The patch adds SMP support for running 32-bit Linux kernel for
Layerscape platforms. Spin-table method is used for SMP support.

Signed-off-by: Alison Wang <alison.w...@nxp.com>
Signed-off-by: Chenhui Zhao <chenhui.z...@nxp.com>
---
 arch/arm/mach-imx/common.h          |  1 +
 arch/arm/mach-imx/mach-layerscape.c |  1 +
 arch/arm/mach-imx/platsmp.c         | 49 +++++++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h
index c4436d9..6362790 100644
--- a/arch/arm/mach-imx/common.h
+++ b/arch/arm/mach-imx/common.h
@@ -152,5 +152,6 @@ static inline void imx_init_l2cache(void) {}
 
 extern const struct smp_operations imx_smp_ops;
 extern const struct smp_operations ls1021a_smp_ops;
+extern const struct smp_operations layerscape_smp_ops;
 
 #endif
diff --git a/arch/arm/mach-imx/mach-layerscape.c 
b/arch/arm/mach-imx/mach-layerscape.c
index acfb2a2..109d488 100644
--- a/arch/arm/mach-imx/mach-layerscape.c
+++ b/arch/arm/mach-imx/mach-layerscape.c
@@ -19,5 +19,6 @@ static const char * const layerscape_dt_compat[] __initconst 
= {
 };
 
 DT_MACHINE_START(LAYERSCAPE_AARCH32, "Freescale LAYERSCAPE")
+       .smp            = smp_ops(layerscape_smp_ops),
        .dt_compat      = layerscape_dt_compat,
 MACHINE_END
diff --git a/arch/arm/mach-imx/platsmp.c b/arch/arm/mach-imx/platsmp.c
index 711dbbd..e2fc7a2 100644
--- a/arch/arm/mach-imx/platsmp.c
+++ b/arch/arm/mach-imx/platsmp.c
@@ -14,6 +14,7 @@
 #include <linux/of_address.h>
 #include <linux/of.h>
 #include <linux/smp.h>
+#include <linux/types.h>
 
 #include <asm/cacheflush.h>
 #include <asm/page.h>
@@ -26,6 +27,8 @@
 u32 g_diag_reg;
 static void __iomem *scu_base;
 
+static u64 cpu_release_addr[NR_CPUS];
+
 static struct map_desc scu_io_desc __initdata = {
        /* .virtual and .pfn are run-time assigned */
        .length         = SZ_4K,
@@ -127,3 +130,49 @@ const struct smp_operations ls1021a_smp_ops __initconst = {
        .smp_prepare_cpus       = ls1021a_smp_prepare_cpus,
        .smp_boot_secondary     = ls1021a_boot_secondary,
 };
+
+static int layerscape_smp_boot_secondary(unsigned int cpu,
+                                        struct task_struct *idle)
+{
+       u32 secondary_startup_phys;
+       __le32 __iomem *release_addr;
+
+       secondary_startup_phys = virt_to_phys(secondary_startup);
+
+       release_addr = memremap((u32)cpu_release_addr[cpu], sizeof(u64),
+                               MEMREMAP_WB);
+       if (!release_addr)
+               return -ENOMEM;
+
+       writel_relaxed(secondary_startup_phys, release_addr);
+       writel_relaxed(0, release_addr + 1);
+       __cpuc_flush_dcache_area((__force void *)release_addr,
+                                sizeof(u64));
+
+       sev();
+
+       iounmap(release_addr);
+
+       return 0;
+}
+
+static void layerscape_smp_init_cpus(void)
+{
+       struct device_node *dnt = NULL;
+       unsigned int cpu = 0;
+
+       while ((dnt = of_find_node_by_type(dnt, "cpu"))) {
+               if (of_property_read_u64(dnt, "cpu-release-addr",
+                   &cpu_release_addr[cpu])) {
+                       pr_err("CPU %d: missing or invalid cpu-release-addr 
property\n",
+                       cpu);
+               }
+
+               cpu++;
+       }
+}
+
+const struct smp_operations layerscape_smp_ops __initconst = {
+       .smp_init_cpus          = layerscape_smp_init_cpus,
+       .smp_boot_secondary     = layerscape_smp_boot_secondary,
+};
-- 
2.1.0.27.g96db324

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