[PATCH v4 4/5] tty: Add SBI debug console support to HVC SBI driver
From: Anup Patel <hidden>
Date: 2023-11-18 03:39:57
Also in:
linux-riscv, linux-serial, lkml
Subsystem:
hypervisor virtual console driver, the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
From: Atish Patra <redacted> 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 <redacted> Signed-off-by: Anup Patel <redacted> --- drivers/tty/hvc/Kconfig | 2 +- drivers/tty/hvc/hvc_riscv_sbi.c | 59 +++++++++++++++++++++++++++++---- 2 files changed, 53 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..697c981221b5 100644
--- a/drivers/tty/hvc/hvc_riscv_sbi.c
+++ b/drivers/tty/hvc/hvc_riscv_sbi.c@@ -39,21 +39,66 @@ 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; + + 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); + } + + return sbi_debug_console_write(count, pa); } -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; + + 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); + } + + return sbi_debug_console_read(count, pa); +} + +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_debug_console_available) { + err = PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_dbcn_ops, 256)); + 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, 256)); + 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);
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2.34.1