I found plenty of patches!
They are for NVIDIA-Linux-x86_64-390.157.run self-extracting archive, which contains some C stubs (BUT SO MUCH of files!! Semi-open-source?)
•Getting source (not knowing yet if it is a whole driver (w/o blob), or patches' part only...):
Patch list is huge (https://github.com/aroldobossoni/nvidia-390-modern-kernel/blob/main/install_nvidia_patches.sh):
"do-div-cast.patch"
"kernel-4.16+-memory-encryption.patch"
"0018-backport-nv_install_notifier-changes-from-418.30.patch"
"nvidia-390xx-kmod-0024-kernel-6.2-adaptation.patch"
"nvidia-390xx-kmod-0025-kernel-6.3-adaptation.patch"
"nvidia-390xx-kmod-0026-kernel-6.4-adaptation.patch"
"nvidia-390xx-kmod-0027-kernel-6.5-garbage-collect-all-references-to-get_user.patch"
"nvidia-390xx-kmod-0028-kernel-6.5-handle-get_user_pages-vmas-argument-remova.patch"
"nvidia-390xx-kmod-0029-kernel-6.6-backport-drm_gem_prime_handle_to_fd-changes-from-470.patch"
"nvidia-390xx-kmod-0030-kernel-6.6-refuse-to-load-legacy-module-if-IBT-is-enabled.patch"
"nvidia-390xx-kmod-0031-kernel-6.8-adaptation.patch"
"nvidia-390xx-kmod-0032-kernel-6.8-conftest_h-wait_on_bit_lock.patch"
"nvidia-390xx-kmod-0033-kernel-5.6-ioremap_nocache_removed.patch"
"nvidia-390xx-kmod-0034-kernel-5.9-dma_is_direct-removed.patch"
"nvidia-390xx-kmod-0035-gcc14-no-previous-prototype-for-nv_load_dma_map_scatterlist.patch"
"nvidia-390xx-kmod-0036-undef-NV_ACPI_BUS_GET_DEVICE_PRESENT-in-conftest_sh.patch"
"nvidia-390xx-kmod-0037-add-RPM_CFLAGS-setup-in-conftest_sh.patch"
"nvidia-390xx-kmod-0038-workaround-NV_EFI_ENABLED-macro.patch"
"nvidia-390xx-kmod-0039-incompatible-function-type-nv_gpu_numa_c.patch"
"nvidia-390xx-kmod-0040-fix-fallthrough-warning-nv_mmap_c.patch"
"nvidia-390xx-kmod-0041-no-previous-prototype-for-exercise_error_forwarding_va.patch"
"nvidia-390xx-kmod-0042-undef-NV_DO_GETTIMEOFDAY_PRESENT-in-conftest_sh.patch"
"nvidia-390xx-kmod-0043-undef-NV_SET_MEMORY_ARRAY_UC_PRESENT-in-conftest_sh.patch"
"nvidia-390xx-kmod-0044-undef-NV_ACQUIRE_CONSOLE_SEM_PRESENT-in-conftest_sh.patch"
"nvidia-390xx-kmod-0045-undef-NV_UNSAFE_FOLLOW_PFN_PRESENT-in-conftest_sh.patch"
"nvidia-390xx-kmod-0046-undef-NV_JIFFIES_TO_TIMESPEC_PRESENT-in-conftest_sh.patch"
"nvidia-390xx-kmod-0047-undef-NV_PNV_NPU2_INIT_CONTEXT_PRESENT-in-conftest_sh.patch"
"nvidia-390xx-kmod-0048-fix-atomic64-include-in-conftest_sh.patch"
"nvidia-390xx-kmod-0049-fix-dma_buf_map-renamed-to-iosys_map.patch"
"nvidia-390xx-kmod-0050-no-previous-prototype-for-nv_pci_register_driver.patch"
"nvidia-390xx-kmod-0051-no-previous-prototype-for-nvidia_init_exit_module-in-nv_c.patch"
"nvidia-390xx-kmod-0052-no-previous-prototype-for-on_nv_assert.patch"
"nvidia-390xx-kmod-0053-no-previous-prototype-for-_raw_q_flush.patch"
"nvidia-390xx-kmod-0054-no-previous-prototype-for-nv-ibmnpu-functions.patch"
"nvidia-390xx-kmod-0055-no-previous-prototype-for-uvm_tools_init_exit.patch"
"nvidia-390xx-kmod-0056-no-previous-prototype-for-uvm8_test_set_prefetch_filtering.patch"
"nvidia-390xx-kmod-0057-no-previous-prototype-in-uvm8_va_space_c.patch"
"nvidia-390xx-kmod-0058-no-previous-prototype-for-uvm_channel_manager_print_pending_pushes.patch"
"nvidia-390xx-kmod-0059-no-previous-prototype-in-uvm8_va_range_c.patch"
"nvidia-390xx-kmod-0060-no-previous-prototype-in-uvm8_range_group_c.patch"
"nvidia-390xx-kmod-0061-no-previous-prototype-in-uvm8_gpu_replayable_faults_c.patch"
"nvidia-390xx-kmod-0062-no-previous-prototype-for-block_map.patch"
"nvidia-390xx-kmod-0063-no-previous-prototype-for-try_get_ptes.patch"
"nvidia-390xx-kmod-0064-no-previous-prototype-in-uvm8_pushbuffer_c.patch"
"nvidia-390xx-kmod-0065-no-previous-prototype-in-uvm8_kepler_mmu_c.patch"
"nvidia-390xx-kmod-0066-no-previous-prototype-in-uvm8_pascal_mmu_c.patch"
"nvidia-390xx-kmod-0067-no-previous-prototype-for-parse_fault_entry_common.patch"
"nvidia-390xx-kmod-0068-no-previous-prototype-in-uvm8_volta_access_counter_buffer_c.patch"
"nvidia-390xx-kmod-0069-no-previous-prototype-for-va_block_set_read_duplication_locked.patch"
"nvidia-390xx-kmod-0070-no-previous-prototype-for-map_rm_pt_range.patch"
)