summaryrefslogtreecommitdiffstats
path: root/arch/riscv/lib/clear_page.S
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/riscv/lib/clear_page.S
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/riscv/lib/clear_page.S')
-rw-r--r--arch/riscv/lib/clear_page.S74
1 files changed, 74 insertions, 0 deletions
diff --git a/arch/riscv/lib/clear_page.S b/arch/riscv/lib/clear_page.S
new file mode 100644
index 0000000000..d7a256eb53
--- /dev/null
+++ b/arch/riscv/lib/clear_page.S
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2023 Ventana Micro Systems Inc.
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm.h>
+#include <asm/alternative-macros.h>
+#include <asm-generic/export.h>
+#include <asm/hwcap.h>
+#include <asm/insn-def.h>
+#include <asm/page.h>
+
+#define CBOZ_ALT(order, old, new) \
+ ALTERNATIVE(old, new, 0, \
+ ((order) << 16) | RISCV_ISA_EXT_ZICBOZ, \
+ CONFIG_RISCV_ISA_ZICBOZ)
+
+/* void clear_page(void *page) */
+SYM_FUNC_START(clear_page)
+ li a2, PAGE_SIZE
+
+ /*
+ * If Zicboz isn't present, or somehow has a block
+ * size larger than 4K, then fallback to memset.
+ */
+ CBOZ_ALT(12, "j .Lno_zicboz", "nop")
+
+ lw a1, riscv_cboz_block_size
+ add a2, a0, a2
+.Lzero_loop:
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBOZ_ALT(11, "bltu a0, a2, .Lzero_loop; ret", "nop; nop")
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBOZ_ALT(10, "bltu a0, a2, .Lzero_loop; ret", "nop; nop")
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBOZ_ALT(9, "bltu a0, a2, .Lzero_loop; ret", "nop; nop")
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBOZ_ALT(8, "bltu a0, a2, .Lzero_loop; ret", "nop; nop")
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBO_zero(a0)
+ add a0, a0, a1
+ CBO_zero(a0)
+ add a0, a0, a1
+ bltu a0, a2, .Lzero_loop
+ ret
+.Lno_zicboz:
+ li a1, 0
+ tail __memset
+SYM_FUNC_END(clear_page)
+EXPORT_SYMBOL(clear_page)