1 files changed, 206 insertions, 0 deletions

diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 174c1eba9ac8..48e1ed89052d 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -13,6 +13,8 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/init.h>
 #include <asm/cputable.h>
 #include <asm/code-patching.h>
 
@@ -107,3 +109,207 @@ void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
                 }
         }
 }
+
+#ifdef CONFIG_FTR_FIXUP_SELFTEST
+
+#define check(x)        \
+        if (!(x)) printk("feature-fixups: test failed at line %d\n", __LINE__);
+
+/* This must be after the text it fixes up, vmlinux.lds.S enforces that atm */
+static struct fixup_entry fixup;
+
+static long calc_offset(struct fixup_entry *entry, unsigned int *p)
+{
+        return (unsigned long)p - (unsigned long)entry;
+}
+
+void test_basic_patching(void)
+{
+        extern unsigned int ftr_fixup_test1;
+        extern unsigned int end_ftr_fixup_test1;
+        extern unsigned int ftr_fixup_test1_orig;
+        extern unsigned int ftr_fixup_test1_expected;
+        int size = &end_ftr_fixup_test1 - &ftr_fixup_test1;
+
+        fixup.value = fixup.mask = 8;
+        fixup.start_off = calc_offset(&fixup, &ftr_fixup_test1 + 1);
+        fixup.end_off = calc_offset(&fixup, &ftr_fixup_test1 + 2);
+        fixup.alt_start_off = fixup.alt_end_off = 0;
+
+        /* Sanity check */
+        check(memcmp(&ftr_fixup_test1, &ftr_fixup_test1_orig, size) == 0);
+
+        /* Check we don't patch if the value matches */
+        patch_feature_section(8, &fixup);
+        check(memcmp(&ftr_fixup_test1, &ftr_fixup_test1_orig, size) == 0);
+
+        /* Check we do patch if the value doesn't match */
+        patch_feature_section(0, &fixup);
+        check(memcmp(&ftr_fixup_test1, &ftr_fixup_test1_expected, size) == 0);
+
+        /* Check we do patch if the mask doesn't match */
+        memcpy(&ftr_fixup_test1, &ftr_fixup_test1_orig, size);
+        check(memcmp(&ftr_fixup_test1, &ftr_fixup_test1_orig, size) == 0);
+        patch_feature_section(~8, &fixup);
+        check(memcmp(&ftr_fixup_test1, &ftr_fixup_test1_expected, size) == 0);
+}
+
+static void test_alternative_patching(void)
+{
+        extern unsigned int ftr_fixup_test2;
+        extern unsigned int end_ftr_fixup_test2;
+        extern unsigned int ftr_fixup_test2_orig;
+        extern unsigned int ftr_fixup_test2_alt;
+        extern unsigned int ftr_fixup_test2_expected;
+        int size = &end_ftr_fixup_test2 - &ftr_fixup_test2;
+
+        fixup.value = fixup.mask = 0xF;
+        fixup.start_off = calc_offset(&fixup, &ftr_fixup_test2 + 1);
+        fixup.end_off = calc_offset(&fixup, &ftr_fixup_test2 + 2);
+        fixup.alt_start_off = calc_offset(&fixup, &ftr_fixup_test2_alt);
+        fixup.alt_end_off = calc_offset(&fixup, &ftr_fixup_test2_alt + 1);
+
+        /* Sanity check */
+        check(memcmp(&ftr_fixup_test2, &ftr_fixup_test2_orig, size) == 0);
+
+        /* Check we don't patch if the value matches */
+        patch_feature_section(0xF, &fixup);
+        check(memcmp(&ftr_fixup_test2, &ftr_fixup_test2_orig, size) == 0);
+
+        /* Check we do patch if the value doesn't match */
+        patch_feature_section(0, &fixup);
+        check(memcmp(&ftr_fixup_test2, &ftr_fixup_test2_expected, size) == 0);
+
+        /* Check we do patch if the mask doesn't match */
+        memcpy(&ftr_fixup_test2, &ftr_fixup_test2_orig, size);
+        check(memcmp(&ftr_fixup_test2, &ftr_fixup_test2_orig, size) == 0);
+        patch_feature_section(~0xF, &fixup);
+        check(memcmp(&ftr_fixup_test2, &ftr_fixup_test2_expected, size) == 0);
+}
+
+static void test_alternative_case_too_big(void)
+{
+        extern unsigned int ftr_fixup_test3;
+        extern unsigned int end_ftr_fixup_test3;
+        extern unsigned int ftr_fixup_test3_orig;
+        extern unsigned int ftr_fixup_test3_alt;
+        int size = &end_ftr_fixup_test3 - &ftr_fixup_test3;
+
+        fixup.value = fixup.mask = 0xC;
+        fixup.start_off = calc_offset(&fixup, &ftr_fixup_test3 + 1);
+        fixup.end_off = calc_offset(&fixup, &ftr_fixup_test3 + 2);
+        fixup.alt_start_off = calc_offset(&fixup, &ftr_fixup_test3_alt);
+        fixup.alt_end_off = calc_offset(&fixup, &ftr_fixup_test3_alt + 2);
+
+        /* Sanity check */
+        check(memcmp(&ftr_fixup_test3, &ftr_fixup_test3_orig, size) == 0);
+
+        /* Expect nothing to be patched, and the error returned to us */
+        check(patch_feature_section(0xF, &fixup) == 1);
+        check(memcmp(&ftr_fixup_test3, &ftr_fixup_test3_orig, size) == 0);
+        check(patch_feature_section(0, &fixup) == 1);
+        check(memcmp(&ftr_fixup_test3, &ftr_fixup_test3_orig, size) == 0);
+        check(patch_feature_section(~0xF, &fixup) == 1);
+        check(memcmp(&ftr_fixup_test3, &ftr_fixup_test3_orig, size) == 0);
+}
+
+static void test_alternative_case_too_small(void)
+{
+        extern unsigned int ftr_fixup_test4;
+        extern unsigned int end_ftr_fixup_test4;
+        extern unsigned int ftr_fixup_test4_orig;
+        extern unsigned int ftr_fixup_test4_alt;
+        extern unsigned int ftr_fixup_test4_expected;
+        int size = &end_ftr_fixup_test4 - &ftr_fixup_test4;
+        unsigned long flag;
+
+        /* Check a high-bit flag */
+        flag = 1UL << ((sizeof(unsigned long) - 1) * 8);
+        fixup.value = fixup.mask = flag;
+        fixup.start_off = calc_offset(&fixup, &ftr_fixup_test4 + 1);
+        fixup.end_off = calc_offset(&fixup, &ftr_fixup_test4 + 5);
+        fixup.alt_start_off = calc_offset(&fixup, &ftr_fixup_test4_alt);
+        fixup.alt_end_off = calc_offset(&fixup, &ftr_fixup_test4_alt + 2);
+
+        /* Sanity check */
+        check(memcmp(&ftr_fixup_test4, &ftr_fixup_test4_orig, size) == 0);
+
+        /* Check we don't patch if the value matches */
+        patch_feature_section(flag, &fixup);
+        check(memcmp(&ftr_fixup_test4, &ftr_fixup_test4_orig, size) == 0);
+
+        /* Check we do patch if the value doesn't match */
+        patch_feature_section(0, &fixup);
+        check(memcmp(&ftr_fixup_test4, &ftr_fixup_test4_expected, size) == 0);
+
+        /* Check we do patch if the mask doesn't match */
+        memcpy(&ftr_fixup_test4, &ftr_fixup_test4_orig, size);
+        check(memcmp(&ftr_fixup_test4, &ftr_fixup_test4_orig, size) == 0);
+        patch_feature_section(~flag, &fixup);
+        check(memcmp(&ftr_fixup_test4, &ftr_fixup_test4_expected, size) == 0);
+}
+
+static void test_alternative_case_with_branch(void)
+{
+        extern unsigned int ftr_fixup_test5;
+        extern unsigned int end_ftr_fixup_test5;
+        extern unsigned int ftr_fixup_test5_expected;
+        int size = &end_ftr_fixup_test5 - &ftr_fixup_test5;
+
+        check(memcmp(&ftr_fixup_test5, &ftr_fixup_test5_expected, size) == 0);
+}
+
+static void test_alternative_case_with_external_branch(void)
+{
+        extern unsigned int ftr_fixup_test6;
+        extern unsigned int end_ftr_fixup_test6;
+        extern unsigned int ftr_fixup_test6_expected;
+        int size = &end_ftr_fixup_test6 - &ftr_fixup_test6;
+
+        check(memcmp(&ftr_fixup_test6, &ftr_fixup_test6_expected, size) == 0);
+}
+
+static void test_cpu_macros(void)
+{
+        extern void ftr_fixup_test_FTR_macros;
+        extern void ftr_fixup_test_FTR_macros_expected;
+        unsigned long size = &ftr_fixup_test_FTR_macros_expected -
+                             &ftr_fixup_test_FTR_macros;
+
+        /* The fixups have already been done for us during boot */
+        check(memcmp(&ftr_fixup_test_FTR_macros,
+                     &ftr_fixup_test_FTR_macros_expected, size) == 0);
+}
+
+static void test_fw_macros(void)
+{
+#ifdef CONFIG_PPC64
+        extern void ftr_fixup_test_FW_FTR_macros;
+        extern void ftr_fixup_test_FW_FTR_macros_expected;
+        unsigned long size = &ftr_fixup_test_FW_FTR_macros_expected -
+                             &ftr_fixup_test_FW_FTR_macros;
+
+        /* The fixups have already been done for us during boot */
+        check(memcmp(&ftr_fixup_test_FW_FTR_macros,
+                     &ftr_fixup_test_FW_FTR_macros_expected, size) == 0);
+#endif
+}
+
+static int __init test_feature_fixups(void)
+{
+        printk(KERN_DEBUG "Running feature fixup self-tests ...\n");
+
+        test_basic_patching();
+        test_alternative_patching();
+        test_alternative_case_too_big();
+        test_alternative_case_too_small();
+        test_alternative_case_with_branch();
+        test_alternative_case_with_external_branch();
+        test_cpu_macros();
+        test_fw_macros();
+
+        return 0;
+}
+late_initcall(test_feature_fixups);
+
+#endif /* CONFIG_FTR_FIXUP_SELFTEST */