From: Atish Patra <atishp@xxxxxxxxxxxx>
RISC-V SBI specification supports advanced debug console
support via SBI DBCN extension.
Extend the HVC SBI driver to support it.
Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx>
Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
---
drivers/tty/hvc/Kconfig | 2 +-
drivers/tty/hvc/hvc_riscv_sbi.c | 82 ++++++++++++++++++++++++++++++---
2 files changed, 76 insertions(+), 8 deletions(-)
diff --git a/drivers/tty/hvc/Kconfig b/drivers/tty/hvc/Kconfig
index 4f9264d005c0..6e05c5c7bca1 100644
--- a/drivers/tty/hvc/Kconfig
+++ b/drivers/tty/hvc/Kconfig
@@ -108,7 +108,7 @@ config HVC_DCC_SERIALIZE_SMP
config HVC_RISCV_SBI
bool "RISC-V SBI console support"
- depends on RISCV_SBI_V01
+ depends on RISCV_SBI
select HVC_DRIVER
help
This enables support for console output via RISC-V SBI calls, which
diff --git a/drivers/tty/hvc/hvc_riscv_sbi.c b/drivers/tty/hvc/hvc_riscv_sbi.c
index 31f53fa77e4a..56da1a4b5aca 100644
--- a/drivers/tty/hvc/hvc_riscv_sbi.c
+++ b/drivers/tty/hvc/hvc_riscv_sbi.c
@@ -39,21 +39,89 @@ static int hvc_sbi_tty_get(uint32_t vtermno, char *buf, int count)
return i;
}
-static const struct hv_ops hvc_sbi_ops = {
+static const struct hv_ops hvc_sbi_v01_ops = {
.get_chars = hvc_sbi_tty_get,
.put_chars = hvc_sbi_tty_put,
};
-static int __init hvc_sbi_init(void)
+static int hvc_sbi_dbcn_tty_put(uint32_t vtermno, const char *buf, int count)
{
- return PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_ops, 16));
+ phys_addr_t pa;
+ struct sbiret ret;
+
+ if (is_vmalloc_addr(buf)) {
+ pa = page_to_phys(vmalloc_to_page(buf)) + offset_in_page(buf);
+ if (PAGE_SIZE < (offset_in_page(buf) + count))
+ count = PAGE_SIZE - offset_in_page(buf);
+ } else {
+ pa = __pa(buf);
+ }
+
+ if (IS_ENABLED(CONFIG_32BIT))
+ ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE,
+ count, lower_32_bits(pa), upper_32_bits(pa),
+ 0, 0, 0);
+ else
+ ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE,
+ count, pa, 0, 0, 0, 0);
+ if (ret.error)
+ return 0;
+
+ return count;
}
-device_initcall(hvc_sbi_init);
-static int __init hvc_sbi_console_init(void)
+static int hvc_sbi_dbcn_tty_get(uint32_t vtermno, char *buf, int count)
{
- hvc_instantiate(0, 0, &hvc_sbi_ops);
+ phys_addr_t pa;
+ struct sbiret ret;
+
+ if (is_vmalloc_addr(buf)) {
+ pa = page_to_phys(vmalloc_to_page(buf)) + offset_in_page(buf);
+ if (PAGE_SIZE < (offset_in_page(buf) + count))
+ count = PAGE_SIZE - offset_in_page(buf);
+ } else {
+ pa = __pa(buf);
+ }
+
+ if (IS_ENABLED(CONFIG_32BIT))
+ ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_READ,
+ count, lower_32_bits(pa), upper_32_bits(pa),
+ 0, 0, 0);
+ else
+ ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_READ,
+ count, pa, 0, 0, 0, 0);
+ if (ret.error)
+ return 0;
+
+ return ret.value;
+}
+
+static const struct hv_ops hvc_sbi_dbcn_ops = {
+ .put_chars = hvc_sbi_dbcn_tty_put,
+ .get_chars = hvc_sbi_dbcn_tty_get,
+};
+
+static int __init hvc_sbi_init(void)
+{
+ int err;
+
+ if ((sbi_spec_version >= sbi_mk_version(2, 0)) &&
+ (sbi_probe_extension(SBI_EXT_DBCN) > 0)) {
+ err = PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_dbcn_ops, 16));
+ if (err)
+ return err;
+ hvc_instantiate(0, 0, &hvc_sbi_dbcn_ops);
+ } else {
+ if (IS_ENABLED(CONFIG_RISCV_SBI_V01)) {
+ err = PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_v01_ops, 16));
+ if (err)
+ return err;
+ hvc_instantiate(0, 0, &hvc_sbi_v01_ops);
+ } else {
+ return -ENODEV;
+ }
+ }
return 0;
}
-console_initcall(hvc_sbi_console_init);
+device_initcall(hvc_sbi_init);
--
2.34.1
