Signed-off-by: Laurent Vivier <lvivier@xxxxxxxxxx>
---
v2:
use "mtxer" instead of "mtspr"
Fix comments in lswx asm()
add "memory" in clobber list
powerpc/emulator.c | 140 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 140 insertions(+)
diff --git a/powerpc/emulator.c b/powerpc/emulator.c
index d97090c..8d0dde2 100644
--- a/powerpc/emulator.c
+++ b/powerpc/emulator.c
@@ -56,6 +56,145 @@ static void test_64bit(void)
report_prefix_pop();
}
+/*
+ * lswx: Load String Word Indexed X-form
+ *
+ * lswx RT,RA,RB
+ *
+ * EA = (RA|0) + RB
+ * n = XER
+ *
+ * Load n bytes from address EA into (n / 4) consecutive registers,
+ * throught RT -> RT + (n / 4) - 1.
+ * - Data are loaded into 4 low order bytes of registers (Word).
+ * - The unfilled bytes are set to 0.
+ * - The sequence of registers wraps around to GPR0.
+ * - if n == 0, content of RT is undefined
+ * - RT <= RA or RB < RT + (n + 4) is invalid or result is undefined
+ * - RT == RA == 0 is invalid
+ *
+ */
+
+static void test_lswx(void)
+{
+ int i;
+ char addr[128];
+ uint64_t regs[32];
+
+ report_prefix_push("lswx");
+
+ /* fill memory with sequence */
+
+ for (i = 0; i < 128; i++)
+ addr[i] = 1 + i;
+
+ /* check incomplete register filling */
+
+ asm volatile ("mtxer %[len];"
+ "li r12,-1;"
+ "mr r11, r12;"
+ "lswx r11, 0, %[addr];"
+ "std r11, 0*8(%[regs]);"
+ "std r12, 1*8(%[regs]);"
+ ::
+ [len] "r" (3),
+ [addr] "r" (addr),
+ [regs] "r" (regs)
+ :
+ "xer", "r11", "r12", "memory");
+
+ report("partial", regs[0] == 0x01020300 && regs[1] == (uint64_t)-1);
+
+ /* check an old know bug: the number of bytes is used as
+ * the number of registers, so try 32 bytes.
+ */
+
+ asm volatile ("mtxer %[len];"
+ "li r19,-1;"
+ "mr r11, r19; mr r12, r19; mr r13, r19;"
+ "mr r14, r19; mr r15, r19; mr r16, r19;"
+ "mr r17, r19; mr r18, r19;"
+ "lswx r11, 0, %[addr];"
+ "std r11, 0*8(%[regs]);"
+ "std r12, 1*8(%[regs]);"
+ "std r13, 2*8(%[regs]);"
+ "std r14, 3*8(%[regs]);"
+ "std r15, 4*8(%[regs]);"
+ "std r16, 5*8(%[regs]);"
+ "std r17, 6*8(%[regs]);"
+ "std r18, 7*8(%[regs]);"
+ "std r19, 8*8(%[regs]);"
+ ::
+ [len] "r" (32),
+ [addr] "r" (addr),
+ [regs] "r" (regs)
+ :
+ /* as 32 is the number of bytes,
+ * we should modify 32/4 = 8 regs, from r11 to r18
+ * We check r19 is unmodified by filling it with 1s
+ * before the instruction.
+ */
+ "xer", "r11", "r12", "r13", "r14", "r15", "r16", "r17",
+ "r18", "r19", "memory");
+
+ report("length", regs[0] == 0x01020304 && regs[1] == 0x05060708 &&
+ regs[2] == 0x090a0b0c && regs[3] == 0x0d0e0f10 &&
+ regs[4] == 0x11121314 && regs[5] == 0x15161718 &&
+ regs[6] == 0x191a1b1c && regs[7] == 0x1d1e1f20 &&
+ regs[8] == (uint64_t)-1);
+
+ /* check wrap around to r0 */
+
+ asm volatile ("mtxer %[len];"
+ "li r31,-1;"
+ "mr r0, r31;"
+ "lswx r31, 0, %[addr];"
+ "std r31, 0*8(%[regs]);"
+ "std r0, 1*8(%[regs]);"
+ ::
+ [len] "r" (8),
+ [addr] "r" (addr),
+ [regs] "r" (regs)
+ :
+ /* modify two registers from r31, wrap around to r0 */
+ "xer", "r31", "r0", "memory");
+
+ report("wrap around to r0", regs[0] == 0x01020304 &&
+ regs[1] == 0x05060708);
+
+ /* check wrap around to r0 over RB doesn't break RB */
+
+ asm volatile ("mtxer %[len];"
+ /* adding r1 in the clobber list doesn't protect it... */
+ "mr r29,r1;"
+ "li r31,-1;"
+ "mr r1,r31;"
+ "mr r0, %[addr];"
+ "lswx r31, 0, r0;"
+ "std r31, 0*8(%[regs]);"
+ "std r0, 1*8(%[regs]);"
+ "std r1, 2*8(%[regs]);"
+ "mr r1,r29;"
+ ::
+ [len] "r" (12),
+ [addr] "r" (addr),
+ [regs] "r" (regs)
+ :
+ /* three registers from r31, wrap arount to r1,
+ * r1 is saved to r29, as adding it to the clobber
+ * list doesn't protect it
+ */
+ "xer", "r31", "r0", "r29", "memory");
+
+ /* doc says it is invalid, real proc stops when it comes to
+ * overwrite the register.
+ * In all the cases, the register must stay untouched
+ */
+ report("Don't overwrite Rb", regs[1] == (uint64_t)addr);
+
+ report_prefix_pop();
+}
+
int main(int argc, char **argv)
{
int i;
@@ -72,6 +211,7 @@ int main(int argc, char **argv)
test_64bit();
test_illegal();
+ test_lswx();
report_prefix_pop();
--
2.5.0
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
