[U-Boot] [PATCH v7 2/2] armv8: fsl-layerscape: SMP support for loading 32-bit OS

[Alison Wang]

Spin-table method is used for secondary cores to load 32-bit OS. The
architecture information will be got through checking FIT image and
saved in the os_arch element of spin-table, then the secondary cores
will check os_arch and jump to 32-bit OS or 64-bit OS automatically.

Signed-off-by: Alison Wang <alison.wang at nxp.com>
Signed-off-by: Chenhui Zhao <chenhui.zhao at nxp.com>
---
Changes in v7:
- Move the call for armv8_switch_to_el2_m into the first patch.

Changes in v6:
- Make secondary_switch_to_el1() always jump to ep when switching to AArch64 or AArch32 modes.

Changes in v5:
- Make secondary_switch_to_el2() always jump to ep when switching to AArch64 or AArch32 modes.

Changes in v4:
- Omit arch and ftaddr arguments.

Changes in v3:
- Adjust the arguments for armv8_switch_to_el2_m and armv8_switch_to_el1_m. 

Changes in v2:
- Support to call armv8_switch_to_el2_m and armv8_switch_to_el1_m.

 arch/arm/cpu/armv8/fsl-layerscape/mp.c        | 10 ++++++++++
 arch/arm/include/asm/arch-fsl-layerscape/mp.h |  2 ++
 arch/arm/lib/bootm.c                          |  6 ++++++
 3 files changed, 18 insertions(+)

diff --git a/arch/arm/cpu/armv8/fsl-layerscape/mp.c b/arch/arm/cpu/armv8/fsl-layerscape/mp.c
index df7ffb8..dd91550 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/mp.c
+++ b/arch/arm/cpu/armv8/fsl-layerscape/mp.c
@@ -22,6 +22,16 @@ phys_addr_t determine_mp_bootpg(void)
 	return (phys_addr_t)&secondary_boot_code;
 }
 
+void update_os_arch_secondary_cores(uint8_t os_arch)
+{
+	u64 *table = get_spin_tbl_addr();
+	int i;
+
+	for (i = 1; i < CONFIG_MAX_CPUS; i++)
+		table[i * WORDS_PER_SPIN_TABLE_ENTRY +
+			SPIN_TABLE_ELEM_OS_ARCH_IDX] = os_arch;
+}
+
 int fsl_layerscape_wake_seconday_cores(void)
 {
 	struct ccsr_gur __iomem *gur = (void *)(CONFIG_SYS_FSL_GUTS_ADDR);
diff --git a/arch/arm/include/asm/arch-fsl-layerscape/mp.h b/arch/arm/include/asm/arch-fsl-layerscape/mp.h
index 14d9fcf..55f0e0c 100644
--- a/arch/arm/include/asm/arch-fsl-layerscape/mp.h
+++ b/arch/arm/include/asm/arch-fsl-layerscape/mp.h
@@ -13,6 +13,7 @@
 *      uint64_t entry_addr;
 *      uint64_t status;
 *      uint64_t lpid;
+*      uint64_t os_arch;
 * };
 * we pad this struct to 64 bytes so each entry is in its own cacheline
 * the actual spin table is an array of these structures
@@ -20,6 +21,7 @@
 #define SPIN_TABLE_ELEM_ENTRY_ADDR_IDX	0
 #define SPIN_TABLE_ELEM_STATUS_IDX	1
 #define SPIN_TABLE_ELEM_LPID_IDX	2
+#define SPIN_TABLE_ELEM_OS_ARCH_IDX	3
 #define WORDS_PER_SPIN_TABLE_ENTRY	8	/* pad to 64 bytes */
 #define SPIN_TABLE_ELEM_SIZE		64
 
diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index 7015573..17758d3 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -270,6 +270,10 @@ bool armv7_boot_nonsec(void)
 #endif
 
 #ifdef CONFIG_ARM64
+__weak void update_os_arch_secondary_cores(uint8_t os_arch)
+{
+}
+
 #ifdef CONFIG_ARMV8_SWITCH_TO_EL1
 static void switch_to_el1(void)
 {
@@ -307,6 +311,8 @@ static void boot_jump_linux(bootm_headers_t *images, int flag)
 	if (!fake) {
 		do_nonsec_virt_switch();
 
+		update_os_arch_secondary_cores(images->os.arch);
+
 #ifdef CONFIG_ARMV8_SWITCH_TO_EL1
 		armv8_switch_to_el2((u64)images->ft_addr, 0, 0,
 				    (u64)switch_to_el1, ES_TO_AARCH64);
-- 
2.1.0.27.g96db324