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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/memcpy.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/memcpy.S')
-rw-r--r--arch/arm64/lib/memcpy.S270
1 files changed, 270 insertions, 0 deletions
diff --git a/arch/arm64/lib/memcpy.S b/arch/arm64/lib/memcpy.S
new file mode 100644
index 000000000..9b99106fb
--- /dev/null
+++ b/arch/arm64/lib/memcpy.S
@@ -0,0 +1,270 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2012-2021, Arm Limited.
+ *
+ * Adapted from the original at:
+ * https://github.com/ARM-software/optimized-routines/blob/afd6244a1f8d9229/string/aarch64/memcpy.S
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+/* Assumptions:
+ *
+ * ARMv8-a, AArch64, unaligned accesses.
+ *
+ */
+
+#define L(label) .L ## label
+
+#define dstin x0
+#define src x1
+#define count x2
+#define dst x3
+#define srcend x4
+#define dstend x5
+#define A_l x6
+#define A_lw w6
+#define A_h x7
+#define B_l x8
+#define B_lw w8
+#define B_h x9
+#define C_l x10
+#define C_lw w10
+#define C_h x11
+#define D_l x12
+#define D_h x13
+#define E_l x14
+#define E_h x15
+#define F_l x16
+#define F_h x17
+#define G_l count
+#define G_h dst
+#define H_l src
+#define H_h srcend
+#define tmp1 x14
+
+/* This implementation handles overlaps and supports both memcpy and memmove
+ from a single entry point. It uses unaligned accesses and branchless
+ sequences to keep the code small, simple and improve performance.
+
+ Copies are split into 3 main cases: small copies of up to 32 bytes, medium
+ copies of up to 128 bytes, and large copies. The overhead of the overlap
+ check is negligible since it is only required for large copies.
+
+ Large copies use a software pipelined loop processing 64 bytes per iteration.
+ The destination pointer is 16-byte aligned to minimize unaligned accesses.
+ The loop tail is handled by always copying 64 bytes from the end.
+*/
+
+SYM_FUNC_START_LOCAL(__pi_memcpy_generic)
+ add srcend, src, count
+ add dstend, dstin, count
+ cmp count, 128
+ b.hi L(copy_long)
+ cmp count, 32
+ b.hi L(copy32_128)
+
+ /* Small copies: 0..32 bytes. */
+ cmp count, 16
+ b.lo L(copy16)
+ ldp A_l, A_h, [src]
+ ldp D_l, D_h, [srcend, -16]
+ stp A_l, A_h, [dstin]
+ stp D_l, D_h, [dstend, -16]
+ ret
+
+ /* Copy 8-15 bytes. */
+L(copy16):
+ tbz count, 3, L(copy8)
+ ldr A_l, [src]
+ ldr A_h, [srcend, -8]
+ str A_l, [dstin]
+ str A_h, [dstend, -8]
+ ret
+
+ .p2align 3
+ /* Copy 4-7 bytes. */
+L(copy8):
+ tbz count, 2, L(copy4)
+ ldr A_lw, [src]
+ ldr B_lw, [srcend, -4]
+ str A_lw, [dstin]
+ str B_lw, [dstend, -4]
+ ret
+
+ /* Copy 0..3 bytes using a branchless sequence. */
+L(copy4):
+ cbz count, L(copy0)
+ lsr tmp1, count, 1
+ ldrb A_lw, [src]
+ ldrb C_lw, [srcend, -1]
+ ldrb B_lw, [src, tmp1]
+ strb A_lw, [dstin]
+ strb B_lw, [dstin, tmp1]
+ strb C_lw, [dstend, -1]
+L(copy0):
+ ret
+
+ .p2align 4
+ /* Medium copies: 33..128 bytes. */
+L(copy32_128):
+ ldp A_l, A_h, [src]
+ ldp B_l, B_h, [src, 16]
+ ldp C_l, C_h, [srcend, -32]
+ ldp D_l, D_h, [srcend, -16]
+ cmp count, 64
+ b.hi L(copy128)
+ stp A_l, A_h, [dstin]
+ stp B_l, B_h, [dstin, 16]
+ stp C_l, C_h, [dstend, -32]
+ stp D_l, D_h, [dstend, -16]
+ ret
+
+ .p2align 4
+ /* Copy 65..128 bytes. */
+L(copy128):
+ ldp E_l, E_h, [src, 32]
+ ldp F_l, F_h, [src, 48]
+ cmp count, 96
+ b.ls L(copy96)
+ ldp G_l, G_h, [srcend, -64]
+ ldp H_l, H_h, [srcend, -48]
+ stp G_l, G_h, [dstend, -64]
+ stp H_l, H_h, [dstend, -48]
+L(copy96):
+ stp A_l, A_h, [dstin]
+ stp B_l, B_h, [dstin, 16]
+ stp E_l, E_h, [dstin, 32]
+ stp F_l, F_h, [dstin, 48]
+ stp C_l, C_h, [dstend, -32]
+ stp D_l, D_h, [dstend, -16]
+ ret
+
+ .p2align 4
+ /* Copy more than 128 bytes. */
+L(copy_long):
+ /* Use backwards copy if there is an overlap. */
+ sub tmp1, dstin, src
+ cbz tmp1, L(copy0)
+ cmp tmp1, count
+ b.lo L(copy_long_backwards)
+
+ /* Copy 16 bytes and then align dst to 16-byte alignment. */
+
+ ldp D_l, D_h, [src]
+ and tmp1, dstin, 15
+ bic dst, dstin, 15
+ sub src, src, tmp1
+ add count, count, tmp1 /* Count is now 16 too large. */
+ ldp A_l, A_h, [src, 16]
+ stp D_l, D_h, [dstin]
+ ldp B_l, B_h, [src, 32]
+ ldp C_l, C_h, [src, 48]
+ ldp D_l, D_h, [src, 64]!
+ subs count, count, 128 + 16 /* Test and readjust count. */
+ b.ls L(copy64_from_end)
+
+L(loop64):
+ stp A_l, A_h, [dst, 16]
+ ldp A_l, A_h, [src, 16]
+ stp B_l, B_h, [dst, 32]
+ ldp B_l, B_h, [src, 32]
+ stp C_l, C_h, [dst, 48]
+ ldp C_l, C_h, [src, 48]
+ stp D_l, D_h, [dst, 64]!
+ ldp D_l, D_h, [src, 64]!
+ subs count, count, 64
+ b.hi L(loop64)
+
+ /* Write the last iteration and copy 64 bytes from the end. */
+L(copy64_from_end):
+ ldp E_l, E_h, [srcend, -64]
+ stp A_l, A_h, [dst, 16]
+ ldp A_l, A_h, [srcend, -48]
+ stp B_l, B_h, [dst, 32]
+ ldp B_l, B_h, [srcend, -32]
+ stp C_l, C_h, [dst, 48]
+ ldp C_l, C_h, [srcend, -16]
+ stp D_l, D_h, [dst, 64]
+ stp E_l, E_h, [dstend, -64]
+ stp A_l, A_h, [dstend, -48]
+ stp B_l, B_h, [dstend, -32]
+ stp C_l, C_h, [dstend, -16]
+ ret
+
+ .p2align 4
+
+ /* Large backwards copy for overlapping copies.
+ Copy 16 bytes and then align dst to 16-byte alignment. */
+L(copy_long_backwards):
+ ldp D_l, D_h, [srcend, -16]
+ and tmp1, dstend, 15
+ sub srcend, srcend, tmp1
+ sub count, count, tmp1
+ ldp A_l, A_h, [srcend, -16]
+ stp D_l, D_h, [dstend, -16]
+ ldp B_l, B_h, [srcend, -32]
+ ldp C_l, C_h, [srcend, -48]
+ ldp D_l, D_h, [srcend, -64]!
+ sub dstend, dstend, tmp1
+ subs count, count, 128
+ b.ls L(copy64_from_start)
+
+L(loop64_backwards):
+ stp A_l, A_h, [dstend, -16]
+ ldp A_l, A_h, [srcend, -16]
+ stp B_l, B_h, [dstend, -32]
+ ldp B_l, B_h, [srcend, -32]
+ stp C_l, C_h, [dstend, -48]
+ ldp C_l, C_h, [srcend, -48]
+ stp D_l, D_h, [dstend, -64]!
+ ldp D_l, D_h, [srcend, -64]!
+ subs count, count, 64
+ b.hi L(loop64_backwards)
+
+ /* Write the last iteration and copy 64 bytes from the start. */
+L(copy64_from_start):
+ ldp G_l, G_h, [src, 48]
+ stp A_l, A_h, [dstend, -16]
+ ldp A_l, A_h, [src, 32]
+ stp B_l, B_h, [dstend, -32]
+ ldp B_l, B_h, [src, 16]
+ stp C_l, C_h, [dstend, -48]
+ ldp C_l, C_h, [src]
+ stp D_l, D_h, [dstend, -64]
+ stp G_l, G_h, [dstin, 48]
+ stp A_l, A_h, [dstin, 32]
+ stp B_l, B_h, [dstin, 16]
+ stp C_l, C_h, [dstin]
+ ret
+SYM_FUNC_END(__pi_memcpy_generic)
+
+#ifdef CONFIG_AS_HAS_MOPS
+ .arch_extension mops
+SYM_FUNC_START(__pi_memcpy)
+alternative_if_not ARM64_HAS_MOPS
+ b __pi_memcpy_generic
+alternative_else_nop_endif
+
+ mov dst, dstin
+ cpyp [dst]!, [src]!, count!
+ cpym [dst]!, [src]!, count!
+ cpye [dst]!, [src]!, count!
+ ret
+SYM_FUNC_END(__pi_memcpy)
+#else
+SYM_FUNC_ALIAS(__pi_memcpy, __pi_memcpy_generic)
+#endif
+
+SYM_FUNC_ALIAS(__memcpy, __pi_memcpy)
+EXPORT_SYMBOL(__memcpy)
+SYM_FUNC_ALIAS_WEAK(memcpy, __memcpy)
+EXPORT_SYMBOL(memcpy)
+
+SYM_FUNC_ALIAS(__pi_memmove, __pi_memcpy)
+
+SYM_FUNC_ALIAS(__memmove, __pi_memmove)
+EXPORT_SYMBOL(__memmove)
+SYM_FUNC_ALIAS_WEAK(memmove, __memmove)
+EXPORT_SYMBOL(memmove)