[PATCH v2 5/6] powerpc/pseries/iommu: Make use of DDW even if it does not map the partition
From: Leonardo Bras <hidden>
Date: 2020-06-24 06:24:47
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
As of today, if a DDW is created and can't map the whole partition, it's removed and the default DMA window "ibm,dma-window" is used instead. Usually this DDW is bigger than the default DMA window, so it would be better to make use of it instead. Signed-off-by: Leonardo Bras <redacted> --- arch/powerpc/platforms/pseries/iommu.c | 28 +++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 4fcf00016fb1..2d217cda4075 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c@@ -685,7 +685,7 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus) struct iommu_table *tbl; struct device_node *dn, *pdn; struct pci_dn *ppci; - const __be32 *dma_window = NULL; + const __be32 *dma_window = NULL, *alt_dma_window = NULL; dn = pci_bus_to_OF_node(bus);
@@ -699,8 +699,13 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus) break; } + /* If there is a DDW available, use it instead */ + alt_dma_window = of_get_property(pdn, DIRECT64_PROPNAME, NULL); + if (alt_dma_window) + dma_window = alt_dma_window; + if (dma_window == NULL) { - pr_debug(" no ibm,dma-window property !\n"); + pr_debug(" no ibm,dma-window nor linux,direct64-ddr-window-info property !\n"); return; }
@@ -1166,16 +1171,19 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn) query.page_size); goto out_failed; } + /* verify the window * number of ptes will map the partition */ - /* check largest block * page size > max memory hotplug addr */ max_addr = ddw_memory_hotplug_max(); if (query.largest_available_block < (max_addr >> page_shift)) { - dev_dbg(&dev->dev, "can't map partition max 0x%llx with %llu " - "%llu-sized pages\n", max_addr, query.largest_available_block, - 1ULL << page_shift); - goto out_failed; + dev_dbg(&dev->dev, "can't map partition max 0x%llx with %llu %llu-sized pages\n", + max_addr, query.largest_available_block, + 1ULL << page_shift); + + len = order_base_2(query.largest_available_block << page_shift); + } else { + len = order_base_2(max_addr); } - len = order_base_2(max_addr); + win64 = kzalloc(sizeof(struct property), GFP_KERNEL); if (!win64) { dev_info(&dev->dev,
@@ -1229,7 +1237,9 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn) list_add(&window->list, &direct_window_list); spin_unlock(&direct_window_list_lock); - dma_addr = be64_to_cpu(ddwprop->dma_base); + /* Only returns the dma_addr if DDW maps the whole partition */ + if (len == order_base_2(max_addr)) + dma_addr = be64_to_cpu(ddwprop->dma_base); goto out_unlock; out_free_window:
--
2.25.4