*/
#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/init.h>
#include <asm/cputable.h>
#include <asm/code-patching.h>
long alt_end_off;
};
-static void patch_feature_section(unsigned long value, struct fixup_entry *fcur)
+static unsigned int *calc_addr(struct fixup_entry *fcur, long offset)
{
- unsigned int *pstart, *pend, *p;
+ /*
+ * We store the offset to the code as a negative offset from
+ * the start of the alt_entry, to support the VDSO. This
+ * routine converts that back into an actual address.
+ */
+ return (unsigned int *)((unsigned long)fcur + offset);
+}
+
+static int patch_alt_instruction(unsigned int *src, unsigned int *dest,
+ unsigned int *alt_start, unsigned int *alt_end)
+{
+ unsigned int instr;
+
+ instr = *src;
+
+ if (instr_is_relative_branch(*src)) {
+ unsigned int *target = (unsigned int *)branch_target(src);
+
+ /* Branch within the section doesn't need translating */
+ if (target < alt_start || target >= alt_end) {
+ instr = translate_branch(dest, src);
+ if (!instr)
+ return 1;
+ }
+ }
+
+ patch_instruction(dest, instr);
+
+ return 0;
+}
+
+static int patch_feature_section(unsigned long value, struct fixup_entry *fcur)
+{
+ unsigned int *start, *end, *alt_start, *alt_end, *src, *dest;
+
+ start = calc_addr(fcur, fcur->start_off);
+ end = calc_addr(fcur, fcur->end_off);
+ alt_start = calc_addr(fcur, fcur->alt_start_off);
+ alt_end = calc_addr(fcur, fcur->alt_end_off);
+
+ if ((alt_end - alt_start) > (end - start))
+ return 1;
if ((value & fcur->mask) == fcur->value)
- return;
+ return 0;
- pstart = ((unsigned int *)fcur) + (fcur->start_off / 4);
- pend = ((unsigned int *)fcur) + (fcur->end_off / 4);
+ src = alt_start;
+ dest = start;
- for (p = pstart; p < pend; p++) {
- *p = PPC_NOP_INSTR;
- asm volatile ("dcbst 0, %0" : : "r" (p));
+ for (; src < alt_end; src++, dest++) {
+ if (patch_alt_instruction(src, dest, alt_start, alt_end))
+ return 1;
}
- asm volatile ("sync" : : : "memory");
- for (p = pstart; p < pend; p++)
- asm volatile ("icbi 0,%0" : : "r" (p));
- asm volatile ("sync; isync" : : : "memory");
+
+ for (; dest < end; dest++)
+ patch_instruction(dest, PPC_INST_NOP);
+
+ return 0;
}
void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
fcur = fixup_start;
fend = fixup_end;
- for (; fcur < fend; fcur++)
- patch_feature_section(value, fcur);
+ for (; fcur < fend; fcur++) {
+ if (patch_feature_section(value, fcur)) {
+ WARN_ON(1);
+ printk("Unable to patch feature section at %p - %p" \
+ " with %p - %p\n",
+ calc_addr(fcur, fcur->start_off),
+ calc_addr(fcur, fcur->end_off),
+ calc_addr(fcur, fcur->alt_start_off),
+ calc_addr(fcur, fcur->alt_end_off));
+ }
+ }
+}
+
+void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
+{
+ unsigned int *start, *end, *dest;
+
+ if (!(value & CPU_FTR_LWSYNC))
+ return ;
+
+ start = fixup_start;
+ end = fixup_end;
+
+ for (; start < end; start++) {
+ dest = (void *)start + *start;
+ patch_instruction(dest, PPC_INST_LWSYNC);
+ }
+}
+
+#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 void test_lwsync_macros(void)
+{
+ extern void lwsync_fixup_test;
+ extern void end_lwsync_fixup_test;
+ extern void lwsync_fixup_test_expected_LWSYNC;
+ extern void lwsync_fixup_test_expected_SYNC;
+ unsigned long size = &end_lwsync_fixup_test -
+ &lwsync_fixup_test;
+
+ /* The fixups have already been done for us during boot */
+ if (cur_cpu_spec->cpu_features & CPU_FTR_LWSYNC) {
+ check(memcmp(&lwsync_fixup_test,
+ &lwsync_fixup_test_expected_LWSYNC, size) == 0);
+ } else {
+ check(memcmp(&lwsync_fixup_test,
+ &lwsync_fixup_test_expected_SYNC, size) == 0);
+ }
+}
+
+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();
+ test_lwsync_macros();
+
+ return 0;
+}
+late_initcall(test_feature_fixups);
+
+#endif /* CONFIG_FTR_FIXUP_SELFTEST */
projects / ~andy / linux / blobdiff