From: Blue Swirl <blauwirbel@gmail.com>
Date: Sun, 7 Aug 2011 20:02:02 +0000 (+0000)
Subject: m48t59: avoid structure holes spotted by pahole
X-Git-Tag: v1.0-rc0~465^2~6
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=42c812b98bbdb1d9e12b111f779a4cc6d987727d;p=users%2Fdwmw2%2Fqemu.git

m48t59: avoid structure holes spotted by pahole

Report from pahole on amd64 host:
struct M48t59State {
	uint32_t                   type;                 /*     0     4 */

	/* XXX 4 bytes hole, try to pack */

	qemu_irq                   IRQ;                  /*     8     8 */
	uint32_t                   io_base;              /*    16     4 */
	uint32_t                   size;                 /*    20     4 */
	time_t                     time_offset;          /*    24     8 */
	time_t                     stop_time;            /*    32     8 */
	struct tm                  alarm;                /*    40    56 */
	/* --- cacheline 1 boundary (64 bytes) was 32 bytes ago --- */
	struct QEMUTimer *         alrm_timer;           /*    96     8 */
	struct QEMUTimer *         wd_timer;             /*   104     8 */
	uint8_t                    lock;                 /*   112     1 */

	/* XXX 1 byte hole, try to pack */

	uint16_t                   addr;                 /*   114     2 */

	/* XXX 4 bytes hole, try to pack */

	uint8_t *                  buffer;               /*   120     8 */
	/* --- cacheline 2 boundary (128 bytes) --- */

	/* size: 128, cachelines: 2 */
	/* sum members: 119, holes: 3, sum holes: 9 */
};	/* definitions: 1 */

Fix by rearranging the structure to avoid padding.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
---

diff --git a/hw/m48t59.c b/hw/m48t59.c
index 401b9693e1..0cc361eedc 100644
--- a/hw/m48t59.c
+++ b/hw/m48t59.c
@@ -50,8 +50,6 @@
  */
 
 struct M48t59State {
-    /* Model parameters */
-    uint32_t type; // 2 = m48t02, 8 = m48t08, 59 = m48t59
     /* Hardware parameters */
     qemu_irq IRQ;
     uint32_t io_base;
@@ -64,9 +62,12 @@ struct M48t59State {
     struct QEMUTimer *alrm_timer;
     struct QEMUTimer *wd_timer;
     /* NVRAM storage */
-    uint8_t  lock;
-    uint16_t addr;
     uint8_t *buffer;
+    /* Model parameters */
+    uint32_t type; /* 2 = m48t02, 8 = m48t08, 59 = m48t59 */
+    /* NVRAM storage */
+    uint16_t addr;
+    uint8_t  lock;
 };
 
 typedef struct M48t59ISAState {