From: Oleksii Kurochko <oleksii.kurochko@gmail.com>
To: xen-devel@lists.xenproject.org
Cc: "Oleksii Kurochko" <oleksii.kurochko@gmail.com>,
"Stefano Stabellini" <sstabellini@kernel.org>,
"Julien Grall" <julien@xen.org>,
"Bertrand Marquis" <bertrand.marquis@arm.com>,
"Michal Orzel" <michal.orzel@amd.com>,
"Volodymyr Babchuk" <Volodymyr_Babchuk@epam.com>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"George Dunlap" <george.dunlap@citrix.com>,
"Jan Beulich" <jbeulich@suse.com>,
"Shawn Anastasio" <sanastasio@raptorengineering.com>,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: [PATCH v9 03/15] xen/bitops: implement fls{l}() in common logic
Date: Mon, 6 May 2024 12:15:12 +0200 [thread overview]
Message-ID: <fe183f7e8ada7c3fb00ebf9b38f1fffffcc9c2d7.1714988096.git.oleksii.kurochko@gmail.com> (raw)
In-Reply-To: <cover.1714988096.git.oleksii.kurochko@gmail.com>
To avoid the compilation error below, it is needed to update to places
in common/page_alloc.c where flsl() is used as now flsl() returns unsigned int:
./include/xen/kernel.h:18:21: error: comparison of distinct pointer types lacks a cast [-Werror]
18 | (void) (&_x == &_y); \
| ^~
common/page_alloc.c:1843:34: note: in expansion of macro 'min'
1843 | unsigned int inc_order = min(MAX_ORDER, flsl(e - s) - 1);
generic_fls{l} was used instead of __builtin_clz{l}(x) as if x is 0,
the result in undefined.
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
The patch is almost independent from Andrew's patch series
( https://lore.kernel.org/xen-devel/20240313172716.2325427-1-andrew.cooper3@citrix.com/T/#t)
except test_fls() function which IMO can be merged as a separate patch after Andrew's patch
will be fully ready.
---
Changes in V9:
- update return type of fls and flsl() to unsigned int to be aligned with other
bit ops.
- update places where return value of fls() and flsl() is compared with int.
- update the commit message.
---
Changes in V8:
- do proper rebase: back definition of fls{l} to the current patch.
- drop the changes which removed ffz() in PPC. it should be done not
in this patch.
- add a message after Signed-off.
---
Changes in V7:
- Code style fixes
---
Changes in V6:
- new patch for the patch series.
---
xen/arch/arm/include/asm/arm32/bitops.h | 2 +-
xen/arch/arm/include/asm/arm64/bitops.h | 6 ++----
xen/arch/arm/include/asm/bitops.h | 7 ++-----
xen/arch/ppc/include/asm/bitops.h | 3 ---
xen/arch/x86/include/asm/bitops.h | 6 ++++--
xen/common/bitops.c | 22 ++++++++++++++++++++++
xen/common/page_alloc.c | 4 ++--
xen/include/xen/bitops.h | 24 ++++++++++++++++++++++++
8 files changed, 57 insertions(+), 17 deletions(-)
diff --git a/xen/arch/arm/include/asm/arm32/bitops.h b/xen/arch/arm/include/asm/arm32/bitops.h
index d0309d47c1..5552d4e945 100644
--- a/xen/arch/arm/include/asm/arm32/bitops.h
+++ b/xen/arch/arm/include/asm/arm32/bitops.h
@@ -1,7 +1,7 @@
#ifndef _ARM_ARM32_BITOPS_H
#define _ARM_ARM32_BITOPS_H
-#define flsl fls
+#define arch_flsl fls
/*
* Little endian assembly bitops. nr = 0 -> byte 0 bit 0.
diff --git a/xen/arch/arm/include/asm/arm64/bitops.h b/xen/arch/arm/include/asm/arm64/bitops.h
index 0efde29068..5f5d97faa0 100644
--- a/xen/arch/arm/include/asm/arm64/bitops.h
+++ b/xen/arch/arm/include/asm/arm64/bitops.h
@@ -22,17 +22,15 @@ static /*__*/always_inline unsigned long __ffs(unsigned long word)
*/
#define ffz(x) __ffs(~(x))
-static inline int flsl(unsigned long x)
+static inline int arch_flsl(unsigned long x)
{
uint64_t ret;
- if (__builtin_constant_p(x))
- return generic_flsl(x);
-
asm("clz\t%0, %1" : "=r" (ret) : "r" (x));
return BITS_PER_LONG - ret;
}
+#define arch_flsl arch_flsl
/* Based on linux/include/asm-generic/bitops/find.h */
diff --git a/xen/arch/arm/include/asm/bitops.h b/xen/arch/arm/include/asm/bitops.h
index 8e16335e76..860d6d4689 100644
--- a/xen/arch/arm/include/asm/bitops.h
+++ b/xen/arch/arm/include/asm/bitops.h
@@ -78,17 +78,14 @@ bool clear_mask16_timeout(uint16_t mask, volatile void *p,
* the clz instruction for much better code efficiency.
*/
-static inline int fls(unsigned int x)
+static inline int arch_fls(unsigned int x)
{
int ret;
- if (__builtin_constant_p(x))
- return generic_fls(x);
-
asm("clz\t%"__OP32"0, %"__OP32"1" : "=r" (ret) : "r" (x));
return 32 - ret;
}
-
+#define arch_fls arch_fls
#define arch_ffs(x) ({ unsigned int __t = (x); fls(ISOLATE_LSB(__t)); })
#define arch_ffsl(x) ({ unsigned long __t = (x); flsl(ISOLATE_LSB(__t)); })
diff --git a/xen/arch/ppc/include/asm/bitops.h b/xen/arch/ppc/include/asm/bitops.h
index e2b6473c8c..ca308fd62b 100644
--- a/xen/arch/ppc/include/asm/bitops.h
+++ b/xen/arch/ppc/include/asm/bitops.h
@@ -119,9 +119,6 @@ static inline int test_and_set_bit(unsigned int nr, volatile void *addr)
(volatile unsigned int *)addr + BITOP_WORD(nr)) != 0;
}
-#define flsl(x) generic_flsl(x)
-#define fls(x) generic_fls(x)
-
/* Based on linux/include/asm-generic/bitops/ffz.h */
/*
* ffz - find first zero in word.
diff --git a/xen/arch/x86/include/asm/bitops.h b/xen/arch/x86/include/asm/bitops.h
index 23f09fdb7a..8f3d76fe44 100644
--- a/xen/arch/x86/include/asm/bitops.h
+++ b/xen/arch/x86/include/asm/bitops.h
@@ -425,7 +425,7 @@ static always_inline unsigned int arch_ffsl(unsigned long x)
*
* This is defined the same way as ffs.
*/
-static inline int flsl(unsigned long x)
+static always_inline int arch_flsl(unsigned long x)
{
long r;
@@ -435,8 +435,9 @@ static inline int flsl(unsigned long x)
"1:" : "=r" (r) : "rm" (x));
return (int)r+1;
}
+#define arch_flsl arch_flsl
-static inline int fls(unsigned int x)
+static always_inline int arch_fls(unsigned int x)
{
int r;
@@ -446,6 +447,7 @@ static inline int fls(unsigned int x)
"1:" : "=r" (r) : "rm" (x));
return r + 1;
}
+#define arch_fls arch_fls
/**
* hweightN - returns the hamming weight of a N-bit word
diff --git a/xen/common/bitops.c b/xen/common/bitops.c
index a8c32f6767..95bc47176b 100644
--- a/xen/common/bitops.c
+++ b/xen/common/bitops.c
@@ -62,9 +62,31 @@ static void test_ffs(void)
CHECK(ffs64, (uint64_t)0x8000000000000000, 64);
}
+static void test_fls(void)
+{
+ /* unsigned int ffs(unsigned int) */
+ CHECK(fls, 1, 1);
+ CHECK(fls, 3, 2);
+ CHECK(fls, 3U << 30, 32);
+
+ /* unsigned int flsl(unsigned long) */
+ CHECK(flsl, 1, 1);
+ CHECK(flsl, 1UL << (BITS_PER_LONG - 1), BITS_PER_LONG);
+#if BITS_PER_LONG > 32
+ CHECK(flsl, 3UL << 32, 34);
+#endif
+
+ /* unsigned int fls64(uint64_t) */
+ CHECK(fls64, 1, 1);
+ CHECK(fls64, 0x00000000C0000000ULL, 32);
+ CHECK(fls64, 0x0000000180000000ULL, 33);
+ CHECK(fls64, 0xC000000000000000ULL, 64);
+}
+
static int __init cf_check test_bitops(void)
{
test_ffs();
+ test_fls();
return 0;
}
diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index be4ba3962a..eed6b2a901 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -1842,7 +1842,7 @@ static void _init_heap_pages(const struct page_info *pg,
* Note that the value of ffsl() and flsl() starts from 1 so we need
* to decrement it by 1.
*/
- unsigned int inc_order = min(MAX_ORDER, flsl(e - s) - 1);
+ unsigned int inc_order = min(MAX_ORDER + 0U, flsl(e - s) - 1);
if ( s )
inc_order = min(inc_order, ffsl(s) - 1U);
@@ -2266,7 +2266,7 @@ void __init xenheap_max_mfn(unsigned long mfn)
ASSERT(!first_node_initialised);
ASSERT(!xenheap_bits);
BUILD_BUG_ON((PADDR_BITS - PAGE_SHIFT) >= BITS_PER_LONG);
- xenheap_bits = min(flsl(mfn + 1) - 1 + PAGE_SHIFT, PADDR_BITS);
+ xenheap_bits = min(flsl(mfn + 1) - 1 + PAGE_SHIFT, PADDR_BITS + 0U);
printk(XENLOG_INFO "Xen heap: %u bits\n", xenheap_bits);
}
diff --git a/xen/include/xen/bitops.h b/xen/include/xen/bitops.h
index 4f3399273a..f5be10b928 100644
--- a/xen/include/xen/bitops.h
+++ b/xen/include/xen/bitops.h
@@ -203,6 +203,30 @@ static always_inline bool test_bit(int nr, const volatile void *addr)
test_bit(nr, addr); \
})
+static always_inline __pure unsigned int fls(unsigned int x)
+{
+ if ( __builtin_constant_p(x) )
+ return generic_fls(x);
+
+#ifndef arch_fls
+#define arch_fls generic_fls
+#endif
+
+ return arch_fls(x);
+}
+
+static always_inline __pure unsigned int flsl(unsigned long x)
+{
+ if ( __builtin_constant_p(x) )
+ return generic_flsl(x);
+
+#ifndef arch_flsl
+#define arch_flsl generic_flsl
+#endif
+
+ return arch_flsl(x);
+}
+
/*
* Find First Set bit. Bits are labelled from 1.
*/
--
2.45.0
next prev parent reply other threads:[~2024-05-06 10:15 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-06 10:15 [PATCH v9 00/15] Enable build of full Xen for RISC-V Oleksii Kurochko
2024-05-06 10:15 ` [PATCH v9 01/15] xen/riscv: disable unnecessary configs Oleksii Kurochko
2024-05-06 10:15 ` [PATCH v9 02/15] xen: introduce generic non-atomic test_*bit() Oleksii Kurochko
2024-05-15 8:52 ` Jan Beulich
2024-05-15 15:29 ` Oleksii K.
2024-05-15 15:41 ` Jan Beulich
2024-05-15 17:03 ` Oleksii K.
2024-05-16 7:04 ` Jan Beulich
2024-05-16 10:34 ` Oleksii K.
2024-05-16 10:49 ` Jan Beulich
2024-05-17 8:42 ` Oleksii K.
2024-05-06 10:15 ` Oleksii Kurochko [this message]
2024-05-15 9:09 ` [PATCH v9 03/15] xen/bitops: implement fls{l}() in common logic Jan Beulich
2024-05-15 13:55 ` Oleksii K.
2024-05-15 14:07 ` Jan Beulich
2024-05-15 15:31 ` Oleksii K.
2024-05-17 9:06 ` Oleksii K.
2024-05-17 9:52 ` Jan Beulich
2024-05-06 10:15 ` [PATCH v9 04/15] xen/bitops: put __ffs() into linux compatible header Oleksii Kurochko
2024-05-15 14:34 ` Michal Orzel
2024-05-15 15:08 ` Rahul Singh
2024-05-06 10:15 ` [PATCH v9 05/15] xen/riscv: introduce bitops.h Oleksii Kurochko
2024-05-15 9:29 ` Jan Beulich
2024-05-06 10:15 ` [PATCH v9 06/15] xen/riscv: introduce cmpxchg.h Oleksii Kurochko
2024-05-15 9:38 ` Jan Beulich
2024-05-06 10:15 ` [PATCH v9 07/15] xen/riscv: introduce atomic.h Oleksii Kurochko
2024-05-15 9:49 ` Jan Beulich
2024-05-15 13:59 ` Oleksii K.
2024-05-06 10:15 ` [PATCH v9 08/15] xen/riscv: introduce monitor.h Oleksii Kurochko
2024-05-06 10:15 ` [PATCH v9 09/15] xen/riscv: add definition of __read_mostly Oleksii Kurochko
2024-05-06 10:15 ` [PATCH v9 10/15] xen/riscv: add required things to current.h Oleksii Kurochko
2024-05-06 10:15 ` [PATCH v9 11/15] xen/riscv: add minimal stuff to mm.h to build full Xen Oleksii Kurochko
2024-05-06 10:15 ` [PATCH v9 12/15] xen/riscv: introduce vm_event_*() functions Oleksii Kurochko
2024-05-06 10:15 ` [PATCH v9 13/15] xen/riscv: add minimal amount of stubs to build full Xen Oleksii Kurochko
2024-05-06 10:15 ` [PATCH v9 14/15] xen/riscv: enable full Xen build Oleksii Kurochko
2024-05-06 10:15 ` [PATCH v9 15/15] xen/README: add compiler and binutils versions for RISC-V64 Oleksii Kurochko
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