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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-24 08:46:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-24 08:46:03 -0700
commitcf9610f9116d55c5a66ef9f1faecacabd93a9322 (patch)
tree757a3d280760c654767631cab5ad8af2d86d1848 /arch/riscv/lib/strlen.S
downloadlinux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.tar.gz
linux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.zip
Merge tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrlgrafted
Pull pin control updates from Linus Walleij: "Core changes: - Use the non-blocking mux_state_try_select() in the generic MUX pin control back-end - Free pin maps on pinctrl_generic_to_map() failure in the core helpers New hardware pin control: - Qualcomm Maili TLMM SoC, PMG1110 PMIC, and Eliza LPASS LPI TLMM SoC (this is for the low power audio, LPASS = Low Power Audio SubSystem portions) - Upboard support on top of the Intel pin controller - Apple T6030 and T6031 support (just compatible strings) - Samsung Exynos 8855 SoC - Mediatek MT6858 SoC - Rockchip RK3308B and RV1106 SoCs - Airoha EN7523 and AN7563 SoCs Improvements: - Qualcomm TLMM GPIOs are unconditionally marked as wakeup capable - Qualcomm improvements on top of the Qualcomm PDC (power domain controller) irqchip improvements from tglx:s tree - Qualcomm IPQ806x and IPQ9650 non-urgent pin grop fixups - The NPCM8xx driver has been put into shape fixing many pin and group definitions - Some non-urgent Tegra 264 pin assignments are fixed up - Some non-urgent fixups to Airoha AN7581 and AN7583 registers and pin assignments, missing features etc" * tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (130 commits) dt-bindings: pinctrl: Convert TI DA850 pupd to DT schema pinctrl: meson: sync some modify from A4 pinctrl: meson: a4: Add input enable pin configuration pinctrl: realtek: rtd1625: remove unused group name spdif_sel pinctrl: realtek: rtd1625: fix base_bit for VE4 GPIO 13 dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema Revert "Merge branch 'ib-rsk7204' into devel" pinctrl: rockchip: Add RV1106 pinctrl support dt-bindings: pinctrl: rockchip: Add RV1106 compatible pinctrl: rockchip: Decode drive strength in the get function pinctrl: fix PINCTRL_GENERIC_MUX not always being selectable pinctrl: airoha: add support of an7563 SoC dt-bindings: pinctrl: airoha: add support of an7563 pin controller pinctrl: airoha: try to find chip scu node by phandle first pinctrl: airoha: add support of en7523 SoC dt-bindings: pinctrl: airoha: add support of en7523 pin controller pinctrl: airoha: an7583: add support for olt pinmux pinctrl: airoha: an7583: add support for pon_alt pinmux pinctrl: airoha: an7583: add support for npu_uart pinmux dt-bindings: pinctrl: airoha: an7583: add missed features ...
Diffstat (limited to 'arch/riscv/lib/strlen.S')
-rw-r--r--arch/riscv/lib/strlen.S133
1 files changed, 133 insertions, 0 deletions
diff --git a/arch/riscv/lib/strlen.S b/arch/riscv/lib/strlen.S
new file mode 100644
index 000000000..e7736ccda
--- /dev/null
+++ b/arch/riscv/lib/strlen.S
@@ -0,0 +1,133 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <linux/linkage.h>
+#include <asm/asm.h>
+#include <asm/alternative-macros.h>
+#include <asm/hwcap.h>
+
+/* int strlen(const char *s) */
+SYM_FUNC_START(strlen)
+
+ __ALTERNATIVE_CFG("nop", "j strlen_zbb", 0, RISCV_ISA_EXT_ZBB,
+ IS_ENABLED(CONFIG_RISCV_ISA_ZBB) && IS_ENABLED(CONFIG_TOOLCHAIN_HAS_ZBB))
+
+ /*
+ * Returns
+ * a0 - string length
+ *
+ * Parameters
+ * a0 - String to measure
+ *
+ * Clobbers:
+ * t0, t1
+ */
+ addi t1, a0, -1
+1:
+ addi t1, t1, 1
+ lbu t0, 0(t1)
+ bnez t0, 1b
+ sub a0, t1, a0
+ ret
+
+/*
+ * Variant of strlen using the ZBB extension if available
+ */
+#if defined(CONFIG_RISCV_ISA_ZBB) && defined(CONFIG_TOOLCHAIN_HAS_ZBB)
+strlen_zbb:
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+# define CZ clz
+# define SHIFT sll
+#else
+# define CZ ctz
+# define SHIFT srl
+#endif
+
+.option push
+.option arch,+zbb
+
+ /*
+ * Returns
+ * a0 - string length
+ *
+ * Parameters
+ * a0 - String to measure
+ *
+ * Clobbers
+ * t0, t1, t2, t3
+ */
+
+ /* Number of irrelevant bytes in the first word. */
+ andi t2, a0, SZREG-1
+
+ /* Align pointer. */
+ andi t0, a0, -SZREG
+
+ li t3, SZREG
+ sub t3, t3, t2
+ slli t2, t2, 3
+
+ /* Get the first word. */
+ REG_L t1, 0(t0)
+
+ /*
+ * Shift away the partial data we loaded to remove the irrelevant bytes
+ * preceding the string with the effect of adding NUL bytes at the
+ * end of the string's first word.
+ */
+ SHIFT t1, t1, t2
+
+ /* Convert non-NUL into 0xff and NUL into 0x00. */
+ orc.b t1, t1
+
+ /* Convert non-NUL into 0x00 and NUL into 0xff. */
+ not t1, t1
+
+ /*
+ * Search for the first set bit (corresponding to a NUL byte in the
+ * original chunk).
+ */
+ CZ t1, t1
+
+ /*
+ * The first chunk is special: compare against the number
+ * of valid bytes in this chunk.
+ */
+ srli a0, t1, 3
+ bgtu t3, a0, 2f
+
+ /* Prepare for the word comparison loop. */
+ addi t2, t0, SZREG
+ li t3, -1
+
+ /*
+ * Our critical loop is 4 instructions and processes data in
+ * 4 byte or 8 byte chunks.
+ */
+ .p2align 3
+1:
+ REG_L t1, SZREG(t0)
+ addi t0, t0, SZREG
+ orc.b t1, t1
+ beq t1, t3, 1b
+
+ not t1, t1
+ CZ t1, t1
+ srli t1, t1, 3
+
+ /* Get number of processed bytes. */
+ sub t2, t0, t2
+
+ /* Add number of characters in the first word. */
+ add a0, a0, t2
+
+ /* Add number of characters in the last word. */
+ add a0, a0, t1
+2:
+ ret
+
+.option pop
+#endif
+SYM_FUNC_END(strlen)
+SYM_FUNC_ALIAS(__pi_strlen, strlen)
+EXPORT_SYMBOL(strlen)