PR #102607: Add support for Linux RISC-V 64

Imported from GitHub PR tensorflow/tensorflow#102607

This commit fixes #102159 which prevented TensorFlow from compiling on RISC-V 64 due to missing codepath in the build system.

RFC: Currently this patch overrides timeout of rules_python for all platforms which is obviously not ideal. How do we set pip package timeout here in Tensorflow?

See also:
- bazelbuild/bazel#25236
- bazelbuild/bazel#25699
- bazel-contrib/rules_python#3350
- #32812
- tensorflow/runtime#135
Copybara import of the project:

--
13b7db883e6ea0aa631490fb5f806c55ceea7cb5 by gns <[email protected]>:

[XLA:CPU] Add support for riscv64

Co-authored-by: Levi Zim <[email protected]>

--
a00c3a3ba94664798960cbc2fb0a6746fe0c3ac1 by gns <[email protected]>:

Add missing llvm:: namespace qualifiers for DTensor

Add the `llvm::` namespace prefix to `cast` and `isa`
where it was missing in the DTensor MLIR code.

--
febc5abc56ab302f5f39fe20176ed00c0c95cb7e by gns <[email protected]>:

runtime: add missing stdint header

Co-authored-by: Levi Zim <[email protected]>

--
6bf63fec56a6d961b06d932fe69b76eae89d8cb7 by gns <[email protected]>:

Add riscv64 support patch for rules_python

bazel-contrib/rules_python#3350

--
68c44fa9613d5577f36c51a192c932795e13ed83 by gns <[email protected]>:

tools: py: add riscv64 to pip and manylinux compilance test

--
3f2fe1e0256476449f64658219d997727c9cc534 by gns <[email protected]>:

Lift timeout of rules_python for BFS wheels

--
252a9b7ad2336b7abbb94e269b4a976b45d5d6e7 by gns <[email protected]>:

Revert llvm toolchain patch for riscv64

As already upstreamed.

Co-authored-by: Levi Zim <[email protected]>

--
51047a86131e991ffea74fccb8f55e3521237a64 by gns <[email protected]>:

Lift timeout for BFS wheels during pip init

--
3b8276420031969423c9a1f150341a0e41fa372e by gns <[email protected]>:

Refresh `rules_python` riscv64 patch

Co-authored-by: Levi Zim <[email protected]>

Merging this change closes #102607

FUTURE_COPYBARA_INTEGRATE_REVIEW=tensorflow/tensorflow#102607 from infiWang:riscv64 3b8276420031969423c9a1f150341a0e41fa372e
PiperOrigin-RevId: 825073762

Author: infiWang

third_party/py/python_init_pip.bzl

@@ -39,4 +39,5 @@ cc_library(
             "numpy": ["numpy_headers"],
         },
         requirements_lock = REQUIREMENTS_WITH_LOCAL_WHEELS,
+        timeout = 3600,
     )

third_party/py/python_init_rules.bzl

@@ -44,5 +44,6 @@ def python_init_rules(extra_patches = []):
             Label("//third_party/py:rules_python_pip_version.patch"),
             Label("//third_party/py:rules_python_freethreaded.patch"),
             Label("//third_party/py:rules_python_versions.patch"),
+            Label("//third_party/py:rules_python_riscv64_pypi.patch"),
         ] + extra_patches,
     )

third_party/py/rules_python_riscv64_pypi.patch

@@ -0,0 +1,131 @@
+From: Levi Zim <[email protected]>
+Date: Sun, 26 Oct 2025 12:35:53 +0800
+Subject: [PATCH] fix: Add linux_riscv64 to _pip_repository_impl (#3350)
+
+Add `linux_riscv64` support for pulling pip dependencies. This is not
+adding any hermetic toolchain support - user has to provide a working
+toolchain.
+
+Fix #2729
+
+---------
+
+Co-authored-by: Ignas Anikevicius <[email protected]>
+---
+ python/private/pypi/pip_repository.bzl                    | 1 +
+ python/private/pypi/whl_installer/platform.py             | 3 +++
+ python/private/pypi/whl_target_platforms.bzl              | 1 +
+ tests/pypi/whl_installer/platform_test.py                 | 6 +++---
+ .../whl_target_platforms/whl_target_platforms_tests.bzl   | 8 ++++++++
+ 5 files changed, 16 insertions(+), 3 deletions(-)
+
+diff --git a/python/private/pypi/pip_repository.bzl b/python/private/pypi/pip_repository.bzl
+index e9a4c44da3..d635651039 100644
+--- a/python/private/pypi/pip_repository.bzl
++++ b/python/private/pypi/pip_repository.bzl
+@@ -96,6 +96,7 @@ def _pip_repository_impl(rctx):
+                 "linux_aarch64",
+                 "linux_arm",
+                 "linux_ppc",
++                "linux_riscv64",
+                 "linux_s390x",
+                 "linux_x86_64",
+                 "osx_aarch64",
+diff --git a/python/private/pypi/whl_installer/platform.py b/python/private/pypi/whl_installer/platform.py
+index ff267fe4aa..0757d86990 100644
+--- a/python/private/pypi/whl_installer/platform.py
++++ b/python/private/pypi/whl_installer/platform.py
+@@ -45,6 +45,7 @@ class Arch(Enum):
+     ppc64le = 5
+     s390x = 6
+     arm = 7
++    riscv64 = 8
+     amd64 = x86_64
+     arm64 = aarch64
+     i386 = x86_32
+@@ -269,6 +270,8 @@ def platform_machine(self) -> str:
+             return "ppc"
+         elif self.arch == Arch.ppc64le:
+             return "ppc64le"
++        elif self.arch == Arch.riscv64:
++            return "riscv64"
+         elif self.arch == Arch.s390x:
+             return "s390x"
+         else:
+diff --git a/python/private/pypi/whl_target_platforms.bzl b/python/private/pypi/whl_target_platforms.bzl
+index 6c3dd5da83..28547c679c 100644
+--- a/python/private/pypi/whl_target_platforms.bzl
++++ b/python/private/pypi/whl_target_platforms.bzl
+@@ -30,6 +30,7 @@ _CPU_ALIASES = {
+     "ppc": "ppc",
+     "ppc64": "ppc",
+     "ppc64le": "ppc64le",
++    "riscv64": "riscv64",
+     "s390x": "s390x",
+     "arm": "arm",
+     "armv6l": "arm",
+diff --git a/tests/pypi/whl_installer/platform_test.py b/tests/pypi/whl_installer/platform_test.py
+index ad65650779..0d944bb196 100644
+--- a/tests/pypi/whl_installer/platform_test.py
++++ b/tests/pypi/whl_installer/platform_test.py
+@@ -38,17 +38,17 @@ def test_can_get_specific_from_string(self):
+ 
+     def test_can_get_all_for_py_version(self):
+         cp39 = Platform.all(minor_version=9, micro_version=0)
+-        self.assertEqual(21, len(cp39), f"Got {cp39}")
++        self.assertEqual(24, len(cp39), f"Got {cp39}")
+         self.assertEqual(cp39, Platform.from_string("cp39.0_*"))
+ 
+     def test_can_get_all_for_os(self):
+         linuxes = Platform.all(OS.linux, minor_version=9)
+-        self.assertEqual(7, len(linuxes))
++        self.assertEqual(8, len(linuxes))
+         self.assertEqual(linuxes, Platform.from_string("cp39_linux_*"))
+ 
+     def test_can_get_all_for_os_for_host_python(self):
+         linuxes = Platform.all(OS.linux)
+-        self.assertEqual(7, len(linuxes))
++        self.assertEqual(8, len(linuxes))
+         self.assertEqual(linuxes, Platform.from_string("linux_*"))
+ 
+     def test_platform_sort(self):
+diff --git a/tests/pypi/whl_target_platforms/whl_target_platforms_tests.bzl b/tests/pypi/whl_target_platforms/whl_target_platforms_tests.bzl
+index a976a0cf95..6bec26c10c 100644
+--- a/tests/pypi/whl_target_platforms/whl_target_platforms_tests.bzl
++++ b/tests/pypi/whl_target_platforms/whl_target_platforms_tests.bzl
+@@ -34,6 +34,9 @@ def _test_simple(env):
+         "musllinux_1_1_ppc64le": [
+             struct(os = "linux", cpu = "ppc64le", abi = None, target_platform = "linux_ppc64le", version = (1, 1)),
+         ],
++        "musllinux_1_2_riscv64": [
++            struct(os = "linux", cpu = "riscv64", abi = None, target_platform = "linux_riscv64", version = (1, 2)),
++        ],
+         "win_amd64": [
+             struct(os = "windows", cpu = "x86_64", abi = None, target_platform = "windows_x86_64", version = (0, 0)),
+         ],
+@@ -66,6 +69,9 @@ def _test_with_abi(env):
+         "musllinux_1_1_ppc64le": [
+             struct(os = "linux", cpu = "ppc64le", abi = "cp311", target_platform = "cp311_linux_ppc64le", version = (1, 1)),
+         ],
++        "musllinux_1_2_riscv64": [
++            struct(os = "linux", cpu = "riscv64", abi = "cp311", target_platform = "cp311_linux_riscv64", version = (1, 2)),
++        ],
+         "win_amd64": [
+             struct(os = "windows", cpu = "x86_64", abi = "cp311", target_platform = "cp311_windows_x86_64", version = (0, 0)),
+         ],
+@@ -103,6 +109,7 @@ def _can_parse_existing_tags(env):
+         "manylinux_11_12_i686": 1,
+         "manylinux_11_12_ppc64": 1,
+         "manylinux_11_12_ppc64le": 1,
++        "manylinux_11_12_riscv64": 1,
+         "manylinux_11_12_s390x": 1,
+         "manylinux_11_12_x86_64": 1,
+         "manylinux_1_2_aarch64": 1,
+@@ -111,6 +118,7 @@ def _can_parse_existing_tags(env):
+         "musllinux_11_12_armv7l": 1,
+         "musllinux_11_12_i686": 1,
+         "musllinux_11_12_ppc64le": 1,
++        "musllinux_11_12_riscv64": 1,
+         "musllinux_11_12_s390x": 1,
+         "musllinux_11_12_x86_64": 1,
+         "win32": 1,