crypto: caam/qi - simplify CGR allocation, freeing

CGRs (Congestion Groups) have to be freed by the same CPU that
initialized them.
This is why currently the driver takes special measures; however, using
set_cpus_allowed_ptr() is incorrect - as reported by Sebastian.

Instead of the generic solution of replacing set_cpus_allowed_ptr() with
work_on_cpu_safe(), we use the qman_delete_cgr_safe() QBMan API instead
of qman_delete_cgr() - which internally takes care of proper CGR
deletion.

Link: https://lkml.kernel.org/r/20181005125443.dfhd2asqktm22ney@linutronix.de
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/caam/qi.c b/drivers/crypto/caam/qi.c
index 67f7f8c42c93202af160109fe3e05c26b33450fa..b84e6c8b1e138226ec4feebf66167738da6a10df 100644 (file)
--- a/drivers/crypto/caam/qi.c
+++ b/drivers/crypto/caam/qi.c
@@ -83,13 +83,6 @@ EXPORT_SYMBOL(caam_congested);
 static u64 times_congested;
 #endif
 
-/*
- * CPU from where the module initialised. This is required because QMan driver
- * requires CGRs to be removed from same CPU from where they were originally
- * allocated.
- */
-static int mod_init_cpu;
-
 /*
  * This is a a cache of buffers, from which the users of CAAM QI driver
  * can allocate short (CAAM_QI_MEMCACHE_SIZE) buffers. It's faster than
@@ -492,12 +485,11 @@ void caam_drv_ctx_rel(struct caam_drv_ctx *drv_ctx)
 }
 EXPORT_SYMBOL(caam_drv_ctx_rel);
 
-int caam_qi_shutdown(struct device *qidev)
+void caam_qi_shutdown(struct device *qidev)
 {
-       int i, ret;
+       int i;
        struct caam_qi_priv *priv = dev_get_drvdata(qidev);
        const cpumask_t *cpus = qman_affine_cpus();
-       struct cpumask old_cpumask = current->cpus_allowed;
 
        for_each_cpu(i, cpus) {
                struct napi_struct *irqtask;
@@ -510,26 +502,12 @@ int caam_qi_shutdown(struct device *qidev)
                        dev_err(qidev, "Rsp FQ kill failed, cpu: %d\n", i);
        }
 
-       /*
-        * QMan driver requires CGRs to be deleted from same CPU from where they
-        * were instantiated. Hence we get the module removal execute from the
-        * same CPU from where it was originally inserted.
-        */
-       set_cpus_allowed_ptr(current, get_cpu_mask(mod_init_cpu));
-
-       ret = qman_delete_cgr(&priv->cgr);
-       if (ret)
-               dev_err(qidev, "Deletion of CGR failed: %d\n", ret);
-       else
-               qman_release_cgrid(priv->cgr.cgrid);
+       qman_delete_cgr_safe(&priv->cgr);
+       qman_release_cgrid(priv->cgr.cgrid);
 
        kmem_cache_destroy(qi_cache);
 
-       /* Now that we're done with the CGRs, restore the cpus allowed mask */
-       set_cpus_allowed_ptr(current, &old_cpumask);
-
        platform_device_unregister(priv->qi_pdev);
-       return ret;
 }
 
 static void cgr_cb(struct qman_portal *qm, struct qman_cgr *cgr, int congested)
@@ -718,22 +696,11 @@ int caam_qi_init(struct platform_device *caam_pdev)
        struct device *ctrldev = &caam_pdev->dev, *qidev;
        struct caam_drv_private *ctrlpriv;
        const cpumask_t *cpus = qman_affine_cpus();
-       struct cpumask old_cpumask = current->cpus_allowed;
        static struct platform_device_info qi_pdev_info = {
                .name = "caam_qi",
                .id = PLATFORM_DEVID_NONE
        };
 
-       /*
-        * QMAN requires CGRs to be removed from same CPU+portal from where it
-        * was originally allocated. Hence we need to note down the
-        * initialisation CPU and use the same CPU for module exit.
-        * We select the first CPU to from the list of portal owning CPUs.
-        * Then we pin module init to this CPU.
-        */
-       mod_init_cpu = cpumask_first(cpus);
-       set_cpus_allowed_ptr(current, get_cpu_mask(mod_init_cpu));
-
        qi_pdev_info.parent = ctrldev;
        qi_pdev_info.dma_mask = dma_get_mask(ctrldev);
        qi_pdev = platform_device_register_full(&qi_pdev_info);
@@ -795,8 +762,6 @@ int caam_qi_init(struct platform_device *caam_pdev)
                return -ENOMEM;
        }
 
-       /* Done with the CGRs; restore the cpus allowed mask */
-       set_cpus_allowed_ptr(current, &old_cpumask);
 #ifdef CONFIG_DEBUG_FS
        debugfs_create_file("qi_congested", 0444, ctrlpriv->ctl,
                            &times_congested, &caam_fops_u64_ro);

diff --git a/drivers/crypto/caam/qi.h b/drivers/crypto/caam/qi.h
index bc421da5ad8b297932d2b75ccb4366be74bc8da3..f93c9c7ed430c976bf7269f58fe8c3721db7d26f 100644 (file)
--- a/drivers/crypto/caam/qi.h
+++ b/drivers/crypto/caam/qi.h
@@ -173,7 +173,7 @@ int caam_drv_ctx_update(struct caam_drv_ctx *drv_ctx, u32 *sh_desc);
 void caam_drv_ctx_rel(struct caam_drv_ctx *drv_ctx);
 
 int caam_qi_init(struct platform_device *pdev);
-int caam_qi_shutdown(struct device *dev);
+void caam_qi_shutdown(struct device *dev);
 
 /**
  * qi_cache_alloc - Allocate buffers from CAAM-QI cache