On Tue, 11 Dec 2018 12:05:49 +1100 Andrew Donnellan andrew.donnellan@au1.ibm.com wrote:

On 11/12/18 2:15 am, Greg Kurz wrote:

...

The only users of free_spa() are alloc_link() and free_link(), and in both cases:

• link->spa != NULL

• free_spa(link) is immediatly followed by kfree(link)

The check isn't needed, and it doesn't bring much to clear the link->spa pointer. Drop both.

Signed-off-by: Greg Kurz groug@kaod.org

I like defensive programming but for this case I don't really care too much either way

I now realize that I should have mentioned the real motivation for this change. I'm working on refactoring the code so that we can use ocxl in a KVM guest. The concept of link can be shared by both powernv and pseries variants but the SPA is definitely a powernv only thingy. The benefit of this patch is hence to kick 'struct link' out of free_spa() so that it can be utimately moved to powernv specific code.

The initial version of this change was just moving the link->spa check and link->spa = NULL to the callers, where it was quite obvious they're not needed... Should I re-post this as two patches for clarity ?

Acked-by: Andrew Donnellan andrew.donnellan@au1.ibm.com

...

---

drivers/misc/ocxl/link.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c index 31695a078485..eed92055184d 100644 --- a/drivers/misc/ocxl/link.c +++ b/drivers/misc/ocxl/link.c @@ -352,11 +352,8 @@ static void free_spa(struct link *link) pr_debug("Freeing SPA for %x:%x:%x\n", link->domain, link->bus, link->dev);

• if (spa && spa->spa_mem) {

• free_pages((unsigned long) spa->spa_mem, spa->spa_order);
  

• kfree(spa);
  

• link->spa = NULL;
  

• }

• free_pages((unsigned long) spa->spa_mem, spa->spa_order);
• kfree(spa); }

static int alloc_link(struct pci_dev *dev, int PE_mask, struct link **out_link)