* [PATCH] x86: boot: Simplified memory.c
@ 2018-11-02 14:56 Jordan Borgner
2018-11-07 8:07 ` [tip:x86/boot] x86/boot: Simplify the detect_memory*() control flow tip-bot for Jordan Borgner
0 siblings, 1 reply; 2+ messages in thread
From: Jordan Borgner @ 2018-11-02 14:56 UTC (permalink / raw)
To: tglx, mingo, x86; +Cc: hpa, linux-kernel
[-- Attachment #1: 0002-x86-boot-Simplified-memory.c.patch --]
[-- Type: text/x-diff, Size: 2802 bytes --]
memory.c contains functions that retrieve the memory-map of the
available RAM.
They are all called inside of "detect_memory()" which is
called in x86/boot/main.c. The return value of "detect_memory()" is
not checked so none of all the return values have any effect
on the program flow.
Define them as void-functions to save overhead.
Done by motivation of Ingo Molnar.
Signed-off-by: Jordan Borgner <mail@jordan-borgner.de>
---
arch/x86/boot/boot.h | 2 +-
arch/x86/boot/memory.c | 31 ++++++++++---------------------
2 files changed, 11 insertions(+), 22 deletions(-)
diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h
index ef5a9cc..32a09eb 100644
--- a/arch/x86/boot/boot.h
+++ b/arch/x86/boot/boot.h
@@ -309,7 +309,7 @@ void query_edd(void);
void __attribute__((noreturn)) die(void);
/* memory.c */
-int detect_memory(void);
+void detect_memory(void);
/* pm.c */
void __attribute__((noreturn)) go_to_protected_mode(void);
diff --git a/arch/x86/boot/memory.c b/arch/x86/boot/memory.c
index 7df2b28..f06c147 100644
--- a/arch/x86/boot/memory.c
+++ b/arch/x86/boot/memory.c
@@ -17,7 +17,7 @@
#define SMAP 0x534d4150 /* ASCII "SMAP" */
-static int detect_memory_e820(void)
+static void detect_memory_e820(void)
{
int count = 0;
struct biosregs ireg, oreg;
@@ -68,10 +68,10 @@ static int detect_memory_e820(void)
count++;
} while (ireg.ebx && count < ARRAY_SIZE(boot_params.e820_table));
- return boot_params.e820_entries = count;
+ boot_params.e820_entries = count;
}
-static int detect_memory_e801(void)
+static void detect_memory_e801(void)
{
struct biosregs ireg, oreg;
@@ -80,7 +80,7 @@ static int detect_memory_e801(void)
intcall(0x15, &ireg, &oreg);
if (oreg.eflags & X86_EFLAGS_CF)
- return -1;
+ return;
/* Do we really need to do this? */
if (oreg.cx || oreg.dx) {
@@ -89,7 +89,7 @@ static int detect_memory_e801(void)
}
if (oreg.ax > 15*1024) {
- return -1; /* Bogus! */
+ return; /* Bogus! */
} else if (oreg.ax == 15*1024) {
boot_params.alt_mem_k = (oreg.bx << 6) + oreg.ax;
} else {
@@ -102,11 +102,9 @@ static int detect_memory_e801(void)
*/
boot_params.alt_mem_k = oreg.ax;
}
-
- return 0;
}
-static int detect_memory_88(void)
+static void detect_memory_88(void)
{
struct biosregs ireg, oreg;
@@ -115,22 +113,13 @@ static int detect_memory_88(void)
intcall(0x15, &ireg, &oreg);
boot_params.screen_info.ext_mem_k = oreg.ax;
-
- return -(oreg.eflags & X86_EFLAGS_CF); /* 0 or -1 */
}
-int detect_memory(void)
+void detect_memory(void)
{
- int err = -1;
-
- if (detect_memory_e820() > 0)
- err = 0;
-
- if (!detect_memory_e801())
- err = 0;
+ detect_memory_e820();
- if (!detect_memory_88())
- err = 0;
+ detect_memory_e801();
- return err;
+ detect_memory_88();
}
--
2.11.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [tip:x86/boot] x86/boot: Simplify the detect_memory*() control flow
2018-11-02 14:56 [PATCH] x86: boot: Simplified memory.c Jordan Borgner
@ 2018-11-07 8:07 ` tip-bot for Jordan Borgner
0 siblings, 0 replies; 2+ messages in thread
From: tip-bot for Jordan Borgner @ 2018-11-07 8:07 UTC (permalink / raw)
To: linux-tip-commits
Cc: hpa, peterz, tglx, torvalds, mail, bp, mingo, linux-kernel
Commit-ID: e8eeb3c8aab044ee8faf5e0389db8518629a9324
Gitweb: https://git.kernel.org/tip/e8eeb3c8aab044ee8faf5e0389db8518629a9324
Author: Jordan Borgner <mail@jordan-borgner.de>
AuthorDate: Fri, 2 Nov 2018 14:56:22 +0000
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 6 Nov 2018 21:05:01 +0100
x86/boot: Simplify the detect_memory*() control flow
The return values of these functions are not used - so simplify the functions.
No change in functionality.
[ mingo: Simplified the changelog. ]
Suggested: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jordan Borgner <mail@jordan-borgner.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20181102145622.zjx2t3mdu3rv6sgy@JordanDesktop
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/boot/boot.h | 2 +-
arch/x86/boot/memory.c | 31 ++++++++++---------------------
2 files changed, 11 insertions(+), 22 deletions(-)
diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h
index ef5a9cc66fb8..32a09eb5c101 100644
--- a/arch/x86/boot/boot.h
+++ b/arch/x86/boot/boot.h
@@ -309,7 +309,7 @@ void query_edd(void);
void __attribute__((noreturn)) die(void);
/* memory.c */
-int detect_memory(void);
+void detect_memory(void);
/* pm.c */
void __attribute__((noreturn)) go_to_protected_mode(void);
diff --git a/arch/x86/boot/memory.c b/arch/x86/boot/memory.c
index 7df2b28207be..f06c147b5140 100644
--- a/arch/x86/boot/memory.c
+++ b/arch/x86/boot/memory.c
@@ -17,7 +17,7 @@
#define SMAP 0x534d4150 /* ASCII "SMAP" */
-static int detect_memory_e820(void)
+static void detect_memory_e820(void)
{
int count = 0;
struct biosregs ireg, oreg;
@@ -68,10 +68,10 @@ static int detect_memory_e820(void)
count++;
} while (ireg.ebx && count < ARRAY_SIZE(boot_params.e820_table));
- return boot_params.e820_entries = count;
+ boot_params.e820_entries = count;
}
-static int detect_memory_e801(void)
+static void detect_memory_e801(void)
{
struct biosregs ireg, oreg;
@@ -80,7 +80,7 @@ static int detect_memory_e801(void)
intcall(0x15, &ireg, &oreg);
if (oreg.eflags & X86_EFLAGS_CF)
- return -1;
+ return;
/* Do we really need to do this? */
if (oreg.cx || oreg.dx) {
@@ -89,7 +89,7 @@ static int detect_memory_e801(void)
}
if (oreg.ax > 15*1024) {
- return -1; /* Bogus! */
+ return; /* Bogus! */
} else if (oreg.ax == 15*1024) {
boot_params.alt_mem_k = (oreg.bx << 6) + oreg.ax;
} else {
@@ -102,11 +102,9 @@ static int detect_memory_e801(void)
*/
boot_params.alt_mem_k = oreg.ax;
}
-
- return 0;
}
-static int detect_memory_88(void)
+static void detect_memory_88(void)
{
struct biosregs ireg, oreg;
@@ -115,22 +113,13 @@ static int detect_memory_88(void)
intcall(0x15, &ireg, &oreg);
boot_params.screen_info.ext_mem_k = oreg.ax;
-
- return -(oreg.eflags & X86_EFLAGS_CF); /* 0 or -1 */
}
-int detect_memory(void)
+void detect_memory(void)
{
- int err = -1;
-
- if (detect_memory_e820() > 0)
- err = 0;
-
- if (!detect_memory_e801())
- err = 0;
+ detect_memory_e820();
- if (!detect_memory_88())
- err = 0;
+ detect_memory_e801();
- return err;
+ detect_memory_88();
}
^ permalink raw reply related [flat|nested] 2+ messages in thread
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2018-11-02 14:56 [PATCH] x86: boot: Simplified memory.c Jordan Borgner
2018-11-07 8:07 ` [tip:x86/boot] x86/boot: Simplify the detect_memory*() control flow tip-bot for Jordan Borgner
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