summaryrefslogtreecommitdiffstats
path: root/arch/riscv/include/asm/word-at-a-time.h
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 18:50:36 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 18:50:36 +0000
commit50ba0232fd5312410f1b65247e774244f89a628e (patch)
treefd8f2fc78e9e548af0ff9590276602ee6125be00 /arch/riscv/include/asm/word-at-a-time.h
parentReleasing progress-linux version 6.7.12-1~progress7.99u1. (diff)
downloadlinux-50ba0232fd5312410f1b65247e774244f89a628e.tar.xz
linux-50ba0232fd5312410f1b65247e774244f89a628e.zip
Merging upstream version 6.8.9.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/riscv/include/asm/word-at-a-time.h')
-rw-r--r--arch/riscv/include/asm/word-at-a-time.h27
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/word-at-a-time.h b/arch/riscv/include/asm/word-at-a-time.h
index 7c086ac6ec..f3f031e341 100644
--- a/arch/riscv/include/asm/word-at-a-time.h
+++ b/arch/riscv/include/asm/word-at-a-time.h
@@ -9,6 +9,7 @@
#define _ASM_RISCV_WORD_AT_A_TIME_H
+#include <asm/asm-extable.h>
#include <linux/kernel.h>
struct word_at_a_time {
@@ -45,4 +46,30 @@ static inline unsigned long find_zero(unsigned long mask)
/* The mask we created is directly usable as a bytemask */
#define zero_bytemask(mask) (mask)
+#ifdef CONFIG_DCACHE_WORD_ACCESS
+
+/*
+ * Load an unaligned word from kernel space.
+ *
+ * In the (very unlikely) case of the word being a page-crosser
+ * and the next page not being mapped, take the exception and
+ * return zeroes in the non-existing part.
+ */
+static inline unsigned long load_unaligned_zeropad(const void *addr)
+{
+ unsigned long ret;
+
+ /* Load word from unaligned pointer addr */
+ asm(
+ "1: " REG_L " %0, %2\n"
+ "2:\n"
+ _ASM_EXTABLE_LOAD_UNALIGNED_ZEROPAD(1b, 2b, %0, %1)
+ : "=&r" (ret)
+ : "r" (addr), "m" (*(unsigned long *)addr));
+
+ return ret;
+}
+
+#endif /* CONFIG_DCACHE_WORD_ACCESS */
+
#endif /* _ASM_RISCV_WORD_AT_A_TIME_H */