MIPS: print MAAR configuration during boot

Verifying that the MAAR configuration is as expected is useful when
debugging the performance of a system. Print out the memory regions
configured via MAAR along with their attributes.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11238/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 074ac5459026..023c164b9eb6 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -291,6 +291,7 @@ unsigned __weak platform_maar_init(unsigned num_pairs)
 static void maar_init(void)
 {
         unsigned num_maars, used, i;
+        phys_addr_t lower, upper, attr;
 
         if (!cpu_has_maar)
                 return;
@@ -313,6 +314,34 @@ static void maar_init(void)
                 write_c0_maar(0);
                 back_to_back_c0_hazard();
         }
+
+        pr_info("MAAR configuration:\n");
+        for (i = 0; i < num_maars; i += 2) {
+                write_c0_maari(i);
+                back_to_back_c0_hazard();
+                upper = read_c0_maar();
+
+                write_c0_maari(i + 1);
+                back_to_back_c0_hazard();
+                lower = read_c0_maar();
+
+                attr = lower & upper;
+                lower = (lower & MIPS_MAAR_ADDR) << 4;
+                upper = ((upper & MIPS_MAAR_ADDR) << 4) | 0xffff;
+
+                pr_info("  [%d]: ", i / 2);
+                if (!(attr & MIPS_MAAR_V)) {
+                        pr_cont("disabled\n");
+                        continue;
+                }
+
+                pr_cont("%pa-%pa", &lower, &upper);
+
+                if (attr & MIPS_MAAR_S)
+                        pr_cont(" speculate");
+
+                pr_cont("\n");
+        }
 }
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES