svn commit: r332286 - head/sys/powerpc/ofw

[Justin Hibbits]

Author: jhibbits
Date: Sun Apr  8 16:43:56 2018
New Revision: 332286
URL: https://svnweb.freebsd.org/changeset/base/332286

Log:
  powerpc/ofw: Fix malloc inside lock
  
  Summary:
  Currently ofw_real_bounce_alloc() is requesting memory, using WAITOK, holding a
  non-sleepable locks, called 'OF Bounce Page'.
  
  Fix this by allocating the pages outside of the lock, and only updating the
  global variables while holding the lock.
  
  Submitted by:	Breno Leitao
  Differential Revision:	https://reviews.freebsd.org/D14955

Modified:
  head/sys/powerpc/ofw/ofw_real.c

Modified: head/sys/powerpc/ofw/ofw_real.c
==============================================================================
--- head/sys/powerpc/ofw/ofw_real.c	Sun Apr  8 16:34:10 2018	(r332285)
+++ head/sys/powerpc/ofw/ofw_real.c	Sun Apr  8 16:43:56 2018	(r332286)
@@ -197,6 +197,8 @@ ofw_real_stop(void)
 static void
 ofw_real_bounce_alloc(void *junk)
 {
+	caddr_t temp;
+
 	/*
 	 * Check that ofw_real is actually in use before allocating wads 
 	 * of memory. Do this by checking if our mutex has been set up.
@@ -208,12 +210,15 @@ ofw_real_bounce_alloc(void *junk)
 	 * Allocate a page of contiguous, wired physical memory that can
 	 * fit into a 32-bit address space and accessed from real mode.
 	 */
+	temp = contigmalloc(4 * PAGE_SIZE, M_OFWREAL, 0, 0,
+	    ulmin(platform_real_maxaddr(), BUS_SPACE_MAXADDR_32BIT), PAGE_SIZE,
+	    4 * PAGE_SIZE);
+	if (temp == NULL)
+		panic("%s: Not able to allocated contiguous memory\n", __func__);
 
 	mtx_lock(&of_bounce_mtx);
 
-	of_bounce_virt = contigmalloc(4 * PAGE_SIZE, M_OFWREAL, 0, 0,
-	    ulmin(platform_real_maxaddr(), BUS_SPACE_MAXADDR_32BIT), PAGE_SIZE,
-	    4 * PAGE_SIZE);
+	of_bounce_virt = temp;
 
 	of_bounce_phys = vtophys(of_bounce_virt);
 	of_bounce_size = 4 * PAGE_SIZE;