svn commit: r368134 - head/sys/cam

[Alexander Motin]

Author: mav
Date: Sun Nov 29 00:49:14 2020
New Revision: 368134
URL: https://svnweb.freebsd.org/changeset/base/368134

Log:
  Remove alignment requirements for KVA buffer mapping.
  
  After r368124 vmapbuf() should happily map misaligned maxphys-sized buffers
  thanks to extra page added to pbuf_zone.

Modified:
  head/sys/cam/cam_periph.c

Modified: head/sys/cam/cam_periph.c
==============================================================================
--- head/sys/cam/cam_periph.c	Sun Nov 29 00:35:13 2020	(r368133)
+++ head/sys/cam/cam_periph.c	Sun Nov 29 00:49:14 2020	(r368134)
@@ -783,7 +783,6 @@ cam_periph_mapmem(union ccb *ccb, struct cam_periph_ma
 	u_int8_t **data_ptrs[CAM_PERIPH_MAXMAPS];
 	u_int32_t lengths[CAM_PERIPH_MAXMAPS];
 	u_int32_t dirs[CAM_PERIPH_MAXMAPS];
-	bool misaligned[CAM_PERIPH_MAXMAPS];
 
 	bzero(mapinfo, sizeof(*mapinfo));
 	if (maxmap == 0)
@@ -901,17 +900,6 @@ cam_periph_mapmem(union ccb *ccb, struct cam_periph_ma
 			       (long)(lengths[i]), (u_long)maxmap);
 			return (E2BIG);
 		}
-
-		/*
-		 * The userland data pointer passed in may not be page
-		 * aligned.  vmapbuf() truncates the address to a page
-		 * boundary, so if the address isn't page aligned, we'll
-		 * need enough space for the given transfer length, plus
-		 * whatever extra space is necessary to make it to the page
-		 * boundary.
-		 */
-		misaligned[i] = (lengths[i] +
-		    (((vm_offset_t)(*data_ptrs[i])) & PAGE_MASK) > maxphys);
 	}
 
 	/*
@@ -934,7 +922,7 @@ cam_periph_mapmem(union ccb *ccb, struct cam_periph_ma
 		 * small allocations malloc is backed by UMA, and so much
 		 * cheaper on SMP systems.
 		 */
-		if ((lengths[i] <= periph_mapmem_thresh || misaligned[i]) &&
+		if (lengths[i] <= periph_mapmem_thresh &&
 		    ccb->ccb_h.func_code != XPT_MMC_IO) {
 			*data_ptrs[i] = malloc(lengths[i], M_CAMPERIPH,
 			    M_WAITOK);