[RISCV] Add support for Smepmp 1.0 (llvm#78489)

Smepmp is a supervisor extension that prevents privileged processes from
accessing unprivileged program and data.

Spec: https://github.com/riscv/riscv-tee/blob/main/Smepmp/Smepmp.pdf

Author: mshockwave

clang/test/Preprocessor/riscv-target-features.c

@@ -21,6 +21,7 @@
 // CHECK-NOT: __riscv_muldiv {{.*$}}
 // CHECK-NOT: __riscv_smaia {{.*$}}
 // CHECK-NOT: __riscv_ssaia {{.*$}}
+// CHECK-NOT: __riscv_smepmp {{.*$}}
 // CHECK-NOT: __riscv_svinval {{.*$}}
 // CHECK-NOT: __riscv_svnapot {{.*$}}
 // CHECK-NOT: __riscv_svpbmt {{.*$}}
@@ -1108,6 +1109,14 @@
 // RUN: -o - | FileCheck --check-prefix=CHECK-SSAIA-EXT %s
 // CHECK-SSAIA-EXT: __riscv_ssaia  1000000{{$}}
 
+// RUN: %clang --target=riscv32 \
+// RUN: -march=rv32ismepmp1p0 -x c -E -dM %s \
+// RUN: -o - | FileCheck --check-prefix=CHECK-SMEPMP-EXT %s
+// RUN: %clang --target=riscv64 \
+// RUN: -march=rv64ismepmp1p0 -x c -E -dM %s \
+// RUN: -o - | FileCheck --check-prefix=CHECK-SMEPMP-EXT %s
+// CHECK-SMEPMP-EXT: __riscv_smepmp  1000000{{$}}
+
 // RUN: %clang --target=riscv32-unknown-linux-gnu \
 // RUN: -march=rv32izfa -x c -E -dM %s \
 // RUN: -o - | FileCheck --check-prefix=CHECK-ZFA-EXT %s

llvm/docs/RISCVUsage.rst

@@ -92,6 +92,7 @@ on support follow.
      ``H``            Assembly Support
      ``M``            Supported
      ``Smaia``        Supported
+     ``Smepmp``       Supported
      ``Ssaia``        Supported
      ``Svinval``      Assembly Support
      ``Svnapot``      Assembly Support

llvm/docs/ReleaseNotes.rst

@@ -160,6 +160,7 @@ Changes to the RISC-V Backend
 * Support was added for the Ziccif, Ziccrse, Ziccamoa, Zicclsm, Za64rs, Za128rs
   and Zic64b extensions which were introduced as a part of the RISC-V Profiles
   specification.
+* The Smepmp 1.0 extension is now supported.
 
 Changes to the WebAssembly Backend
 ----------------------------------

llvm/lib/Support/RISCVISAInfo.cpp

@@ -55,6 +55,7 @@ static const RISCVSupportedExtension SupportedExtensions[] = {
     {"m", {2, 0}},
 
     {"smaia", {1, 0}},
+    {"smepmp", {1, 0}},
     {"ssaia", {1, 0}},
     {"svinval", {1, 0}},
     {"svnapot", {1, 0}},

llvm/lib/Target/RISCV/RISCVFeatures.td

@@ -748,6 +748,10 @@ def FeatureStdExtSsaia
                        "'Ssaia' (Advanced Interrupt Architecture Supervisor "
                        "Level)", []>;
 
+def FeatureStdExtSmepmp
+    : SubtargetFeature<"smepmp", "HasStdExtSmepmp", "true",
+                       "'Smepmp' (Enhanced Physical Memory Protection)", []>;
+
 def HasHalfFPLoadStoreMove
     : Predicate<"Subtarget->hasHalfFPLoadStoreMove()">,
                 AssemblerPredicate<(any_of FeatureStdExtZfh, FeatureStdExtZfhmin,

llvm/test/CodeGen/RISCV/attributes.ll

@@ -89,6 +89,7 @@
 ; RUN: llc -mtriple=riscv32 -mattr=+experimental-zcmop %s -o - | FileCheck --check-prefix=RV32ZCMOP %s
 ; RUN: llc -mtriple=riscv32 -mattr=+smaia %s -o - | FileCheck --check-prefixes=CHECK,RV32SMAIA %s
 ; RUN: llc -mtriple=riscv32 -mattr=+ssaia %s -o - | FileCheck --check-prefixes=CHECK,RV32SSAIA %s
+; RUN: llc -mtriple=riscv32 -mattr=+smepmp %s -o - | FileCheck --check-prefixes=CHECK,RV32SMEPMP %s
 ; RUN: llc -mtriple=riscv32 -mattr=+experimental-zfbfmin %s -o - | FileCheck --check-prefixes=CHECK,RV32ZFBFMIN %s
 ; RUN: llc -mtriple=riscv32 -mattr=+experimental-zvfbfmin %s -o - | FileCheck --check-prefixes=CHECK,RV32ZVFBFMIN %s
 ; RUN: llc -mtriple=riscv32 -mattr=+experimental-zvfbfwma %s -o - | FileCheck --check-prefixes=CHECK,RV32ZVFBFWMA %s
@@ -190,6 +191,7 @@
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-zcmop %s -o - | FileCheck --check-prefix=RV64ZCMOP %s
 ; RUN: llc -mtriple=riscv64 -mattr=+smaia %s -o - | FileCheck --check-prefixes=CHECK,RV64SMAIA %s
 ; RUN: llc -mtriple=riscv64 -mattr=+ssaia %s -o - | FileCheck --check-prefixes=CHECK,RV64SSAIA %s
+; RUN: llc -mtriple=riscv64 -mattr=+smepmp %s -o - | FileCheck --check-prefixes=CHECK,RV64SMEPMP %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-zfbfmin %s -o - | FileCheck --check-prefixes=CHECK,RV64ZFBFMIN %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-zvfbfmin %s -o - | FileCheck --check-prefixes=CHECK,RV64ZVFBFMIN %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-zvfbfwma %s -o - | FileCheck --check-prefixes=CHECK,RV64ZVFBFWMA %s
@@ -286,6 +288,7 @@
 ; RV32ZCMOP: .attribute 5, "rv32i2p1_zca1p0_zcmop0p2"
 ; RV32SMAIA: .attribute 5, "rv32i2p1_smaia1p0"
 ; RV32SSAIA: .attribute 5, "rv32i2p1_ssaia1p0"
+; RV32SMEPMP: .attribute 5, "rv32i2p1_smepmp1p0"
 ; RV32ZFBFMIN: .attribute 5, "rv32i2p1_f2p2_zicsr2p0_zfbfmin1p0"
 ; RV32ZVFBFMIN: .attribute 5, "rv32i2p1_f2p2_zicsr2p0_zve32f1p0_zve32x1p0_zvfbfmin1p0_zvl32b1p0"
 ; RV32ZVFBFWMA: .attribute 5, "rv32i2p1_f2p2_zicsr2p0_zfbfmin1p0_zve32f1p0_zve32x1p0_zvfbfmin1p0_zvfbfwma1p0_zvl32b1p0"
@@ -386,6 +389,7 @@
 ; RV64ZCMOP: .attribute 5, "rv64i2p1_zca1p0_zcmop0p2"
 ; RV64SMAIA: .attribute 5, "rv64i2p1_smaia1p0"
 ; RV64SSAIA: .attribute 5, "rv64i2p1_ssaia1p0"
+; RV64SMEPMP: .attribute 5, "rv64i2p1_smepmp1p0"
 ; RV64ZFBFMIN: .attribute 5, "rv64i2p1_f2p2_zicsr2p0_zfbfmin1p0"
 ; RV64ZVFBFMIN: .attribute 5, "rv64i2p1_f2p2_zicsr2p0_zve32f1p0_zve32x1p0_zvfbfmin1p0_zvl32b1p0"
 ; RV64ZVFBFWMA: .attribute 5, "rv64i2p1_f2p2_zicsr2p0_zfbfmin1p0_zve32f1p0_zve32x1p0_zvfbfmin1p0_zvfbfwma1p0_zvl32b1p0"

llvm/test/MC/RISCV/attribute-arch.s

@@ -294,6 +294,9 @@
 .attribute arch, "rv32i_ssaia1p0"
 # CHECK: attribute      5, "rv32i2p1_ssaia1p0"
 
+.attribute arch, "rv32i_smepmp1p0"
+# CHECK: attribute      5, "rv32i2p1_smepmp1p0"
+
 .attribute arch, "rv32i_zfbfmin1p0"
 # CHECK: .attribute     5, "rv32i2p1_f2p2_zicsr2p0_zfbfmin1p0"
 

llvm/unittests/Support/RISCVISAInfoTest.cpp

@@ -760,6 +760,7 @@ R"(All available -march extensions for RISC-V
     zhinx               1.0
     zhinxmin            1.0
     smaia               1.0
+    smepmp              1.0
     ssaia               1.0
     svinval             1.0
     svnapot             1.0