This patch adds a function to adjust the length of a transfer so that
it doesn't cross a page boundary in softmmu mode. It does nothing in
user mode.
Cc: Alexander Graf <ag...@suse.de>
Cc: Richard Henderson <r...@twiddle.net>
Signed-off-by: Aurelien Jarno <aurel...@aurel32.net>
---
target-s390x/mem_helper.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/target-s390x/mem_helper.c b/target-s390x/mem_helper.c
index b4e5d44..b8d3a5f 100644
--- a/target-s390x/mem_helper.c
+++ b/target-s390x/mem_helper.c
@@ -54,6 +54,17 @@ void tlb_fill(CPUState *cs, target_ulong addr, int is_write,
int mmu_idx,
#define HELPER_LOG(x...)
#endif
+/* Reduce the length so that addr + len doesn't cross a page boundary. */
+static inline uint64_t adj_len_to_page(uint64_t len, uint64_t addr)
+{
+#ifndef CONFIG_USER_ONLY
+ if ((addr & ~TARGET_PAGE_MASK) + len - 1 >= TARGET_PAGE_SIZE) {
+ return -addr & ~TARGET_PAGE_MASK;
+ }
+#endif
+ return len;
+}
+
#ifndef CONFIG_USER_ONLY
static void mvc_fast_memset(CPUS390XState *env, uint32_t l, uint64_t dest,
uint8_t byte)
--
2.1.4
