From 955fec6d52229bfd78514739300b6f754dcc40a3 Mon Sep 17 00:00:00 2001
From: Russell King <rmk@arm.linux.org.uk>
Date: Sat, 22 Jun 2013 22:52:16 +0100
Subject: Use free-by-physical address kernel API

Use the new free-by-physical address kernel API.  This allows us
to free bmm buffers which have not been mapped into user memory.
This also allows us to free a bmm buffer which failed to mmap().
---
 bmm_lib.c      | 33 ++++++++++++++++++++++++---------
 bmm_lib_priv.h |  1 +
 2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/bmm_lib.c b/bmm_lib.c
index 3e4ebd2..64a11e7 100644
--- a/bmm_lib.c
+++ b/bmm_lib.c
@@ -35,10 +35,11 @@
 #endif
 
 #define API_FEAT_MIN		0x0000
-#define API_COMP_MAX		0x0000
+#define API_COMP_MAX		0x0001
 #define API_FEAT(x)		((x) >> 16)
 #define API_COMP(x)		((x) & 0xffff)
 #define API_FEAT_GET_DMABUF_FD	0x0001
+#define API_FEAT_FREE_PHYS	0x0002
 
 static unsigned bmm_api;
 static int bmm_fd = -1;
@@ -249,10 +250,8 @@ void *bmm_malloc_aligned(unsigned long size, int attr, unsigned align)
 	pr_debug("bmm_malloc return paddr = 0x%08lx\n", io.output);
 
 	vaddr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, bmm_fd, io.output);
-	if ((int)vaddr == -1) {
-		/* FIXME: we can't free the bmm buffer without a vaddr! */
-		goto err_free_buf;
-	}
+	if ((int)vaddr == -1)
+		goto err_free_bmm;
 
 	buf->vaddr = vaddr;
 	buf->paddr = io.output;
@@ -265,6 +264,15 @@ void *bmm_malloc_aligned(unsigned long size, int attr, unsigned align)
 
 	return vaddr;
 
+ err_free_bmm:
+	if (API_FEAT(bmm_api) >= API_FEAT_FREE_PHYS) {
+		/* Modern APIs allow us to free this failed allocation */
+		io.input = io.output;
+		io.output = 0;
+		io.arg = 0;
+		ioctl(bmm_fd, BMM_FREE_PHYS, &io);
+	}
+
  err_free_buf:
 	free(buf);
 	return NULL;
@@ -293,10 +301,17 @@ void bmm_free(void *vaddr)
 
 	munmap(buf->vaddr, buf->size);
 
-	io.input = (unsigned long)buf->vaddr;
-	io.output = 0;
-	io.arg = 0;
-	ioctl(bmm_fd, BMM_FREE, &io);
+	if (API_FEAT(bmm_api) >= API_FEAT_FREE_PHYS) {
+		io.input = buf->paddr;
+		io.output = 0;
+		io.arg = 0;
+		ioctl(bmm_fd, BMM_FREE_PHYS, &io);
+	} else {
+		io.input = (unsigned long)buf->vaddr;
+		io.output = 0;
+		io.arg = 0;
+		ioctl(bmm_fd, BMM_FREE, &io);
+	}
 	free(buf);
 }
 
diff --git a/bmm_lib_priv.h b/bmm_lib_priv.h
index a93db78..f10a77b 100644
--- a/bmm_lib_priv.h
+++ b/bmm_lib_priv.h
@@ -43,6 +43,7 @@ typedef struct {
 #define BMM_MALLOC_ALIGNED	_IOWR(BMEM_IOCTL_MAGIC, 17, ioctl_arg_t)
 #define BMM_API_VERSION		_IOWR(BMEM_IOCTL_MAGIC, 18, ioctl_arg_t)
 #define BMM_GET_DMABUF_FD	_IOWR(BMEM_IOCTL_MAGIC, 19, ioctl_arg_t)
+#define BMM_FREE_PHYS		_IOWR(BMEM_IOCTL_MAGIC, 20, ioctl_arg_t)
 
 #define BMM_DEVICE_FILE	"/dev/bmm"
 
-- 
cgit