[PATCH v3 01/12] riscv: Add initial support for P8700 SoC
Uros Stajic
uros.stajic at htecgroup.com
Tue Jul 29 18:22:03 CEST 2025
From: Chao-ying Fu <cfu at mips.com>
Add initial platform support for the P8700-F, a high-performance
multi-core RV64GC SoC with optional multi-cluster configuration and
hardware multithreading.
This patch introduces the initial platform code necessary to support
the P8700 CPU in U-Boot.
Signed-off-by: Chao-ying Fu <cfu at mips.com>
Signed-off-by: Uros Stajic <uros.stajic at htecgroup.com>
---
arch/riscv/Kconfig | 1 +
arch/riscv/cpu/p8700/Kconfig | 15 ++
arch/riscv/cpu/p8700/Makefile | 9 ++
arch/riscv/cpu/p8700/cache.c | 93 +++++++++++
arch/riscv/cpu/p8700/cpu.c | 13 ++
arch/riscv/cpu/p8700/dram.c | 37 +++++
arch/riscv/cpu/p8700/p8700_platform_setup.S | 169 ++++++++++++++++++++
arch/riscv/include/asm/arch-p8700/p8700.h | 110 +++++++++++++
8 files changed, 447 insertions(+)
create mode 100644 arch/riscv/cpu/p8700/Kconfig
create mode 100644 arch/riscv/cpu/p8700/Makefile
create mode 100644 arch/riscv/cpu/p8700/cache.c
create mode 100644 arch/riscv/cpu/p8700/cpu.c
create mode 100644 arch/riscv/cpu/p8700/dram.c
create mode 100644 arch/riscv/cpu/p8700/p8700_platform_setup.S
create mode 100644 arch/riscv/include/asm/arch-p8700/p8700.h
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 8c6feae5735..eb721edca2c 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -127,6 +127,7 @@ source "arch/riscv/cpu/jh7110/Kconfig"
source "arch/riscv/cpu/k1/Kconfig"
source "arch/riscv/cpu/k230/Kconfig"
source "arch/riscv/cpu/th1520/Kconfig"
+source "arch/riscv/cpu/p8700/Kconfig"
# architecture-specific options below
diff --git a/arch/riscv/cpu/p8700/Kconfig b/arch/riscv/cpu/p8700/Kconfig
new file mode 100644
index 00000000000..0e5e4c9eda6
--- /dev/null
+++ b/arch/riscv/cpu/p8700/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (C) 2021, Chao-ying Fu <cfu at mips.com>
+
+config P8700_RISCV
+ bool
+ select ARCH_EARLY_INIT_R
+ imply CPU
+ imply CPU_RISCV
+ imply RISCV_TIMER
+ imply SIFIVE_CLINT if (RISCV_MMODE || SPL_RISCV_MMODE)
+ imply CMD_CPU
+ imply SPL_CPU_SUPPORT
+ imply SPL_OPENSBI
+ imply SPL_LOAD_FIT
diff --git a/arch/riscv/cpu/p8700/Makefile b/arch/riscv/cpu/p8700/Makefile
new file mode 100644
index 00000000000..4dfbddc5cba
--- /dev/null
+++ b/arch/riscv/cpu/p8700/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (C) 2021, Chao-ying Fu <cfu at mips.com>
+
+obj-y += cache.o
+obj-y += cpu.o
+obj-y += dram.o
+
+obj-$(CONFIG_P8700_RISCV) += p8700_platform_setup.o
diff --git a/arch/riscv/cpu/p8700/cache.c b/arch/riscv/cpu/p8700/cache.c
new file mode 100644
index 00000000000..7559c688321
--- /dev/null
+++ b/arch/riscv/cpu/p8700/cache.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2021, Chao-ying Fu <cfu at mips.com>
+ */
+
+#include <cpu_func.h>
+#include <asm/global_data.h>
+#include <asm/io.h>
+#include <asm/arch-p8700/p8700.h>
+
+#define MCACHE_BASE_INST 0xec0500f3
+
+/* NOTE: We force to use a0 in mcache to encode via .word.
+ * 0xec0500f3 is a manually encoded custom RISC-V MCACHE instruction.
+ * The bits [19:15] are set to 01010, selecting register x10 (a0)
+ * as the source operand.
+ * The bits [24:20] represent the 'op' field, which is currently set to 0.
+ * Different cache operations are applied by OR-ing (op << 20) dynamically
+ * to this base value.
+ * Because of this encoding, the variable 'addr' is forced into register a0,
+ * so that the MCACHE instruction uses the address in a0 as its operand.
+ */
+#define cache_loop(start, end, lsize, op) do { \
+ const __typeof__(lsize) __lsize = (lsize); \
+ const register void *addr asm("a0") = (const void *)((start) & ~(__lsize - 1)); \
+ const void *aend = (const void *)(((end) - 1) & ~(__lsize - 1)); \
+ for (; addr <= aend; addr += __lsize) \
+ asm volatile (".word %0 | %1 # force to use %2" \
+ ::"i"(MCACHE_BASE_INST), "i"((op) << 20), "r"(addr)); \
+} while (0)
+
+static unsigned long lsize;
+static unsigned long l1d_total_size;
+static unsigned long slsize;
+
+static void probe_cache_config(void)
+{
+ lsize = 64;
+ l1d_total_size = 64 * 1024;
+
+ int l2_config = 0;
+
+ l2_config = readl((void __iomem *)GCR_L2_CONFIG);
+ int l2_line_size_info = (l2_config >> L2_LINE_SIZE_SHIFT)
+ & L2_LINE_SIZE_MASK;
+ slsize = (l2_line_size_info == 0) ? 0 : 1 << (l2_line_size_info + 1);
+}
+
+void flush_dcache_range(unsigned long start, unsigned long end)
+{
+ if (lsize == 0)
+ probe_cache_config();
+
+ /* aend will be miscalculated when size is zero, so we return here */
+ if (start >= end)
+ return;
+
+ cache_loop(start, end, lsize, HIT_WRITEBACK_INV_D);
+
+ /* flush L2 cache */
+ if (slsize)
+ cache_loop(start, end, slsize, HIT_WRITEBACK_INV_SD);
+
+ /* Instruction Hazard Barrier (IHB) — a hint-encoded SLLI (rd=0, rs1=0, imm=1).
+ * Ensures that all subsequent instruction fetches, including speculative ones,
+ * observe state changes from prior instructions.
+ * Required after MCACHE instructions when instruction fetch depends on cache ops.
+ */
+ asm volatile ("slli x0,x0,1 # ihb");
+}
+
+void invalidate_dcache_range(unsigned long start, unsigned long end)
+{
+ if (lsize == 0)
+ probe_cache_config();
+
+ /* aend will be miscalculated when size is zero, so we return here */
+ if (start >= end)
+ return;
+
+ /* invalidate L2 cache */
+ if (slsize)
+ cache_loop(start, end, slsize, HIT_INVALIDATE_SD);
+
+ cache_loop(start, end, lsize, HIT_INVALIDATE_D);
+
+ /* Instruction Hazard Barrier (IHB) — a hint-encoded SLLI (rd=0, rs1=0, imm=1).
+ * Ensures that all subsequent instruction fetches, including speculative ones,
+ * observe state changes from prior instructions.
+ * Required after MCACHE instructions when instruction fetch depends on cache ops.
+ */
+ asm volatile ("slli x0,x0,1 # ihb");
+}
diff --git a/arch/riscv/cpu/p8700/cpu.c b/arch/riscv/cpu/p8700/cpu.c
new file mode 100644
index 00000000000..ee0d8f377ac
--- /dev/null
+++ b/arch/riscv/cpu/p8700/cpu.c
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2021, Chao-ying Fu <cfu at mips.com>
+ */
+
+extern void p8700_platform_setup(void);
+extern void set_flash_uncached(void);
+
+void harts_early_init(void)
+{
+ p8700_platform_setup();
+ set_flash_uncached();
+}
diff --git a/arch/riscv/cpu/p8700/dram.c b/arch/riscv/cpu/p8700/dram.c
new file mode 100644
index 00000000000..2b54326be39
--- /dev/null
+++ b/arch/riscv/cpu/p8700/dram.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
+ */
+
+#include <fdtdec.h>
+#include <init.h>
+#include <linux/sizes.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int dram_init(void)
+{
+ return fdtdec_setup_mem_size_base();
+}
+
+int dram_init_banksize(void)
+{
+ return fdtdec_setup_memory_banksize();
+}
+
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
+{
+ if (IS_ENABLED(CONFIG_64BIT)) {
+ /*
+ * Ensure that we run from first 4GB so that all
+ * addresses used by U-Boot are 32bit addresses.
+ *
+ * This in-turn ensures that 32bit DMA capable
+ * devices work fine because DMA mapping APIs will
+ * provide 32bit DMA addresses only.
+ */
+ if (gd->ram_top > SZ_4G)
+ return SZ_4G;
+ }
+ return gd->ram_top;
+}
diff --git a/arch/riscv/cpu/p8700/p8700_platform_setup.S b/arch/riscv/cpu/p8700/p8700_platform_setup.S
new file mode 100644
index 00000000000..7c4475a03dd
--- /dev/null
+++ b/arch/riscv/cpu/p8700/p8700_platform_setup.S
@@ -0,0 +1,169 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2021, Chao-ying Fu <cfu at mips.com>
+ */
+
+#include <asm-offsets.h>
+#include <config.h>
+#include <elf.h>
+#include <system-constants.h>
+#include <asm/encoding.h>
+#include <generated/asm-offsets.h>
+#include <asm/arch-p8700/p8700.h>
+
+.global p8700_platform_setup
+.global set_flash_uncached
+
+p8700_platform_setup:
+ addi sp, sp, -48
+ sd s6, 0(sp)
+ sd s7, 8(sp)
+ sd s8, 16(sp)
+ sd s9, 24(sp)
+ sd s10, 32(sp)
+ sd s11, 40(sp)
+
+ move s6, ra
+ move s7, x10
+ move s8, x5
+ move s9, x6
+ move s10, x7
+ move s11, x8
+
+ li x1, 0
+ li x5, 0
+ li x6, 0
+ li x7, 0
+ li x8, 0
+ li x10, 0
+
+ /* a0 has mhartid */
+ csrr a0, CSR_MHARTID
+
+ li t0, BOSTON_PLAT_DDR3STAT
+1: lw t1, 0(t0)
+ andi t1, t1, BOSTON_PLAT_DDR3STAT_CALIB
+ beqz t1, 1b
+
+ /* Test mhartid lowest 4 bits */
+ andi t0, a0, 0xf
+ bne t0, zero, setup_pmp
+
+ li s0, CM_BASE
+ li t0, 0x1fb80000
+ /* Get cluster number to update CM_BASE */
+ srl t1, a0, MHARTID_CLUSTER_SHIFT
+ andi t1, t1, MHARTID_CLUSTER_MASK
+ sll t1, t1, CM_BASE_CLUSTER_SHIFT
+ add s0, s0, t1
+ move t1, s0
+
+ /* Test mhartid lowest 16 bits */
+ li t2, 0xffff
+ and t2, a0, t2
+ bne t2, zero, cm_relocate_done
+ sd t1, GCR_BASE_OFFSET(t0)
+cm_relocate_done:
+
+ li t0, GCR_CL_COH_EN_EN
+
+ /* Get core number to update CM_BASE */
+ srl t1, a0, MHARTID_CORE_SHIFT
+ andi t1, t1, MHARTID_CORE_MASK
+ sll t1, t1, CM_BASE_CORE_SHIFT
+ add s0, s0, t1
+ INDEXED(sd, t0, t1, P8700_GCR_C0_COH_EN, s0)
+3:
+
+ /* Test mhartid */
+ bne a0, zero, setup_pmp
+
+ /* Map all PCIe DMA access to its default, non-IOCU, target */
+ li t0, BOSTON_PLAT_NOCPCIE0ADDR
+ sw zero, 0(t0)
+ li t0, BOSTON_PLAT_NOCPCIE1ADDR
+ sw zero, 0(t0)
+ li t0, BOSTON_PLAT_NOCPCIE2ADDR
+ sw zero, 0(t0)
+
+setup_pmp:
+ /* Setup PMP */
+ li t0, 0x2fffffff # 2G from 0x80000000
+ csrw pmpaddr1, t0
+ li t0, 0x07ff7fff # 0x40000 from 0x1ffc0000
+ csrw pmpaddr2, t0
+ li t0, 0x07f3ffff # 2M from 0x1fc00000
+ csrw pmpaddr3, t0
+ li t0, 0x1fffffffffffffff # All from 0x0
+ csrw pmpaddr4, t0
+ li t0, ((PMP_NAPOT | PMP_R | PMP_W | PMP_X) << 32) | \
+ ((PMP_NAPOT | PMP_R | PMP_X) << 24) | \
+ ((PMP_NAPOT | PMP_R | PMP_W | PMP_X) << 16) | \
+ ((PMP_NAPOT | PMP_R | PMP_W | PMP_X) << 8)
+ csrw pmpcfg0, t0
+
+ /* Test mhartid */
+ bne a0, zero, 2f
+ /* HART 0: Set cacheable for pmp0, pmp1, pmp3, uncacheable for pmp2, pmp4 */
+ li t0, (CCA_CACHE_DISABLE << 32) | (CCA_CACHE_ENABLE << 24) | \
+ (CCA_CACHE_DISABLE << 16) | (CCA_CACHE_ENABLE << 8) | CCA_CACHE_ENABLE
+ j 3f
+2: /* HART 1 or above: Set cacheable for pmp0, pmp1, uncacheable for pmp2, pmp3, pmp4 */
+ li t0, (CCA_CACHE_DISABLE << 32) | (CCA_CACHE_DISABLE << 24) | \
+ (CCA_CACHE_DISABLE << 16) | (CCA_CACHE_ENABLE << 8) | CCA_CACHE_ENABLE
+3:
+ csrw CSR_PMACFG0, t0
+ fence
+
+ /* Test mhartid */
+ beq a0, zero, 1f
+ /* Jump to 0x80000000 */
+ li t0, CONFIG_SYS_LOAD_ADDR
+ jr t0
+1:
+ move ra, s6
+ move x10, s7
+ move x5, s8
+ move x6, s9
+ move x7, s10
+ move x8, s11
+
+ ld s6, 0(sp)
+ ld s7, 8(sp)
+ ld s8, 16(sp)
+ ld s9, 24(sp)
+ ld s10, 32(sp)
+ ld s11, 40(sp)
+ addi sp, sp, 48
+
+ ret
+
+set_flash_uncached:
+ addi sp, sp, -32
+ sd s6, 0(sp)
+ sd s7, 8(sp)
+ sd s8, 16(sp)
+
+ move s6, ra
+ move s7, x5
+ move s8, x6
+
+ /* Set flash uncached at pmp3 */
+ csrr t0, CSR_PMACFG0
+ li t1, 0xffffffffffffffff - (0xff << 24)
+ and t0, t0, t1
+ li t1, (CCA_CACHE_DISABLE << 24)
+ or t0, t0, t1
+ csrw CSR_PMACFG0, t0
+ fence
+
+ move ra, s6
+ move x5, s7
+ move x6, s8
+
+ ld s8, 16(sp)
+ ld s7, 8(sp)
+ ld s6, 0(sp)
+ addi sp, sp, 32
+
+ ret
diff --git a/arch/riscv/include/asm/arch-p8700/p8700.h b/arch/riscv/include/asm/arch-p8700/p8700.h
new file mode 100644
index 00000000000..5ca9b4b9497
--- /dev/null
+++ b/arch/riscv/include/asm/arch-p8700/p8700.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2021, Chao-ying Fu <cfu at mips.com>
+ */
+
+#ifndef __P8700_H__
+#define __P8700_H__
+
+#define CSR_MIPSCONFIG7 0x7d7
+#define CSR_PMACFG0 0x7e0
+
+#define MHARTID_HART_SHIFT 0
+#define MHARTID_HART_MASK 0xf
+#define MHARTID_CORE_SHIFT 4
+#define MHARTID_CORE_MASK 0xff
+#define MHARTID_CLUSTER_SHIFT 16
+#define MHARTID_CLUSTER_MASK 0xf
+
+#define MARCHID_UARCH_SHIFT 0
+#define MARCHID_UARCH_MASK 0xff
+#define MARCHID_CLASS_SHIFT 8
+#define MARCHID_CLASS_MASK 0xff
+#define MARCHID_CLASS_M 0
+#define MARCHID_CLASS_I 1
+#define MARCHID_CLASS_P 2
+
+#define CM_BASE_CORE_SHIFT 8
+#define CM_BASE_CLUSTER_SHIFT 19
+
+#define P8700_TIMER_ADDR 0x16108050
+
+#define CCA_CACHE_ENABLE 0
+#define CCA_BUFFER_CACHE 1
+#define CCA_CACHE_DISABLE 2
+#define CCA_UNCACHE_ACC 3
+#define PMA_SPECULATION (0x1 << 3)
+
+#define L1_I_CACHE 0
+#define L1_D_CACHE 1
+#define L3_CACHE 2
+#define L2_CACHE 3
+
+#define HIT_INVALIDATE 4
+#define HIT_WRITEBACK_INV 5
+
+#define HIT_INVALIDATE_D ((HIT_INVALIDATE << 2) | L1_D_CACHE)
+#define HIT_INVALIDATE_SD ((HIT_INVALIDATE << 2) | L2_CACHE)
+#define HIT_WRITEBACK_INV_D ((HIT_WRITEBACK_INV << 2) | L1_D_CACHE)
+#define HIT_WRITEBACK_INV_SD ((HIT_WRITEBACK_INV << 2) | L2_CACHE)
+
+#define L1D_LINE_SIZE_SHIFT 10
+#define L1D_LINE_SIZE_MASK 0x7
+
+#define GCR_L2_CONFIG 0x16100130
+#define L2_LINE_SIZE_SHIFT 8
+#define L2_LINE_SIZE_MASK 0xf
+
+#define PMP_R 0x01
+#define PMP_W 0x02
+#define PMP_X 0x04
+#define PMP_TOR 0x8
+#define PMP_NA4 0x10
+#define PMP_NAPOT 0x18
+
+#define CM_BASE 0x16100000
+#define CPC_BASE (CM_BASE + 0x8000)
+
+/* CPC Block offsets */
+#define CPC_OFF_LOCAL 0x2000
+
+#define CPC_PWRUP_CTL 0x0030
+
+#define CPC_SYS_CONFIG 0x0140
+
+#define CPC_Cx_CMD 0x0000
+#define CPC_Cx_CMD_RESET 0x4
+
+#define P8700_GCR_C0_COH_EN 0x20f8
+#define P8700_GCR_C1_COH_EN 0x21f8
+#define P8700_GCR_C2_COH_EN 0x22f8
+#define P8700_GCR_C3_COH_EN 0x23f8
+#define P8700_GCR_C4_COH_EN 0x24f8
+#define P8700_GCR_C5_COH_EN 0x25f8
+
+#define GCR_CL_COH_EN 0x2008
+#define GCR_CL_COH_EN_EN (0x1 << 0)
+#define GCR_BASE_OFFSET 0x0008
+#define GIC_BASE_OFFSET 0x0080
+#define CPC_BASE_OFFSET 0x0088
+#define ENABLE 0x1
+#define COUNT_STOP (0x1 << 28)
+#define GIC_LOCAL_SECTION_OFS 0x8000
+#define GIC_VL_MASK 0x08
+#define GIC_VL_RMASK 0x0c
+#define GIC_VL_SMASK 0x10
+#define GIC_VL_COMPARE_MAP 0x44
+
+#define INDEXED(op, reg, idx, offset, base) \
+ li idx, offset ;\
+ add idx, idx, base ;\
+ op reg, (idx)
+
+#define BOSTON_PLAT_BASE 0x17ffd000
+#define BOSTON_PLAT_DDR3STAT (BOSTON_PLAT_BASE + 0x14)
+#define BOSTON_PLAT_DDR3STAT_CALIB (0x1 << 2)
+#define BOSTON_PLAT_NOCPCIE0ADDR (BOSTON_PLAT_BASE + 0x3c)
+#define BOSTON_PLAT_NOCPCIE1ADDR (BOSTON_PLAT_BASE + 0x40)
+#define BOSTON_PLAT_NOCPCIE2ADDR (BOSTON_PLAT_BASE + 0x44)
+
+#endif /* __P8700_H__ */
--
2.34.1
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