Re: [PATCH v2 06/25] util: Add CRC16 (CCITT) calculation routines
On 1/24/21 10:41 PM, Richard Henderson wrote: > On 1/24/21 10:24 AM, Philippe Mathieu-Daudé wrote: >> On 1/24/21 9:07 PM, Richard Henderson wrote: >>> Doesn't this get put in libutil, where it is only pulled from the archive >>> when >>> needed? Also, libutil is built once, not per-target. >> >> Hmm I just sent a pull request with this change squashed in. >> Should I cancel it? > > I guess not. > >> My view is we don't install libqemuutil.a anywhere, so why overload >> building unused objects when some configuration don't need it? > > My view is that util/meson.build should not be overly complicated with > conditionals. Well I do see an impact when building on slow hosts. > If we were building objects per-target, that would be one thing. If we were > doing --whole-archive, and including unused code in the executables, that > would > be another thing. But otherwise... I understand your position :) Thanks, Phil.
Re: [PATCH v2 06/25] util: Add CRC16 (CCITT) calculation routines
On 1/24/21 10:24 AM, Philippe Mathieu-Daudé wrote: > On 1/24/21 9:07 PM, Richard Henderson wrote: >> Doesn't this get put in libutil, where it is only pulled from the archive >> when >> needed? Also, libutil is built once, not per-target. > > Hmm I just sent a pull request with this change squashed in. > Should I cancel it? I guess not. > My view is we don't install libqemuutil.a anywhere, so why overload > building unused objects when some configuration don't need it? My view is that util/meson.build should not be overly complicated with conditionals. If we were building objects per-target, that would be one thing. If we were doing --whole-archive, and including unused code in the executables, that would be another thing. But otherwise... r~
Re: [PATCH v2 06/25] util: Add CRC16 (CCITT) calculation routines
On 1/24/21 9:07 PM, Richard Henderson wrote:
> On 1/24/21 8:59 AM, Philippe Mathieu-Daudé wrote:
>> On 1/23/21 11:39 AM, Bin Meng wrote:
>>> From: Bin Meng
>>>
>>> Import CRC16 calculation routines from Linux kernel v5.10:
>>>
>>> include/linux/crc-ccitt.h
>>> lib/crc-ccitt.c
>>>
>>> to QEMU:
>>>
>>> include/qemu/crc-ccitt.h
>>> util/crc-ccitt.c
>>>
>>> Signed-off-by: Bin Meng
>>> Acked-by: Alistair Francis
>>> ---
>>>
>>> (no changes since v1)
>>>
>>> include/qemu/crc-ccitt.h | 33 ++
>>> util/crc-ccitt.c | 127 +++
>>> util/meson.build | 1 +
>>> 3 files changed, 161 insertions(+)
>>> create mode 100644 include/qemu/crc-ccitt.h
>>> create mode 100644 util/crc-ccitt.c
>> ...
>>
>>> diff --git a/util/meson.build b/util/meson.build
>>> index 540a605b78..05a376ae02 100644
>>> --- a/util/meson.build
>>> +++ b/util/meson.build
>>> @@ -29,6 +29,7 @@ util_ss.add(files('qemu-config.c', 'notify.c'))
>>> util_ss.add(files('qemu-option.c', 'qemu-progress.c'))
>>> util_ss.add(files('keyval.c'))
>>> util_ss.add(files('crc32c.c'))
>>> +util_ss.add(files('crc-ccitt.c'))
>>
>> OK but we can restrict this to system-mode emulation, as user-mode
>> and tools don't require it.
>
> Doesn't this get put in libutil, where it is only pulled from the archive when
> needed? Also, libutil is built once, not per-target.
Hmm I just sent a pull request with this change squashed in.
Should I cancel it?
My view is we don't install libqemuutil.a anywhere, so why overload
building unused objects when some configuration don't need it?
Some of the configurations I test:
- build tools only
- build linux-user only
dbus.o and yank.o are also restricted to have_system.
various objects are restricted to have_block (which is
have_system or have_tools).
Re: [PATCH v2 06/25] util: Add CRC16 (CCITT) calculation routines
On 1/24/21 8:59 AM, Philippe Mathieu-Daudé wrote:
> On 1/23/21 11:39 AM, Bin Meng wrote:
>> From: Bin Meng
>>
>> Import CRC16 calculation routines from Linux kernel v5.10:
>>
>> include/linux/crc-ccitt.h
>> lib/crc-ccitt.c
>>
>> to QEMU:
>>
>> include/qemu/crc-ccitt.h
>> util/crc-ccitt.c
>>
>> Signed-off-by: Bin Meng
>> Acked-by: Alistair Francis
>> ---
>>
>> (no changes since v1)
>>
>> include/qemu/crc-ccitt.h | 33 ++
>> util/crc-ccitt.c | 127 +++
>> util/meson.build | 1 +
>> 3 files changed, 161 insertions(+)
>> create mode 100644 include/qemu/crc-ccitt.h
>> create mode 100644 util/crc-ccitt.c
> ...
>
>> diff --git a/util/meson.build b/util/meson.build
>> index 540a605b78..05a376ae02 100644
>> --- a/util/meson.build
>> +++ b/util/meson.build
>> @@ -29,6 +29,7 @@ util_ss.add(files('qemu-config.c', 'notify.c'))
>> util_ss.add(files('qemu-option.c', 'qemu-progress.c'))
>> util_ss.add(files('keyval.c'))
>> util_ss.add(files('crc32c.c'))
>> +util_ss.add(files('crc-ccitt.c'))
>
> OK but we can restrict this to system-mode emulation, as user-mode
> and tools don't require it.
Doesn't this get put in libutil, where it is only pulled from the archive when
needed? Also, libutil is built once, not per-target.
r~
Re: [PATCH v2 06/25] util: Add CRC16 (CCITT) calculation routines
On 1/23/21 11:39 AM, Bin Meng wrote:
> From: Bin Meng
>
> Import CRC16 calculation routines from Linux kernel v5.10:
>
> include/linux/crc-ccitt.h
> lib/crc-ccitt.c
>
> to QEMU:
>
> include/qemu/crc-ccitt.h
> util/crc-ccitt.c
>
> Signed-off-by: Bin Meng
> Acked-by: Alistair Francis
> ---
>
> (no changes since v1)
>
> include/qemu/crc-ccitt.h | 33 ++
> util/crc-ccitt.c | 127 +++
> util/meson.build | 1 +
> 3 files changed, 161 insertions(+)
> create mode 100644 include/qemu/crc-ccitt.h
> create mode 100644 util/crc-ccitt.c
...
> diff --git a/util/meson.build b/util/meson.build
> index 540a605b78..05a376ae02 100644
> --- a/util/meson.build
> +++ b/util/meson.build
> @@ -29,6 +29,7 @@ util_ss.add(files('qemu-config.c', 'notify.c'))
> util_ss.add(files('qemu-option.c', 'qemu-progress.c'))
> util_ss.add(files('keyval.c'))
> util_ss.add(files('crc32c.c'))
> +util_ss.add(files('crc-ccitt.c'))
OK but we can restrict this to system-mode emulation, as user-mode
and tools don't require it.
Reviewed-by: Philippe Mathieu-Daudé
[PATCH v2 06/25] util: Add CRC16 (CCITT) calculation routines
From: Bin Meng
Import CRC16 calculation routines from Linux kernel v5.10:
include/linux/crc-ccitt.h
lib/crc-ccitt.c
to QEMU:
include/qemu/crc-ccitt.h
util/crc-ccitt.c
Signed-off-by: Bin Meng
Acked-by: Alistair Francis
---
(no changes since v1)
include/qemu/crc-ccitt.h | 33 ++
util/crc-ccitt.c | 127 +++
util/meson.build | 1 +
3 files changed, 161 insertions(+)
create mode 100644 include/qemu/crc-ccitt.h
create mode 100644 util/crc-ccitt.c
diff --git a/include/qemu/crc-ccitt.h b/include/qemu/crc-ccitt.h
new file mode 100644
index 00..06ee55b159
--- /dev/null
+++ b/include/qemu/crc-ccitt.h
@@ -0,0 +1,33 @@
+/*
+ * CRC16 (CCITT) Checksum Algorithm
+ *
+ * Copyright (c) 2021 Wind River Systems, Inc.
+ *
+ * Author:
+ * Bin Meng
+ *
+ * From Linux kernel v5.10 include/linux/crc-ccitt.h
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef _CRC_CCITT_H
+#define _CRC_CCITT_H
+
+extern uint16_t const crc_ccitt_table[256];
+extern uint16_t const crc_ccitt_false_table[256];
+
+extern uint16_t crc_ccitt(uint16_t crc, const uint8_t *buffer, size_t len);
+extern uint16_t crc_ccitt_false(uint16_t crc, const uint8_t *buffer, size_t
len);
+
+static inline uint16_t crc_ccitt_byte(uint16_t crc, const uint8_t c)
+{
+return (crc >> 8) ^ crc_ccitt_table[(crc ^ c) & 0xff];
+}
+
+static inline uint16_t crc_ccitt_false_byte(uint16_t crc, const uint8_t c)
+{
+return (crc << 8) ^ crc_ccitt_false_table[(crc >> 8) ^ c];
+}
+
+#endif /* _CRC_CCITT_H */
diff --git a/util/crc-ccitt.c b/util/crc-ccitt.c
new file mode 100644
index 00..b981d8ac55
--- /dev/null
+++ b/util/crc-ccitt.c
@@ -0,0 +1,127 @@
+/*
+ * CRC16 (CCITT) Checksum Algorithm
+ *
+ * Copyright (c) 2021 Wind River Systems, Inc.
+ *
+ * Author:
+ * Bin Meng
+ *
+ * From Linux kernel v5.10 lib/crc-ccitt.c
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/crc-ccitt.h"
+
+/*
+ * This mysterious table is just the CRC of each possible byte. It can be
+ * computed using the standard bit-at-a-time methods. The polynomial can
+ * be seen in entry 128, 0x8408. This corresponds to x^0 + x^5 + x^12.
+ * Add the implicit x^16, and you have the standard CRC-CCITT.
+ */
+uint16_t const crc_ccitt_table[256] = {
+0x, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
+0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
+0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
+0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
+0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
+0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
+0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
+0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
+0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
+0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
+0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
+0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
+0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
+0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
+0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
+0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
+0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
+0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
+0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
+0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
+0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
+0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
+0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
+0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
+0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
+0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
+0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
+0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
+0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
+0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
+0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
+0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
+};
+
+/*
+ * Similar table to calculate CRC16 variant known as CRC-CCITT-FALSE
+ * Reflected bits order, does not augment final value.
+ */
+uint16_t const crc_ccitt_false_table[256] = {
+0x, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
+0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
+0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6,
+0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
