diff options
| -rw-r--r-- | arch/riscv/include/asm/sbi.h | 5 | ||||
| -rw-r--r-- | arch/riscv/kernel/sbi.c | 66 |
2 files changed, 71 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index 66f3933c14f6..9eef25308d53 100644 --- a/arch/riscv/include/asm/sbi.h +++ b/arch/riscv/include/asm/sbi.h @@ -334,6 +334,11 @@ static inline unsigned long sbi_mk_version(unsigned long major, } int sbi_err_map_linux_errno(int err); + +extern bool sbi_debug_console_available; +int sbi_debug_console_write(const char *bytes, unsigned int num_bytes); +int sbi_debug_console_read(char *bytes, unsigned int num_bytes); + #else /* CONFIG_RISCV_SBI */ static inline int sbi_remote_fence_i(const struct cpumask *cpu_mask) { return -1; } static inline void sbi_init(void) {} diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index 5a62ed1da453..e66e0999a800 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -7,6 +7,7 @@ #include <linux/bits.h> #include <linux/init.h> +#include <linux/mm.h> #include <linux/pm.h> #include <linux/reboot.h> #include <asm/sbi.h> @@ -571,6 +572,66 @@ long sbi_get_mimpid(void) } EXPORT_SYMBOL_GPL(sbi_get_mimpid); +bool sbi_debug_console_available; + +int sbi_debug_console_write(const char *bytes, unsigned int num_bytes) +{ + phys_addr_t base_addr; + struct sbiret ret; + + if (!sbi_debug_console_available) + return -EOPNOTSUPP; + + if (is_vmalloc_addr(bytes)) + base_addr = page_to_phys(vmalloc_to_page(bytes)) + + offset_in_page(bytes); + else + base_addr = __pa(bytes); + if (PAGE_SIZE < (offset_in_page(bytes) + num_bytes)) + num_bytes = PAGE_SIZE - offset_in_page(bytes); + + if (IS_ENABLED(CONFIG_32BIT)) + ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE, + num_bytes, lower_32_bits(base_addr), + upper_32_bits(base_addr), 0, 0, 0); + else + ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE, + num_bytes, base_addr, 0, 0, 0, 0); + + if (ret.error == SBI_ERR_FAILURE) + return -EIO; + return ret.error ? sbi_err_map_linux_errno(ret.error) : ret.value; +} + +int sbi_debug_console_read(char *bytes, unsigned int num_bytes) +{ + phys_addr_t base_addr; + struct sbiret ret; + + if (!sbi_debug_console_available) + return -EOPNOTSUPP; + + if (is_vmalloc_addr(bytes)) + base_addr = page_to_phys(vmalloc_to_page(bytes)) + + offset_in_page(bytes); + else + base_addr = __pa(bytes); + if (PAGE_SIZE < (offset_in_page(bytes) + num_bytes)) + num_bytes = PAGE_SIZE - offset_in_page(bytes); + + if (IS_ENABLED(CONFIG_32BIT)) + ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_READ, + num_bytes, lower_32_bits(base_addr), + upper_32_bits(base_addr), 0, 0, 0); + else + ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_READ, + num_bytes, base_addr, 0, 0, 0, 0); + + if (ret.error == SBI_ERR_FAILURE) + return -EIO; + return ret.error ? sbi_err_map_linux_errno(ret.error) : ret.value; +} + void __init sbi_init(void) { int ret; @@ -612,6 +673,11 @@ void __init sbi_init(void) sbi_srst_reboot_nb.priority = 192; register_restart_handler(&sbi_srst_reboot_nb); } + if ((sbi_spec_version >= sbi_mk_version(2, 0)) && + (sbi_probe_extension(SBI_EXT_DBCN) > 0)) { + pr_info("SBI DBCN extension detected\n"); + sbi_debug_console_available = true; + } } else { __sbi_set_timer = __sbi_set_timer_v01; __sbi_send_ipi = __sbi_send_ipi_v01; |