cxl: Rework context lifetimes

This reworks contexts lifetimes a bit to enable the kernel API where we may
want to reuse contexts. Here we will want to start and stop contexts without
freeing them.

Start context does the get pid & ctx so stop context will need to do the puts.
Here we move put pid & ctx to the detach context path which will become part of
the stop context path.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

drivers/misc/cxl/context.c

diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
index 7d857b7..2a4c80a 100644
--- a/drivers/misc/cxl/context.c
+++ b/drivers/misc/cxl/context.c
@@ -186,6 +186,9 @@
 		return -EBUSY;
 
 	WARN_ON(cxl_detach_process(ctx));
+	flush_work(&ctx->fault_work); /* Only needed for dedicated process */
+	put_pid(ctx->pid);
+	cxl_ctx_put();
 	return 0;
 }
 
@@ -204,7 +207,6 @@
 		return;
 
 	afu_release_irqs(ctx, ctx);
-	flush_work(&ctx->fault_work); /* Only needed for dedicated process */
 	wake_up_all(&ctx->wq);
 }
 
@@ -245,7 +247,6 @@
 	free_page((u64)ctx->sstp);
 	ctx->sstp = NULL;
 
-	put_pid(ctx->pid);
 	kfree(ctx);
 }
 

drivers/misc/cxl/file.c

diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c
index 676e2c8..c16bd6f 100644
--- a/drivers/misc/cxl/file.c
+++ b/drivers/misc/cxl/file.c
@@ -128,7 +128,6 @@
 	 */
 	cxl_context_free(ctx);
 
-	cxl_ctx_put();
 	return 0;
 }