141b43c63fccf22a 100644 (file)
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -953,9 +953,9 @@ void __init e820__finish_early_params(void)
        }
 }
 
-static const char *__init e820_type_to_string(int e820_type)
+static const char *__init e820_type_to_string(struct e820_entry *entry)
 {
-       switch (e820_type) {
+       switch (entry->type) {
        case E820_RESERVED_KERN: /* Fall-through: */
        case E820_RAM:           return "System RAM";
        case E820_ACPI:          return "ACPI Tables";
@@ -967,9 +967,9 @@ static const char *__init e820_type_to_string(int e820_type)
        }
 }
 
-static unsigned long __init e820_type_to_iomem_type(int e820_type)
+static unsigned long __init e820_type_to_iomem_type(struct e820_entry *entry)
 {
-       switch (e820_type) {
+       switch (entry->type) {
        case E820_RESERVED_KERN: /* Fall-through: */
        case E820_RAM:           return IORESOURCE_SYSTEM_RAM;
        case E820_ACPI:          /* Fall-through: */
@@ -981,9 +981,9 @@ static unsigned long __init e820_type_to_iomem_type(int e820_type)
        }
 }
 
-static unsigned long __init e820_type_to_iores_desc(int e820_type)
+static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry)
 {
-       switch (e820_type) {
+       switch (entry->type) {
        case E820_ACPI:          return IORES_DESC_ACPI_TABLES;
        case E820_NVS:           return IORES_DESC_ACPI_NV_STORAGE;
        case E820_PMEM:          return IORES_DESC_PERSISTENT_MEMORY;
@@ -1027,27 +1027,29 @@ void __init e820_reserve_resources(void)
        struct resource *res;
        u64 end;
 
-       res = alloc_bootmem(sizeof(struct resource) * e820_table->nr_entries);
+       res = alloc_bootmem(sizeof(*res) * e820_table->nr_entries);
        e820_res = res;
+
        for (i = 0; i < e820_table->nr_entries; i++) {
-               end = e820_table->entries[i].addr + e820_table->entries[i].size - 1;
+               struct e820_entry *entry = e820_table->entries + i;
+
+               end = entry->addr + entry->size - 1;
                if (end != (resource_size_t)end) {
                        res++;
                        continue;
                }
-               res->name = e820_type_to_string(e820_table->entries[i].type);
-               res->start = e820_table->entries[i].addr;
-               res->end = end;
-
-               res->flags = e820_type_to_iomem_type(e820_table->entries[i].type);
-               res->desc = e820_type_to_iores_desc(e820_table->entries[i].type);
+               res->start = entry->addr;
+               res->end   = end;
+               res->name  = e820_type_to_string(entry);
+               res->flags = e820_type_to_iomem_type(entry);
+               res->desc  = e820_type_to_iores_desc(entry);
 
                /*
                 * don't register the region that could be conflicted with
                 * pci device BAR resource and insert them later in
                 * pcibios_resource_survey()
                 */
-               if (do_mark_busy(e820_table->entries[i].type, res)) {
+               if (do_mark_busy(entry->type, res)) {
                        res->flags |= IORESOURCE_BUSY;
                        insert_resource(&iomem_resource, res);
                }
@@ -1055,9 +1057,9 @@ void __init e820_reserve_resources(void)
        }
 
        for (i = 0; i < e820_table_firmware->nr_entries; i++) {
-               struct e820_entry *entry = &e820_table_firmware->entries[i];
+               struct e820_entry *entry = e820_table_firmware->entries + i;
 
-               firmware_map_add_early(entry->addr, entry->addr + entry->size, e820_type_to_string(entry->type));
+               firmware_map_add_early(entry->addr, entry->addr + entry->size, e820_type_to_string(entry));
        }
 }