[PATCH 3/4] lib/gpgpu_shader: add inline support for iga64 assembly
Zbigniew Kempczyński
zbigniew.kempczynski at intel.com
Fri May 10 05:52:05 UTC 2024
On Mon, Apr 29, 2024 at 02:08:19PM +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.
>
> Signed-off-by: Andrzej Hajda <andrzej.hajda at intel.com>
> ---
> lib/generate_iga64_codes | 104 ++++++++++++++++++++++++++++++++++++++++++++
> lib/gpgpu_shader.c | 39 +++++++++++++++++
> lib/gpgpu_shader.h | 25 +++++++++++
> lib/iga64_generated_codes.c | 6 +++
> lib/iga64_macros.h | 10 +++++
> lib/meson.build | 18 ++++++++
> 6 files changed, 202 insertions(+)
>
> diff --git a/lib/generate_iga64_codes b/lib/generate_iga64_codes
> new file mode 100755
> index 000000000000..efc2a29b409c
> --- /dev/null
> +++ b/lib/generate_iga64_codes
> @@ -0,0 +1,104 @@
> +#!/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 $f.p/*.o; done)
> +
> +# check if we need to recompile - checksum difference and compiler present
> +MD5_ASMS="$(for a in "${ASMS[@]}"; do echo "${a#*:}"; done | md5sum|cut -b1-32)"
> +MD5_PRE="$(grep -Po '(?<=^#define MD5_SUM )\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
Great, igt will compile without iga if asm code md5 isn't changed.
> +
> +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 $OUTPUT
> + exit 0
> +}
This might be confusing. Binary existence is not enough, it should
support superset of platforms defined in GEN_VERIONS, otherwise someone
will be confused - libigc-tools is installed but why it is failing?
The best imo would be to compare platform supported in iga64 with
GEN_VERSIONS and print warning and switch to fallback and compile
with predefined file.
I'm still staring on your code so I might have more comments later.
Your solution how to keep inline assembly for gpu is impressive
and definitely we want to merge it.
--
Zbigniew
> +
> +# returns count of numbers in strings of format "0x1234, 0x23434, ..."
> +dword_count() {
> + n=${1//[^x]}
> + echo ${#n}
> +}
> +
> +# generate code file
> +WD=$OUTPUT.d
> +mkdir -p $WD
> +
> +echo "Generating new $OUTPUT"
> +
> +cat <<-EOF >$OUTPUT
> +/* SPDX-License-Identifier: MIT */
> +/* Generated using $(iga64 |& head -1) */
> +
> +#include "gpgpu_shader.h"
> +
> +#define MD5_SUM $MD5_ASMS
> +EOF
> +
> +for asm in "${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/lib/gpgpu_shader.c b/lib/gpgpu_shader.c
> index d14301789421..3317e9e35c91 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);
> +}
> +
> +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];
> + }
> +
> + 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..0b997deba8bb 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..449c5e9bcf31
> --- /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 d41d8cd98f00b204e9800998ecf8427e
> diff --git a/lib/iga64_macros.h b/lib/iga64_macros.h
> new file mode 100644
> index 000000000000..33375763a1d0
> --- /dev/null
> +++ b/lib/iga64_macros.h
> @@ -0,0 +1,10 @@
> +/* SPDX-License-Identifier: MIT */
> +
> +#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
> diff --git a/lib/meson.build b/lib/meson.build
> index 0a3084f8aea2..843c74e5187f 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 +233,23 @@ foreach f: lib_sources
> ])
>
> lib_intermediates += lib
> + if f in iga64_assembly_sources
> + iga64_assembly_libs += lib
> + endif
> endforeach
>
> +iga64_generated_codes = custom_target(
> + 'iga64_generated_codes.c',
> + output : 'iga64_generated_codes.c',
> + input : [ 'iga64_generated_codes.c' ] + iga64_assembly_libs,
> + command : [ './generate_iga64_codes', '-o', '@OUTPUT@', '-i', '@INPUT@' ],
> + depend_files: [ 'generate_iga64_codes' ]
> +)
> +
> +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,
>
> --
> 2.34.1
>
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