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From: Sylwester Nawrocki <s.nawrocki@samsung.com>
To: u-boot@lists.denx.de
Subject: [RESEND PATCH v3 6/9] linux/bitfield.h: Add primitives for manipulating bitfields both in host- and fixed-endian
Date: Tue, 12 May 2020 21:04:32 +0200	[thread overview]
Message-ID: <20200512190432.3916-1-s.nawrocki@samsung.com> (raw)
In-Reply-To: <20200512184716.2869-7-s.nawrocki@samsung.com>

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

Imports Al Viro's original Linux commit 00b0c9b82663a, which contains
an in depth explanation and two fixes from Johannes Berg:
 e7d4a95da86e0 "bitfield: fix *_encode_bits()",
 37a3862e12382 "bitfield: add u8 helpers".

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
[s.nawrocki: added empty lines between functions and macros]
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
---
Resending as I sent wrong version of [PATCH v3 6/9] by mistake.

Changes since v2:
 - added some more missing whitespaces as pointed out by checkpatch.pl.

Changes since v1:
 - added empty lines between functions and macros.

Changes since RFC:
 - new patch.
---
 include/linux/bitfield.h | 52 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h
index 8b9d6ff..7ad8b08 100644
--- a/include/linux/bitfield.h
+++ b/include/linux/bitfield.h
@@ -103,4 +103,56 @@
 		(typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask));	\
 	})

+extern void __compiletime_error("value doesn't fit into mask")
+__field_overflow(void);
+extern void __compiletime_error("bad bitfield mask")
+__bad_mask(void);
+
+static __always_inline u64 field_multiplier(u64 field)
+{
+	if ((field | (field - 1)) & ((field | (field - 1)) + 1))
+		__bad_mask();
+	return field & -field;
+}
+
+static __always_inline u64 field_mask(u64 field)
+{
+	return field / field_multiplier(field);
+}
+
+#define ____MAKE_OP(type, base, to, from)				\
+static __always_inline __##type type##_encode_bits(base v, base field)	\
+{									\
+	if (__builtin_constant_p(v) && (v & ~field_mask(field)))	\
+		__field_overflow();					\
+	return to((v & field_mask(field)) * field_multiplier(field));	\
+}									\
+static __always_inline __##type type##_replace_bits(__##type old,	\
+					base val, base field)		\
+{									\
+	return (old & ~to(field)) | type##_encode_bits(val, field);	\
+}									\
+static __always_inline void type##p_replace_bits(__##type * p,		\
+					base val, base field)		\
+{									\
+	*p = (*p & ~to(field)) | type##_encode_bits(val, field);	\
+}									\
+static __always_inline base type##_get_bits(__##type v, base field)	\
+{									\
+	return (from(v) & field) / field_multiplier(field);		\
+}
+
+#define __MAKE_OP(size)							\
+	____MAKE_OP(le##size, u##size, cpu_to_le##size, le##size##_to_cpu) \
+	____MAKE_OP(be##size, u##size, cpu_to_be##size, be##size##_to_cpu) \
+	____MAKE_OP(u##size, u##size, ,)
+
+____MAKE_OP(u8, u8, ,)
+__MAKE_OP(16)
+__MAKE_OP(32)
+__MAKE_OP(64)
+
+#undef __MAKE_OP
+#undef ____MAKE_OP
+
 #endif
--
2.7.4

  parent reply	other threads:[~2020-05-12 19:04 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20200512184724eucas1p24bb9730834234cebf5061a614c2c8c54@eucas1p2.samsung.com>
2020-05-12 18:47 ` [PATCH v3 0/9] USB host support for Raspberry Pi 4 board (64-bit) Sylwester Nawrocki
     [not found]   ` <CGME20200512184740eucas1p2912f07b9e34cc769604d641adb0e13c9@eucas1p2.samsung.com>
2020-05-12 18:47     ` [PATCH v3 1/9] usb: xhci: Add missing cache flush in the scratchpad array initialization Sylwester Nawrocki
     [not found]   ` <CGME20200512184743eucas1p28e9d93ba5e46ed900a88bf0bf85fda58@eucas1p2.samsung.com>
2020-05-12 18:47     ` [PATCH v3 2/9] usb: xhci: Use only 32-bit accesses in xhci_writeq/xhci_readq Sylwester Nawrocki
     [not found]   ` <CGME20200512184747eucas1p25ed7fb872416271dd34806ccfb4197e5@eucas1p2.samsung.com>
2020-05-12 18:47     ` [PATCH v3 3/9] pci: Move some PCIe register offset definitions to a common header Sylwester Nawrocki
     [not found]   ` <CGME20200512184829eucas1p10c67592f9af7879f51eee9bff8fa76d7@eucas1p1.samsung.com>
2020-05-12 18:47     ` [PATCH v3 4/9] rpi4: shorten a mapping for the DRAM Sylwester Nawrocki
     [not found]   ` <CGME20200512184830eucas1p198b1439122e2da299c563726fe17f9ef@eucas1p1.samsung.com>
2020-05-12 18:47     ` [PATCH v3 5/9] rpi4: add a mapping for the PCIe XHCI controller MMIO registers (ARM 64bit) Sylwester Nawrocki
     [not found]   ` <CGME20200512184832eucas1p1b75fca7f5ed42e3cb38f98410f51f1ad@eucas1p1.samsung.com>
2020-05-12 18:47     ` [PATCH v3 6/9] linux/bitfield.h: Add primitives for manipulating bitfields both in host- and fixed-endian Sylwester Nawrocki
     [not found]       ` <CGME20200512190442eucas1p278509fbc3a5d4bc7303797e5b8b284d6@eucas1p2.samsung.com>
2020-05-12 19:04         ` Sylwester Nawrocki [this message]
     [not found]   ` <CGME20200512184836eucas1p2f357a332cd99d6e287a74405d75c0985@eucas1p2.samsung.com>
2020-05-12 18:47     ` [PATCH v3 7/9] pci: Add some PCI Express capability register offset definitions Sylwester Nawrocki
     [not found]   ` <CGME20200512184838eucas1p249588f9ee76dcb5a10209fcb7de01fae@eucas1p2.samsung.com>
2020-05-12 18:47     ` [PATCH v3 8/9] pci: Add driver for Broadcom BCM2711 SoC PCIe controller Sylwester Nawrocki
     [not found]   ` <CGME20200512184842eucas1p1b2edc2128ddf134553805db77451648f@eucas1p1.samsung.com>
2020-05-12 18:47     ` [PATCH v3 9/9] configs: Enable support for the XHCI controller on RPI4 board (ARM 64-bit) Sylwester Nawrocki
2020-05-13  9:21       ` Sylwester Nawrocki
2020-05-24 18:30         ` Matthias Brugger
2020-05-25  9:25           ` Sylwester Nawrocki

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