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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /arch/arm/lib/findbit.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/findbit.S')
| -rw-r--r-- | arch/arm/lib/findbit.S | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/arm/lib/findbit.S b/arch/arm/lib/findbit.S new file mode 100644 index 000000000..b7ac2d3c0 --- /dev/null +++ b/arch/arm/lib/findbit.S @@ -0,0 +1,139 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/lib/findbit.S + * + * Copyright (C) 1995-2000 Russell King + * + * 16th March 2001 - John Ripley <jripley@sonicblue.com> + * Fixed so that "size" is an exclusive not an inclusive quantity. + * All users of these functions expect exclusive sizes, and may + * also call with zero size. + * Reworked by rmk. + */ +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/unwind.h> + .text + +#ifdef __ARMEB__ +#define SWAB_ENDIAN le +#else +#define SWAB_ENDIAN be +#endif + + .macro find_first, endian, set, name +ENTRY(_find_first_\name\()bit_\endian) + UNWIND( .fnstart) + teq r1, #0 + beq 3f + mov r2, #0 +1: ldr r3, [r0], #4 + .ifeq \set + mvns r3, r3 @ invert/test bits + .else + movs r3, r3 @ test bits + .endif + .ifc \endian, SWAB_ENDIAN + bne .L_found_swab + .else + bne .L_found @ found the bit? + .endif + add r2, r2, #32 @ next index +2: cmp r2, r1 @ any more? + blo 1b +3: mov r0, r1 @ no more bits + ret lr + UNWIND( .fnend) +ENDPROC(_find_first_\name\()bit_\endian) + .endm + + .macro find_next, endian, set, name +ENTRY(_find_next_\name\()bit_\endian) + UNWIND( .fnstart) + cmp r2, r1 + bhs 3b + mov ip, r2, lsr #5 @ word index + add r0, r0, ip, lsl #2 + ands ip, r2, #31 @ bit position + beq 1b + ldr r3, [r0], #4 + .ifeq \set + mvn r3, r3 @ invert bits + .endif + .ifc \endian, SWAB_ENDIAN + rev_l r3, ip + .if .Lrev_l_uses_tmp + @ we need to recompute ip because rev_l will have overwritten + @ it. + and ip, r2, #31 @ bit position + .endif + .endif + movs r3, r3, lsr ip @ shift off unused bits + bne .L_found + orr r2, r2, #31 @ no zero bits + add r2, r2, #1 @ align bit pointer + b 2b @ loop for next bit + UNWIND( .fnend) +ENDPROC(_find_next_\name\()bit_\endian) + .endm + + .macro find_bit, endian, set, name + find_first \endian, \set, \name + find_next \endian, \set, \name + .endm + +/* _find_first_zero_bit_le and _find_next_zero_bit_le */ + find_bit le, 0, zero_ + +/* _find_first_bit_le and _find_next_bit_le */ + find_bit le, 1 + +#ifdef __ARMEB__ + +/* _find_first_zero_bit_be and _find_next_zero_bit_be */ + find_bit be, 0, zero_ + +/* _find_first_bit_be and _find_next_bit_be */ + find_bit be, 1 + +#endif + +/* + * One or more bits in the LSB of r3 are assumed to be set. + */ +.L_found_swab: + UNWIND( .fnstart) + rev_l r3, ip +.L_found: +#if __LINUX_ARM_ARCH__ >= 7 + rbit r3, r3 @ reverse bits + clz r3, r3 @ count high zero bits + add r0, r2, r3 @ add offset of first set bit +#elif __LINUX_ARM_ARCH__ >= 5 + rsb r0, r3, #0 + and r3, r3, r0 @ mask out lowest bit set + clz r3, r3 @ count high zero bits + rsb r3, r3, #31 @ offset of first set bit + add r0, r2, r3 @ add offset of first set bit +#else + mov ip, #~0 + tst r3, ip, lsr #16 @ test bits 0-15 + addeq r2, r2, #16 + moveq r3, r3, lsr #16 + tst r3, #0x00ff + addeq r2, r2, #8 + moveq r3, r3, lsr #8 + tst r3, #0x000f + addeq r2, r2, #4 + moveq r3, r3, lsr #4 + tst r3, #0x0003 + addeq r2, r2, #2 + moveq r3, r3, lsr #2 + tst r3, #0x0001 + addeq r2, r2, #1 + mov r0, r2 +#endif + cmp r1, r0 @ Clamp to maxbit + movlo r0, r1 + ret lr + UNWIND( .fnend) |
