diff mbox

x86, acpi: LLVMLinux: Remove nested functions from Thinkpad ACPI

Message ID 1392238726-18787-1-git-send-email-dl9pf@gmx.de
State Accepted
Commit a4d44ba1266a04cdfda4b2c4ee496d684a47f567
Headers show

Commit Message

Jan-Simon Möller Feb. 12, 2014, 8:58 p.m. UTC 
From: Behan Webster <behanw@converseincode.com>

The only real change is passing in event_mask to the formerly nested functions.
Otherwise it's just moving around function and macro code.

This is the only place in the Linux kernel where nested functions are still in
use. Nested functions aren't part of the C standards, and complicate the
generated code. Although the Linux Kernel has never set out to be entirely C
standard compliant, it is increasingly compliant to the standard which is
supported by other compilers such as Clang. The LLVMLinux project is working on
being able to compile the Linux kernel with Clang. The use of nested functions
blocks this effort.

Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de>

CC: David Woodhouse <David.Woodhouse@intel.com>
CC: Matthew Garrett <matthew.garrett@nebula.com>
CC: ibm-acpi-devel@lists.sourceforge.net
CC: platform-driver-x86@vger.kernel.org
CC: linux-kernel@vger.kernel.org
---
 drivers/platform/x86/thinkpad_acpi.c | 86 +++++++++++++++++++-----------------
 1 file changed, 45 insertions(+), 41 deletions(-)

Comments

Behan Webster Feb. 12, 2014, 9:20 p.m. UTC | #1 
On 02/12/14 13:11, Christoph Hellwig wrote:
> On Wed, Feb 12, 2014 at 09:58:46PM +0100, dl9pf@gmx.de wrote:
>> being able to compile the Linux kernel with Clang. The use of nested functions
>> blocks this effort.
> Is there any good way to make gcc warn about the use of nested functions?
Interesting idea.

'-Wtrampolines'
      Warn about trampolines generated for pointers to nested functions.

      A trampoline is a small piece of data or code that is created at
      run time on the stack when the address of a nested function is
      taken, and is used to call the nested function indirectly.  For
      some targets, it is made up of data only and thus requires no
      special treatment.  But, for most targets, it is made up of code
      and thus requires the stack to be made executable in order for the
      program to work properly.


That might work.

Behan
diff mbox

Patch

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index defb6af..e6e068e 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -2321,53 +2321,55 @@  static void hotkey_read_nvram(struct tp_nvram_state *n, const u32 m)
 	}
 }
 
-static void hotkey_compare_and_issue_event(struct tp_nvram_state *oldn,
-					   struct tp_nvram_state *newn,
-					   const u32 event_mask)
-{
-
 #define TPACPI_COMPARE_KEY(__scancode, __member) \
-	do { \
-		if ((event_mask & (1 << __scancode)) && \
-		    oldn->__member != newn->__member) \
-			tpacpi_hotkey_send_key(__scancode); \
-	} while (0)
+do { \
+	if ((event_mask & (1 << __scancode)) && \
+	    oldn->__member != newn->__member) \
+		tpacpi_hotkey_send_key(__scancode); \
+} while (0)
 
 #define TPACPI_MAY_SEND_KEY(__scancode) \
-	do { \
-		if (event_mask & (1 << __scancode)) \
-			tpacpi_hotkey_send_key(__scancode); \
-	} while (0)
+do { \
+	if (event_mask & (1 << __scancode)) \
+		tpacpi_hotkey_send_key(__scancode); \
+} while (0)
 
-	void issue_volchange(const unsigned int oldvol,
-			     const unsigned int newvol)
-	{
-		unsigned int i = oldvol;
+static void issue_volchange(const unsigned int oldvol,
+			    const unsigned int newvol,
+			    const u32 event_mask)
+{
+	unsigned int i = oldvol;
 
-		while (i > newvol) {
-			TPACPI_MAY_SEND_KEY(TP_ACPI_HOTKEYSCAN_VOLUMEDOWN);
-			i--;
-		}
-		while (i < newvol) {
-			TPACPI_MAY_SEND_KEY(TP_ACPI_HOTKEYSCAN_VOLUMEUP);
-			i++;
-		}
+	while (i > newvol) {
+		TPACPI_MAY_SEND_KEY(TP_ACPI_HOTKEYSCAN_VOLUMEDOWN);
+		i--;
+	}
+	while (i < newvol) {
+		TPACPI_MAY_SEND_KEY(TP_ACPI_HOTKEYSCAN_VOLUMEUP);
+		i++;
 	}
+}
 
-	void issue_brightnesschange(const unsigned int oldbrt,
-				    const unsigned int newbrt)
-	{
-		unsigned int i = oldbrt;
+static void issue_brightnesschange(const unsigned int oldbrt,
+				   const unsigned int newbrt,
+				   const u32 event_mask)
+{
+	unsigned int i = oldbrt;
 
-		while (i > newbrt) {
-			TPACPI_MAY_SEND_KEY(TP_ACPI_HOTKEYSCAN_FNEND);
-			i--;
-		}
-		while (i < newbrt) {
-			TPACPI_MAY_SEND_KEY(TP_ACPI_HOTKEYSCAN_FNHOME);
-			i++;
-		}
+	while (i > newbrt) {
+		TPACPI_MAY_SEND_KEY(TP_ACPI_HOTKEYSCAN_FNEND);
+		i--;
 	}
+	while (i < newbrt) {
+		TPACPI_MAY_SEND_KEY(TP_ACPI_HOTKEYSCAN_FNHOME);
+		i++;
+	}
+}
+
+static void hotkey_compare_and_issue_event(struct tp_nvram_state *oldn,
+					   struct tp_nvram_state *newn,
+					   const u32 event_mask)
+{
 
 	TPACPI_COMPARE_KEY(TP_ACPI_HOTKEYSCAN_THINKPAD, thinkpad_toggle);
 	TPACPI_COMPARE_KEY(TP_ACPI_HOTKEYSCAN_FNSPACE, zoom_toggle);
@@ -2402,7 +2404,8 @@  static void hotkey_compare_and_issue_event(struct tp_nvram_state *oldn,
 		    oldn->volume_level != newn->volume_level) {
 			/* recently muted, or repeated mute keypress, or
 			 * multiple presses ending in mute */
-			issue_volchange(oldn->volume_level, newn->volume_level);
+			issue_volchange(oldn->volume_level, newn->volume_level,
+				event_mask);
 			TPACPI_MAY_SEND_KEY(TP_ACPI_HOTKEYSCAN_MUTE);
 		}
 	} else {
@@ -2412,7 +2415,8 @@  static void hotkey_compare_and_issue_event(struct tp_nvram_state *oldn,
 			TPACPI_MAY_SEND_KEY(TP_ACPI_HOTKEYSCAN_VOLUMEUP);
 		}
 		if (oldn->volume_level != newn->volume_level) {
-			issue_volchange(oldn->volume_level, newn->volume_level);
+			issue_volchange(oldn->volume_level, newn->volume_level,
+				event_mask);
 		} else if (oldn->volume_toggle != newn->volume_toggle) {
 			/* repeated vol up/down keypress at end of scale ? */
 			if (newn->volume_level == 0)
@@ -2425,7 +2429,7 @@  static void hotkey_compare_and_issue_event(struct tp_nvram_state *oldn,
 	/* handle brightness */
 	if (oldn->brightness_level != newn->brightness_level) {
 		issue_brightnesschange(oldn->brightness_level,
-				       newn->brightness_level);
+				       newn->brightness_level, event_mask);
 	} else if (oldn->brightness_toggle != newn->brightness_toggle) {
 		/* repeated key presses that didn't change state */
 		if (newn->brightness_level == 0)