Re: [PATCH v8 02/22] RISC-V: Add Sxcsrind ISA extension CSR definitions

[Paul Walmsley <pjw@kernel.org>]

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On Wed, 1 Jul 2026, Atish Patra wrote:

> From: Kaiwen Xue <kaiwenx@rivosinc.com>
> 
> This adds definitions of new CSRs and bits defined in Sxcsrind ISA
> extension. These CSR enables indirect accesses mechanism to access
> any CSRs in M-, S-, and VS-mode. The range of the select values
> and ireg will be define by the ISA extension using Sxcsrind extension.
> 
> Signed-off-by: Kaiwen Xue <kaiwenx@rivosinc.com>
> Reviewed-by: Clément Léger <cleger@rivosinc.com>
> Signed-off-by: Atish Patra <atishp@rivosinc.com>

Thanks.  It's easier for folks to grep and cross-reference if the official 
RISC-V extension names are used whenever possible, rather than something 
like Sxcsrind.  Queued the following patch for v7.3.


- Paul


RISC-V: Add Smcsrind and Sscrind ISA extension CSR definitions

From: Kaiwen Xue <kaiwenx@rivosinc.com>

This adds definitions of new CSRs and bits defined in the Smcsrind and
Sscrinq ISA extensions. These CSRs enable the indirect CSR accesses
mechanism to access any indirect CSRs in M-, S-, and VS-mode. The
range of the select values and ireg will be defined by the ISA
extension that are based on the Smcsrind and Sscsrind extensions.

Signed-off-by: Kaiwen Xue <kaiwenx@rivosinc.com>
Reviewed-by: Clément Léger <cleger@rivosinc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Charlie Jenkins <thecharlesjenkins@gmail.com>
Tested-by: Charlie Jenkins <thecharlesjenkins@gmail.com>
Link: https://patch.msgid.link/20260701-counter_delegation-v8-2-7909f863a645@meta.com
[pjw@kernel.org: clean up the patch description; use official RISC-V extension names]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
---
 arch/riscv/include/asm/csr.h |   30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 31b8988f4488..7f09e54a0f9a 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -347,6 +347,12 @@
 /* Supervisor-Level Window to Indirectly Accessed Registers (AIA) */
 #define CSR_SISELECT		0x150
 #define CSR_SIREG		0x151
+/* Supervisor-Level Window to Indirectly Accessed Registers (Sscsrind) */
+#define CSR_SIREG2		0x152
+#define CSR_SIREG3		0x153
+#define CSR_SIREG4		0x155
+#define CSR_SIREG5		0x156
+#define CSR_SIREG6		0x157
 
 /* Supervisor-Level Interrupts (AIA) */
 #define CSR_STOPEI		0x15c
@@ -394,6 +400,14 @@
 /* VS-Level Window to Indirectly Accessed Registers (H-extension with AIA) */
 #define CSR_VSISELECT		0x250
 #define CSR_VSIREG		0x251
+/*
+ * VS-Level Window to Indirectly Accessed Registers (H-extension with Sscsrind)
+ */
+#define CSR_VSIREG2		0x252
+#define CSR_VSIREG3		0x253
+#define CSR_VSIREG4		0x255
+#define CSR_VSIREG5		0x256
+#define CSR_VSIREG6		0x257
 
 /* VS-Level Interrupts (H-extension with AIA) */
 #define CSR_VSTOPEI		0x25c
@@ -436,6 +450,12 @@
 /* Machine-Level Window to Indirectly Accessed Registers (AIA) */
 #define CSR_MISELECT		0x350
 #define CSR_MIREG		0x351
+/* Machine-Level Window to Indirectly Accessed Registers (Smcsrind) */
+#define CSR_MIREG2		0x352
+#define CSR_MIREG3		0x353
+#define CSR_MIREG4		0x355
+#define CSR_MIREG5		0x356
+#define CSR_MIREG6		0x357
 
 /* Machine-Level Interrupts (AIA) */
 #define CSR_MTOPEI		0x35c
@@ -498,6 +518,11 @@
 # define CSR_IEH		CSR_MIEH
 # define CSR_ISELECT	CSR_MISELECT
 # define CSR_IREG	CSR_MIREG
+# define CSR_IREG2	CSR_MIREG2
+# define CSR_IREG3	CSR_MIREG3
+# define CSR_IREG4	CSR_MIREG4
+# define CSR_IREG5	CSR_MIREG5
+# define CSR_IREG6	CSR_MIREG6
 # define CSR_IPH		CSR_MIPH
 # define CSR_TOPEI	CSR_MTOPEI
 # define CSR_TOPI	CSR_MTOPI
@@ -523,6 +548,11 @@
 # define CSR_IEH		CSR_SIEH
 # define CSR_ISELECT	CSR_SISELECT
 # define CSR_IREG	CSR_SIREG
+# define CSR_IREG2	CSR_SIREG2
+# define CSR_IREG3	CSR_SIREG3
+# define CSR_IREG4	CSR_SIREG4
+# define CSR_IREG5	CSR_SIREG5
+# define CSR_IREG6	CSR_SIREG6
 # define CSR_IPH		CSR_SIPH
 # define CSR_TOPEI	CSR_STOPEI
 # define CSR_TOPI	CSR_STOPI