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authorHeiko Stuebner2022-07-07 01:15:36 +0200
committerPalmer Dabbelt2022-08-03 17:29:59 -0700
commitd20ec7529236a2fcdb2d856fc0bd80b409a217fc (patch)
tree97c41e3c370f0ec170fb1b3aab81c42e8f1d105e /arch/riscv/errata
parent1631ba1259d6d7f49b6028f2a1a0fa02be1c522a (diff)
riscv: implement cache-management errata for T-Head SoCs
The T-Head C906 and C910 implement a scheme for handling cache operations different from the generic Zicbom extension. Add an errata for it next to the generic dma coherency ops. Reviewed-by: Samuel Holland <samuel@sholland.org> Tested-by: Samuel Holland <samuel@sholland.org> Reviewed-by: Guo Ren <guoren@kernel.org> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Link: https://lore.kernel.org/r/20220706231536.2041855-5-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/errata')
-rw-r--r--arch/riscv/errata/thead/errata.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
index b37b6fedd53b..202c83f677b2 100644
--- a/arch/riscv/errata/thead/errata.c
+++ b/arch/riscv/errata/thead/errata.c
@@ -27,6 +27,23 @@ static bool errata_probe_pbmt(unsigned int stage,
return false;
}
+static bool errata_probe_cmo(unsigned int stage,
+ unsigned long arch_id, unsigned long impid)
+{
+#ifdef CONFIG_ERRATA_THEAD_CMO
+ if (arch_id != 0 || impid != 0)
+ return false;
+
+ if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
+ return false;
+
+ riscv_noncoherent_supported();
+ return true;
+#else
+ return false;
+#endif
+}
+
static u32 thead_errata_probe(unsigned int stage,
unsigned long archid, unsigned long impid)
{
@@ -35,6 +52,9 @@ static u32 thead_errata_probe(unsigned int stage,
if (errata_probe_pbmt(stage, archid, impid))
cpu_req_errata |= (1U << ERRATA_THEAD_PBMT);
+ if (errata_probe_cmo(stage, archid, impid))
+ cpu_req_errata |= (1U << ERRATA_THEAD_CMO);
+
return cpu_req_errata;
}