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Date:      Wed, 18 Nov 2015 22:20:22 +0000 (UTC)
From:      "Conrad E. Meyer" <cem@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r291031 - head/sys/dev/ntb/ntb_hw
Message-ID:  <201511182220.tAIMKMh7084251@repo.freebsd.org>
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Author: cem
Date: Wed Nov 18 22:20:21 2015
New Revision: 291031
URL: https://svnweb.freebsd.org/changeset/base/291031

Log:
  ntb_hw: Add programmatic interface to enable/disable WC
  
  Enable users to enable/disable WC on memory windows programmatically.
  
  Sponsored by:	EMC / Isilon Storage Division

Modified:
  head/sys/dev/ntb/ntb_hw/ntb_hw.c
  head/sys/dev/ntb/ntb_hw/ntb_hw.h

Modified: head/sys/dev/ntb/ntb_hw/ntb_hw.c
==============================================================================
--- head/sys/dev/ntb/ntb_hw/ntb_hw.c	Wed Nov 18 22:20:13 2015	(r291030)
+++ head/sys/dev/ntb/ntb_hw/ntb_hw.c	Wed Nov 18 22:20:21 2015	(r291031)
@@ -113,6 +113,7 @@ struct ntb_pci_bar_info {
 	vm_paddr_t		pbase;
 	caddr_t			vbase;
 	vm_size_t		size;
+	bool			mapped_wc : 1;
 
 	/* Configuration register offsets */
 	uint32_t		psz_off;
@@ -777,14 +778,15 @@ map_memory_window_bar(struct ntb_softc *
 	/* Mark bar region as write combining to improve performance. */
 	rc = pmap_change_attr((vm_offset_t)bar->vbase, bar->size,
 	    VM_MEMATTR_WRITE_COMBINING);
-	if (rc == 0)
+	if (rc == 0) {
+		bar->mapped_wc = true;
 		device_printf(ntb->device,
 		    "Marked BAR%d v:[%p-%p] p:[%p-%p] as "
 		    "WRITE_COMBINING.\n",
 		    PCI_RID2BAR(bar->pci_resource_id), bar->vbase,
 		    (char *)bar->vbase + bar->size - 1,
 		    (void *)bar->pbase, (void *)(bar->pbase + bar->size - 1));
-	else
+	} else
 		device_printf(ntb->device,
 		    "Unable to mark BAR%d v:[%p-%p] p:[%p-%p] as "
 		    "WRITE_COMBINING: %d\n",
@@ -2629,6 +2631,60 @@ ntb_mw_clear_trans(struct ntb_softc *ntb
 	return (ntb_mw_set_trans(ntb, mw_idx, 0, 0));
 }
 
+/*
+ * ntb_mw_get_wc - Get the write-combine status of a memory window
+ *
+ * Returns:  Zero on success, setting *wc; otherwise an error number (e.g. if
+ * idx is an invalid memory window).
+ */
+int
+ntb_mw_get_wc(struct ntb_softc *ntb, unsigned idx, bool *wc)
+{
+	struct ntb_pci_bar_info *bar;
+
+	if (idx >= ntb_mw_count(ntb))
+		return (EINVAL);
+
+	bar = &ntb->bar_info[ntb_mw_to_bar(ntb, idx)];
+	*wc = bar->mapped_wc;
+	return (0);
+}
+
+/*
+ * ntb_mw_set_wc - Set the write-combine status of a memory window
+ *
+ * If 'wc' matches the current status, this does nothing and succeeds.
+ *
+ * Returns:  Zero on success, setting the caching attribute on the virtual
+ * mapping of the BAR; otherwise an error number (e.g. if idx is an invalid
+ * memory window, or if changing the caching attribute fails).
+ */
+int
+ntb_mw_set_wc(struct ntb_softc *ntb, unsigned idx, bool wc)
+{
+	struct ntb_pci_bar_info *bar;
+	vm_memattr_t attr;
+	int rc;
+
+	if (idx >= ntb_mw_count(ntb))
+		return (EINVAL);
+
+	bar = &ntb->bar_info[ntb_mw_to_bar(ntb, idx)];
+	if (bar->mapped_wc == wc)
+		return (0);
+
+	if (wc)
+		attr = VM_MEMATTR_WRITE_COMBINING;
+	else
+		attr = VM_MEMATTR_DEFAULT;
+
+	rc = pmap_change_attr((vm_offset_t)bar->vbase, bar->size, attr);
+	if (rc == 0)
+		bar->mapped_wc = wc;
+
+	return (rc);
+}
+
 /**
  * ntb_peer_db_set() - Set the doorbell on the secondary/external side
  * @ntb: pointer to ntb_softc instance

Modified: head/sys/dev/ntb/ntb_hw/ntb_hw.h
==============================================================================
--- head/sys/dev/ntb/ntb_hw/ntb_hw.h	Wed Nov 18 22:20:13 2015	(r291030)
+++ head/sys/dev/ntb/ntb_hw/ntb_hw.h	Wed Nov 18 22:20:21 2015	(r291031)
@@ -81,6 +81,9 @@ int ntb_mw_get_range(struct ntb_softc *,
 int ntb_mw_set_trans(struct ntb_softc *, unsigned mw_idx, bus_addr_t, size_t);
 int ntb_mw_clear_trans(struct ntb_softc *, unsigned mw_idx);
 
+int ntb_mw_get_wc(struct ntb_softc *, unsigned mw_idx, bool *wc);
+int ntb_mw_set_wc(struct ntb_softc *, unsigned mw_idx, bool wc);
+
 uint8_t ntb_get_max_spads(struct ntb_softc *ntb);
 int ntb_spad_write(struct ntb_softc *ntb, unsigned int idx, uint32_t val);
 int ntb_spad_read(struct ntb_softc *ntb, unsigned int idx, uint32_t *val);

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