[PATCH kernel] powerpc/powernv/ioda2: Fix calculation for memory allocated for TCE table

* [PATCH kernel] powerpc/powernv/ioda2: Fix calculation for memory allocated for TCE table
@ 2015-07-20 10:45 Alexey Kardashevskiy
  2015-07-21  5:11 ` David Gibson
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Alexey Kardashevskiy @ 2015-07-20 10:45 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Alexey Kardashevskiy, David Gibson, Michael Ellerman,
	Paul Mackerras, linux-kernel

The existing code stores the amount of memory allocated for a TCE table.
At the moment it uses @offset which is a virtual offset in the TCE table
which is only correct for a one level tables and it does not include
memory allocated for intermediate levels. When multilevel TCE table is
requested, WARN_ON in tce_iommu_create_table() prints a warning.

This adds an additional counter to pnv_pci_ioda2_table_do_alloc_pages()
to count actually allocated memory.

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

I was sure I sent it already but could not find it anywhere so reposting.
Sorry if it is a duplicate.


---
 arch/powerpc/platforms/powernv/pci-ioda.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 5738d31..85cbc96 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -2220,7 +2220,7 @@ static void pnv_pci_ioda_setup_opal_tce_kill(struct pnv_phb *phb)
 
 static __be64 *pnv_pci_ioda2_table_do_alloc_pages(int nid, unsigned shift,
 		unsigned levels, unsigned long limit,
-		unsigned long *current_offset)
+		unsigned long *current_offset, unsigned long *total_allocated)
 {
 	struct page *tce_mem = NULL;
 	__be64 *addr, *tmp;
@@ -2236,6 +2236,7 @@ static __be64 *pnv_pci_ioda2_table_do_alloc_pages(int nid, unsigned shift,
 	}
 	addr = page_address(tce_mem);
 	memset(addr, 0, allocated);
+	*total_allocated += allocated;
 
 	--levels;
 	if (!levels) {
@@ -2245,7 +2246,7 @@ static __be64 *pnv_pci_ioda2_table_do_alloc_pages(int nid, unsigned shift,
 
 	for (i = 0; i < entries; ++i) {
 		tmp = pnv_pci_ioda2_table_do_alloc_pages(nid, shift,
-				levels, limit, current_offset);
+				levels, limit, current_offset, total_allocated);
 		if (!tmp)
 			break;
 
@@ -2267,7 +2268,7 @@ static long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
 		struct iommu_table *tbl)
 {
 	void *addr;
-	unsigned long offset = 0, level_shift;
+	unsigned long offset = 0, level_shift, total_allocated = 0;
 	const unsigned window_shift = ilog2(window_size);
 	unsigned entries_shift = window_shift - page_shift;
 	unsigned table_shift = max_t(unsigned, entries_shift + 3, PAGE_SHIFT);
@@ -2286,7 +2287,7 @@ static long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
 
 	/* Allocate TCE table */
 	addr = pnv_pci_ioda2_table_do_alloc_pages(nid, level_shift,
-			levels, tce_table_size, &offset);
+			levels, tce_table_size, &offset, &total_allocated);
 
 	/* addr==NULL means that the first level allocation failed */
 	if (!addr)
@@ -2308,7 +2309,7 @@ static long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
 			page_shift);
 	tbl->it_level_size = 1ULL << (level_shift - 3);
 	tbl->it_indirect_levels = levels - 1;
-	tbl->it_allocated_size = offset;
+	tbl->it_allocated_size = total_allocated;
 
 	pr_devel("Created TCE table: ws=%08llx ts=%lx @%08llx\n",
 			window_size, tce_table_size, bus_offset);
-- 
2.4.0.rc3.8.gfb3e7d5


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