Fix lockdown.

Signed-off-by: Christopher Kenna <cjk@cs.unc.edu>

1 files changed, 80 insertions, 12 deletions

diff --git a/litmus/lockdown.c b/litmus/lockdown.c
index b8c25006bc4f..1a38be23674f 100644
--- a/litmus/lockdown.c
+++ b/litmus/lockdown.c
@@ -3,6 +3,7 @@
 #include <linux/kernel.h>
 #include <linux/io.h>
 #include <linux/spinlock.h>
+#include <linux/time.h>
 
 #include <linux/smp.h> /* smp_call_func */
 #include <asm/processor.h> /* cpu relax */
@@ -54,7 +55,6 @@ static u32 read_in_page(u32 lock_val,
 "       .align 5\n"
 "       str     %[lockval], [%[cachereg]]\n"
 "1:     ldr     %[tmp], [%[addr]], #32          @ 32 bytes = 1 cache line\n"
-"       add     %[val], %[val], %[tmp]\n"
 "       cmp     %[addr], %[end]\n"
 "       bne     1b\n"
 "       str     %[unlockval], [%[cachereg]]\n"
@@ -72,6 +72,16 @@ static u32 read_in_page(u32 lock_val,
 }
 
 /*
+ * Ensure that this page is not in the L1 or L2 cache.
+ * Since the L1 cache is VIPT and the L2 cache is PIPT, we can use either the
+ * kernel or user vaddr.
+ */
+void color_flush_page(void *vaddr)
+{
+        v7_flush_kern_dcache_area(vaddr, PAGE_SIZE);
+}
+
+/*
  * unlocked[i] : allocation can occur in way i
  *
  * 0 = allocation can occur in the corresponding way
@@ -157,15 +167,79 @@ static void test_lockdown(void *ignore)
         printk("End lockdown test.\n");
 }
 
+static long update_timeval(struct timespec lhs, struct timespec rhs)
+{
+        long val;
+        struct timespec ts;
+
+        ts = timespec_sub(rhs, lhs);
+        val = ts.tv_sec*NSEC_PER_SEC + ts.tv_nsec;
+
+        return val;
+}
+
+#define TRIALS 1000
+static int perf_test(void) {
+        struct timespec before, after;
+        struct page *page;
+        void *vaddr;
+        u32 *data;
+        long time;
+        int i;
+
+        page = alloc_page(GFP_HIGHUSER | __GFP_MOVABLE);
+        if (!page) {
+                printk(KERN_WARNING "No memory\n");
+                return -ENOMEM;
+        }
+
+        vaddr = phys_to_virt(page_to_phys(page));
+        data = (u32*) vaddr;
+
+        getnstimeofday(&before);
+        barrier();
+        for (i = 0; i < TRIALS; i++) {
+                color_flush_page(vaddr);
+        }
+        barrier();
+        getnstimeofday(&after);
+        time = update_timeval(before, after);
+        printk("Average for flushes without re-reading: %ld\n", time / TRIALS);
+
+        read_in_page(unlocked[0], UNLOCK_ALL, vaddr, vaddr + PAGE_SIZE);
+        barrier();
+        getnstimeofday(&before);
+        barrier();
+        for (i = 0; i < TRIALS; i++) {
+                read_in_page(unlocked[0], UNLOCK_ALL, vaddr, vaddr + PAGE_SIZE);
+        }
+        barrier();
+        getnstimeofday(&after);
+        time = update_timeval(before, after);
+        printk("Average for read in (no flush): %ld\n", time / TRIALS);
+
+        getnstimeofday(&before);
+        barrier();
+        for (i = 0; i < TRIALS; i++) {
+                read_in_page(unlocked[0], UNLOCK_ALL, vaddr, vaddr + PAGE_SIZE);
+                color_flush_page(vaddr);
+        }
+        barrier();
+        getnstimeofday(&after);
+        time = update_timeval(before, after);
+        printk("Average for read in and then flush: %ld\n", time / TRIALS);
+
+        free_page(page);
+        return 0;
+}
+
 #define LOCKREG_TEST_VAL        0x00000002
-#define PREFETCH_SUM_TEST_VAL   65024 /* = 0 + 8 + ... + 127 */
 int litmus_test_prefetch(struct ctl_table *table, int write, void __user *buffer,
                 size_t *lenp, loff_t *ppos)
 {
         struct page *page;
         void *vaddr;
         u32 *data;
-        u32 sum = 0;
         int i;
         
         if (!write)
@@ -183,14 +257,6 @@ int litmus_test_prefetch(struct ctl_table *table, int write, void __user *buffer
         for (i = 0; i < PAGE_SIZE / sizeof(u32); i++)
                 data[i] = i;
 
-        sum = read_in_page(UNLOCK_ALL, LOCKREG_TEST_VAL, vaddr, vaddr + PAGE_SIZE);
-        if (PREFETCH_SUM_TEST_VAL != sum) {
-                printk("%s: Expected sum %u but got %u!\n", __FUNCTION__,
-                                PREFETCH_SUM_TEST_VAL, sum);
-        } else {
-                printk("%s: Prefetch test passed.\n", __FUNCTION__);
-        }
-
         if (LOCKREG_TEST_VAL != readl_relaxed(lockreg_d)) {
                 printk("%s: Expected lockreg value 0x%8x but got 0x%8x!\n",
                                 __FUNCTION__, LOCKREG_TEST_VAL,
@@ -202,7 +268,9 @@ int litmus_test_prefetch(struct ctl_table *table, int write, void __user *buffer
 
         writel_relaxed(UNLOCK_ALL, ld_d_reg(i));
 
-        free_page(page_to_pfn(page));
+        free_page(page);
+
+        perf_test();
 
         return 0;
 }