diff mbox series

[v4,4/5] tty: Add SBI debug console support to HVC SBI driver

Message ID 20231118033859.726692-5-apatel@ventanamicro.com
State New
Headers show
Series RISC-V SBI debug console extension support | expand

Commit Message

Anup Patel Nov. 18, 2023, 3:38 a.m. UTC 
From: Atish Patra <atishp@rivosinc.com>

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@rivosinc.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/tty/hvc/Kconfig         |  2 +-
 drivers/tty/hvc/hvc_riscv_sbi.c | 59 +++++++++++++++++++++++++++++----
 2 files changed, 53 insertions(+), 8 deletions(-)

Comments

Jiri Slaby Nov. 20, 2023, 7:16 a.m. UTC | #1 
On 18. 11. 23, 4:38, Anup Patel wrote:
> 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
...
> -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)) {

I wonder, where does this buf come from, so that you have to check for 
vmalloc?

> +		pa = page_to_phys(vmalloc_to_page(buf)) + offset_in_page(buf);
> +		if (PAGE_SIZE < (offset_in_page(buf) + count))

Am I the only one who would prefer:
   if (count + offset_in_page(buf) > PAGE_SIZE)
?

> +			count = PAGE_SIZE - offset_in_page(buf);
> +	} else {
> +		pa = __pa(buf);
> +	}
> +
> +	return sbi_debug_console_read(count, pa);
> +}


thanks,
diff mbox series

Patch

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);