Re: [PATCH v2 04/10] riscv: cpu: ax25: Simplify cache enabling logic in harts_early_init()

[Rick Chen]

> From: Peter Yu-Chien Lin(林宇謙) 
> Sent: Monday, February 06, 2023 4:11 PM
> To: u-boot@lists.denx.de
> Cc: Leo Yu-Chi Liang(梁育齊) ; Rick Jian-Zhi Chen(陳建志) 
> ; prabhakar.cse...@gmail.com; Peter Yu-Chien Lin(林宇謙) 
> 
> Subject: [PATCH v2 04/10] riscv: cpu: ax25: Simplify cache enabling logic in 
> harts_early_init()
>
> As the OpenSBI v1.2 does not enable the cache [0], we enable the i/d-cache in 
> harts_early_init() and do not disable in cleanup_before_linux(). This patch 
> also simplifies the logic and moves the CSR encoding to 
> include/asm/arch-andes/csr.h.
>
> [0] 
> https://github.com/riscv-software-src/opensbi/commit/bd7ef4139829da5c30fa980f7498d385124408fa
>
> Signed-off-by: Yu Chien Peter Lin 
> Reviewed-by: Leo Yu-Chi Liang 
> ---
>  arch/riscv/cpu/ax25/cpu.c   | 49 ++---
>  arch/riscv/include/asm/arch-andes/csr.h | 29 +++
>  2 files changed, 41 insertions(+), 37 deletions(-)  create mode 100644 
> arch/riscv/include/asm/arch-andes/csr.h

Reviewed-by: Rick Chen 

[PATCH v2 04/10] riscv: cpu: ax25: Simplify cache enabling logic in harts_early_init()

[Yu Chien Peter Lin]

As the OpenSBI v1.2 does not enable the cache [0], we enable
the i/d-cache in harts_early_init() and do not disable in
cleanup_before_linux(). This patch also simplifies the logic
and moves the CSR encoding to include/asm/arch-andes/csr.h.

[0] 
https://github.com/riscv-software-src/opensbi/commit/bd7ef4139829da5c30fa980f7498d385124408fa

Signed-off-by: Yu Chien Peter Lin 
Reviewed-by: Leo Yu-Chi Liang 
---
 arch/riscv/cpu/ax25/cpu.c   | 49 ++---
 arch/riscv/include/asm/arch-andes/csr.h | 29 +++
 2 files changed, 41 insertions(+), 37 deletions(-)
 create mode 100644 arch/riscv/include/asm/arch-andes/csr.h

diff --git a/arch/riscv/cpu/ax25/cpu.c b/arch/riscv/cpu/ax25/cpu.c
index a46674f7c2..2c7565ad49 100644
--- a/arch/riscv/cpu/ax25/cpu.c
+++ b/arch/riscv/cpu/ax25/cpu.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * Copyright (C) 2017 Andes Technology Corporation
+ * Copyright (C) 2023 Andes Technology Corporation
  * Rick Chen, Andes Technology Corporation 
  */
 
@@ -10,23 +10,7 @@
 #include 
 #include 
 #include 
-
-#define CSR_MCACHE_CTL 0x7ca
-#define CSR_MMISC_CTL  0x7d0
-#define CSR_MARCHID0xf12
-
-#define V5_MCACHE_CTL_IC_EN_OFFSET  0
-#define V5_MCACHE_CTL_DC_EN_OFFSET  1
-#define V5_MCACHE_CTL_CCTL_SUEN_OFFSET 8
-#define V5_MCACHE_CTL_DC_COHEN_OFFSET  19
-#define V5_MCACHE_CTL_DC_COHSTA_OFFSET 20
-
-#define V5_MCACHE_CTL_IC_EN
BIT(V5_MCACHE_CTL_IC_EN_OFFSET)
-#define V5_MCACHE_CTL_DC_EN
BIT(V5_MCACHE_CTL_DC_EN_OFFSET)
-#define V5_MCACHE_CTL_CCTL_SUEN
BIT(V5_MCACHE_CTL_CCTL_SUEN_OFFSET)
-#define V5_MCACHE_CTL_DC_COHEN_EN   BIT(V5_MCACHE_CTL_DC_COHEN_OFFSET)
-#define V5_MCACHE_CTL_DC_COHSTA_EN  BIT(V5_MCACHE_CTL_DC_COHSTA_OFFSET)
-
+#include 
 
 /*
  * cleanup_before_linux() is called just before we call linux
@@ -38,38 +22,29 @@ int cleanup_before_linux(void)
 {
disable_interrupts();
 
-   /* turn off I/D-cache */
cache_flush();
-   icache_disable();
-   dcache_disable();
 
return 0;
 }
 
 void harts_early_init(void)
 {
+   /* Enable I/D-cache in SPL */
if (CONFIG_IS_ENABLED(RISCV_MMODE)) {
-   unsigned long long mcache_ctl_val = csr_read(CSR_MCACHE_CTL);
+   unsigned long mcache_ctl_val = csr_read(CSR_MCACHE_CTL);
+
+   mcache_ctl_val |= (MCACHE_CTL_DC_COHEN | MCACHE_CTL_IC_EN |
+  MCACHE_CTL_DC_EN);
 
-   if (!(mcache_ctl_val & V5_MCACHE_CTL_DC_COHEN_EN))
-   mcache_ctl_val |= V5_MCACHE_CTL_DC_COHEN_EN;
-   if (!(mcache_ctl_val & V5_MCACHE_CTL_IC_EN))
-   mcache_ctl_val |= V5_MCACHE_CTL_IC_EN;
-   if (!(mcache_ctl_val & V5_MCACHE_CTL_DC_EN))
-   mcache_ctl_val |= V5_MCACHE_CTL_DC_EN;
-   if (!(mcache_ctl_val & V5_MCACHE_CTL_CCTL_SUEN))
-   mcache_ctl_val |= V5_MCACHE_CTL_CCTL_SUEN;
csr_write(CSR_MCACHE_CTL, mcache_ctl_val);
 
/*
-* Check DC_COHEN_EN, if cannot write to mcache_ctl,
-* we assume this bitmap not support L2 CM
+* Check mcache_ctl.DC_COHEN, we assume this platform does
+* not support CM if the bit is hard-wired to 0.
 */
-   mcache_ctl_val = csr_read(CSR_MCACHE_CTL);
-   if ((mcache_ctl_val & V5_MCACHE_CTL_DC_COHEN_EN)) {
-   /* Wait for DC_COHSTA bit be set */
-   while (!(mcache_ctl_val & V5_MCACHE_CTL_DC_COHSTA_EN))
-   mcache_ctl_val = csr_read(CSR_MCACHE_CTL);
+   if (csr_read(CSR_MCACHE_CTL) & MCACHE_CTL_DC_COHEN) {
+   /* Wait for DC_COHSTA bit to be set */
+   while (!(csr_read(CSR_MCACHE_CTL)& 
MCACHE_CTL_DC_COHSTA));
}
}
 }
diff --git a/arch/riscv/include/asm/arch-andes/csr.h 
b/arch/riscv/include/asm/arch-andes/csr.h
new file mode 100644
index 00..a03ccd5b3e
--- /dev/null
+++ b/arch/riscv/include/asm/arch-andes/csr.h
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2023 Andes Technology Corporation
+ */
+
+#ifndef _ASM_ANDES_CSR_H
+#define _ASM_ANDES_CSR_H
+
+#include 
+#include 
+
+#define CSR_MCACHE_CTL 0x7ca
+#define CSR_MMISC_CTL 0x7d0
+#define CSR_MARCHID 0xf12
+#define CSR_MCCTLCOMMAND 0x7cc
+
+#define MCACHE_CTL_IC_EN_OFFSET 0
+#define MCACHE_CTL_DC_EN_OFFSET 1
+#define MCACHE_CTL_DC_COHEN_OFFSET 19
+#define MCACHE_CTL_DC_COHSTA_OFFSET 20
+
+#define MCACHE_CTL_IC_EN BIT(MCACHE_CTL_IC_EN_OFFSET)
+#define MCACHE_CTL_DC_EN BIT(MCACHE_CTL_DC_EN_OFFSET)
+#define MCACHE_CTL_DC_COHEN BIT(MCACHE_CTL_DC_COHEN_OFFSET)
+#define MCACHE_CTL_DC_COHSTA BIT(MCACHE_CTL_DC_COHSTA_OFFSET)
+
+#define CCTL_L1D_WBINVAL_ALL 6
+
+#endif /*