[PATCH v2 2/6] powerpc/pseries/iommu: Update call to ibm, query-pe-dma-windows

[Leonardo Bras <leobras.c@gmail.com>]

From LoPAR level 2.8, "ibm,ddw-extensions" index 3 can make the number of
outputs from "ibm,query-pe-dma-windows" go from 5 to 6.

This change of output size is meant to expand the address size of
largest_available_block PE TCE from 32-bit to 64-bit, which ends up
shifting page_size and migration_capable.

This ends up requiring the update of
ddw_query_response->largest_available_block from u32 to u64, and manually
assigning the values from the buffer into this struct, according to
output size.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
---
 arch/powerpc/platforms/pseries/iommu.c | 57 +++++++++++++++++++++-----
 1 file changed, 47 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 68d2aa9c71a8..558e5441c355 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -44,6 +44,10 @@
 #define DDW_REMOVE_PE_DMA_WIN	2
 #define DDW_APPLICABLE_SIZE	3
 
+#define DDW_EXT_SIZE		0
+#define DDW_EXT_RESET_DMA_WIN	1
+#define DDW_EXT_QUERY_OUT_SIZE	2
+
 static struct iommu_table_group *iommu_pseries_alloc_group(int node)
 {
 	struct iommu_table_group *table_group;
@@ -339,7 +343,7 @@ struct direct_window {
 /* Dynamic DMA Window support */
 struct ddw_query_response {
 	u32 windows_available;
-	u32 largest_available_block;
+	u64 largest_available_block;
 	u32 page_size;
 	u32 migration_capable;
 };
@@ -875,13 +879,29 @@ static int find_existing_ddw_windows(void)
 machine_arch_initcall(pseries, find_existing_ddw_windows);
 
 static int query_ddw(struct pci_dev *dev, const u32 *ddw_avail,
-			struct ddw_query_response *query)
+		     struct ddw_query_response *query,
+		     struct device_node *parent)
 {
 	struct device_node *dn;
 	struct pci_dn *pdn;
-	u32 cfg_addr;
+	u32 cfg_addr, query_out[5], ddw_ext[DDW_EXT_QUERY_OUT_SIZE + 1];
 	u64 buid;
-	int ret;
+	int ret, out_sz;
+
+	/*
+	 * From LoPAR level 2.8, "ibm,ddw-extensions" index 3 can rule how many
+	 * output parameters ibm,query-pe-dma-windows will have, ranging from
+	 * 5 to 6.
+	 */
+
+	ret = of_property_read_u32_array(parent, "ibm,ddw-extensions",
+					 &ddw_ext[0],
+					 DDW_EXT_QUERY_OUT_SIZE + 1);
+	if (ret && ddw_ext[DDW_EXT_SIZE] > 1 &&
+	    ddw_ext[DDW_EXT_QUERY_OUT_SIZE] == 1)
+		out_sz = 6;
+	else
+		out_sz = 5;
 
 	/*
 	 * Get the config address and phb buid of the PE window.
@@ -894,11 +914,28 @@ static int query_ddw(struct pci_dev *dev, const u32 *ddw_avail,
 	buid = pdn->phb->buid;
 	cfg_addr = ((pdn->busno << 16) | (pdn->devfn << 8));
 
-	ret = rtas_call(ddw_avail[DDW_QUERY_PE_DMA_WIN], 3, 5, (u32 *)query,
+	ret = rtas_call(ddw_avail[DDW_QUERY_PE_DMA_WIN], 3, out_sz, query_out,
 			cfg_addr, BUID_HI(buid), BUID_LO(buid));
-	dev_info(&dev->dev, "ibm,query-pe-dma-windows(%x) %x %x %x"
-		" returned %d\n", ddw_avail[DDW_QUERY_PE_DMA_WIN], cfg_addr,
-		 BUID_HI(buid), BUID_LO(buid), ret);
+	dev_info(&dev->dev, "ibm,query-pe-dma-windows(%x) %x %x %x returned %d\n",
+		 ddw_avail[DDW_QUERY_PE_DMA_WIN], cfg_addr, BUID_HI(buid),
+		 BUID_LO(buid), ret);
+
+	switch (out_sz) {
+	case 5:
+		query->windows_available = query_out[0];
+		query->largest_available_block = query_out[1];
+		query->page_size = query_out[2];
+		query->migration_capable = query_out[3];
+		break;
+	case 6:
+		query->windows_available = query_out[0];
+		query->largest_available_block = ((u64)query_out[1] << 32) |
+						 query_out[2];
+		query->page_size = query_out[3];
+		query->migration_capable = query_out[4];
+		break;
+	}
+
 	return ret;
 }
 
@@ -1046,7 +1083,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
 	 * of page sizes: supported and supported for migrate-dma.
 	 */
 	dn = pci_device_to_OF_node(dev);
-	ret = query_ddw(dev, ddw_avail, &query);
+	ret = query_ddw(dev, ddw_avail, &query, pdn);
 	if (ret != 0)
 		goto out_failed;
 
@@ -1074,7 +1111,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
 	/* 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 %u "
+		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;
-- 
2.25.4