[PATCH V4 04/14] LoongArch: Adjust boot & setup for 32BIT/64BIT

Huacai Chen
2025-11-27T15:51:16Z

Adjust boot & setup for both 32BIT and 64BIT, including: efi header
definition, MAX_IO_PICS definition, kernel entry and environment setup
routines, etc.

Add a fallback path in fdt_cpu_clk_init() to avoid 0MHz in /proc/cpuinfo
if there is no valid clock freq from firmware.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---
arch/loongarch/include/asm/addrspace.h | 2 +-
arch/loongarch/include/asm/irq.h | 5 ++++
arch/loongarch/kernel/efi-header.S | 4 +++
arch/loongarch/kernel/efi.c | 4 ++-
arch/loongarch/kernel/env.c | 5 +++-
arch/loongarch/kernel/head.S | 39 +++++++++++---------------
arch/loongarch/kernel/relocate.c | 9 +++++-
7 files changed, 42 insertions(+), 26 deletions(-)

diff --git a/arch/loongarch/include/asm/addrspace.h b/arch/loongarch/include/asm/addrspace.h
index e739dbc6329d..9766a100504a 100644
--- a/arch/loongarch/include/asm/addrspace.h
+++ b/arch/loongarch/include/asm/addrspace.h
@@ -42,7 +42,7 @@ extern unsigned long vm_map_base;
#endif

#define DMW_PABITS 48
-#define TO_PHYS_MASK ((1ULL << DMW_PABITS) - 1)
+#define TO_PHYS_MASK ((_ULL(1) << _ULL(DMW_PABITS)) - 1)

/*
* Memory above this physical address will be considered highmem.
diff --git a/arch/loongarch/include/asm/irq.h b/arch/loongarch/include/asm/irq.h
index 12bd15578c33..cf6c82a9117b 100644
--- a/arch/loongarch/include/asm/irq.h
+++ b/arch/loongarch/include/asm/irq.h
@@ -53,7 +53,12 @@ void spurious_interrupt(void);
#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
void arch_trigger_cpumask_backtrace(const struct cpumask *mask, int exclude_cpu);

+#ifdef CONFIG_32BIT
+#define MAX_IO_PICS 1
+#else
#define MAX_IO_PICS 8
+#endif
+
#define NR_IRQS (64 + NR_VECTORS * (NR_CPUS + MAX_IO_PICS))

struct acpi_vector_group {
diff --git a/arch/loongarch/kernel/efi-header.S b/arch/loongarch/kernel/efi-header.S
index ba0bdbf86aa8..6df56241cb95 100644
--- a/arch/loongarch/kernel/efi-header.S
+++ b/arch/loongarch/kernel/efi-header.S
@@ -9,7 +9,11 @@
.macro __EFI_PE_HEADER
.long IMAGE_NT_SIGNATURE
.Lcoff_header:
+#ifdef CONFIG_32BIT
+ .short IMAGE_FILE_MACHINE_LOONGARCH32 /* Machine */
+#else
.short IMAGE_FILE_MACHINE_LOONGARCH64 /* Machine */
+#endif
.short .Lsection_count /* NumberOfSections */
.long 0 /* TimeDateStamp */
.long 0 /* PointerToSymbolTable */
diff --git a/arch/loongarch/kernel/efi.c b/arch/loongarch/kernel/efi.c
index 860a3bc030e0..52c21c895318 100644
--- a/arch/loongarch/kernel/efi.c
+++ b/arch/loongarch/kernel/efi.c
@@ -115,7 +115,9 @@ void __init efi_init(void)

efi_systab_report_header(&efi_systab->hdr, efi_systab->fw_vendor);

- set_bit(EFI_64BIT, &efi.flags);
+ if (IS_ENABLED(CONFIG_64BIT))
+ set_bit(EFI_64BIT, &efi.flags);
+
efi_nr_tables = efi_systab->nr_tables;
efi_config_table = (unsigned long)efi_systab->tables;

diff --git a/arch/loongarch/kernel/env.c b/arch/loongarch/kernel/env.c
index 23bd5ae2212c..841206fde3ab 100644
--- a/arch/loongarch/kernel/env.c
+++ b/arch/loongarch/kernel/env.c
@@ -72,9 +72,12 @@ static int __init fdt_cpu_clk_init(void)

clk = of_clk_get(np, 0);
of_node_put(np);
+ cpu_clock_freq = 200 * 1000 * 1000;

- if (IS_ERR(clk))
+ if (IS_ERR(clk)) {
+ pr_warn("No valid CPU clock freq, assume 200MHz.\n");
return -ENODEV;
+ }

cpu_clock_freq = clk_get_rate(clk);
clk_put(clk);
diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S
index e3865e92a917..aba548db2446 100644
--- a/arch/loongarch/kernel/head.S
+++ b/arch/loongarch/kernel/head.S
@@ -43,36 +43,29 @@ SYM_DATA(kernel_fsize, .long _kernel_fsize);

SYM_CODE_START(kernel_entry) # kernel entry point

- /* Config direct window and set PG */
- SETUP_DMWINS t0
+ SETUP_TWINS
+ SETUP_MODES t0
JUMP_VIRT_ADDR t0, t1
-
- /* Enable PG */
- li.w t0, 0xb0 # PLV=0, IE=0, PG=1
- csrwr t0, LOONGARCH_CSR_CRMD
- li.w t0, 0x04 # PLV=0, PIE=1, PWE=0
- csrwr t0, LOONGARCH_CSR_PRMD
- li.w t0, 0x00 # FPE=0, SXE=0, ASXE=0, BTE=0
- csrwr t0, LOONGARCH_CSR_EUEN
+ SETUP_DMWINS t0

la.pcrel t0, __bss_start # clear .bss
- st.d zero, t0, 0
+ LONG_S zero, t0, 0
la.pcrel t1, __bss_stop - LONGSIZE
1:
- addi.d t0, t0, LONGSIZE
- st.d zero, t0, 0
+ PTR_ADDI t0, t0, LONGSIZE
+ LONG_S zero, t0, 0
bne t0, t1, 1b

la.pcrel t0, fw_arg0
- st.d a0, t0, 0 # firmware arguments
+ PTR_S a0, t0, 0 # firmware arguments
la.pcrel t0, fw_arg1
- st.d a1, t0, 0
+ PTR_S a1, t0, 0
la.pcrel t0, fw_arg2
- st.d a2, t0, 0
+ PTR_S a2, t0, 0

#ifdef CONFIG_PAGE_SIZE_4KB
- li.d t0, 0
- li.d t1, CSR_STFILL
+ LONG_LI t0, 0
+ LONG_LI t1, CSR_STFILL
csrxchg t0, t1, LOONGARCH_CSR_IMPCTL1
#endif
/* KSave3 used for percpu base, initialized as 0 */
@@ -98,7 +91,7 @@ SYM_CODE_START(kernel_entry) # kernel entry point

/* Jump to the new kernel: new_pc = current_pc + random_offset */
pcaddi t0, 0
- add.d t0, t0, a0
+ PTR_ADD t0, t0, a0
jirl zero, t0, 0xc
#endif /* CONFIG_RANDOMIZE_BASE */

@@ -121,12 +114,14 @@ SYM_CODE_END(kernel_entry)
*/
SYM_CODE_START(smpboot_entry)

- SETUP_DMWINS t0
+ SETUP_TWINS
+ SETUP_MODES t0
JUMP_VIRT_ADDR t0, t1
+ SETUP_DMWINS t0

#ifdef CONFIG_PAGE_SIZE_4KB
- li.d t0, 0
- li.d t1, CSR_STFILL
+ LONG_LI t0, 0
+ LONG_LI t1, CSR_STFILL
csrxchg t0, t1, LOONGARCH_CSR_IMPCTL1
#endif
/* Enable PG */
diff --git a/arch/loongarch/kernel/relocate.c b/arch/loongarch/kernel/relocate.c
index 76abbb8d2931..82aa3f035927 100644
--- a/arch/loongarch/kernel/relocate.c
+++ b/arch/loongarch/kernel/relocate.c
@@ -68,18 +68,25 @@ static inline void __init relocate_absolute(long random_offset)

for (p = begin; (void *)p < end; p++) {
long v = p->symvalue;
- uint32_t lu12iw, ori, lu32id, lu52id;
+ uint32_t lu12iw, ori;
+#ifdef CONFIG_64BIT
+ uint32_t lu32id, lu52id;
+#endif
union loongarch_instruction *insn = (void *)p->pc;

lu12iw = (v >> 12) & 0xfffff;
ori = v & 0xfff;
+#ifdef CONFIG_64BIT
lu32id = (v >> 32) & 0xfffff;
lu52id = v >> 52;
+#endif

insn[0].reg1i20_format.immediate = lu12iw;
insn[1].reg2i12_format.immediate = ori;
+#ifdef CONFIG_64BIT
insn[2].reg1i20_format.immediate = lu32id;
insn[3].reg2i12_format.immediate = lu52id;
+#endif
}
}

--
2.47.3