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authorLinus Torvalds <torvalds@linux-foundation.org>2023-11-10 20:23:17 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-11-10 20:23:17 +0300
commit56d428ae1c4e27fbe02cb554b2192cd66e4df05a (patch)
tree0fa353d09d206a2206ef8861f489f50c4d80f9fe /arch/riscv/include/asm/bitops.h
parent656d88c3b654c0ccc0ff63aa75101c6c9f0a5300 (diff)
parent457926b253200bd9bdfae9a016a3b1d1dc661d55 (diff)
downloadlinux-56d428ae1c4e27fbe02cb554b2192cd66e4df05a.tar.xz
Merge tag 'riscv-for-linus-6.7-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull more RISC-V updates from Palmer Dabbelt: - Support for handling misaligned accesses in S-mode - Probing for misaligned access support is now properly cached and handled in parallel - PTDUMP now reflects the SW reserved bits, as well as the PBMT and NAPOT extensions - Performance improvements for TLB flushing - Support for many new relocations in the module loader - Various bug fixes and cleanups * tag 'riscv-for-linus-6.7-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (51 commits) riscv: Optimize bitops with Zbb extension riscv: Rearrange hwcap.h and cpufeature.h drivers: perf: Do not broadcast to other cpus when starting a counter drivers: perf: Check find_first_bit() return value of: property: Add fw_devlink support for msi-parent RISC-V: Don't fail in riscv_of_parent_hartid() for disabled HARTs riscv: Fix set_memory_XX() and set_direct_map_XX() by splitting huge linear mappings riscv: Don't use PGD entries for the linear mapping RISC-V: Probe misaligned access speed in parallel RISC-V: Remove __init on unaligned_emulation_finish() RISC-V: Show accurate per-hart isa in /proc/cpuinfo RISC-V: Don't rely on positional structure initialization riscv: Add tests for riscv module loading riscv: Add remaining module relocations riscv: Avoid unaligned access when relocating modules riscv: split cache ops out of dma-noncoherent.c riscv: Improve flush_tlb_kernel_range() riscv: Make __flush_tlb_range() loop over pte instead of flushing the whole tlb riscv: Improve flush_tlb_range() for hugetlb pages riscv: Improve tlb_flush() ...
Diffstat (limited to 'arch/riscv/include/asm/bitops.h')
-rw-r--r--arch/riscv/include/asm/bitops.h254
1 files changed, 251 insertions, 3 deletions
diff --git a/arch/riscv/include/asm/bitops.h b/arch/riscv/include/asm/bitops.h
index 65f6eee4ab8d..224b4dc02b50 100644
--- a/arch/riscv/include/asm/bitops.h
+++ b/arch/riscv/include/asm/bitops.h
@@ -15,13 +15,261 @@
#include <asm/barrier.h>
#include <asm/bitsperlong.h>
+#if !defined(CONFIG_RISCV_ISA_ZBB) || defined(NO_ALTERNATIVE)
#include <asm-generic/bitops/__ffs.h>
-#include <asm-generic/bitops/ffz.h>
-#include <asm-generic/bitops/fls.h>
#include <asm-generic/bitops/__fls.h>
+#include <asm-generic/bitops/ffs.h>
+#include <asm-generic/bitops/fls.h>
+
+#else
+#include <asm/alternative-macros.h>
+#include <asm/hwcap.h>
+
+#if (BITS_PER_LONG == 64)
+#define CTZW "ctzw "
+#define CLZW "clzw "
+#elif (BITS_PER_LONG == 32)
+#define CTZW "ctz "
+#define CLZW "clz "
+#else
+#error "Unexpected BITS_PER_LONG"
+#endif
+
+static __always_inline unsigned long variable__ffs(unsigned long word)
+{
+ int num;
+
+ asm_volatile_goto(ALTERNATIVE("j %l[legacy]", "nop", 0,
+ RISCV_ISA_EXT_ZBB, 1)
+ : : : : legacy);
+
+ asm volatile (".option push\n"
+ ".option arch,+zbb\n"
+ "ctz %0, %1\n"
+ ".option pop\n"
+ : "=r" (word) : "r" (word) :);
+
+ return word;
+
+legacy:
+ num = 0;
+#if BITS_PER_LONG == 64
+ if ((word & 0xffffffff) == 0) {
+ num += 32;
+ word >>= 32;
+ }
+#endif
+ if ((word & 0xffff) == 0) {
+ num += 16;
+ word >>= 16;
+ }
+ if ((word & 0xff) == 0) {
+ num += 8;
+ word >>= 8;
+ }
+ if ((word & 0xf) == 0) {
+ num += 4;
+ word >>= 4;
+ }
+ if ((word & 0x3) == 0) {
+ num += 2;
+ word >>= 2;
+ }
+ if ((word & 0x1) == 0)
+ num += 1;
+ return num;
+}
+
+/**
+ * __ffs - find first set bit in a long word
+ * @word: The word to search
+ *
+ * Undefined if no set bit exists, so code should check against 0 first.
+ */
+#define __ffs(word) \
+ (__builtin_constant_p(word) ? \
+ (unsigned long)__builtin_ctzl(word) : \
+ variable__ffs(word))
+
+static __always_inline unsigned long variable__fls(unsigned long word)
+{
+ int num;
+
+ asm_volatile_goto(ALTERNATIVE("j %l[legacy]", "nop", 0,
+ RISCV_ISA_EXT_ZBB, 1)
+ : : : : legacy);
+
+ asm volatile (".option push\n"
+ ".option arch,+zbb\n"
+ "clz %0, %1\n"
+ ".option pop\n"
+ : "=r" (word) : "r" (word) :);
+
+ return BITS_PER_LONG - 1 - word;
+
+legacy:
+ num = BITS_PER_LONG - 1;
+#if BITS_PER_LONG == 64
+ if (!(word & (~0ul << 32))) {
+ num -= 32;
+ word <<= 32;
+ }
+#endif
+ if (!(word & (~0ul << (BITS_PER_LONG - 16)))) {
+ num -= 16;
+ word <<= 16;
+ }
+ if (!(word & (~0ul << (BITS_PER_LONG - 8)))) {
+ num -= 8;
+ word <<= 8;
+ }
+ if (!(word & (~0ul << (BITS_PER_LONG - 4)))) {
+ num -= 4;
+ word <<= 4;
+ }
+ if (!(word & (~0ul << (BITS_PER_LONG - 2)))) {
+ num -= 2;
+ word <<= 2;
+ }
+ if (!(word & (~0ul << (BITS_PER_LONG - 1))))
+ num -= 1;
+ return num;
+}
+
+/**
+ * __fls - find last set bit in a long word
+ * @word: the word to search
+ *
+ * Undefined if no set bit exists, so code should check against 0 first.
+ */
+#define __fls(word) \
+ (__builtin_constant_p(word) ? \
+ (unsigned long)(BITS_PER_LONG - 1 - __builtin_clzl(word)) : \
+ variable__fls(word))
+
+static __always_inline int variable_ffs(int x)
+{
+ int r;
+
+ if (!x)
+ return 0;
+
+ asm_volatile_goto(ALTERNATIVE("j %l[legacy]", "nop", 0,
+ RISCV_ISA_EXT_ZBB, 1)
+ : : : : legacy);
+
+ asm volatile (".option push\n"
+ ".option arch,+zbb\n"
+ CTZW "%0, %1\n"
+ ".option pop\n"
+ : "=r" (r) : "r" (x) :);
+
+ return r + 1;
+
+legacy:
+ r = 1;
+ if (!(x & 0xffff)) {
+ x >>= 16;
+ r += 16;
+ }
+ if (!(x & 0xff)) {
+ x >>= 8;
+ r += 8;
+ }
+ if (!(x & 0xf)) {
+ x >>= 4;
+ r += 4;
+ }
+ if (!(x & 3)) {
+ x >>= 2;
+ r += 2;
+ }
+ if (!(x & 1)) {
+ x >>= 1;
+ r += 1;
+ }
+ return r;
+}
+
+/**
+ * ffs - find first set bit in a word
+ * @x: the word to search
+ *
+ * This is defined the same way as the libc and compiler builtin ffs routines.
+ *
+ * ffs(value) returns 0 if value is 0 or the position of the first set bit if
+ * value is nonzero. The first (least significant) bit is at position 1.
+ */
+#define ffs(x) (__builtin_constant_p(x) ? __builtin_ffs(x) : variable_ffs(x))
+
+static __always_inline int variable_fls(unsigned int x)
+{
+ int r;
+
+ if (!x)
+ return 0;
+
+ asm_volatile_goto(ALTERNATIVE("j %l[legacy]", "nop", 0,
+ RISCV_ISA_EXT_ZBB, 1)
+ : : : : legacy);
+
+ asm volatile (".option push\n"
+ ".option arch,+zbb\n"
+ CLZW "%0, %1\n"
+ ".option pop\n"
+ : "=r" (r) : "r" (x) :);
+
+ return 32 - r;
+
+legacy:
+ r = 32;
+ if (!(x & 0xffff0000u)) {
+ x <<= 16;
+ r -= 16;
+ }
+ if (!(x & 0xff000000u)) {
+ x <<= 8;
+ r -= 8;
+ }
+ if (!(x & 0xf0000000u)) {
+ x <<= 4;
+ r -= 4;
+ }
+ if (!(x & 0xc0000000u)) {
+ x <<= 2;
+ r -= 2;
+ }
+ if (!(x & 0x80000000u)) {
+ x <<= 1;
+ r -= 1;
+ }
+ return r;
+}
+
+/**
+ * fls - find last set bit in a word
+ * @x: the word to search
+ *
+ * This is defined in a similar way as ffs, but returns the position of the most
+ * significant set bit.
+ *
+ * fls(value) returns 0 if value is 0 or the position of the last set bit if
+ * value is nonzero. The last (most significant) bit is at position 32.
+ */
+#define fls(x) \
+({ \
+ typeof(x) x_ = (x); \
+ __builtin_constant_p(x_) ? \
+ (int)((x_ != 0) ? (32 - __builtin_clz(x_)) : 0) \
+ : \
+ variable_fls(x_); \
+})
+
+#endif /* !defined(CONFIG_RISCV_ISA_ZBB) || defined(NO_ALTERNATIVE) */
+
+#include <asm-generic/bitops/ffz.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/sched.h>
-#include <asm-generic/bitops/ffs.h>
#include <asm-generic/bitops/hweight.h>