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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-05 11:59:05 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-05 11:59:05 -0700 |
| commit | 9f0346dcbea363787186c94ef94dd01aaa215afa (patch) | |
| tree | b81c168f4d0dbe4c7f4750f4598d48a6deb72094 /arch/alpha/lib/strrchr.S | |
| download | linux-stable-9f0346dcbea363787186c94ef94dd01aaa215afa.tar.gz linux-stable-9f0346dcbea363787186c94ef94dd01aaa215afa.zip | |
Merge tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-coregrafted
Pull driver core fixes from Danilo Krummrich:
- Fix kernfs listxattr() not returning security xattr names (e.g.
SELinux labels) when the kernfs node has no allocated kernfs_iattrs
- Fix silent truncation of IRQ vector indices in the Rust PCI
abstractions
- Don't select OF from DRIVER_PE_KUNIT_TEST; skip the test when OF is
disabled instead of silently enabling extra kernel functionality
- Russ Weight is retiring from kernel development; update the Firmware
Loader sysfs contact to the driver-core mailing list, add a CREDITS
entry for Firmware Upload, and update MAINTAINERS accordingly
* tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
MAINTAINERS: Remove Russ Weight from Firmware Loader
CREDITS: Add CREDITS entry for Firmware Upload
firmware_loader: Change contact for sysfs nodes
rust: pci: reject IRQ vector indices that do not fit in u32
kernfs: preserve security xattrs without allocating iattrs
drivers: base: test: DRIVER_PE_KUNIT_TEST should not select OF
Diffstat (limited to 'arch/alpha/lib/strrchr.S')
| -rw-r--r-- | arch/alpha/lib/strrchr.S | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/arch/alpha/lib/strrchr.S b/arch/alpha/lib/strrchr.S new file mode 100644 index 000000000..dd8e073b6 --- /dev/null +++ b/arch/alpha/lib/strrchr.S @@ -0,0 +1,89 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * arch/alpha/lib/strrchr.S + * Contributed by Richard Henderson (rth@tamu.edu) + * + * Return the address of the last occurrence of a given character + * within a null-terminated string, or null if it is not found. + */ +#include <linux/export.h> +#include <asm/regdef.h> + + .set noreorder + .set noat + + .align 3 + .ent strrchr + .globl strrchr +strrchr: + .frame sp, 0, ra + .prologue 0 + + zapnot a1, 1, a1 # e0 : zero extend our test character + mov zero, t6 # .. e1 : t6 is last match aligned addr + sll a1, 8, t5 # e0 : replicate our test character + mov zero, t8 # .. e1 : t8 is last match byte compare mask + or t5, a1, a1 # e0 : + ldq_u t0, 0(a0) # .. e1 : load first quadword + sll a1, 16, t5 # e0 : + andnot a0, 7, v0 # .. e1 : align source addr + or t5, a1, a1 # e0 : + lda t4, -1 # .. e1 : build garbage mask + sll a1, 32, t5 # e0 : + cmpbge zero, t0, t1 # .. e1 : bits set iff byte == zero + mskqh t4, a0, t4 # e0 : + or t5, a1, a1 # .. e1 : character replication complete + xor t0, a1, t2 # e0 : make bytes == c zero + cmpbge zero, t4, t4 # .. e1 : bits set iff byte is garbage + cmpbge zero, t2, t3 # e0 : bits set iff byte == c + andnot t1, t4, t1 # .. e1 : clear garbage from null test + andnot t3, t4, t3 # e0 : clear garbage from char test + bne t1, $eos # .. e1 : did we already hit the terminator? + + /* Character search main loop */ +$loop: + ldq t0, 8(v0) # e0 : load next quadword + cmovne t3, v0, t6 # .. e1 : save previous comparisons match + cmovne t3, t3, t8 # e0 : + addq v0, 8, v0 # .. e1 : + xor t0, a1, t2 # e0 : + cmpbge zero, t0, t1 # .. e1 : bits set iff byte == zero + cmpbge zero, t2, t3 # e0 : bits set iff byte == c + beq t1, $loop # .. e1 : if we havnt seen a null, loop + + /* Mask out character matches after terminator */ +$eos: + negq t1, t4 # e0 : isolate first null byte match + and t1, t4, t4 # e1 : + subq t4, 1, t5 # e0 : build a mask of the bytes up to... + or t4, t5, t4 # e1 : ... and including the null + + and t3, t4, t3 # e0 : mask out char matches after null + cmovne t3, t3, t8 # .. e1 : save it, if match found + cmovne t3, v0, t6 # e0 : + + /* Locate the address of the last matched character */ + + /* Retain the early exit for the ev4 -- the ev5 mispredict penalty + is 5 cycles -- the same as just falling through. */ + beq t8, $retnull # .. e1 : + + and t8, 0xf0, t2 # e0 : binary search for the high bit set + cmovne t2, t2, t8 # .. e1 (zdb) + cmovne t2, 4, t2 # e0 : + and t8, 0xcc, t1 # .. e1 : + cmovne t1, t1, t8 # e0 : + cmovne t1, 2, t1 # .. e1 : + and t8, 0xaa, t0 # e0 : + cmovne t0, 1, t0 # .. e1 (zdb) + addq t2, t1, t1 # e0 : + addq t6, t0, v0 # .. e1 : add our aligned base ptr to the mix + addq v0, t1, v0 # e0 : + ret # .. e1 : + +$retnull: + mov zero, v0 # e0 : + ret # .. e1 : + + .end strrchr + EXPORT_SYMBOL(strrchr) |
