[PATCH kernel] powerpc/pseries/iommu: Print ibm,query-pe-dma-windows parameters

[PATCH kernel] powerpc/pseries/iommu: Print ibm,query-pe-dma-windows parameters

[Alexey Kardashevskiy]

PowerVM has a stricter policy about allocating TCEs for LPARs and
often there is not enough TCEs for 1:1 mapping, this adds the supported
numbers into dev_info() to help analyzing bugreports.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---

A PowerVM admin can enable "enlarged IO capacity" for a passed
though PCI device but there is no way from inside LPAR to know if that
worked or how many more TCEs became available.

---
 arch/powerpc/platforms/pseries/iommu.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 7639e7355df2..84edc8d730e1 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1022,9 +1022,6 @@ static int query_ddw(struct pci_dev *dev, const u32 *ddw_avail,
 
 	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);
 
 	switch (out_sz) {
 	case 5:
@@ -1042,6 +1039,11 @@ static int query_ddw(struct pci_dev *dev, const u32 *ddw_avail,
 		break;
 	}
 
+	dev_info(&dev->dev, "ibm,query-pe-dma-windows(%x) %x %x %x returned %d, lb=%llx ps=%x wn=%d\n",
+		 ddw_avail[DDW_QUERY_PE_DMA_WIN], cfg_addr, BUID_HI(buid),
+		 BUID_LO(buid), ret, query->largest_available_block,
+		 query->page_size, query->windows_available);
+
 	return ret;
 }
 
-- 
2.30.2

Re: [PATCH kernel] powerpc/pseries/iommu: Print ibm,query-pe-dma-windows parameters

[Michael Ellerman]

On Wed, 1 Jun 2022 14:01:17 +1000, Alexey Kardashevskiy wrote:
> PowerVM has a stricter policy about allocating TCEs for LPARs and
> often there is not enough TCEs for 1:1 mapping, this adds the supported
> numbers into dev_info() to help analyzing bugreports.
> 
> 

Applied to powerpc/next.

[1/1] powerpc/pseries/iommu: Print ibm,query-pe-dma-windows parameters
      https://git.kernel.org/powerpc/c/a28a2eff1e0ff684f51b3dc6371ff5b651a063d4

cheers