[PATCH 0/2] Add SiFive private L2 cache driver

[PATCH 0/2] Add SiFive private L2 cache driver

[Zong Li]

SiFive private L2 cache is per core cache, add this driver to control
its features by a MMIO register. In this series, we try to enable the
power gating feature of pL2 cache in SPL stage

Zong Li (2):
  cache: add sifive private L2 cache driver
  riscv: cache: support cache enable in SPL stage

 arch/riscv/lib/sifive_cache.c    | 21 +++++++++++++++
 drivers/cache/Kconfig            |  7 +++++
 drivers/cache/Makefile           |  1 +
 drivers/cache/cache-sifive-pl2.c | 44 ++++++++++++++++++++++++++++++++
 4 files changed, 73 insertions(+)
 create mode 100644 drivers/cache/cache-sifive-pl2.c

-- 
2.17.1

[PATCH 1/2] cache: add sifive private L2 cache driver

[Zong Li]

This driver is currently responsible for enabling the clock gating
feature of SiFive pre core's private L2 cache.

Signed-off-by: Zong Li <zong.li@sifive.com>
---
 drivers/cache/Kconfig            |  7 +++++
 drivers/cache/Makefile           |  1 +
 drivers/cache/cache-sifive-pl2.c | 44 ++++++++++++++++++++++++++++++++
 3 files changed, 52 insertions(+)
 create mode 100644 drivers/cache/cache-sifive-pl2.c

diff --git a/drivers/cache/Kconfig b/drivers/cache/Kconfig
index 6cb8c3e980..26c2d80a1c 100644
--- a/drivers/cache/Kconfig
+++ b/drivers/cache/Kconfig
@@ -45,4 +45,11 @@ config SIFIVE_CCACHE
 	  This driver is for SiFive Composable L2/L3 cache. It enables cache
 	  ways of composable cache.
 
+config SIFIVE_PL2
+	bool "SiFive private L2 cache"
+	select CACHE
+	help
+	  This driver is for SiFive Private L2 cache. It configures registers
+	  to enable the clock gating feature.
+
 endmenu
diff --git a/drivers/cache/Makefile b/drivers/cache/Makefile
index ad765774e3..78e673d09e 100644
--- a/drivers/cache/Makefile
+++ b/drivers/cache/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_L2X0_CACHE) += cache-l2x0.o
 obj-$(CONFIG_NCORE_CACHE) += cache-ncore.o
 obj-$(CONFIG_V5L2_CACHE) += cache-v5l2.o
 obj-$(CONFIG_SIFIVE_CCACHE) += cache-sifive-ccache.o
+obj-$(CONFIG_SIFIVE_PL2) += cache-sifive-pl2.o
diff --git a/drivers/cache/cache-sifive-pl2.c b/drivers/cache/cache-sifive-pl2.c
new file mode 100644
index 0000000000..ae689e18ed
--- /dev/null
+++ b/drivers/cache/cache-sifive-pl2.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 SiFive
+ */
+
+#include <cache.h>
+#include <dm.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <dm/device.h>
+#include <dm/device-internal.h>
+
+#define	SIFIVE_PL2CHICKENBIT_OFFSET			0x1000
+#define	SIFIVE_PL2CHICKENBIT_REGIONCLOCKDISABLE_MASK	BIT(3)
+
+static int sifive_pl2_probe(struct udevice *dev)
+{
+	fdt_addr_t base;
+	u32 val;
+
+	base = dev_read_addr(dev);
+	if (base == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	/* Enable regionClockDisable bit */
+	val = readl((void __iomem *)(base + SIFIVE_PL2CHICKENBIT_OFFSET));
+	writel(val & ~SIFIVE_PL2CHICKENBIT_REGIONCLOCKDISABLE_MASK,
+	       (void __iomem *)(base + SIFIVE_PL2CHICKENBIT_OFFSET));
+
+	return 0;
+}
+
+static const struct udevice_id sifive_pl2_ids[] = {
+	{ .compatible = "sifive,pl2cache0" },
+	{ .compatible = "sifive,pl2cache1" },
+	{}
+};
+
+U_BOOT_DRIVER(sifive_pl2) = {
+	.name = "sifive_pl2",
+	.id = UCLASS_CACHE,
+	.of_match = sifive_pl2_ids,
+	.probe = sifive_pl2_probe,
+};
-- 
2.17.1

Re: [PATCH 1/2] cache: add sifive private L2 cache driver

[Leo Liang]

On Thu, Dec 14, 2023 at 02:09:36PM +0000, Zong Li wrote:
> This driver is currently responsible for enabling the clock gating
> feature of SiFive pre core's private L2 cache.
> 
> Signed-off-by: Zong Li <zong.li@sifive.com>
> ---
>  drivers/cache/Kconfig            |  7 +++++
>  drivers/cache/Makefile           |  1 +
>  drivers/cache/cache-sifive-pl2.c | 44 ++++++++++++++++++++++++++++++++
>  3 files changed, 52 insertions(+)
>  create mode 100644 drivers/cache/cache-sifive-pl2.c

Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>

[PATCH 2/2] riscv: cache: support cache enable in SPL stage

[Zong Li]

The power gating feature of pl2 should be enabled as early as possible,
it would be better to put it in SPL stage.

Signed-off-by: Zong Li <zong.li@sifive.com>
---
 arch/riscv/lib/sifive_cache.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/arch/riscv/lib/sifive_cache.c b/arch/riscv/lib/sifive_cache.c
index 39b0248c32..d8fe1dfa95 100644
--- a/arch/riscv/lib/sifive_cache.c
+++ b/arch/riscv/lib/sifive_cache.c
@@ -7,7 +7,10 @@
 #include <cpu_func.h>
 #include <log.h>
 #include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/uclass-internal.h>
 
+#ifndef CONFIG_SPL_BUILD
 void enable_caches(void)
 {
 	struct udevice *dev;
@@ -25,3 +28,21 @@ void enable_caches(void)
 			log_debug("ccache enable failed");
 	}
 }
+#else
+static inline void probe_cache_device(struct driver *driver, struct udevice *dev)
+{
+	for (uclass_find_first_device(UCLASS_CACHE, &dev);
+	     dev;
+	     uclass_find_next_device(&dev)) {
+		if (dev->driver == driver)
+			device_probe(dev);
+	}
+}
+
+void enable_caches(void)
+{
+	struct udevice *dev = NULL;
+
+	probe_cache_device(DM_DRIVER_GET(sifive_pl2), dev);
+}
+#endif /* !CONFIG_SPL_BUILD */
-- 
2.17.1

Re: [PATCH 2/2] riscv: cache: support cache enable in SPL stage

[Leo Liang]

On Thu, Dec 14, 2023 at 02:09:37PM +0000, Zong Li wrote:
> The power gating feature of pl2 should be enabled as early as possible,
> it would be better to put it in SPL stage.
> 
> Signed-off-by: Zong Li <zong.li@sifive.com>
> ---
>  arch/riscv/lib/sifive_cache.c | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)

Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>