[PATCH v3] ARM: imx: add smp support for imx7d
Fabio Estevam
festevam at denx.de
Tue May 25 17:14:16 PDT 2021
From: Anson Huang <b20788 at freescale.com>
Add SMP support for i.MX7D, including CPU hotplug support, for
systems where TFA is not present.
The motivation for bringing up the second i.MX7D core inside the kernel
is that legacy vendor bootloaders usually do not implement PSCI support.
This is a significant blocker for systems in the field that are running old
bootloader versions to upgrade to a modern mainline kernel version, as only
one CPU of the i.MX7D would be brought up.
Bring up the second i.MX7D core inside the kernel to make the migration
path to mainline kernel easier for the existing iMX7D users.
Signed-off-by: Anson Huang <b20788 at freescale.com>
Signed-off-by: Arulpandiyan Vadivel <arulpandiyan_vadivel at mentor.com> # Fix merge conflicts
Signed-off-by: Leonard Crestez <leonard.crestez at nxp.com>
Signed-off-by: Marek Vasut <marex at denx.de> # heavy cleanup
Signed-off-by: Fabio Estevam <festevam at denx.de>
---
Changes since v2:
- Removed the DT comment part from the commit log - Shawn
- Added comments in the code explaining the motivation of bringing
up the second core inside the kernel - Shawn
- Fixed checkpatch warnings, except the one regarding NR_CPUS,
which Russell King explained that the current usage is correct - Shawn
- Made imx_gpcv2_set_m_core_pgc() static - Shawn
- Read PDN/PUP register after imx_gpcv2_set_m_core_pgc() - Shawn
- Removed WARN_ON() occurrences - Shawn
- Added comments in the commit log explaining the motivation of bringing
up the second core inside the kernel.
arch/arm/mach-imx/Makefile | 2 +-
arch/arm/mach-imx/common.h | 3 +
arch/arm/mach-imx/headsmp.S | 9 +++
arch/arm/mach-imx/hotplug.c | 3 +
arch/arm/mach-imx/mach-imx7d.c | 3 +-
arch/arm/mach-imx/platsmp.c | 26 +++++++++
arch/arm/mach-imx/src.c | 101 ++++++++++++++++++++++++++++++---
7 files changed, 136 insertions(+), 11 deletions(-)
diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 9cebd360d58e..d1506ef7a537 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -35,7 +35,7 @@ obj-$(CONFIG_HAVE_IMX_ANATOP) += anatop.o
obj-$(CONFIG_HAVE_IMX_GPC) += gpc.o
obj-$(CONFIG_HAVE_IMX_MMDC) += mmdc.o
obj-$(CONFIG_HAVE_IMX_SRC) += src.o
-ifneq ($(CONFIG_SOC_IMX6)$(CONFIG_SOC_LS1021A),)
+ifneq ($(CONFIG_SOC_IMX6)$(CONFIG_SOC_IMX7D_CA7)$(CONFIG_SOC_LS1021A),)
AFLAGS_headsmp.o :=-Wa,-march=armv7-a
obj-$(CONFIG_SMP) += headsmp.o platsmp.o
obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h
index 474dedb73bc7..f0a073a71401 100644
--- a/arch/arm/mach-imx/common.h
+++ b/arch/arm/mach-imx/common.h
@@ -68,11 +68,13 @@ void imx_set_cpu_arg(int cpu, u32 arg);
void v7_secondary_startup(void);
void imx_scu_map_io(void);
void imx_smp_prepare(void);
+void imx_gpcv2_set_core1_pdn_pup_by_software(bool pdn);
#else
static inline void imx_scu_map_io(void) {}
static inline void imx_smp_prepare(void) {}
#endif
void imx_src_init(void);
+void imx7_src_init(void);
void imx_gpc_pre_suspend(bool arm_power_off);
void imx_gpc_post_resume(void);
void imx_gpc_mask_all(void);
@@ -131,6 +133,7 @@ static inline void imx_init_l2cache(void) {}
#endif
extern const struct smp_operations imx_smp_ops;
+extern const struct smp_operations imx7_smp_ops;
extern const struct smp_operations ls1021a_smp_ops;
#endif
diff --git a/arch/arm/mach-imx/headsmp.S b/arch/arm/mach-imx/headsmp.S
index 766dbdb2ae27..fcba58be8e79 100644
--- a/arch/arm/mach-imx/headsmp.S
+++ b/arch/arm/mach-imx/headsmp.S
@@ -21,6 +21,15 @@ diag_reg_offset:
ENTRY(v7_secondary_startup)
ARM_BE8(setend be) @ go BE8 if entered LE
+ mrc p15, 0, r0, c0, c0, 0
+ lsl r0, r0, #16
+ lsr r0, r0, #20
+ /* 0xc07 is cortex A7's ID */
+ mov r1, #0xc00
+ orr r1, #0x7
+ cmp r0, r1
+ beq secondary_startup
+
set_diag_reg
b secondary_startup
ENDPROC(v7_secondary_startup)
diff --git a/arch/arm/mach-imx/hotplug.c b/arch/arm/mach-imx/hotplug.c
index 82e22398d43d..e24a46dc5703 100644
--- a/arch/arm/mach-imx/hotplug.c
+++ b/arch/arm/mach-imx/hotplug.c
@@ -11,6 +11,7 @@
#include <asm/proc-fns.h>
#include "common.h"
+#include "hardware.h"
/*
* platform-specific code to shutdown a CPU
@@ -40,5 +41,7 @@ int imx_cpu_kill(unsigned int cpu)
return 0;
imx_enable_cpu(cpu, false);
imx_set_cpu_arg(cpu, 0);
+ if (cpu_is_imx7d())
+ imx_gpcv2_set_core1_pdn_pup_by_software(true);
return 1;
}
diff --git a/arch/arm/mach-imx/mach-imx7d.c b/arch/arm/mach-imx/mach-imx7d.c
index ccf64ddf8b7e..6fdd06bcf988 100644
--- a/arch/arm/mach-imx/mach-imx7d.c
+++ b/arch/arm/mach-imx/mach-imx7d.c
@@ -69,7 +69,7 @@ static void __init imx7d_init_late(void)
static void __init imx7d_init_irq(void)
{
imx_init_revision_from_anatop();
- imx_src_init();
+ imx7_src_init();
irqchip_init();
}
@@ -80,6 +80,7 @@ static const char *const imx7d_dt_compat[] __initconst = {
};
DT_MACHINE_START(IMX7D, "Freescale i.MX7 Dual (Device Tree)")
+ .smp = smp_ops(imx7_smp_ops),
.init_irq = imx7d_init_irq,
.init_machine = imx7d_init_machine,
.init_late = imx7d_init_late,
diff --git a/arch/arm/mach-imx/platsmp.c b/arch/arm/mach-imx/platsmp.c
index cf4e9335831c..972639038be5 100644
--- a/arch/arm/mach-imx/platsmp.c
+++ b/arch/arm/mach-imx/platsmp.c
@@ -92,6 +92,32 @@ const struct smp_operations imx_smp_ops __initconst = {
#endif
};
+/*
+ * Initialise the CPU possible map early - this describes the CPUs
+ * which may be present or become present in the system.
+ */
+static void __init imx7_smp_init_cpus(void)
+{
+ struct device_node *np;
+ int i, ncores = 0;
+
+ /* The iMX7D SCU does not report core count, get it from DT */
+ for_each_of_cpu_node(np)
+ ncores++;
+
+ for (i = ncores; i < NR_CPUS; i++)
+ set_cpu_possible(i, false);
+}
+
+const struct smp_operations imx7_smp_ops __initconst = {
+ .smp_init_cpus = imx7_smp_init_cpus,
+ .smp_boot_secondary = imx_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_die = imx_cpu_die,
+ .cpu_kill = imx_cpu_kill,
+#endif
+};
+
#define DCFG_CCSR_SCRATCHRW1 0x200
static int ls1021a_boot_secondary(unsigned int cpu, struct task_struct *idle)
diff --git a/arch/arm/mach-imx/src.c b/arch/arm/mach-imx/src.c
index f52f371292ac..95fd1fbb0826 100644
--- a/arch/arm/mach-imx/src.c
+++ b/arch/arm/mach-imx/src.c
@@ -6,15 +6,19 @@
#include <linux/init.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/reset-controller.h>
#include <linux/smp.h>
#include <asm/smp_plat.h>
#include "common.h"
+#include "hardware.h"
#define SRC_SCR 0x000
-#define SRC_GPR1 0x020
+#define SRC_GPR1_V1 0x020
+#define SRC_GPR1_V2 0x074
+#define SRC_GPR1(gpr_v2) ((gpr_v2) ? SRC_GPR1_V2 : SRC_GPR1_V1)
#define BP_SRC_SCR_WARM_RESET_ENABLE 0
#define BP_SRC_SCR_SW_GPU_RST 1
#define BP_SRC_SCR_SW_VPU_RST 2
@@ -23,9 +27,18 @@
#define BP_SRC_SCR_SW_IPU2_RST 12
#define BP_SRC_SCR_CORE1_RST 14
#define BP_SRC_SCR_CORE1_ENABLE 22
+/* below is for i.MX7D */
+#define SRC_A7RCR1 0x008
+#define BP_SRC_A7RCR1_A7_CORE1_ENABLE 1
+#define GPC_CPU_PGC_SW_PUP_REQ 0xf0
+#define GPC_CPU_PGC_SW_PDN_REQ 0xfc
+#define GPC_PGC_C1 0x840
+#define BM_CPU_PGC_SW_PDN_PUP_REQ_CORE1_A7 0x2
static void __iomem *src_base;
static DEFINE_SPINLOCK(scr_lock);
+static bool gpr_v2;
+static void __iomem *gpc_base;
static const int sw_reset_bits[5] = {
BP_SRC_SCR_SW_GPU_RST,
@@ -73,17 +86,64 @@ static struct reset_controller_dev imx_reset_controller = {
.nr_resets = ARRAY_SIZE(sw_reset_bits),
};
+static void imx_gpcv2_set_m_core_pgc(bool enable, u32 offset)
+{
+ writel_relaxed(enable, gpc_base + offset);
+}
+
+/*
+ * The motivation for bringing up the second i.MX7D core inside the kernel
+ * is that legacy vendor bootloaders usually do not implement PSCI support.
+ * This is a significant blocker for systems in the field that are running old
+ * bootloader versions to upgrade to a modern mainline kernel version, as only
+ * one CPU of the i.MX7D would be brought up.
+ * Bring up the second i.MX7D core inside the kernel to make the migration
+ * path to mainline kernel easier for the existing iMX7D users.
+ */
+void imx_gpcv2_set_core1_pdn_pup_by_software(bool pdn)
+{
+ u32 reg = pdn ? GPC_CPU_PGC_SW_PDN_REQ : GPC_CPU_PGC_SW_PUP_REQ;
+ u32 val, pup;
+ int ret;
+
+ imx_gpcv2_set_m_core_pgc(true, GPC_PGC_C1);
+ val = readl_relaxed(gpc_base + reg);
+ val |= BM_CPU_PGC_SW_PDN_PUP_REQ_CORE1_A7;
+ writel_relaxed(val, gpc_base + reg);
+
+ ret = readl_relaxed_poll_timeout_atomic(gpc_base + reg, pup,
+ !(pup & BM_CPU_PGC_SW_PDN_PUP_REQ_CORE1_A7),
+ 5, 1000000);
+ if (ret < 0) {
+ pr_err("i.MX7D: CORE1_A7 power up timeout\n");
+ val &= ~BM_CPU_PGC_SW_PDN_PUP_REQ_CORE1_A7;
+ writel_relaxed(val, gpc_base + reg);
+ }
+
+ imx_gpcv2_set_m_core_pgc(false, GPC_PGC_C1);
+}
+
void imx_enable_cpu(int cpu, bool enable)
{
u32 mask, val;
cpu = cpu_logical_map(cpu);
- mask = 1 << (BP_SRC_SCR_CORE1_ENABLE + cpu - 1);
spin_lock(&scr_lock);
- val = readl_relaxed(src_base + SRC_SCR);
- val = enable ? val | mask : val & ~mask;
- val |= 1 << (BP_SRC_SCR_CORE1_RST + cpu - 1);
- writel_relaxed(val, src_base + SRC_SCR);
+ if (gpr_v2) {
+ if (enable)
+ imx_gpcv2_set_core1_pdn_pup_by_software(false);
+
+ mask = 1 << (BP_SRC_A7RCR1_A7_CORE1_ENABLE + cpu - 1);
+ val = readl_relaxed(src_base + SRC_A7RCR1);
+ val = enable ? val | mask : val & ~mask;
+ writel_relaxed(val, src_base + SRC_A7RCR1);
+ } else {
+ mask = 1 << (BP_SRC_SCR_CORE1_ENABLE + cpu - 1);
+ val = readl_relaxed(src_base + SRC_SCR);
+ val = enable ? val | mask : val & ~mask;
+ val |= 1 << (BP_SRC_SCR_CORE1_RST + cpu - 1);
+ writel_relaxed(val, src_base + SRC_SCR);
+ }
spin_unlock(&scr_lock);
}
@@ -91,19 +151,19 @@ void imx_set_cpu_jump(int cpu, void *jump_addr)
{
cpu = cpu_logical_map(cpu);
writel_relaxed(__pa_symbol(jump_addr),
- src_base + SRC_GPR1 + cpu * 8);
+ src_base + SRC_GPR1(gpr_v2) + cpu * 8);
}
u32 imx_get_cpu_arg(int cpu)
{
cpu = cpu_logical_map(cpu);
- return readl_relaxed(src_base + SRC_GPR1 + cpu * 8 + 4);
+ return readl_relaxed(src_base + SRC_GPR1(gpr_v2) + cpu * 8 + 4);
}
void imx_set_cpu_arg(int cpu, u32 arg)
{
cpu = cpu_logical_map(cpu);
- writel_relaxed(arg, src_base + SRC_GPR1 + cpu * 8 + 4);
+ writel_relaxed(arg, src_base + SRC_GPR1(gpr_v2) + cpu * 8 + 4);
}
void __init imx_src_init(void)
@@ -131,3 +191,26 @@ void __init imx_src_init(void)
writel_relaxed(val, src_base + SRC_SCR);
spin_unlock(&scr_lock);
}
+
+void __init imx7_src_init(void)
+{
+ struct device_node *np;
+
+ gpr_v2 = true;
+
+ np = of_find_compatible_node(NULL, NULL, "fsl,imx7d-src");
+ if (!np)
+ return;
+
+ src_base = of_iomap(np, 0);
+ if (!src_base)
+ return;
+
+ np = of_find_compatible_node(NULL, NULL, "fsl,imx7d-gpc");
+ if (!np)
+ return;
+
+ gpc_base = of_iomap(np, 0);
+ if (!gpc_base)
+ return;
+}
--
2.25.1
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