Thread (11 messages) flat view 11 messages, 5 authors, 2017-08-14

Re: [PATCH] powerpc/mm: Invalidate partition table cache on host proc tbl base update

From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2017-08-09 10:30:14
Subsystem: linux for powerpc (32-bit and 64-bit), the rest · Maintainers: Madhavan Srinivasan, Linus Torvalds

Suraj Jitindar Singh [off-list ref] writes:
quoted hunk ↗ jump to hunk
The host process table base is stored in the partition table by calling
the function native_register_process_table(). Currently this just sets
the entry in memory and is missing a proceeding cache invalidation
instruction. Any update to the partition table should be followed by a
cache invalidation instruction specifying invalidation of the caching of
any partition table entries (RIC = 2, PRS = 0).

We already have a function to update the partition table with the
required cache invalidation instructions - mmu_partition_table_set_entry().
Update the native_register_process_table() function to call
mmu_partition_table_set_entry(), this ensures all appropriate
invalidation will be performed.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
---
 arch/powerpc/mm/pgtable-radix.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 671a45d..1d5178f 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -33,7 +33,8 @@ static int native_register_process_table(unsigned long base, unsigned long pg_sz
 {
 	unsigned long patb1 = base | table_size | PATB_GR;
 
-	partition_tb->patb1 = cpu_to_be64(patb1);
+	mmu_partition_table_set_entry(0, be64_to_cpu(partition_tb->patb0),
+				      patb1);
This is really a bit gross.

Can we agree on whether partition_tb is an array or not?

How about ...

cheers
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index c1185c8ecb22..5d8be076f8e5 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -28,9 +28,13 @@
 static int native_register_process_table(unsigned long base, unsigned long pg_sz,
                                         unsigned long table_size)
 {
-       unsigned long patb1 = base | table_size | PATB_GR;
+       unsigned long patb0, patb1;
+
+       patb0 = be64_to_cpu(partition_tb[0].patb0);
+       patb1 = base | table_size | PATB_GR;
+
+       mmu_partition_table_set_entry(0, patb0, patb1);
 
-       partition_tb->patb1 = cpu_to_be64(patb1);
        return 0;
 }
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