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[129.46.96.20]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-14324410092sm15547054c88.14.2026.09.05.19.17.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 05 Sep 2026 19:17:24 -0700 (PDT) From: Brian Cain To: linux-hexagon@vger.kernel.org Cc: sid.manning@oss.qualcomm.com, pierrick.bouvier@oss.qualcomm.com, Brian Cain Subject: [PATCH 4/7] hexagon: read the thread-info register with a volatile asm Date: Sat, 5 Sep 2026 19:17:09 -0700 Message-Id: <20260906021712.2498266-5-brian.cain@oss.qualcomm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260906021712.2498266-1-brian.cain@oss.qualcomm.com> References: <20260906021712.2498266-1-brian.cain@oss.qualcomm.com> Precedence: bulk X-Mailing-List: linux-hexagon@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-Proofpoint-GUID: 1_KxXT0pJh0F23uNhKH27V4N1zNtp4Cg X-Proofpoint-ORIG-GUID: 1_KxXT0pJh0F23uNhKH27V4N1zNtp4Cg X-Proofpoint-Spam-Info: AW1haW4tMjYwOTA2MDAyMiBTYWx0ZWRfX6mJRPuwy+IJY WqAFpk3gwwG/KGD7p0Koq7xKGdIokRRC9NhN0TJrUhOs2L1mE4KNJYTpjDW3lOOQLLo8NQzA3ym 5Rbg3uBeEHDDdqURbd05V7kQKNIbQ9U= X-Authority-Analysis: v=2.4 cv=dfmwG3Xe c=1 sm=1 tr=0 ts=6a9ccd36 cx=c_pps a=IZJwPbhc+fLeJZngyXXI0A==:117 a=ouPCqIW2jiPt+lZRy3xVPw==:17 a=IkcTkHD0fZMA:10 a=VdqzKS8jKosA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=eoimf2acIAo5FJnRuUoq:22 a=EUspDBNiAAAA:8 a=QFdjFJDKsErBmVjQFIoA:9 a=QEXdDO2ut3YA:10 a=uG9DUKGECoFWVXl0Dc02:22 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwOTA2MDAyMiBTYWx0ZWRfX+3k0hOBnhvbp 0XWQzU2dZPr4GDCcD3XugDcEkOnLNe1xCo/Fu4Mk9PTkVuoVDegebx+J+zT/e9+GBpaSByL5MTn olQQ8K4XbG2MhbQ7mGJALMe48KXZRyz/LbVYR5GF60uxAsKFolbLCrfKoc6WuVNdwk07V5b5Z8L EzH9CO6jTw5SCP5nMdXF52Glr7dJCHWvQAuLsHr8mkZzkIfEn4/1x4Qg8T/gHK8EOngbGhsN4cO P6yw50zOKCSILdhcaWFhU3DvNtbBgh8rclThA1jze1mQ0A5G82HiefKhTJbFFgrxT/YNKhlInHK zeOo/G3ZLGOADWw6qzPp6+hLa5q0jcseOHDjuETjiuDWvZZFNmZQ+9w63g0uNLFbH/I2yL7XCGV oSVnYQsmfNRLpPXil+wlpObcxzOlwdUw6FPJcks8SonGatHb6SJFPUVWAiyqEj9cUcuOgPFEaB0 B+eTCR1c1GL5RD01aNQ== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-09-05_08,2026-09-03_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 adultscore=0 priorityscore=1501 spamscore=0 malwarescore=0 lowpriorityscore=0 bulkscore=0 phishscore=0 suspectscore=0 clxscore=1015 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2609060022 current_thread_info() was a global register variable. Replace it with an explicit read of the same register, marked volatile: the register changes under us at every context switch, so the read must not be treated as a pure expression the compiler is free to hoist out of a loop or reuse across a call to switch_to(). Signed-off-by: Brian Cain --- arch/hexagon/include/asm/thread_info.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/hexagon/include/asm/thread_info.h b/arch/hexagon/include/asm/thread_info.h index e90f280b9ce3..3d4a40091a5a 100644 --- a/arch/hexagon/include/asm/thread_info.h +++ b/arch/hexagon/include/asm/thread_info.h @@ -70,8 +70,14 @@ struct thread_info { #define qstr(s) #s #define QUOTED_THREADINFO_REG qqstr(THREADINFO_REG) -register struct thread_info *__current_thread_info asm(QUOTED_THREADINFO_REG); -#define current_thread_info() __current_thread_info +static inline struct thread_info *current_thread_info(void) +{ + struct thread_info *ti; + + asm volatile("%0 = " QUOTED_THREADINFO_REG : "=r"(ti)); + + return ti; +} #endif /* __ASSEMBLY__ */ -- 2.34.1