From 217b4e023d733d20a37aa7665ed90c0effca8a34 Mon Sep 17 00:00:00 2001
From: Alexander Motin <mav@FreeBSD.org>
Date: Sat, 15 Aug 2015 21:46:02 +0000
Subject: [PATCH] Remove UMA allocation of ATA requests.

After CAM replaced old ATA stack, this driver processes no more then one
request at a time per channel.  Using UMA after that is overkill, so
replace it with simple preallocation of one request per channel.

MFC after:	2 weeks
---
 sys/dev/ata/ata-all.c | 28 ++--------------------------
 sys/dev/ata/ata-all.h |  9 +--------
 2 files changed, 3 insertions(+), 34 deletions(-)

diff --git a/sys/dev/ata/ata-all.c b/sys/dev/ata/ata-all.c
index 52db44dce35..217b47e148e 100644
--- a/sys/dev/ata/ata-all.c
+++ b/sys/dev/ata/ata-all.c
@@ -75,7 +75,6 @@ static void ata_uninit(void);
 MALLOC_DEFINE(M_ATA, "ata_generic", "ATA driver generic layer");
 int (*ata_raid_ioctl_func)(u_long cmd, caddr_t data) = NULL;
 devclass_t ata_devclass;
-uma_zone_t ata_request_zone;
 int ata_dma_check_80pin = 1;
 
 /* sysctl vars */
@@ -650,12 +649,7 @@ ata_cam_begin_transaction(device_t dev, union ccb *ccb)
 	struct ata_channel *ch = device_get_softc(dev);
 	struct ata_request *request;
 
-	if (!(request = ata_alloc_request())) {
-		device_printf(dev, "FAILURE - out of memory in start\n");
-		ccb->ccb_h.status = CAM_REQ_INVALID;
-		xpt_done(ccb);
-		return;
-	}
+	request = &ch->request;
 	bzero(request, sizeof(*request));
 
 	/* setup request */
@@ -794,7 +788,6 @@ ata_cam_process_sense(device_t dev, struct ata_request *request)
 		ccb->ccb_h.status |= CAM_AUTOSENSE_FAIL;
 	}
 
-	ata_free_request(request);
 	xpt_done(ccb);
 	/* Do error recovery if needed. */
 	if (fatalerr)
@@ -865,10 +858,8 @@ ata_cam_end_transaction(device_t dev, struct ata_request *request)
 	if ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_SCSI_STATUS_ERROR &&
 	    (ccb->ccb_h.flags & CAM_DIS_AUTOSENSE) == 0)
 		ata_cam_request_sense(dev, request);
-	else {
-		ata_free_request(request);
+	else
 		xpt_done(ccb);
-	}
 	/* Do error recovery if needed. */
 	if (fatalerr)
 		ata_reinit(dev);
@@ -1148,18 +1139,3 @@ static moduledata_t ata_moduledata = { "ata", ata_module_event_handler, NULL };
 DECLARE_MODULE(ata, ata_moduledata, SI_SUB_CONFIGURE, SI_ORDER_SECOND);
 MODULE_VERSION(ata, 1);
 MODULE_DEPEND(ata, cam, 1, 1, 1);
-
-static void
-ata_init(void)
-{
-    ata_request_zone = uma_zcreate("ata_request", sizeof(struct ata_request),
-				   NULL, NULL, NULL, NULL, 0, 0);
-}
-SYSINIT(ata_register, SI_SUB_DRIVERS, SI_ORDER_SECOND, ata_init, NULL);
-
-static void
-ata_uninit(void)
-{
-    uma_zdestroy(ata_request_zone);
-}
-SYSUNINIT(ata_unregister, SI_SUB_DRIVERS, SI_ORDER_SECOND, ata_uninit, NULL);
diff --git a/sys/dev/ata/ata-all.h b/sys/dev/ata/ata-all.h
index 19cb7efb278..cf8ed784e7b 100644
--- a/sys/dev/ata/ata-all.h
+++ b/sys/dev/ata/ata-all.h
@@ -450,6 +450,7 @@ struct ata_channel {
 	struct ata_cam_device	curr[16];       /* Current settings */
 	int			requestsense;	/* CCB waiting for SENSE. */
 	struct callout		poll_callout;	/* Periodic status poll. */
+	struct ata_request	request;
 };
 
 /* disk bay/enclosure related */
@@ -507,14 +508,6 @@ int ata_sata_getrev(device_t dev, int target);
 int ata_request2fis_h2d(struct ata_request *request, u_int8_t *fis);
 void ata_pm_identify(device_t dev);
 
-/* macros for alloc/free of struct ata_request */
-extern uma_zone_t ata_request_zone;
-#define ata_alloc_request() uma_zalloc(ata_request_zone, M_NOWAIT | M_ZERO)
-#define ata_free_request(request) { \
-	if (!(request->flags & ATA_R_DANGER2)) \
-	    uma_zfree(ata_request_zone, request); \
-	}
-
 MALLOC_DECLARE(M_ATA);
 
 /* misc newbus defines */