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

From: Leonardo Bras
Date: Wed Jun 24 2020 - 02:24:39 EST


>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@xxxxxxxxx>
---
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