From 34cf71f7ef97161c440390344a3c063fc589ccd8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B8ren=20Schmidt?= <sos@FreeBSD.org>
Date: Mon, 19 Nov 2007 20:47:31 +0000
Subject: [PATCH] Try to workaound silicon bugs in Promise gen2 (ie TX4) chips

Initial patch by Alexander Sabourenkov who found it in Promise's own driver.

Further fixes and sanity checks by yours truely.
---
 sys/dev/ata/ata-chipset.c | 46 ++++++++++++++++++++++++++++++++++++++-
 sys/dev/ata/ata-dma.c     |  1 +
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/sys/dev/ata/ata-chipset.c b/sys/dev/ata/ata-chipset.c
index 4f8943b8c53..f7ed1eb09cb 100644
--- a/sys/dev/ata/ata-chipset.c
+++ b/sys/dev/ata/ata-chipset.c
@@ -142,6 +142,7 @@ static int ata_promise_mio_status(device_t dev);
 static int ata_promise_mio_command(struct ata_request *request);
 static void ata_promise_mio_reset(device_t dev);
 static void ata_promise_mio_dmainit(device_t dev);
+static void ata_promise_mio_setprd(void *xsc, bus_dma_segment_t *segs, int nsegs, int error);
 static void ata_promise_mio_setmode(device_t dev, int mode);
 static void ata_promise_sx4_intr(void *data);
 static int ata_promise_sx4_command(struct ata_request *request);
@@ -859,6 +860,7 @@ ata_ahci_dmasetprd(void *xsc, bus_dma_segment_t *segs, int nsegs, int error)
 	    prd[i].dbc = htole32((segs[i].ds_len - 1) & ATA_AHCI_PRD_MASK);
 	}
     }
+    KASSERT(nsegs <= ATA_DMA_ENTRIES, "too many DMA segment entries\n");
     args->nsegs = nsegs;
 }
 
@@ -2783,6 +2785,8 @@ ata_marvell_edma_dmasetprd(void *xsc, bus_dma_segment_t *segs, int nsegs,
 	prd[i].addrhi = htole32((u_int64_t)segs[i].ds_addr >> 32);
     }
     prd[i - 1].count |= htole32(ATA_DMA_EOT);
+    KASSERT(nsegs <= ATA_DMA_ENTRIES, "too many DMA segment entries\n");
+    args->nsegs = nsegs;
 }
 
 static void
@@ -3310,9 +3314,13 @@ sataii:
 	/* prime fake interrupt register */
 	ATA_OUTL(ctlr->r_res2, fake_reg, 0xffffffff);
 
-	/* clear SATA status */
+	/* clear SATA status and unmask interrupts */
 	ATA_OUTL(ctlr->r_res2, stat_reg, 0x000000ff);
 
+	/* enable "long burst lenght" on gen2 chips */
+	if ((ctlr->chip->cfg2 == PRSATA2) || (ctlr->chip->cfg2 == PRCMBO2))
+	    ATA_OUTL(ctlr->r_res2, 0x44, ATA_INL(ctlr->r_res2, 0x44) | 0x2000);
+
 	ctlr->allocate = ata_promise_mio_allocate;
 	ctlr->reset = ata_promise_mio_reset;
 	ctlr->dmainit = ata_promise_mio_dmainit;
@@ -3800,8 +3808,42 @@ ata_promise_mio_reset(device_t dev)
 static void
 ata_promise_mio_dmainit(device_t dev)
 {
+    struct ata_channel *ch = device_get_softc(dev);
+
     /* note start and stop are not used here */
     ata_dmainit(dev);
+    if (ch->dma) 
+	ch->dma->setprd = ata_promise_mio_setprd;
+}
+
+
+#define MAXLASTSGSIZE (32 * sizeof(u_int32_t))
+static void 
+ata_promise_mio_setprd(void *xsc, bus_dma_segment_t *segs, int nsegs, int error)
+{
+    struct ata_dmasetprd_args *args = xsc;
+    struct ata_dma_prdentry *prd = args->dmatab;
+    int i;
+
+    if ((args->error = error))
+	return;
+
+    for (i = 0; i < nsegs; i++) {
+	prd[i].addr = htole32(segs[i].ds_addr);
+	prd[i].count = htole32(segs[i].ds_len);
+    }
+    if (segs[i - 1].ds_len > MAXLASTSGSIZE) {
+	//printf("split last SG element of %u\n", segs[i - 1].ds_len);
+	prd[i - 1].count = htole32(segs[i - 1].ds_len - MAXLASTSGSIZE);
+	prd[i].count = htole32(MAXLASTSGSIZE);
+	prd[i].addr = htole32(segs[i - 1].ds_addr +
+			      (segs[i - 1].ds_len - MAXLASTSGSIZE));
+	nsegs++;
+	i++;
+    }
+    prd[i - 1].count |= htole32(ATA_DMA_EOT);
+    KASSERT(nsegs <= ATA_DMA_ENTRIES, "too many DMA segment entries\n");
+    args->nsegs = nsegs;
 }
 
 static void
@@ -4862,6 +4904,8 @@ ata_siiprb_dmasetprd(void *xsc, bus_dma_segment_t *segs, int nsegs, int error)
 	prd[i].count = htole32(segs[i].ds_len);
     }
     prd[i - 1].control = htole32(ATA_DMA_EOT);
+    KASSERT(nsegs <= ATA_DMA_ENTRIES, "too many DMA segment entries\n");
+    args->nsegs = nsegs;
 }
 
 static void
diff --git a/sys/dev/ata/ata-dma.c b/sys/dev/ata/ata-dma.c
index 582cbd47495..1220a469176 100644
--- a/sys/dev/ata/ata-dma.c
+++ b/sys/dev/ata/ata-dma.c
@@ -213,6 +213,7 @@ ata_dmasetprd(void *xsc, bus_dma_segment_t *segs, int nsegs, int error)
 	prd[i].count = htole32(segs[i].ds_len);
     }
     prd[i - 1].count |= htole32(ATA_DMA_EOT);
+    KASSERT(nsegs <= ATA_DMA_ENTRIES, "too many DMA segment entries\n");
     args->nsegs = nsegs;
 }