svn commit: r289825 - in head/sys: arm/arm arm64/arm64 vm x86/x86

[Jason A. Harmening]

Author: jah
Date: Fri Oct 23 12:03:25 2015
New Revision: 289825
URL: https://svnweb.freebsd.org/changeset/base/289825

Log:
  Remove unclear comment about address truncation in busdma.  Add (hopefully much clearer) comment at declaration of PHYS_TO_VM_PAGE().
  
  Noted by:	avg

Modified:
  head/sys/arm/arm/busdma_machdep-v6.c
  head/sys/arm/arm/busdma_machdep.c
  head/sys/arm64/arm64/busdma_bounce.c
  head/sys/vm/vm_page.h
  head/sys/x86/x86/busdma_bounce.c

Modified: head/sys/arm/arm/busdma_machdep-v6.c
==============================================================================
--- head/sys/arm/arm/busdma_machdep-v6.c	Fri Oct 23 11:45:38 2015	(r289824)
+++ head/sys/arm/arm/busdma_machdep-v6.c	Fri Oct 23 12:03:25 2015	(r289825)
@@ -1089,10 +1089,6 @@ _bus_dmamap_load_phys(bus_dma_tag_t dmat
 				sl++;
 				sl->vaddr = 0;
 				sl->datacount = sgsize;
-				/*
-				 * PHYS_TO_VM_PAGE() will truncate
-				 * unaligned addresses.
-				 */
 				sl->pages = PHYS_TO_VM_PAGE(curaddr);
 				sl->dataoffs = curaddr & PAGE_MASK;
 			} else
@@ -1214,10 +1210,6 @@ _bus_dmamap_load_buffer(bus_dma_tag_t dm
 				sl++;
 				sl->vaddr = kvaddr;
 				sl->datacount = sgsize;
-				/*
-				 * PHYS_TO_VM_PAGE() will truncate
-				 * unaligned addresses.
-				 */
 				sl->pages = PHYS_TO_VM_PAGE(curaddr);
 				sl->dataoffs = curaddr & PAGE_MASK;
 			} else
@@ -1687,7 +1679,6 @@ add_bounce_page(bus_dma_tag_t dmat, bus_
 		bpage->busaddr |= addr & PAGE_MASK;
 	}
 	bpage->datavaddr = vaddr;
-	/* PHYS_TO_VM_PAGE() will truncate unaligned addresses. */
 	bpage->datapage = PHYS_TO_VM_PAGE(addr);
 	bpage->dataoffs = addr & PAGE_MASK;
 	bpage->datacount = size;

Modified: head/sys/arm/arm/busdma_machdep.c
==============================================================================
--- head/sys/arm/arm/busdma_machdep.c	Fri Oct 23 11:45:38 2015	(r289824)
+++ head/sys/arm/arm/busdma_machdep.c	Fri Oct 23 12:03:25 2015	(r289825)
@@ -993,10 +993,6 @@ _bus_dmamap_load_phys(bus_dma_tag_t dmat
 				sl++;
 				sl->vaddr = 0;
 				sl->datacount = sgsize;
-				/*
-				 * PHYS_TO_VM_PAGE() will truncate
-				 * unaligned addresses.
-				 */
 				sl->pages = PHYS_TO_VM_PAGE(curaddr);
 				sl->dataoffs = curaddr & PAGE_MASK;
 			} else
@@ -1108,10 +1104,6 @@ _bus_dmamap_load_buffer(bus_dma_tag_t dm
 				sl++;
 				sl->vaddr = kvaddr;
 				sl->datacount = sgsize;
-				/*
-				 * PHYS_TO_VM_PAGE() will truncate
-				 * unaligned addresses.
-				 */
 				sl->pages = PHYS_TO_VM_PAGE(curaddr);
 				sl->dataoffs = curaddr & PAGE_MASK;
 			} else
@@ -1541,7 +1533,6 @@ add_bounce_page(bus_dma_tag_t dmat, bus_
 		bpage->busaddr |= addr & PAGE_MASK;
 	}
 	bpage->datavaddr = vaddr;
-	/* PHYS_TO_VM_PAGE() will truncate unaligned addresses. */
 	bpage->datapage = PHYS_TO_VM_PAGE(addr);
 	bpage->dataoffs = addr & PAGE_MASK;
 	bpage->datacount = size;

Modified: head/sys/arm64/arm64/busdma_bounce.c
==============================================================================
--- head/sys/arm64/arm64/busdma_bounce.c	Fri Oct 23 11:45:38 2015	(r289824)
+++ head/sys/arm64/arm64/busdma_bounce.c	Fri Oct 23 12:03:25 2015	(r289825)
@@ -1009,7 +1009,6 @@ add_bounce_page(bus_dma_tag_t dmat, bus_
 		bpage->busaddr |= addr & PAGE_MASK;
 	}
 	bpage->datavaddr = vaddr;
-	/* PHYS_TO_VM_PAGE() will truncate unaligned addresses. */
 	bpage->datapage = PHYS_TO_VM_PAGE(addr);
 	bpage->dataoffs = addr & PAGE_MASK;
 	bpage->datacount = size;

Modified: head/sys/vm/vm_page.h
==============================================================================
--- head/sys/vm/vm_page.h	Fri Oct 23 11:45:38 2015	(r289824)
+++ head/sys/vm/vm_page.h	Fri Oct 23 12:03:25 2015	(r289825)
@@ -375,6 +375,11 @@ extern long first_page;			/* first physi
 
 #define VM_PAGE_TO_PHYS(entry)	((entry)->phys_addr)
 
+/*
+ * PHYS_TO_VM_PAGE() Returns the vm_page_t object that represents a memory
+ * page to which the given physical address belongs. The correct vm_page_t
+ * object is returned for addresses that are not page-aligned.
+ */
 vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
 
 /*

Modified: head/sys/x86/x86/busdma_bounce.c
==============================================================================
--- head/sys/x86/x86/busdma_bounce.c	Fri Oct 23 11:45:38 2015	(r289824)
+++ head/sys/x86/x86/busdma_bounce.c	Fri Oct 23 12:03:25 2015	(r289825)
@@ -1006,7 +1006,6 @@ add_bounce_page(bus_dma_tag_t dmat, bus_
 		bpage->busaddr |= addr & PAGE_MASK;
 	}
 	bpage->datavaddr = vaddr;
-	/* PHYS_TO_VM_PAGE() will truncate unaligned addresses. */
 	bpage->datapage = PHYS_TO_VM_PAGE(addr);
 	bpage->dataoffs = addr & PAGE_MASK;
 	bpage->datacount = size;