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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /arch/arm64/lib/memcmp.S
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
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Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'arch/arm64/lib/memcmp.S')
-rw-r--r--arch/arm64/lib/memcmp.S139
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/arm64/lib/memcmp.S b/arch/arm64/lib/memcmp.S
new file mode 100644
index 000000000..a5ccf2c55
--- /dev/null
+++ b/arch/arm64/lib/memcmp.S
@@ -0,0 +1,139 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2013-2021, Arm Limited.
+ *
+ * Adapted from the original at:
+ * https://github.com/ARM-software/optimized-routines/blob/e823e3abf5f89ecb/string/aarch64/memcmp.S
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+/* Assumptions:
+ *
+ * ARMv8-a, AArch64, unaligned accesses.
+ */
+
+#define L(label) .L ## label
+
+/* Parameters and result. */
+#define src1 x0
+#define src2 x1
+#define limit x2
+#define result w0
+
+/* Internal variables. */
+#define data1 x3
+#define data1w w3
+#define data1h x4
+#define data2 x5
+#define data2w w5
+#define data2h x6
+#define tmp1 x7
+#define tmp2 x8
+
+SYM_FUNC_START(__pi_memcmp)
+ subs limit, limit, 8
+ b.lo L(less8)
+
+ ldr data1, [src1], 8
+ ldr data2, [src2], 8
+ cmp data1, data2
+ b.ne L(return)
+
+ subs limit, limit, 8
+ b.gt L(more16)
+
+ ldr data1, [src1, limit]
+ ldr data2, [src2, limit]
+ b L(return)
+
+L(more16):
+ ldr data1, [src1], 8
+ ldr data2, [src2], 8
+ cmp data1, data2
+ bne L(return)
+
+ /* Jump directly to comparing the last 16 bytes for 32 byte (or less)
+ strings. */
+ subs limit, limit, 16
+ b.ls L(last_bytes)
+
+ /* We overlap loads between 0-32 bytes at either side of SRC1 when we
+ try to align, so limit it only to strings larger than 128 bytes. */
+ cmp limit, 96
+ b.ls L(loop16)
+
+ /* Align src1 and adjust src2 with bytes not yet done. */
+ and tmp1, src1, 15
+ add limit, limit, tmp1
+ sub src1, src1, tmp1
+ sub src2, src2, tmp1
+
+ /* Loop performing 16 bytes per iteration using aligned src1.
+ Limit is pre-decremented by 16 and must be larger than zero.
+ Exit if <= 16 bytes left to do or if the data is not equal. */
+ .p2align 4
+L(loop16):
+ ldp data1, data1h, [src1], 16
+ ldp data2, data2h, [src2], 16
+ subs limit, limit, 16
+ ccmp data1, data2, 0, hi
+ ccmp data1h, data2h, 0, eq
+ b.eq L(loop16)
+
+ cmp data1, data2
+ bne L(return)
+ mov data1, data1h
+ mov data2, data2h
+ cmp data1, data2
+ bne L(return)
+
+ /* Compare last 1-16 bytes using unaligned access. */
+L(last_bytes):
+ add src1, src1, limit
+ add src2, src2, limit
+ ldp data1, data1h, [src1]
+ ldp data2, data2h, [src2]
+ cmp data1, data2
+ bne L(return)
+ mov data1, data1h
+ mov data2, data2h
+ cmp data1, data2
+
+ /* Compare data bytes and set return value to 0, -1 or 1. */
+L(return):
+#ifndef __AARCH64EB__
+ rev data1, data1
+ rev data2, data2
+#endif
+ cmp data1, data2
+L(ret_eq):
+ cset result, ne
+ cneg result, result, lo
+ ret
+
+ .p2align 4
+ /* Compare up to 8 bytes. Limit is [-8..-1]. */
+L(less8):
+ adds limit, limit, 4
+ b.lo L(less4)
+ ldr data1w, [src1], 4
+ ldr data2w, [src2], 4
+ cmp data1w, data2w
+ b.ne L(return)
+ sub limit, limit, 4
+L(less4):
+ adds limit, limit, 4
+ beq L(ret_eq)
+L(byte_loop):
+ ldrb data1w, [src1], 1
+ ldrb data2w, [src2], 1
+ subs limit, limit, 1
+ ccmp data1w, data2w, 0, ne /* NZCV = 0b0000. */
+ b.eq L(byte_loop)
+ sub result, data1w, data2w
+ ret
+SYM_FUNC_END(__pi_memcmp)
+SYM_FUNC_ALIAS_WEAK(memcmp, __pi_memcmp)
+EXPORT_SYMBOL_NOKASAN(memcmp)