{"id":2222217,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2222217/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/87ik9yzg9g.ffs@tglx/","project":{"id":2,"url":"http://patchwork.ozlabs.org/api/1.1/projects/2/?format=json","name":"Linux PPC development","link_name":"linuxppc-dev","list_id":"linuxppc-dev.lists.ozlabs.org","list_email":"linuxppc-dev@lists.ozlabs.org","web_url":"https://github.com/linuxppc/wiki/wiki","scm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git","webscm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/"},"msgid":"<87ik9yzg9g.ffs@tglx>","date":"2026-04-10T20:56:11","name":"[V1.1,11/38] misc: sgi-gru: Remove get_cycles() [ab]use","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"a8da5805f98eea1ab3b68b8d57715dc93c5e1333","submitter":{"id":92397,"url":"http://patchwork.ozlabs.org/api/1.1/people/92397/?format=json","name":"Thomas Gleixner","email":"tglx@kernel.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/87ik9yzg9g.ffs@tglx/mbox/","series":[{"id":499508,"url":"http://patchwork.ozlabs.org/api/1.1/series/499508/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=499508","date":"2026-04-10T20:56:11","name":null,"version":1,"mbox":"http://patchwork.ozlabs.org/series/499508/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2222217/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2222217/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256\n header.s=k20201202 header.b=GQ142PFW;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org\n (client-ip=2404:9400:21b9:f100::1; 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a=rsa-sha256; c=relaxed/simple; d=kernel.org;\n\ts=k20201202; t=1775854576;\n\tbh=Pl/TPuj3MEjAUAkiR6iNGQuG7vTK4etd1CQHextbc1Q=;\n\th=From:To:Cc:Subject:In-Reply-To:References:Date:From;\n\tb=GQ142PFWFm6CPGgxzIstxv+Opw0b8SXuQ9OyBP6RDGrB9wMYrgGJRlAIcXmjiMiJQ\n\t uvHLzYRX996/8mwPCxIT6HNprAxZjHfiZYVGdKL2zkx4tDdEJ1Qjhj23YsuYeVWZUk\n\t qB897HhG8G4RkSYw8g0MDIEY8t5mxlaTJQ0hQJRlVPLc72Bfpv47WYQcen6mmTC6UB\n\t IDYz08Lq5Ox+catFPgX2TnERo0NsyMmc6D+DEo5bfEi3Zb8CozxsaaIUnftUYBffz4\n\t eRJ2pErWPmB+XVojMvRq9gH2C+KSLENGTN6u78aH1Po3BWHW2gKcN/A+CamqsNtu9t\n\t mhyolj1ID3OUA==","From":"Thomas Gleixner ","To":"LKML ","Cc":"Arnd Bergmann , x86@kernel.org, Lu Baolu\n , iommu@lists.linux.dev, Michael Grzeschik\n , netdev@vger.kernel.org,\n linux-wireless@vger.kernel.org, Herbert Xu ,\n linux-crypto@vger.kernel.org, Vlastimil Babka ,\n linux-mm@kvack.org, David Woodhouse , Bernie Thompson\n , linux-fbdev@vger.kernel.org, Theodore Tso\n , linux-ext4@vger.kernel.org, Andrew Morton\n , Uladzislau Rezki , Marco\n Elver , Dmitry Vyukov ,\n kasan-dev@googlegroups.com, Andrey Ryabinin ,\n Thomas Sailer , linux-hams@vger.kernel.org,\n \"Jason A. Donenfeld\" , Richard Henderson\n , linux-alpha@vger.kernel.org, Russell King\n , linux-arm-kernel@lists.infradead.org, Catalin\n Marinas , Huacai Chen ,\n loongarch@lists.linux.dev, Geert Uytterhoeven ,\n linux-m68k@lists.linux-m68k.org, Dinh Nguyen , Jonas\n Bonn , linux-openrisc@vger.kernel.org, Helge Deller\n , linux-parisc@vger.kernel.org, Michael Ellerman\n , linuxppc-dev@lists.ozlabs.org, Paul Walmsley\n , linux-riscv@lists.infradead.org, Heiko Carstens\n , linux-s390@vger.kernel.org, \"David S. Miller\"\n , sparclinux@vger.kernel.org","Subject":"[patch V1.1 11/38] misc: sgi-gru: Remove get_cycles() [ab]use","In-Reply-To":"<20260410120318.320727701@kernel.org>","References":"<20260410120044.031381086@kernel.org>\n <20260410120318.320727701@kernel.org>","Date":"Fri, 10 Apr 2026 22:56:11 +0200","Message-ID":"<87ik9yzg9g.ffs@tglx>","X-Mailing-List":"linuxppc-dev@lists.ozlabs.org","List-Id":"","List-Help":"","List-Owner":"","List-Post":"","List-Archive":",\n ","List-Subscribe":",\n ,\n ","List-Unsubscribe":"","Precedence":"list","MIME-Version":"1.0","Content-Type":"text/plain","X-Spam-Status":"No, score=-0.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,\n\tDKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS\n\tautolearn=disabled version=4.0.1 OzLabs 8","X-Spam-Checker-Version":"SpamAssassin 4.0.1 (2024-03-25) on lists.ozlabs.org"},"content":"Calculating a timeout from get_cycles() is a historical leftover without\nany functional requirement.\n\nUse ktime_get() instead.\n\nSigned-off-by: Thomas Gleixner \n---\nV2: Fix typo\n---\n drivers/misc/sgi-gru/gruhandles.c | 20 ++++++++------------\n drivers/misc/sgi-gru/grukservices.c | 3 ++-\n drivers/misc/sgi-gru/grutlbpurge.c | 5 ++---\n 3 files changed, 12 insertions(+), 16 deletions(-)","diff":"--- a/drivers/misc/sgi-gru/gruhandles.c\n+++ b/drivers/misc/sgi-gru/gruhandles.c\n@@ -6,26 +6,22 @@\n */\n \n #include \n+#include \n #include \"gru.h\"\n #include \"grulib.h\"\n #include \"grutables.h\"\n \n-/* 10 sec */\n #include \n-#include \n-#define GRU_OPERATION_TIMEOUT\t((cycles_t) tsc_khz*10*1000)\n-#define CLKS2NSEC(c)\t\t((c) * 1000000 / tsc_khz)\n+\n+#define GRU_OPERATION_TIMEOUT_NSEC\t(((ktime_t)10 * NSEC_PER_SEC))\n \n /* Extract the status field from a kernel handle */\n #define GET_MSEG_HANDLE_STATUS(h)\t(((*(unsigned long *)(h)) >> 16) & 3)\n \n struct mcs_op_statistic mcs_op_statistics[mcsop_last];\n \n-static void update_mcs_stats(enum mcs_op op, unsigned long clks)\n+static void update_mcs_stats(enum mcs_op op, unsigned long nsec)\n {\n-\tunsigned long nsec;\n-\n-\tnsec = CLKS2NSEC(clks);\n \tatomic_long_inc(&mcs_op_statistics[op].count);\n \tatomic_long_add(nsec, &mcs_op_statistics[op].total);\n \tif (mcs_op_statistics[op].max < nsec)\n@@ -58,21 +54,21 @@ static void report_instruction_timeout(v\n \n static int wait_instruction_complete(void *h, enum mcs_op opc)\n {\n+\tktime_t start_time = ktime_get();\n \tint status;\n-\tunsigned long start_time = get_cycles();\n \n \twhile (1) {\n \t\tcpu_relax();\n \t\tstatus = GET_MSEG_HANDLE_STATUS(h);\n \t\tif (status != CCHSTATUS_ACTIVE)\n \t\t\tbreak;\n-\t\tif (GRU_OPERATION_TIMEOUT < (get_cycles() - start_time)) {\n+\t\tif (GRU_OPERATION_TIMEOUT_NSEC < (ktime_get() - start_time)) {\n \t\t\treport_instruction_timeout(h);\n-\t\t\tstart_time = get_cycles();\n+\t\t\tstart_time = ktime_get();\n \t\t}\n \t}\n \tif (gru_options & OPT_STATS)\n-\t\tupdate_mcs_stats(opc, get_cycles() - start_time);\n+\t\tupdate_mcs_stats(opc, (unsigned long)(ktime_get() - start_time));\n \treturn status;\n }\n \n--- a/drivers/misc/sgi-gru/grukservices.c\n+++ b/drivers/misc/sgi-gru/grukservices.c\n@@ -20,6 +20,7 @@\n #include \n #include \n #include \n+#include \n #include \n #include \"gru.h\"\n #include \"grulib.h\"\n@@ -1106,7 +1107,7 @@ static int quicktest3(unsigned long arg)\n \tint ret = 0;\n \n \tmemset(buf2, 0, sizeof(buf2));\n-\tmemset(buf1, get_cycles() & 255, sizeof(buf1));\n+\tmemset(buf1, get_random_u32() & 255, sizeof(buf1));\n \tgru_copy_gpa(uv_gpa(buf2), uv_gpa(buf1), BUFSIZE);\n \tif (memcmp(buf1, buf2, BUFSIZE)) {\n \t\tprintk(KERN_DEBUG \"GRU:%d quicktest3 error\\n\", smp_processor_id());\n--- a/drivers/misc/sgi-gru/grutlbpurge.c\n+++ b/drivers/misc/sgi-gru/grutlbpurge.c\n@@ -22,13 +22,12 @@\n #include \n #include \n #include \n+#include \n #include \n #include \"gru.h\"\n #include \"grutables.h\"\n #include \n \n-#define gru_random()\tget_cycles()\n-\n /* ---------------------------------- TLB Invalidation functions --------\n * get_tgh_handle\n *\n@@ -49,7 +48,7 @@ static inline int get_off_blade_tgh(stru\n \tint n;\n \n \tn = GRU_NUM_TGH - gru->gs_tgh_first_remote;\n-\tn = gru_random() % n;\n+\tn = get_random_u32() % n;\n \tn += gru->gs_tgh_first_remote;\n \treturn n;\n }\n","prefixes":["V1.1","11/38"]}