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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
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| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /arch/arm/lib/lib1funcs.S | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'arch/arm/lib/lib1funcs.S')
| -rw-r--r-- | arch/arm/lib/lib1funcs.S | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/arch/arm/lib/lib1funcs.S b/arch/arm/lib/lib1funcs.S new file mode 100644 index 000000000..c23f9d9e2 --- /dev/null +++ b/arch/arm/lib/lib1funcs.S @@ -0,0 +1,371 @@ +/* + * linux/arch/arm/lib/lib1funcs.S: Optimized ARM division routines + * + * Author: Nicolas Pitre <nico@fluxnic.net> + * - contributed to gcc-3.4 on Sep 30, 2003 + * - adapted for the Linux kernel on Oct 2, 2003 + */ + +/* Copyright 1995, 1996, 1998, 1999, 2000, 2003 Free Software Foundation, Inc. + +This file is free software; you can redistribute it and/or modify it +under the terms of the GNU General Public License as published by the +Free Software Foundation; either version 2, or (at your option) any +later version. + +In addition to the permissions in the GNU General Public License, the +Free Software Foundation gives you unlimited permission to link the +compiled version of this file into combinations with other programs, +and to distribute those combinations without any restriction coming +from the use of this file. (The General Public License restrictions +do apply in other respects; for example, they cover modification of +the file, and distribution when not linked into a combine +executable.) + +This file is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this program; see the file COPYING. If not, write to +the Free Software Foundation, 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA. */ + + +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/unwind.h> + +.macro ARM_DIV_BODY dividend, divisor, result, curbit + +#if __LINUX_ARM_ARCH__ >= 5 + + clz \curbit, \divisor + clz \result, \dividend + sub \result, \curbit, \result + mov \curbit, #1 + mov \divisor, \divisor, lsl \result + mov \curbit, \curbit, lsl \result + mov \result, #0 + +#else + + @ Initially shift the divisor left 3 bits if possible, + @ set curbit accordingly. This allows for curbit to be located + @ at the left end of each 4 bit nibbles in the division loop + @ to save one loop in most cases. + tst \divisor, #0xe0000000 + moveq \divisor, \divisor, lsl #3 + moveq \curbit, #8 + movne \curbit, #1 + + @ Unless the divisor is very big, shift it up in multiples of + @ four bits, since this is the amount of unwinding in the main + @ division loop. Continue shifting until the divisor is + @ larger than the dividend. +1: cmp \divisor, #0x10000000 + cmplo \divisor, \dividend + movlo \divisor, \divisor, lsl #4 + movlo \curbit, \curbit, lsl #4 + blo 1b + + @ For very big divisors, we must shift it a bit at a time, or + @ we will be in danger of overflowing. +1: cmp \divisor, #0x80000000 + cmplo \divisor, \dividend + movlo \divisor, \divisor, lsl #1 + movlo \curbit, \curbit, lsl #1 + blo 1b + + mov \result, #0 + +#endif + + @ Division loop +1: cmp \dividend, \divisor + subhs \dividend, \dividend, \divisor + orrhs \result, \result, \curbit + cmp \dividend, \divisor, lsr #1 + subhs \dividend, \dividend, \divisor, lsr #1 + orrhs \result, \result, \curbit, lsr #1 + cmp \dividend, \divisor, lsr #2 + subhs \dividend, \dividend, \divisor, lsr #2 + orrhs \result, \result, \curbit, lsr #2 + cmp \dividend, \divisor, lsr #3 + subhs \dividend, \dividend, \divisor, lsr #3 + orrhs \result, \result, \curbit, lsr #3 + cmp \dividend, #0 @ Early termination? + movsne \curbit, \curbit, lsr #4 @ No, any more bits to do? + movne \divisor, \divisor, lsr #4 + bne 1b + +.endm + + +.macro ARM_DIV2_ORDER divisor, order + +#if __LINUX_ARM_ARCH__ >= 5 + + clz \order, \divisor + rsb \order, \order, #31 + +#else + + cmp \divisor, #(1 << 16) + movhs \divisor, \divisor, lsr #16 + movhs \order, #16 + movlo \order, #0 + + cmp \divisor, #(1 << 8) + movhs \divisor, \divisor, lsr #8 + addhs \order, \order, #8 + + cmp \divisor, #(1 << 4) + movhs \divisor, \divisor, lsr #4 + addhs \order, \order, #4 + + cmp \divisor, #(1 << 2) + addhi \order, \order, #3 + addls \order, \order, \divisor, lsr #1 + +#endif + +.endm + + +.macro ARM_MOD_BODY dividend, divisor, order, spare + +#if __LINUX_ARM_ARCH__ >= 5 + + clz \order, \divisor + clz \spare, \dividend + sub \order, \order, \spare + mov \divisor, \divisor, lsl \order + +#else + + mov \order, #0 + + @ Unless the divisor is very big, shift it up in multiples of + @ four bits, since this is the amount of unwinding in the main + @ division loop. Continue shifting until the divisor is + @ larger than the dividend. +1: cmp \divisor, #0x10000000 + cmplo \divisor, \dividend + movlo \divisor, \divisor, lsl #4 + addlo \order, \order, #4 + blo 1b + + @ For very big divisors, we must shift it a bit at a time, or + @ we will be in danger of overflowing. +1: cmp \divisor, #0x80000000 + cmplo \divisor, \dividend + movlo \divisor, \divisor, lsl #1 + addlo \order, \order, #1 + blo 1b + +#endif + + @ Perform all needed subtractions to keep only the reminder. + @ Do comparisons in batch of 4 first. + subs \order, \order, #3 @ yes, 3 is intended here + blt 2f + +1: cmp \dividend, \divisor + subhs \dividend, \dividend, \divisor + cmp \dividend, \divisor, lsr #1 + subhs \dividend, \dividend, \divisor, lsr #1 + cmp \dividend, \divisor, lsr #2 + subhs \dividend, \dividend, \divisor, lsr #2 + cmp \dividend, \divisor, lsr #3 + subhs \dividend, \dividend, \divisor, lsr #3 + cmp \dividend, #1 + mov \divisor, \divisor, lsr #4 + subsge \order, \order, #4 + bge 1b + + tst \order, #3 + teqne \dividend, #0 + beq 5f + + @ Either 1, 2 or 3 comparison/subtractions are left. +2: cmn \order, #2 + blt 4f + beq 3f + cmp \dividend, \divisor + subhs \dividend, \dividend, \divisor + mov \divisor, \divisor, lsr #1 +3: cmp \dividend, \divisor + subhs \dividend, \dividend, \divisor + mov \divisor, \divisor, lsr #1 +4: cmp \dividend, \divisor + subhs \dividend, \dividend, \divisor +5: +.endm + + +#ifdef CONFIG_ARM_PATCH_IDIV + .align 3 +#endif + +ENTRY(__udivsi3) +ENTRY(__aeabi_uidiv) +UNWIND(.fnstart) + + subs r2, r1, #1 + reteq lr + bcc Ldiv0 + cmp r0, r1 + bls 11f + tst r1, r2 + beq 12f + + ARM_DIV_BODY r0, r1, r2, r3 + + mov r0, r2 + ret lr + +11: moveq r0, #1 + movne r0, #0 + ret lr + +12: ARM_DIV2_ORDER r1, r2 + + mov r0, r0, lsr r2 + ret lr + +UNWIND(.fnend) +ENDPROC(__udivsi3) +ENDPROC(__aeabi_uidiv) + +ENTRY(__umodsi3) +UNWIND(.fnstart) + + subs r2, r1, #1 @ compare divisor with 1 + bcc Ldiv0 + cmpne r0, r1 @ compare dividend with divisor + moveq r0, #0 + tsthi r1, r2 @ see if divisor is power of 2 + andeq r0, r0, r2 + retls lr + + ARM_MOD_BODY r0, r1, r2, r3 + + ret lr + +UNWIND(.fnend) +ENDPROC(__umodsi3) + +#ifdef CONFIG_ARM_PATCH_IDIV + .align 3 +#endif + +ENTRY(__divsi3) +ENTRY(__aeabi_idiv) +UNWIND(.fnstart) + + cmp r1, #0 + eor ip, r0, r1 @ save the sign of the result. + beq Ldiv0 + rsbmi r1, r1, #0 @ loops below use unsigned. + subs r2, r1, #1 @ division by 1 or -1 ? + beq 10f + movs r3, r0 + rsbmi r3, r0, #0 @ positive dividend value + cmp r3, r1 + bls 11f + tst r1, r2 @ divisor is power of 2 ? + beq 12f + + ARM_DIV_BODY r3, r1, r0, r2 + + cmp ip, #0 + rsbmi r0, r0, #0 + ret lr + +10: teq ip, r0 @ same sign ? + rsbmi r0, r0, #0 + ret lr + +11: movlo r0, #0 + moveq r0, ip, asr #31 + orreq r0, r0, #1 + ret lr + +12: ARM_DIV2_ORDER r1, r2 + + cmp ip, #0 + mov r0, r3, lsr r2 + rsbmi r0, r0, #0 + ret lr + +UNWIND(.fnend) +ENDPROC(__divsi3) +ENDPROC(__aeabi_idiv) + +ENTRY(__modsi3) +UNWIND(.fnstart) + + cmp r1, #0 + beq Ldiv0 + rsbmi r1, r1, #0 @ loops below use unsigned. + movs ip, r0 @ preserve sign of dividend + rsbmi r0, r0, #0 @ if negative make positive + subs r2, r1, #1 @ compare divisor with 1 + cmpne r0, r1 @ compare dividend with divisor + moveq r0, #0 + tsthi r1, r2 @ see if divisor is power of 2 + andeq r0, r0, r2 + bls 10f + + ARM_MOD_BODY r0, r1, r2, r3 + +10: cmp ip, #0 + rsbmi r0, r0, #0 + ret lr + +UNWIND(.fnend) +ENDPROC(__modsi3) + +#ifdef CONFIG_AEABI + +ENTRY(__aeabi_uidivmod) +UNWIND(.fnstart) +UNWIND(.save {r0, r1, ip, lr} ) + + stmfd sp!, {r0, r1, ip, lr} + bl __aeabi_uidiv + ldmfd sp!, {r1, r2, ip, lr} + mul r3, r0, r2 + sub r1, r1, r3 + ret lr + +UNWIND(.fnend) +ENDPROC(__aeabi_uidivmod) + +ENTRY(__aeabi_idivmod) +UNWIND(.fnstart) +UNWIND(.save {r0, r1, ip, lr} ) + stmfd sp!, {r0, r1, ip, lr} + bl __aeabi_idiv + ldmfd sp!, {r1, r2, ip, lr} + mul r3, r0, r2 + sub r1, r1, r3 + ret lr + +UNWIND(.fnend) +ENDPROC(__aeabi_idivmod) + +#endif + +Ldiv0: +UNWIND(.fnstart) +UNWIND(.pad #4) +UNWIND(.save {lr}) + str lr, [sp, #-8]! + bl __div0 + mov r0, #0 @ About as wrong as it could be. + ldr pc, [sp], #8 +UNWIND(.fnend) +ENDPROC(Ldiv0) |
