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authorDave Airlie <airlied@redhat.com>2015-04-20 11:32:26 +1000
committerDave Airlie <airlied@redhat.com>2015-04-20 13:05:20 +1000
commit2c33ce009ca2389dbf0535d0672214d09738e35e (patch)
tree6186a6458c3c160385d794a23eaf07c786a9e61b /arch/um/kernel/physmem.c
parentcec32a47010647e8b0603726ebb75b990a4057a4 (diff)
parent09d51602cf84a1264946711dd4ea0dddbac599a1 (diff)
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Merge Linus master into drm-next
The merge is clean, but the arm build fails afterwards, due to API changes in the regulator tree. I've included the patch into the merge to fix the build. Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'arch/um/kernel/physmem.c')
-rw-r--r--arch/um/kernel/physmem.c41
1 files changed, 35 insertions, 6 deletions
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index 549ecf3f5857..9034fc8056b4 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -57,22 +57,51 @@ void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
extern int __syscall_stub_start;
+/**
+ * setup_physmem() - Setup physical memory for UML
+ * @start: Start address of the physical kernel memory,
+ * i.e start address of the executable image.
+ * @reserve_end: end address of the physical kernel memory.
+ * @len: Length of total physical memory that should be mapped/made
+ * available, in bytes.
+ * @highmem: Number of highmem bytes that should be mapped/made available.
+ *
+ * Creates an unlinked temporary file of size (len + highmem) and memory maps
+ * it on the last executable image address (uml_reserved).
+ *
+ * The offset is needed as the length of the total physical memory
+ * (len + highmem) includes the size of the memory used be the executable image,
+ * but the mapped-to address is the last address of the executable image
+ * (uml_reserved == end address of executable image).
+ *
+ * The memory mapped memory of the temporary file is used as backing memory
+ * of all user space processes/kernel tasks.
+ */
void __init setup_physmem(unsigned long start, unsigned long reserve_end,
unsigned long len, unsigned long long highmem)
{
unsigned long reserve = reserve_end - start;
- int pfn = PFN_UP(__pa(reserve_end));
- int delta = (len - reserve) >> PAGE_SHIFT;
- int err, offset, bootmap_size;
+ unsigned long pfn = PFN_UP(__pa(reserve_end));
+ unsigned long delta = (len - reserve) >> PAGE_SHIFT;
+ unsigned long offset, bootmap_size;
+ long map_size;
+ int err;
+
+ offset = uml_reserved - uml_physmem;
+ map_size = len - offset;
+ if(map_size <= 0) {
+ printf("Too few physical memory! Needed=%d, given=%d\n",
+ offset, len);
+ exit(1);
+ }
physmem_fd = create_mem_file(len + highmem);
- offset = uml_reserved - uml_physmem;
err = os_map_memory((void *) uml_reserved, physmem_fd, offset,
- len - offset, 1, 1, 1);
+ map_size, 1, 1, 1);
if (err < 0) {
printf("setup_physmem - mapping %ld bytes of memory at 0x%p "
- "failed - errno = %d\n", len - offset,
+ "failed - errno = %d\n", map_size,
(void *) uml_reserved, err);
exit(1);
}