[PATCH v3 1/2] cache: Add StarFive StarLink cache management for StarFive JH8100
From: Joshua Yeong
Date: Wed Apr 24 2024 - 04:13:55 EST
Add StarFive Starlink cache management driver for
JH8100 SoC. This driver enables RISC-V
non-standard cache operation on JH8100 that does
not support Zicbom extension instructions.
Signed-off-by: Joshua Yeong <joshua.yeong@xxxxxxxxxxxxxxxx>
---
drivers/cache/Kconfig | 9 ++
drivers/cache/Makefile | 5 +-
drivers/cache/starfive_starlink_cache.c | 135 ++++++++++++++++++++++++
3 files changed, 147 insertions(+), 2 deletions(-)
create mode 100644 drivers/cache/starfive_starlink_cache.c
diff --git a/drivers/cache/Kconfig b/drivers/cache/Kconfig
index 9345ce4976d7..9181cd391f53 100644
--- a/drivers/cache/Kconfig
+++ b/drivers/cache/Kconfig
@@ -14,4 +14,13 @@ config SIFIVE_CCACHE
help
Support for the composable cache controller on SiFive platforms.
+config STARFIVE_STARLINK_CACHE
+ bool "StarFive StarLink Cache controller"
+ depends on RISCV
+ depends on ARCH_STARFIVE
+ select RISCV_DMA_NONCOHERENT
+ select RISCV_NONSTANDARD_CACHE_OPS
+ help
+ Support for the StarLink cache controller on StarFive platforms.
+
endmenu
diff --git a/drivers/cache/Makefile b/drivers/cache/Makefile
index 7657cff3bd6c..55c5e851034d 100644
--- a/drivers/cache/Makefile
+++ b/drivers/cache/Makefile
@@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_AX45MP_L2_CACHE) += ax45mp_cache.o
-obj-$(CONFIG_SIFIVE_CCACHE) += sifive_ccache.o
+obj-$(CONFIG_AX45MP_L2_CACHE) += ax45mp_cache.o
+obj-$(CONFIG_SIFIVE_CCACHE) += sifive_ccache.o
+obj-$(CONFIG_STARFIVE_STARLINK_CACHE) += starfive_starlink_cache.o
diff --git a/drivers/cache/starfive_starlink_cache.c b/drivers/cache/starfive_starlink_cache.c
new file mode 100644
index 000000000000..2f1fa6a923ee
--- /dev/null
+++ b/drivers/cache/starfive_starlink_cache.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cache Management Operations for StarFive's Starlink cache controller
+ *
+ * Copyright (C) 2024 Shanghai StarFive Technology Co., Ltd.
+ *
+ * Author: Joshua Yeong <joshua.yeong@xxxxxxxxxxxxxxxx>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/cacheflush.h>
+#include <linux/iopoll.h>
+#include <linux/of_address.h>
+
+#include <asm/dma-noncoherent.h>
+
+#define STARLINK_CACHE_FLUSH_START_ADDR 0x0
+#define STARLINK_CACHE_FLUSH_END_ADDR 0x8
+#define STARLINK_CACHE_FLUSH_CTL 0x10
+#define STARLINK_CACHE_ALIGN 0x40
+
+#define STARLINK_CACHE_ADDRESS_RANGE_MASK GENMASK(39, 0)
+#define STARLINK_CACHE_FLUSH_CTL_MODE_MASK GENMASK(2, 1)
+#define STARLINK_CACHE_FLUSH_CTL_ENABLE_MASK BIT(0)
+
+#define STARLINK_CACHE_FLUSH_CTL_CLEAN_INVALIDATE 0
+#define STARLINK_CACHE_FLUSH_CTL_MAKE_INVALIDATE 1
+#define STARLINK_CACHE_FLUSH_CTL_CLEAN_SHARED 2
+#define STARLINK_CACHE_FLUSH_POLL_DELAY_US 1
+#define STARLINK_CACHE_FLUSH_TIMEOUT_US 5000000
+
+struct starlink_cache_priv {
+ void __iomem *base_addr;
+};
+
+static struct starlink_cache_priv starlink_cache_priv;
+
+static void starlink_cache_flush_complete(void)
+{
+ volatile void __iomem *ctl = starlink_cache_priv.base_addr +
+ STARLINK_CACHE_FLUSH_CTL;
+ u64 v;
+ int ret;
+
+ ret = readq_poll_timeout_atomic(ctl, v, !(v & STARLINK_CACHE_FLUSH_CTL_ENABLE_MASK),
+ STARLINK_CACHE_FLUSH_POLL_DELAY_US,
+ STARLINK_CACHE_FLUSH_TIMEOUT_US);
+ if (ret)
+ WARN(1, "StarFive Starlink cache flush operation timeout\n");
+}
+
+static void starlink_cache_dma_cache_wback(phys_addr_t paddr, unsigned long size)
+{
+ writeq(FIELD_PREP(STARLINK_CACHE_ADDRESS_RANGE_MASK, paddr),
+ starlink_cache_priv.base_addr + STARLINK_CACHE_FLUSH_START_ADDR);
+ writeq(FIELD_PREP(STARLINK_CACHE_ADDRESS_RANGE_MASK, paddr + size),
+ starlink_cache_priv.base_addr + STARLINK_CACHE_FLUSH_END_ADDR);
+
+ mb();
+ writeq(FIELD_PREP(STARLINK_CACHE_FLUSH_CTL_MODE_MASK,
+ STARLINK_CACHE_FLUSH_CTL_CLEAN_SHARED),
+ starlink_cache_priv.base_addr + STARLINK_CACHE_FLUSH_CTL);
+
+ starlink_cache_flush_complete();
+}
+
+static void starlink_cache_dma_cache_invalidate(phys_addr_t paddr, unsigned long size)
+{
+ writeq(FIELD_PREP(STARLINK_CACHE_ADDRESS_RANGE_MASK, paddr),
+ starlink_cache_priv.base_addr + STARLINK_CACHE_FLUSH_START_ADDR);
+ writeq(FIELD_PREP(STARLINK_CACHE_ADDRESS_RANGE_MASK, paddr + size),
+ starlink_cache_priv.base_addr + STARLINK_CACHE_FLUSH_END_ADDR);
+
+ mb();
+ writeq(FIELD_PREP(STARLINK_CACHE_FLUSH_CTL_MODE_MASK,
+ STARLINK_CACHE_FLUSH_CTL_MAKE_INVALIDATE),
+ starlink_cache_priv.base_addr + STARLINK_CACHE_FLUSH_CTL);
+
+ starlink_cache_flush_complete();
+}
+
+static void starlink_cache_dma_cache_wback_inv(phys_addr_t paddr, unsigned long size)
+{
+ writeq(FIELD_PREP(STARLINK_CACHE_ADDRESS_RANGE_MASK, paddr),
+ starlink_cache_priv.base_addr + STARLINK_CACHE_FLUSH_START_ADDR);
+ writeq(FIELD_PREP(STARLINK_CACHE_ADDRESS_RANGE_MASK, paddr + size),
+ starlink_cache_priv.base_addr + STARLINK_CACHE_FLUSH_END_ADDR);
+
+ mb();
+ writeq(FIELD_PREP(STARLINK_CACHE_FLUSH_CTL_MODE_MASK,
+ STARLINK_CACHE_FLUSH_CTL_CLEAN_INVALIDATE),
+ starlink_cache_priv.base_addr + STARLINK_CACHE_FLUSH_CTL);
+
+ starlink_cache_flush_complete();
+}
+
+static const struct riscv_nonstd_cache_ops starlink_cache_ops = {
+ .wback = &starlink_cache_dma_cache_wback,
+ .inv = &starlink_cache_dma_cache_invalidate,
+ .wback_inv = &starlink_cache_dma_cache_wback_inv,
+};
+
+static const struct of_device_id starlink_cache_ids[] = {
+ { .compatible = "starfive,jh8100-starlink-cache" },
+ { /* sentinel */ }
+};
+
+static int __init starlink_cache_init(void)
+{
+ struct device_node *np;
+ u32 block_size = 0;
+ int ret;
+
+ np = of_find_matching_node(NULL, starlink_cache_ids);
+ if (!of_device_is_available(np))
+ return -ENODEV;
+
+ ret = of_property_read_u32(np, "cache-block-size", &block_size);
+ if (ret)
+ return ret;
+
+ if (block_size % STARLINK_CACHE_ALIGN)
+ return -EINVAL;
+
+ starlink_cache_priv.base_addr = of_iomap(np, 0);
+ if (!starlink_cache_priv.base_addr)
+ return -ENOMEM;
+
+ riscv_cbom_block_size = block_size;
+ riscv_noncoherent_supported();
+ riscv_noncoherent_register_cache_ops(&starlink_cache_ops);
+
+ return 0;
+}
+early_initcall(starlink_cache_init);
--
2.25.1