[PATCH v7 3/5] lib/gpgpu_shader: add inline support for iga64 assembly
Andrzej Hajda
andrzej.hajda at intel.com
Wed Jun 19 09:08:15 UTC 2024
On 19.06.2024 08:40, Zbigniew Kempczyński wrote:
> On Wed, Jun 12, 2024 at 11:39:01AM +0200, Andrzej Hajda wrote:
>> With this patch adding iga64 assembly should be similar to
>> adding x86 assembly inline. Simple example:
>> emit_iga64_code(shdr, set_exception, R"ASM(
>> or (1|M0) cr0.1<1>:ud cr0.1<0;1,0>:ud ARG(0):ud
>> )ASM", value);
>> Note presence of 'ARG(0)', it will be replaced by 'value' argument,
>> multiple arguments are possible.
>> More sophisticated examples in following patches.
>> How does it works:
>> 1. Raw string literals (C++ feature available in gcc as extension):
>> R"ASM(...)ASM" allows to use multiline/unescaped string literals.
>> If for some reason they cannot be used we could always fallback to
>> old ugly way of handling multiline strings with escape characters:
>> emit_iga64_code(shdr, set_exception, "\n\
>> or (1|M0) cr0.1<1>:ud cr0.1<0;1,0>:ud ARG(0):ud\n\
>> ", value);
>> 2. emit_iga64_code puts the assembly string into special linker section,
>> and calls __emit_iga64_code with pointer to external variable
>> which will contain code templates generated from the assembly for all
>> supported platforms, remaining arguments are put to temporal array
>> to eventually patch the code with positional arguments.
>> 3. During build phase the linker section is scanned for assemblies.
>> Every assembly is preprocessed with cpp, to replace ARG(x) macros with
>> magic numbers, and to provide different code for different platforms
>> if needed. Then output file is compiled with iga64, and then .c file
>> is generated with global variables pointing to hexified iga64 codes.
>>
>> v2:
>> - fixed meson paths to script,
>> - added check if compiler supports all platforms,
>> - include assembly names in MD5 calculations,
>> - use more specific name for MD5 sum
>> v3:
>> - bump minimal meson version to kill "ERROR: Expecting eol got id." bug
>> v4:
>> - set minimal meson to 0.49.2 - builder uses it
>> v5:
>> - revert back minimal ver of meson, instead use old syntax a.contains(b)
>> v6:
>> - generate_iga64_codes moved to scripts dir,
>> - added include guards to iga64_macros.h
>> v7:
>> - use C++ style comments in generated file,
>> - style fixes
>>
>> Signed-off-by: Andrzej Hajda <andrzej.hajda at intel.com>
>> ---
>> lib/gpgpu_shader.c | 39 +++++++++++++++
>> lib/gpgpu_shader.h | 25 ++++++++++
>> lib/iga64_generated_codes.c | 6 +++
>> lib/iga64_macros.h | 18 +++++++
>> lib/meson.build | 17 +++++++
>> meson.build | 9 ++--
>> scripts/generate_iga64_codes | 115 +++++++++++++++++++++++++++++++++++++++++++
>> scripts/meson.build | 1 +
>> 8 files changed, 226 insertions(+), 4 deletions(-)
>>
>> diff --git a/lib/gpgpu_shader.c b/lib/gpgpu_shader.c
>> index 080eef2445da..98a7ffc151ee 100644
>> --- a/lib/gpgpu_shader.c
>> +++ b/lib/gpgpu_shader.c
>> @@ -11,6 +11,9 @@
>> #include "gpgpu_shader.h"
>> #include "gpu_cmds.h"
>>
>> +#define IGA64_ARG0 0xc0ded000
>> +#define IGA64_ARG_MASK 0xffffff00
>> +
>> #define SUPPORTED_GEN_VER 1200 /* Support TGL and up */
>>
>> #define PAGE_SIZE 4096
>> @@ -22,6 +25,42 @@
>> #define GPGPU_CURBE_SIZE 0
>> #define GEN7_VFE_STATE_GPGPU_MODE 1
>>
>> +static void gpgpu_shader_extend(struct gpgpu_shader *shdr)
>> +{
>> + shdr->max_size <<= 1;
>> + shdr->code = realloc(shdr->code, 4 * shdr->max_size);
> Assert in case of unsuccessful realloc.
>
>> +}
>> +
>> +void
>> +__emit_iga64_code(struct gpgpu_shader *shdr, struct iga64_template const *tpls,
>> + int argc, uint32_t *argv)
>> +{
>> + uint32_t *ptr;
>> +
>> + igt_require_f(shdr->gen_ver >= SUPPORTED_GEN_VER,
>> + "No available shader templates for platforms older than XeLP\n");
>> +
>> + while (shdr->gen_ver < tpls->gen_ver)
>> + tpls++;
>> +
>> + while (shdr->max_size < shdr->size + tpls->size)
>> + gpgpu_shader_extend(shdr);
>> +
>> + ptr = shdr->code + shdr->size;
>> + memcpy(ptr, tpls->code, 4 * tpls->size);
>> +
>> + /* patch the template */
>> + for (int n, i = 0; i < tpls->size; ++i) {
>> + if ((ptr[i] & IGA64_ARG_MASK) != IGA64_ARG0)
>> + continue;
>> + n = ptr[i] - IGA64_ARG0;
>> + igt_assert(n < argc);
>> + ptr[i] = argv[n];
>> + }
> This is the part I'm afraid might be problematic. You've probably
> expected this question - how can you be sure, no instruction uses
> magic value as a part of instruction and it will be incidentally
> patched as well?
You can't be, there is minor chance it will be generated by some
configuration of bits, or
user crafted command:
add xxxx ARG(0) 0xc0ded0xx
I have just reused what we have internally, with reusing the risks as well.
>
> I think we can at least protect this in script part, by processing
> file twice - first with using some artificial macros file (instead
> iga64_macros.h), substitute all ARGs with 0x0 and check if your
> selected magic (0xc0ded0XX) doesn't exist. If it exists then it
> must be changed to something else. If not process this with
> iga64_macros.h and we're fine.
And you want to kill the potential excitement of developer/bug hunter
realizing such unusual configuration of stars (or bits) occurred :)
It will complicate the script but of course it is possible, it can be even:
foreach (ARG_MASK)
generate_and_check
I can try to play with it.
Regards
Andrzej
>
> --
> Zbigniew
>
>
>
>> +
>> + shdr->size += tpls->size;
>> +}
>> +
>> static uint32_t fill_sip(struct intel_bb *ibb,
>> const uint32_t sip[][4],
>> const size_t size)
>> diff --git a/lib/gpgpu_shader.h b/lib/gpgpu_shader.h
>> index 02f6f1aad1e3..255f93b4dd81 100644
>> --- a/lib/gpgpu_shader.h
>> +++ b/lib/gpgpu_shader.h
>> @@ -23,6 +23,27 @@ struct gpgpu_shader {
>> };
>> };
>>
>> +struct iga64_template {
>> + uint32_t gen_ver;
>> + uint32_t size;
>> + const uint32_t *code;
>> +};
>> +
>> +#pragma GCC diagnostic ignored "-Wnested-externs"
>> +
>> +void
>> +__emit_iga64_code(struct gpgpu_shader *shdr, const struct iga64_template *tpls,
>> + int argc, uint32_t *argv);
>> +
>> +#define emit_iga64_code(__shdr, __name, __txt, __args...) \
>> +({ \
>> + static const char t[] __attribute__ ((section(".iga64_assembly"), used)) =\
>> + "iga64_assembly_" #__name ":" __txt "\n"; \
>> + extern struct iga64_template const iga64_code_ ## __name[]; \
>> + u32 args[] = { __args }; \
>> + __emit_iga64_code(__shdr, iga64_code_ ## __name, ARRAY_SIZE(args), args); \
>> +})
>> +
>> struct gpgpu_shader *gpgpu_shader_create(int fd);
>> void gpgpu_shader_destroy(struct gpgpu_shader *shdr);
>>
>> @@ -35,4 +56,8 @@ void gpgpu_shader_exec(struct intel_bb *ibb,
>> struct gpgpu_shader *sip,
>> uint64_t ring, bool explicit_engine);
>>
>> +void gpgpu_shader__eot(struct gpgpu_shader *shdr);
>> +void gpgpu_shader__write_dword(struct gpgpu_shader *shdr, uint32_t value,
>> + uint32_t y_offset);
>> +
>> #endif /* GPGPU_SHADER_H */
>> diff --git a/lib/iga64_generated_codes.c b/lib/iga64_generated_codes.c
>> new file mode 100644
>> index 000000000000..452d4b3dae53
>> --- /dev/null
>> +++ b/lib/iga64_generated_codes.c
>> @@ -0,0 +1,6 @@
>> +// SPDX-License-Identifier: MIT
>> +// Generated using Intel Graphics Assembler 1.1.0-int
>> +
>> +#include "gpgpu_shader.h"
>> +
>> +#define MD5_SUM_IGA64_ASMS 68b329da9893e34099c7d8ad5cb9c940
>> diff --git a/lib/iga64_macros.h b/lib/iga64_macros.h
>> new file mode 100644
>> index 000000000000..394e95a21039
>> --- /dev/null
>> +++ b/lib/iga64_macros.h
>> @@ -0,0 +1,18 @@
>> +/* SPDX-License-Identifier: MIT */
>> +/* Copyright © 2024 Intel Corporation */
>> +
>> +/* Header used during pre-process phase of iga64 assembly. */
>> +
>> +#ifndef IGA64_MACROS_H
>> +#define IGA64_MACROS_H
>> +
>> +#define ARG(n) (0xc0ded000 + (n))
>> +
>> +/* send instruction for DG2+ requires 0 length in case src1 is null, BSpec: 47443 */
>> +#if GEN_VER < 1271
>> +#define src1_null null
>> +#else
>> +#define src1_null null:0
>> +#endif
>> +
>> +#endif
>> diff --git a/lib/meson.build b/lib/meson.build
>> index 0a3084f8aea2..82e7dacad153 100644
>> --- a/lib/meson.build
>> +++ b/lib/meson.build
>> @@ -216,7 +216,10 @@ lib_version = vcs_tag(input : 'version.h.in', output : 'version.h',
>> fallback : 'NO-GIT',
>> command : vcs_command )
>>
>> +iga64_assembly_sources = [ 'gpgpu_shader.c' ]
>> +
>> lib_intermediates = []
>> +iga64_assembly_libs = []
>> foreach f: lib_sources
>> name = f.underscorify()
>> lib = static_library('igt-' + name,
>> @@ -230,8 +233,22 @@ foreach f: lib_sources
>> ])
>>
>> lib_intermediates += lib
>> + if iga64_assembly_sources.contains(f)
>> + iga64_assembly_libs += lib
>> + endif
>> endforeach
>>
>> +iga64_generated_codes = custom_target(
>> + 'iga64_generated_codes.c',
>> + input : [ 'iga64_generated_codes.c' ] + iga64_assembly_libs,
>> + output : 'iga64_generated_codes.c',
>> + command : [ generate_iga64_codes, '-o', '@OUTPUT@', '-i', '@INPUT@' ]
>> +)
>> +
>> +lib_intermediates += static_library('igt-iga64_generated_codes.c',
>> + [ iga64_generated_codes, lib_version ]
>> + )
>> +
>> lib_igt_build = shared_library('igt',
>> ['dummy.c'],
>> link_whole: lib_intermediates,
>> diff --git a/meson.build b/meson.build
>> index ab44aadb1fdf..716a4d7bde85 100644
>> --- a/meson.build
>> +++ b/meson.build
>> @@ -341,6 +341,11 @@ else
>> vmwgfx_rpathdir = ''
>> endif
>>
>> +build_testplan = get_option('testplan')
>> +build_sphinx = get_option('sphinx')
>> +
>> +subdir('scripts')
>> +
>> subdir('lib')
>> if build_tests
>> subdir('tests')
>> @@ -349,9 +354,6 @@ else
>> endif
>> build_info += 'Build tests: @0@'.format(build_tests)
>>
>> -build_testplan = get_option('testplan')
>> -build_sphinx = get_option('sphinx')
>> -
>> subdir('benchmarks')
>> subdir('tools')
>> subdir('runner')
>> @@ -360,7 +362,6 @@ if libdrm_intel.found()
>> endif
>> subdir('overlay')
>> subdir('man')
>> -subdir('scripts')
>> subdir('docs')
>>
>> message('Build options')
>> diff --git a/scripts/generate_iga64_codes b/scripts/generate_iga64_codes
>> new file mode 100755
>> index 000000000000..8abfdc4c2009
>> --- /dev/null
>> +++ b/scripts/generate_iga64_codes
>> @@ -0,0 +1,115 @@
>> +#!/bin/bash
>> +# SPDX-License-Identifier: MIT
>> +# Copyright © 2024 Intel Corporation
>> +# Author: Andrzej Hajda <andrzej.hajda at intel.com>
>> +
>> +# List of supported platforms, in format gen100:platform, where gen100 equals
>> +# to minimal GPU generation supported by platform multiplied by 100 and platform
>> +# is one of platforms supported by -p switch of iga64.
>> +#
>> +# Must be in decreasing order, the last one must have gen100 equal 0"
>> +GEN_VERSIONS="2000:2 1272:12p72 1250:12p5 0:12p1"
>> +
>> +warn() {
>> + echo -e "$1" >/dev/stderr
>> +}
>> +
>> +die() {
>> + warn "DIE: $1"
>> + exit 1
>> +}
>> +
>> +# parse args
>> +while getopts ':i:o:' opt; do
>> + case $opt in
>> + i) INPUT=$OPTARG;;
>> + o) OUTPUT=$OPTARG;;
>> + ?) die "Usage: $0 -i pre-generated-iga64-file -o generated-iga64-file libs-with-iga64-assembly [...]"
>> + esac
>> +done
>> +LIBS=${@:OPTIND}
>> +
>> +# read all assemblies into ASMS array
>> +ASMS=()
>> +while read -d $'\0' asm; do
>> + test -z "$asm" && continue
>> + ASMS+=( "$asm" )
>> +done < <(for f in $LIBS; do objcopy --dump-section .iga64_assembly=/dev/stdout $f.p/*.o; done)
>> +
>> +# check if we need to recompile - checksum difference and compiler present
>> +MD5_ASMS="$(md5sum <<< "${ASMS[@]}" | cut -b1-32)"
>> +MD5_PRE="$(grep -Po '(?<=^#define MD5_SUM_IGA64_ASMS )\S{32,32}' $INPUT 2>/dev/null)"
>> +
>> +if [ "$MD5_ASMS" = "$MD5_PRE" ]; then
>> + echo "iga64 assemblies not changed, reusing pre-compiled file $INPUT."
>> + cp $INPUT $OUTPUT
>> + exit 0
>> +fi
>> +
>> +type iga64 >/dev/null || {
>> + warn "WARNING: iga64 assemblies changed, but iga64 compiler not present, CHANGES will have no effect. Install iga64 (libigc-tools package) to re-compile code."
>> + cp $INPUT $OUTPUT
>> + exit 0
>> +}
>> +
>> +# generate code file
>> +WD=$OUTPUT.d
>> +mkdir -p $WD
>> +
>> +# check if all required platforms are supported
>> +touch $WD/empty
>> +for gen in $GEN_VERSIONS; do
>> + gen_name="${gen#*:}"
>> + iga64 -p=$gen_name -d $WD/empty 2>/dev/null || {
>> + warn "WARNING: iga64 assemblies changed, but iga64 compiler does not support platform '$gen_name', CHANGES will have no effect. Update iga64 (libigc-tools package) to re-compile code."
>> + cp $INPUT $OUTPUT
>> + exit 0
>> + }
>> +done
>> +
>> +# returns count of numbers in strings of format "0x1234, 0x23434, ..."
>> +dword_count() {
>> + n=${1//[^x]}
>> + echo ${#n}
>> +}
>> +
>> +echo "Generating new $OUTPUT"
>> +
>> +cat <<-EOF >$OUTPUT
>> +// SPDX-License-Identifier: MIT
>> +// Generated using $(iga64 |& head -1)
>> +
>> +#include "gpgpu_shader.h"
>> +
>> +#define MD5_SUM_IGA64_ASMS $MD5_ASMS
>> +EOF
>> +
>> +for asm in "${ASMS[@]}"; do
>> + asm_name="${asm%%:*}"
>> + asm_code="${asm_name/assembly/code}"
>> + asm_body="${asm#*:}"
>> + cur_code=""
>> + cur_ver=""
>> + echo -e "\nstruct iga64_template const $asm_code[] = {" >>$OUTPUT
>> + for gen in $GEN_VERSIONS; do
>> + gen_ver="${gen%%:*}"
>> + gen_name="${gen#*:}"
>> + warn "Generating $asm_code for platform $gen_name"
>> + cmd="cpp -P - -o $WD/$asm_name.$gen_name.asm"
>> + cmd+=" -DGEN_VER=$gen_ver -imacros ../lib/iga64_macros.h"
>> + eval "$cmd" <<<"$asm_body" || die "cpp error for $asm_name.$gen_name\ncmd: $cmd"
>> + cmd="iga64 -Xauto-deps -Wall -p=$gen_name"
>> + cmd+=" $WD/$asm_name.$gen_name.asm -o $WD/$asm_name.$gen_name.bin"
>> + eval "$cmd" || die "iga64 error for $asm_name.$gen_name\ncmd: $cmd"
>> + code="$(hexdump -e '"\t\t" 4/4 "0x%08x, " "\n"' $WD/$asm_name.$gen_name.bin)"
>> + [ -z "$cur_code" ] && cur_code="$code"
>> + [ "$cur_code" != "$code" ] && {
>> + echo -e "\t{ .gen_ver = $cur_ver, .size = $(dword_count "$cur_code"), .code = (const uint32_t []) {\n$cur_code\n\t}}," >>$OUTPUT
>> + cur_code="$code"
>> + }
>> + cur_ver=$gen_ver
>> + done
>> + echo -e "\t{ .gen_ver = $cur_ver, .size = $(dword_count "$cur_code"), .code = (const uint32_t []) {\n$cur_code\n\t}}\n};" >>$OUTPUT
>> +done
>> +
>> +cp $OUTPUT $INPUT
>> diff --git a/scripts/meson.build b/scripts/meson.build
>> index 98783222b6fc..6e64065c5ee7 100644
>> --- a/scripts/meson.build
>> +++ b/scripts/meson.build
>> @@ -14,3 +14,4 @@ endif
>>
>> igt_doc_script = find_program('igt_doc.py', required : build_testplan)
>> gen_rst_index = find_program('gen_rst_index', required : build_sphinx)
>> +generate_iga64_codes = find_program('generate_iga64_codes')
>>
>> --
>> 2.34.1
>>
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