From patchwork series 502734

https://patchwork.ozlabs.org//project/linuxppc-dev/list/?series=502734

Author: Fox Snowpatch

arch/powerpc/platforms/pseries/iommu.c

@@ -69,6 +69,8 @@ static struct iommu_table *iommu_pseries_alloc_table(int node)
 	return tbl;
 }
 
+static phys_addr_t pseries_ddw_max_ram;
+
 #ifdef CONFIG_IOMMU_API
 static struct iommu_table_group_ops spapr_tce_table_group_ops;
 #endif
@@ -1285,15 +1287,19 @@ static LIST_HEAD(failed_ddw_pdn_list);
 
 static phys_addr_t ddw_memory_hotplug_max(void)
 {
-	resource_size_t max_addr;
+	resource_size_t max_addr = memory_hotplug_max();
+	struct device_node *memory;
 
-#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
-	max_addr = hot_add_drconf_memory_max();
-#else
-	max_addr = memblock_end_of_DRAM();
-#endif
+	for_each_node_by_type(memory, "memory") {
+		struct resource res;
+
+		if (of_address_to_resource(memory, 0, &res))
+			continue;
 
-	return max_addr;
+		max_addr = max_t(resource_size_t, max_addr, res.end + 1);
+		}
+
+		return max_addr;
 }
 
 /*
@@ -1446,7 +1452,7 @@ static struct property *ddw_property_create(const char *propname, u32 liobn, u64
 static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn, u64 dma_mask)
 {
 	int len = 0, ret;
-	int max_ram_len = order_base_2(ddw_memory_hotplug_max());
+	int max_ram_len = order_base_2(pseries_ddw_max_ram);
 	struct ddw_query_response query;
 	struct ddw_create_response create;
 	int page_shift;
@@ -1668,7 +1674,7 @@ static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn, u64 dma_mas
 
 	if (direct_mapping) {
 		/* DDW maps the whole partition, so enable direct DMA mapping */
-		ret = walk_system_ram_range(0, ddw_memory_hotplug_max() >> PAGE_SHIFT,
+		ret = walk_system_ram_range(0, pseries_ddw_max_ram >> PAGE_SHIFT,
 					    win64->value, tce_setrange_multi_pSeriesLP_walk);
 		if (ret) {
 			dev_info(&dev->dev, "failed to map DMA window for %pOF: %d\n",
@@ -2423,15 +2429,15 @@ static int iommu_mem_notifier(struct notifier_block *nb, unsigned long action,
 
 	/* This notifier can get called when onlining persistent memory as well.
 	 * TCEs are not pre-mapped for persistent memory. Persistent memory will
-	 * always be above ddw_memory_hotplug_max()
+	 * always be above pseries_ddw_max_ram
 	 */
 
 	switch (action) {
 	case MEM_GOING_ONLINE:
 		spin_lock(&dma_win_list_lock);
 		list_for_each_entry(window, &dma_win_list, list) {
 			if (window->direct && (arg->start_pfn << PAGE_SHIFT) <
-				ddw_memory_hotplug_max()) {
+				pseries_ddw_max_ram) {
 				ret |= tce_setrange_multi_pSeriesLP(arg->start_pfn,
 						arg->nr_pages, window->prop);
 			}
@@ -2444,7 +2450,7 @@ static int iommu_mem_notifier(struct notifier_block *nb, unsigned long action,
 		spin_lock(&dma_win_list_lock);
 		list_for_each_entry(window, &dma_win_list, list) {
 			if (window->direct && (arg->start_pfn << PAGE_SHIFT) <
-				ddw_memory_hotplug_max()) {
+				pseries_ddw_max_ram) {
 				ret |= tce_clearrange_multi_pSeriesLP(arg->start_pfn,
 						arg->nr_pages, window->prop);
 			}
@@ -2532,6 +2538,14 @@ void __init iommu_init_early_pSeries(void)
 	register_memory_notifier(&iommu_mem_nb);
 
 	set_pci_dma_ops(&dma_iommu_ops);
+
+	/* During init determine the max memory an LPAR can have and set it. This
+	 * will be used for pre-mapping RAM in DDW. memblock_end_of_DRAM() can
+	 * change during the running of LPAR - daxctl can add pmemory as
+	 * "system-ram". This memory range should not be pre-mapped in DDW since
+	 * the address of pmemory can be much higher than the DDW size.
+	 */
+	pseries_ddw_max_ram = ddw_memory_hotplug_max();
 }
 
 static int __init disable_multitce(char *str)