path: root/drivers/misc/cxl/api.c
diff options
authorIan Munsie <imunsie@au1.ibm.com>2015-08-27 19:50:19 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2015-08-30 18:47:26 +1000
commit55e07668fbba9466e6a9ef7650718356cda38406 (patch)
tree8125e4c7a0504f582f50817e3830790ccc788923 /drivers/misc/cxl/api.c
parentaf2a50bb0ce1ca7a9c4784813419c922bf2285df (diff)
cxl: Fix force unmapping mmaps of contexts allocated through the kernel api
The cxl user api uses the address_space associated with the file when we need to force unmap all cxl mmap regions (e.g. on eeh, driver detach, etc). Currently, contexts allocated through the kernel api do not do this and instead skip the mmap invalidation, potentially allowing them to poke at the hardware after such an event, which may cause all sorts of trouble. This patch allocates an address_space for cxl contexts allocated through the kernel api so that the same invalidate path will for these contexts as well. We don't use the anonymous inode's address_space, as doing so could invalidate any mmaps of completely unrelated drivers using anonymous file descriptors. This patch also introduces a kernelapi flag, so we know when freeing the context if the address_space was allocated by us and needs to be freed. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/misc/cxl/api.c')
1 files changed, 30 insertions, 3 deletions
diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
index 005adc7d33a2..8af12c884b04 100644
--- a/drivers/misc/cxl/api.c
+++ b/drivers/misc/cxl/api.c
@@ -12,11 +12,13 @@
#include <linux/anon_inodes.h>
#include <linux/file.h>
#include <misc/cxl.h>
+#include <linux/fs.h>
#include "cxl.h"
struct cxl_context *cxl_dev_context_init(struct pci_dev *dev)
+ struct address_space *mapping;
struct cxl_afu *afu;
struct cxl_context *ctx;
int rc;
@@ -30,14 +32,32 @@ struct cxl_context *cxl_dev_context_init(struct pci_dev *dev)
goto err_dev;
+ ctx->kernelapi = true;
+ /*
+ * Make our own address space since we won't have one from the
+ * filesystem like the user api has, and even if we do associate a file
+ * with this context we don't want to use the global anonymous inode's
+ * address space as that can invalidate unrelated users:
+ */
+ mapping = kmalloc(sizeof(struct address_space), GFP_KERNEL);
+ if (!mapping) {
+ rc = -ENOMEM;
+ goto err_ctx;
+ }
+ address_space_init_once(mapping);
/* Make it a slave context. We can promote it later? */
- rc = cxl_context_init(ctx, afu, false, NULL);
+ rc = cxl_context_init(ctx, afu, false, mapping);
if (rc)
- goto err_ctx;
+ goto err_mapping;
return ctx;
+ kfree(mapping);
@@ -260,9 +280,16 @@ struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops,
file = anon_inode_getfile("cxl", fops, ctx, flags);
if (IS_ERR(file))
- put_unused_fd(fdtmp);
+ goto err_fd;
+ file->f_mapping = ctx->mapping;
*fd = fdtmp;
return file;
+ put_unused_fd(fdtmp);
+ return NULL;