Merge branch 'for-6.5/cxl-region-fixes' into for-6.5/cxl

[platform/kernel/linux-starfive.git] / drivers / cxl / core / region.c

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 013f365..38db377 100644 (file)
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -125,10 +125,38 @@ static struct cxl_region_ref *cxl_rr_load(struct cxl_port *port,
        return xa_load(&port->regions, (unsigned long)cxlr);
 }
 
+static int cxl_region_invalidate_memregion(struct cxl_region *cxlr)
+{
+       if (!cpu_cache_has_invalidate_memregion()) {
+               if (IS_ENABLED(CONFIG_CXL_REGION_INVALIDATION_TEST)) {
+                       dev_warn_once(
+                               &cxlr->dev,
+                               "Bypassing cpu_cache_invalidate_memregion() for testing!\n");
+                       return 0;
+               } else {
+                       dev_err(&cxlr->dev,
+                               "Failed to synchronize CPU cache state\n");
+                       return -ENXIO;
+               }
+       }
+
+       cpu_cache_invalidate_memregion(IORES_DESC_CXL);
+       return 0;
+}
+
 static int cxl_region_decode_reset(struct cxl_region *cxlr, int count)
 {
        struct cxl_region_params *p = &cxlr->params;
-       int i;
+       int i, rc = 0;
+
+       /*
+        * Before region teardown attempt to flush, and if the flush
+        * fails cancel the region teardown for data consistency
+        * concerns
+        */
+       rc = cxl_region_invalidate_memregion(cxlr);
+       if (rc)
+               return rc;
 
        for (i = count - 1; i >= 0; i--) {
                struct cxl_endpoint_decoder *cxled = p->targets[i];
@@ -136,7 +164,6 @@ static int cxl_region_decode_reset(struct cxl_region *cxlr, int count)
                struct cxl_port *iter = cxled_to_port(cxled);
                struct cxl_dev_state *cxlds = cxlmd->cxlds;
                struct cxl_ep *ep;
-               int rc = 0;
 
                if (cxlds->rcd)
                        goto endpoint_reset;
@@ -155,14 +182,19 @@ static int cxl_region_decode_reset(struct cxl_region *cxlr, int count)
                                rc = cxld->reset(cxld);
                        if (rc)
                                return rc;
+                       set_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
                }
 
 endpoint_reset:
                rc = cxled->cxld.reset(&cxled->cxld);
                if (rc)
                        return rc;
+               set_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
        }
 
+       /* all decoders associated with this region have been torn down */
+       clear_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
+
        return 0;
 }
 
@@ -256,9 +288,19 @@ static ssize_t commit_store(struct device *dev, struct device_attribute *attr,
                goto out;
        }
 
-       if (commit)
+       /*
+        * Invalidate caches before region setup to drop any speculative
+        * consumption of this address space
+        */
+       rc = cxl_region_invalidate_memregion(cxlr);
+       if (rc)
+               return rc;
+
+       if (commit) {
                rc = cxl_region_decode_commit(cxlr);
-       else {
+               if (rc == 0)
+                       p->state = CXL_CONFIG_COMMIT;
+       } else {
                p->state = CXL_CONFIG_RESET_PENDING;
                up_write(&cxl_region_rwsem);
                device_release_driver(&cxlr->dev);
@@ -268,18 +310,20 @@ static ssize_t commit_store(struct device *dev, struct device_attribute *attr,
                 * The lock was dropped, so need to revalidate that the reset is
                 * still pending.
                 */
-               if (p->state == CXL_CONFIG_RESET_PENDING)
+               if (p->state == CXL_CONFIG_RESET_PENDING) {
                        rc = cxl_region_decode_reset(cxlr, p->interleave_ways);
+                       /*
+                        * Revert to committed since there may still be active
+                        * decoders associated with this region, or move forward
+                        * to active to mark the reset successful
+                        */
+                       if (rc)
+                               p->state = CXL_CONFIG_COMMIT;
+                       else
+                               p->state = CXL_CONFIG_ACTIVE;
+               }
        }
 
-       if (rc)
-               goto out;
-
-       if (commit)
-               p->state = CXL_CONFIG_COMMIT;
-       else if (p->state == CXL_CONFIG_RESET_PENDING)
-               p->state = CXL_CONFIG_ACTIVE;
-
 out:
        up_write(&cxl_region_rwsem);
 
@@ -1686,7 +1730,6 @@ static int cxl_region_attach(struct cxl_region *cxlr,
                if (rc)
                        goto err_decrement;
                p->state = CXL_CONFIG_ACTIVE;
-               set_bit(CXL_REGION_F_INCOHERENT, &cxlr->flags);
        }
 
        cxled->cxld.interleave_ways = p->interleave_ways;
@@ -2815,30 +2858,6 @@ out:
 }
 EXPORT_SYMBOL_NS_GPL(cxl_add_to_region, CXL);
 
-static int cxl_region_invalidate_memregion(struct cxl_region *cxlr)
-{
-       if (!test_bit(CXL_REGION_F_INCOHERENT, &cxlr->flags))
-               return 0;
-
-       if (!cpu_cache_has_invalidate_memregion()) {
-               if (IS_ENABLED(CONFIG_CXL_REGION_INVALIDATION_TEST)) {
-                       dev_warn_once(
-                               &cxlr->dev,
-                               "Bypassing cpu_cache_invalidate_memregion() for testing!\n");
-                       clear_bit(CXL_REGION_F_INCOHERENT, &cxlr->flags);
-                       return 0;
-               } else {
-                       dev_err(&cxlr->dev,
-                               "Failed to synchronize CPU cache state\n");
-                       return -ENXIO;
-               }
-       }
-
-       cpu_cache_invalidate_memregion(IORES_DESC_CXL);
-       clear_bit(CXL_REGION_F_INCOHERENT, &cxlr->flags);
-       return 0;
-}
-
 static int is_system_ram(struct resource *res, void *arg)
 {
        struct cxl_region *cxlr = arg;
@@ -2866,7 +2885,12 @@ static int cxl_region_probe(struct device *dev)
                goto out;
        }
 
-       rc = cxl_region_invalidate_memregion(cxlr);
+       if (test_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags)) {
+               dev_err(&cxlr->dev,
+                       "failed to activate, re-commit region and retry\n");
+               rc = -ENXIO;
+               goto out;
+       }
 
        /*
         * From this point on any path that changes the region's state away from