x86/boot/e820: Fix and clean up e820_type switch() statements

A test-build of e820.o with -Wswitch-enum shows the following warnings:

  arch/x86/kernel/e820.c: In function ‘e820_type_to_string’:
  arch/x86/kernel/e820.c:965:2: warning: enumeration value ‘E820_TYPE_RESERVED’ not handled in switch [-Wswitch-enum]
    switch (entry->type) {
    ^

  arch/x86/kernel/e820.c: In function ‘e820_type_to_iomem_type’:
  arch/x86/kernel/e820.c:979:2: warning: enumeration value ‘E820_TYPE_RESERVED’ not handled in switch [-Wswitch-enum]
    switch (entry->type) {
    ^

  arch/x86/kernel/e820.c: In function ‘e820_type_to_iores_desc’:
  arch/x86/kernel/e820.c:993:2: warning: enumeration value ‘E820_TYPE_RESERVED’ not handled in switch [-Wswitch-enum]
    switch (entry->type) {
    ^

  arch/x86/kernel/e820.c: In function ‘do_mark_busy’:
  arch/x86/kernel/e820.c:1015:2: warning: enumeration value ‘E820_TYPE_RAM’ not handled in switch [-Wswitch-enum]
    switch (type) {
	    ^

Here's the four warnings:

  - The one in e820_type_to_string() is a borderline bug, we should differentiate
    known-reserved E820 types from unknown types. Fix it by printing a separate
    message for unknown E820 types.

  - The ones in e820_type_to_iomem_type(), e820_type_to_iores_desc() and
    do_mark_busy() are worth documenting, at least to the extent of
    enumerating them explicitly.

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 d2c6468a8d38d7dd55ac4bc24b77aa59abb264a0..20834a81854e96267c5a0a0e89bacbdae3c44a61 100644 (file)
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -970,7 +970,8 @@ static const char *__init e820_type_to_string(struct e820_entry *entry)
        case E820_TYPE_UNUSABLE:        return "Unusable memory";
        case E820_TYPE_PRAM:            return "Persistent Memory (legacy)";
        case E820_TYPE_PMEM:            return "Persistent Memory";
-       default:                        return "Reserved";
+       case E820_TYPE_RESERVED:        return "Reserved";
+       default:                        return "Unknown E820 type";
        }
 }
 
@@ -984,6 +985,7 @@ static unsigned long __init e820_type_to_iomem_type(struct e820_entry *entry)
        case E820_TYPE_UNUSABLE:        /* Fall-through: */
        case E820_TYPE_PRAM:            /* Fall-through: */
        case E820_TYPE_PMEM:            /* Fall-through: */
+       case E820_TYPE_RESERVED:        /* Fall-through: */
        default:                        return IORESOURCE_MEM;
        }
 }
@@ -998,11 +1000,12 @@ static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry)
        case E820_TYPE_RESERVED_KERN:   /* Fall-through: */
        case E820_TYPE_RAM:             /* Fall-through: */
        case E820_TYPE_UNUSABLE:        /* Fall-through: */
+       case E820_TYPE_RESERVED:        /* Fall-through: */
        default:                        return IORES_DESC_NONE;
        }
 }
 
-static bool __init do_mark_busy(u32 type, struct resource *res)
+static bool __init do_mark_busy(enum e820_type type, struct resource *res)
 {
        /* this is the legacy bios/dos rom-shadow + mmio region */
        if (res->start < (1ULL<<20))
@@ -1017,6 +1020,11 @@ static bool __init do_mark_busy(u32 type, struct resource *res)
        case E820_TYPE_PRAM:
        case E820_TYPE_PMEM:
                return false;
+       case E820_TYPE_RESERVED_KERN:
+       case E820_TYPE_RAM:
+       case E820_TYPE_ACPI:
+       case E820_TYPE_NVS:
+       case E820_TYPE_UNUSABLE:
        default:
                return true;
        }