[PATCH] powerpc/vas: Fix IRQ name allocation

[Cédric Le Goater]

The VAS device allocates a generic interrupt to handle page faults but
the IRQ name doesn't show under /proc. This is because it's on
stack. Allocate the name.

Signed-off-by: Cédric Le Goater <c...@kaod.org>
---

 I didn't understand this part in init_vas_instance() :

        if (vinst->virq) {
                rc = vas_irq_fault_window_setup(vinst);
                /*
                 * Fault window is used only for user space send windows.
                 * So if vinst->virq is NULL, tx_win_open returns -ENODEV
                 * for user space.
                 */
                if (rc)
                        vinst->virq = 0;
        }

 If the IRQ cannot be requested, the device probing should fail but
 it's not today. The use of 'vinst->virq' is suspicious.

 arch/powerpc/platforms/powernv/vas.h |  1 +
 arch/powerpc/platforms/powernv/vas.c | 11 ++++++++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/vas.h 
b/arch/powerpc/platforms/powernv/vas.h
index 70f793e8f6cc..c7db3190baca 100644
--- a/arch/powerpc/platforms/powernv/vas.h
+++ b/arch/powerpc/platforms/powernv/vas.h
@@ -340,6 +340,7 @@ struct vas_instance {
        struct vas_window *rxwin[VAS_COP_TYPE_MAX];
        struct vas_window *windows[VAS_WINDOWS_PER_CHIP];
 
+       char *name;
        char *dbgname;
        struct dentry *dbgdir;
 };
diff --git a/arch/powerpc/platforms/powernv/vas.c 
b/arch/powerpc/platforms/powernv/vas.c
index 598e4cd563fb..b65256a63e87 100644
--- a/arch/powerpc/platforms/powernv/vas.c
+++ b/arch/powerpc/platforms/powernv/vas.c
@@ -28,12 +28,10 @@ static DEFINE_PER_CPU(int, cpu_vas_id);
 
 static int vas_irq_fault_window_setup(struct vas_instance *vinst)
 {
-       char devname[64];
        int rc = 0;
 
-       snprintf(devname, sizeof(devname), "vas-%d", vinst->vas_id);
        rc = request_threaded_irq(vinst->virq, vas_fault_handler,
-                               vas_fault_thread_fn, 0, devname, vinst);
+                               vas_fault_thread_fn, 0, vinst->name, vinst);
 
        if (rc) {
                pr_err("VAS[%d]: Request IRQ(%d) failed with %d\n",
@@ -80,6 +78,12 @@ static int init_vas_instance(struct platform_device *pdev)
        if (!vinst)
                return -ENOMEM;
 
+       vinst->name = kasprintf(GFP_KERNEL, "vas-%d", vasid);
+       if (!vinst->name) {
+               kfree(vinst);
+               return -ENOMEM;
+       }
+
        INIT_LIST_HEAD(&vinst->node);
        ida_init(&vinst->ida);
        mutex_init(&vinst->mutex);
@@ -162,6 +166,7 @@ static int init_vas_instance(struct platform_device *pdev)
        return 0;
 
 free_vinst:
+       kfree(vinst->name);
        kfree(vinst);
        return -ENODEV;
 
-- 
2.26.2