[PATCH v2] platform: generic: spacemit: add K1
Anup Patel
anup at brainfault.org
Sun Sep 21 20:25:25 PDT 2025
On Mon, Sep 22, 2025 at 6:46 AM Troy Mitchell
<troy.mitchell at linux.spacemit.com> wrote:
>
> From: Xianbin Zhu <xianbin.zhu at linux.spacemit.com>
>
> Extend generic platform to support SpacemiT K1.
>
> On K1, the BROM only brings up the primary core and leaves the
> other cores in a disabled state. This prevents Linux from booting
> SMP and only one core is available.
>
> Add code to bring up all 8 cores during OpenSBI initialization so
> that the Linux kernel can detect and use all cores properly.
>
> Co-authored-by: Troy Mitchell <troy.mitchell at linux.spacemit.com>
> Signed-off-by: Troy Mitchell <troy.mitchell at linux.spacemit.com>
> Signed-off-by: Xianbin Zhu <xianbin.zhu at linux.spacemit.com>
> ---
> Changes in v2:
> - remove __sbi_hsm_hart_get_state() in spacemit_cold_boot_allowed()
> - plus PMU_AP_BASE in PMU_AP_CORE(0|4)_(WAKEUP|IDLE)_OFFSET
> - Link to v1: https://lore.kernel.org/r/20250916-smt-k1-8-cores-v1-1-5b76e06d12da@linux.spacemit.com
It is better to have a separate fdt_hsm_spacemit driver under
lib/utils/hsm directory.
Regards,
Anup
> ---
> platform/generic/Kconfig | 4 +
> platform/generic/configs/defconfig | 5 +-
> platform/generic/spacemit/k1.c | 329 +++++++++++++++++++++++++++++++++++
> platform/generic/spacemit/objects.mk | 7 +
> 4 files changed, 343 insertions(+), 2 deletions(-)
>
> diff --git a/platform/generic/Kconfig b/platform/generic/Kconfig
> index 7559a4bd8ccfcf7e0e7366141f632f5f5e13bd98..d0835126287ef080a44e30140b49c022695efd17 100644
> --- a/platform/generic/Kconfig
> +++ b/platform/generic/Kconfig
> @@ -76,6 +76,10 @@ config PLATFORM_MIPS_P8700
> bool "MIPS P8700 support"
> default n
>
> +config PLATFORM_SPACEMIT_K1
> + bool "Spacemit K1 support"
> + default n
> +
> source "$(OPENSBI_SRC_DIR)/platform/generic/andes/Kconfig"
> source "$(OPENSBI_SRC_DIR)/platform/generic/thead/Kconfig"
>
> diff --git a/platform/generic/configs/defconfig b/platform/generic/configs/defconfig
> index 4b93d0bc55233f83a907ff81234c78540e33d828..86e7bb9e3d859dcf72e7775fae0844ff066be0f8 100644
> --- a/platform/generic/configs/defconfig
> +++ b/platform/generic/configs/defconfig
> @@ -1,5 +1,6 @@
> CONFIG_PLATFORM_ALLWINNER_D1=y
> CONFIG_PLATFORM_ANDES_AE350=y
> +CONFIG_PLATFORM_OPENHWGROUP_OPENPITON=y
> CONFIG_PLATFORM_RENESAS_RZFIVE=y
> CONFIG_PLATFORM_SIFIVE_FU540=y
> CONFIG_PLATFORM_SIFIVE_FU740=y
> @@ -7,7 +8,7 @@ CONFIG_PLATFORM_SOPHGO_SG2042=y
> CONFIG_PLATFORM_STARFIVE_JH7110=y
> CONFIG_PLATFORM_THEAD=y
> CONFIG_PLATFORM_MIPS_P8700=y
> -CONFIG_PLATFORM_OPENHWGROUP_OPENPITON=y
> +CONFIG_PLATFORM_SPACEMIT_K1=y
> CONFIG_FDT_CPPC=y
> CONFIG_FDT_CPPC_RPMI=y
> CONFIG_FDT_GPIO=y
> @@ -36,8 +37,8 @@ CONFIG_FDT_RESET_ATCWDT200=y
> CONFIG_FDT_RESET_GPIO=y
> CONFIG_FDT_RESET_HTIF=y
> CONFIG_FDT_RESET_RPMI=y
> -CONFIG_FDT_RESET_SUNXI_WDT=y
> CONFIG_FDT_RESET_SG2042_HWMON_MCU=y
> +CONFIG_FDT_RESET_SUNXI_WDT=y
> CONFIG_FDT_RESET_SYSCON=y
> CONFIG_FDT_SERIAL=y
> CONFIG_FDT_SERIAL_CADENCE=y
> diff --git a/platform/generic/spacemit/k1.c b/platform/generic/spacemit/k1.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..1a0576c94ca98b13a970a56459cf6ac3b75e879c
> --- /dev/null
> +++ b/platform/generic/spacemit/k1.c
> @@ -0,0 +1,329 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2025 SpacemiT
> + * Authors:
> + * Xianbin Zhu <xianbin.zhu at linux.spacemit.com>
> + * Troy Mitchell <troy.mitchell at linux.spacemit.com>
> + */
> +
> +#include <platform_override.h>
> +#include <sbi/riscv_io.h>
> +#include <sbi/sbi_hsm.h>
> +
> +#define CSR_MSETUP 0x7c0
> +#define CSR_MHCR 0x7c1
> +#define CSR_MRAOP 0x7c2
> +#define CSR_MHINT 0x7c5
> +#define CSR_ML2SETUP 0x7f0
> +
> +/* decache enable */
> +#define MSETUP_DE BIT(0)
> +/* icache enable */
> +#define MSETUP_IE BIT(1)
> +/* branch prediction enable */
> +#define MSETUP_BPE BIT(4)
> +/* prefetch functionality enable */
> +#define MSETUP_PFE BIT(5)
> +/* misaligned memory access enable */
> +#define MSETUP_MME BIT(6)
> +/* ECC enable */
> +#define MSETUP_ECCE BIT(16)
> +
> +/* icache invalidation */
> +#define MRAOP_ICACHE_INVALID GENMASK(1, 0)
> +
> +#define PMU_AP_BASE 0xd4282800
> +
> +#define PMU_AP_CORE0_WAKEUP_OFFSET (PMU_AP_BASE + 0x12c)
> +#define PMU_AP_CORE4_WAKEUP_OFFSET (PMU_AP_BASE + 0x324)
> +#define PMU_AP_CLUSTER0_WAKEUP_OFFSET(index) (PMU_AP_CORE0_WAKEUP_OFFSET + index * 4)
> +#define PMU_AP_CLUSTER1_WAKEUP_OFFSET(index) (PMU_AP_CORE4_WAKEUP_OFFSET + index * 4)
> +
> +#define PMU_AP_CORE0_IDLE_CFG_OFFSET (PMU_AP_BASE + 0x124)
> +#define PMU_AP_CORE4_IDLE_CFG_OFFSET (PMU_AP_BASE + 0x304)
> +#define PMU_AP_CLUSTER0_IDLE_CFG_OFFSET(index) (PMU_AP_CORE0_IDLE_CFG_OFFSET + index * 4)
> +#define PMU_AP_CLUSTER1_IDLE_CFG_OFFSET(index) (PMU_AP_CORE4_IDLE_CFG_OFFSET + index * 4)
> +
> +#define PMU_AP_CORE0_WAKEUP PMU_AP_CLUSTER0_WAKEUP_OFFSET(0)
> +#define PMU_AP_CORE1_WAKEUP PMU_AP_CLUSTER0_WAKEUP_OFFSET(1)
> +#define PMU_AP_CORE2_WAKEUP PMU_AP_CLUSTER0_WAKEUP_OFFSET(2)
> +#define PMU_AP_CORE3_WAKEUP PMU_AP_CLUSTER0_WAKEUP_OFFSET(3)
> +#define PMU_AP_CORE4_WAKEUP PMU_AP_CLUSTER1_WAKEUP_OFFSET(0)
> +#define PMU_AP_CORE5_WAKEUP PMU_AP_CLUSTER1_WAKEUP_OFFSET(1)
> +#define PMU_AP_CORE6_WAKEUP PMU_AP_CLUSTER1_WAKEUP_OFFSET(2)
> +#define PMU_AP_CORE7_WAKEUP PMU_AP_CLUSTER1_WAKEUP_OFFSET(3)
> +
> +#define PMU_AP_CORE0_IDLE_CFG PMU_AP_CLUSTER0_IDLE_CFG_OFFSET(0)
> +#define PMU_AP_CORE1_IDLE_CFG PMU_AP_CLUSTER0_IDLE_CFG_OFFSET(1)
> +#define PMU_AP_CORE2_IDLE_CFG PMU_AP_CLUSTER0_IDLE_CFG_OFFSET(2)
> +#define PMU_AP_CORE3_IDLE_CFG PMU_AP_CLUSTER0_IDLE_CFG_OFFSET(3)
> +#define PMU_AP_CORE4_IDLE_CFG PMU_AP_CLUSTER1_IDLE_CFG_OFFSET(0)
> +#define PMU_AP_CORE5_IDLE_CFG PMU_AP_CLUSTER1_IDLE_CFG_OFFSET(1)
> +#define PMU_AP_CORE6_IDLE_CFG PMU_AP_CLUSTER1_IDLE_CFG_OFFSET(2)
> +#define PMU_AP_CORE7_IDLE_CFG PMU_AP_CLUSTER1_IDLE_CFG_OFFSET(3)
> +
> +/* power down */
> +#define PMU_AP_IDLE_PWRDWN BIT(0)
> +/* sram power down */
> +#define PMU_AP_IDLE_SRAM_PWRDWN BIT(1)
> +/* enable wake up the memory controller */
> +#define PMU_AP_IDLE_WAKE_MCE BIT(3)
> +/* disable memory controller software req */
> +#define PMU_AP_IDLE_MC_SW_REQ BIT(4)
> +
> +#define PMU_AP_IDLE_PWRDOWN_MASK (PMU_AP_IDLE_PWRDWN | PMU_AP_IDLE_SRAM_PWRDWN | \
> + PMU_AP_IDLE_WAKE_MCE | PMU_AP_IDLE_MC_SW_REQ)
> +/* cci */
> +#define C0_RVBADDR_LO_ADDR 0xd4282db0
> +#define C0_RVBADDR_HI_ADDR 0xd4282db4
> +#define C1_RVBADDR_LO_ADDR 0xd4282eb0
> +#define C1_RVBADDR_HI_ADDR 0xd4282c04
> +
> +#define CCI_550_PLATFORM_CCI_ADDR 0xd8500000
> +
> +/* relative to cci base */
> +#define CCI_550_STATUS 0x000c
> +/* status register bits */
> +#define CCI_550_STATUS_CHANGE_PENDING BIT(0)
> +
> +/* slave interface registers */
> +#define CCI_550_SLAVE_IFACE0_OFFSET 0x1000
> +#define CCI_550_SLAVE_IFACE_OFFSET(idx) (CCI_550_SLAVE_IFACE0_OFFSET + ((0x1000) * (idx)))
> +
> +/* relative to slave interface base */
> +#define CCI_550_SNOOP_CTRL 0x0000
> +/* snoop control register bits */
> +#define CCI_550_SNOOP_CTRL_ENABLE_SNOOPS BIT(0)
> +#define CCI_550_SNOOP_CTRL_ENABLE_DVMS BIT(1)
> +
> +/* clusters and CPU mapping */
> +#define PLATFORM_MAX_CPUS_PER_CLUSTER 4
> +#define CPU_TO_CLUSTER(cpu) ((cpu) / PLATFORM_MAX_CPUS_PER_CLUSTER)
> +
> +#define PLAT_CCI_CLUSTER0_IFACE_IX 0
> +#define PLAT_CCI_CLUSTER1_IFACE_IX 1
> +
> +static const u64 cpu_wakeup_reg[] = {
> + PMU_AP_CORE0_WAKEUP,
> + PMU_AP_CORE1_WAKEUP,
> + PMU_AP_CORE2_WAKEUP,
> + PMU_AP_CORE3_WAKEUP,
> + PMU_AP_CORE4_WAKEUP,
> + PMU_AP_CORE5_WAKEUP,
> + PMU_AP_CORE6_WAKEUP,
> + PMU_AP_CORE7_WAKEUP,
> +};
> +
> +static const u64 cpu_idle_reg[] = {
> + PMU_AP_CORE0_IDLE_CFG,
> + PMU_AP_CORE1_IDLE_CFG,
> + PMU_AP_CORE2_IDLE_CFG,
> + PMU_AP_CORE3_IDLE_CFG,
> + PMU_AP_CORE4_IDLE_CFG,
> + PMU_AP_CORE5_IDLE_CFG,
> + PMU_AP_CORE6_IDLE_CFG,
> + PMU_AP_CORE7_IDLE_CFG,
> +};
> +
> +/* only use 0-1 cluster in SpacemiT K1 */
> +static const int cci_map[] = {
> + PLAT_CCI_CLUSTER0_IFACE_IX,
> + PLAT_CCI_CLUSTER1_IFACE_IX,
> +};
> +
> +extern struct sbi_platform platform;
> +
> +static void cci_enable_snoop_dvm_reqs(unsigned int master_id)
> +{
> + int slave_if_id = cci_map[master_id];
> +
> + /*
> + * Enable Snoops and DVM messages, no need for Read/Modify/Write as
> + * rest of bits are write ignore
> + */
> + writel(CCI_550_SNOOP_CTRL_ENABLE_DVMS | CCI_550_SNOOP_CTRL_ENABLE_SNOOPS,
> + (void *)(u64)CCI_550_PLATFORM_CCI_ADDR +
> + CCI_550_SLAVE_IFACE_OFFSET(slave_if_id) + CCI_550_SNOOP_CTRL);
> +
> + /*
> + * Wait for the completion of the write to the Snoop Control Register
> + * before testing the change_pending bit
> + */
> + mb();
> +
> + /* Wait for the dust to settle down */
> + while (!(readl((void *)(u64)CCI_550_PLATFORM_CCI_ADDR + CCI_550_STATUS) &
> + CCI_550_STATUS_CHANGE_PENDING))
> + ;
> +}
> +
> +static inline void spacemit_set_cpu_power(u32 hartid, bool enable)
> +{
> + unsigned int value;
> + unsigned int *cpu_idle_base = (unsigned int *)cpu_idle_reg[hartid];
> +
> + value = readl(cpu_idle_base);
> +
> + if (enable)
> + value &= ~PMU_AP_IDLE_PWRDOWN_MASK;
> + else
> + value |= PMU_AP_IDLE_PWRDOWN_MASK;
> +
> + writel(value, cpu_idle_base);
> +}
> +
> +static void spacemit_wakeup_cpu(u32 mpidr)
> +{
> + unsigned int *cpu_reset_base;
> + unsigned int cur_hartid = current_hartid();
> +
> + cpu_reset_base = (unsigned int *)cpu_wakeup_reg[cur_hartid];
> +
> + writel(1 << mpidr, cpu_reset_base);
> +}
> +
> +static void spacemit_assert_cpu(void)
> +{
> + spacemit_set_cpu_power(current_hartid(), false);
> +}
> +
> +static void spacemit_deassert_cpu(void)
> +{
> + spacemit_set_cpu_power(current_hartid(), true);
> +}
> +
> +static void spacemit_k1_pre_init(void)
> +{
> + unsigned int hartid, clusterid, cluster_enabled = 0;
> + unsigned int cur_hartid = current_hartid();
> + struct sbi_scratch *scratch;
> + int i;
> +
> + scratch = sbi_hartid_to_scratch(cur_hartid);
> +
> + writel(scratch->warmboot_addr, (unsigned int *)C0_RVBADDR_LO_ADDR);
> + writel(scratch->warmboot_addr >> 32, (unsigned int *)C0_RVBADDR_HI_ADDR);
> +
> + writel(scratch->warmboot_addr, (unsigned int *)C1_RVBADDR_LO_ADDR);
> + writel(scratch->warmboot_addr >> 32, (unsigned int *)C1_RVBADDR_HI_ADDR);
> +
> + for (i = 0; i < platform.hart_count; i++) {
> + hartid = platform.hart_index2id[i];
> + clusterid = CPU_TO_CLUSTER(hartid);
> +
> + if (!(cluster_enabled & (1 << clusterid))) {
> + cluster_enabled |= 1 << clusterid;
> + cci_enable_snoop_dvm_reqs(clusterid);
> + }
> + }
> +}
> +
> +/* Start (or power-up) the given hart */
> +static int spacemit_hart_start(unsigned int hartid, unsigned long saddr)
> +{
> + spacemit_wakeup_cpu(hartid);
> +
> + return 0;
> +}
> +
> +/*
> + * Stop (or power-down) the current hart from running. This call
> + * doesn't expect to return if success.
> + */
> +static int spacemit_hart_stop(void)
> +{
> + csr_write(CSR_STIMECMP, GENMASK_ULL(63, 0));
> + csr_clear(CSR_MIE, MIP_SSIP | MIP_MSIP | MIP_STIP | MIP_MTIP | MIP_SEIP | MIP_MEIP);
> +
> + /* disable data preftch */
> + csr_clear(CSR_MSETUP, MSETUP_PFE);
> + asm volatile ("fence iorw, iorw");
> +
> + /* flush local dcache */
> + csr_write(CSR_MRAOP, MRAOP_ICACHE_INVALID);
> + asm volatile ("fence iorw, iorw");
> +
> + /* disable dcache */
> + csr_clear(CSR_MSETUP, MSETUP_DE);
> + asm volatile ("fence iorw, iorw");
> +
> + /*
> + * Core4-7 do not have dedicated bits in ML2SETUP;
> + * instead, they reuse the same bits as core0-3.
> + *
> + * Therefore, use modulo with PLATFORM_MAX_CPUS_PER_CLUSTER
> + * to select the proper bit.
> + */
> + csr_clear(CSR_ML2SETUP, 1 << (current_hartid() % PLATFORM_MAX_CPUS_PER_CLUSTER));
> + asm volatile ("fence iorw, iorw");
> +
> + spacemit_assert_cpu();
> +
> + wfi();
> +
> + return SBI_ENOTSUPP;
> +}
> +
> +static const struct sbi_hsm_device spacemit_hsm_ops = {
> + .name = "spacemit-hsm",
> + .hart_start = spacemit_hart_start,
> + .hart_stop = spacemit_hart_stop,
> +};
> +
> +/*
> + * Platform early initialization.
> + */
> +static int spacemit_k1_early_init(bool cold_boot)
> +{
> + int rc;
> +
> + rc = generic_early_init(cold_boot);
> + if (rc)
> + return rc;
> +
> + csr_set(CSR_MSETUP, MSETUP_DE | MSETUP_IE | MSETUP_BPE |
> + MSETUP_PFE | MSETUP_MME | MSETUP_ECCE);
> +
> + if (cold_boot)
> + spacemit_k1_pre_init();
> + else
> + spacemit_deassert_cpu();
> +
> + return 0;
> +}
> +
> +static int spacemit_k1_final_init(bool cold_boot)
> +{
> + if (cold_boot)
> + sbi_hsm_set_device(&spacemit_hsm_ops);
> +
> + return generic_final_init(cold_boot);
> +}
> +
> +static bool spacemit_cold_boot_allowed(u32 hartid)
> +{
> + csr_set(CSR_ML2SETUP, 1 << (hartid % PLATFORM_MAX_CPUS_PER_CLUSTER));
> +
> + return !hartid;
> +}
> +
> +static int spacemit_k1_platform_init(const void *fdt, int nodeoff,
> + const struct fdt_match *match)
> +{
> + generic_platform_ops.early_init = spacemit_k1_early_init;
> + generic_platform_ops.final_init = spacemit_k1_final_init;
> + generic_platform_ops.cold_boot_allowed = spacemit_cold_boot_allowed;
> +
> + return 0;
> +}
> +
> +static const struct fdt_match spacemit_k1_match[] = {
> + { .compatible = "spacemit,k1" },
> + { /* sentinel */ }
> +};
> +
> +const struct fdt_driver spacemit_k1 = {
> + .match_table = spacemit_k1_match,
> + .init = spacemit_k1_platform_init,
> +};
> diff --git a/platform/generic/spacemit/objects.mk b/platform/generic/spacemit/objects.mk
> new file mode 100644
> index 0000000000000000000000000000000000000000..4bf973aab1ba749b59cfdc14a572226d54c3ff15
> --- /dev/null
> +++ b/platform/generic/spacemit/objects.mk
> @@ -0,0 +1,7 @@
> +#
> +# SPDX-License-Identifier: BSD-2-Clause
> +#
> +# Copyright (c) 2025 SpacemiT
> +
> +carray-platform_override_modules-$(CONFIG_PLATFORM_SPACEMIT_K1) += spacemit_k1
> +platform-objs-$(CONFIG_PLATFORM_SPACEMIT_K1) += spacemit/k1.o
>
> ---
> base-commit: 153cdeea5350837c1206a2d2b6189fd0ba06d1f2
> change-id: 20250911-smt-k1-8-cores-8985c5f40c5f
>
> Best regards,
> --
> Troy Mitchell <troy.mitchell at linux.spacemit.com>
>
>
> --
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