From: Rajnesh Kanwal <rkanwal@xxxxxxxxxxxx>
Early console buffer needs to be shared with the host for CoVE Guest.
Signed-off-by: Rajnesh Kanwal <rkanwal@xxxxxxxxxxxx>
Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx>
---
drivers/tty/serial/earlycon-riscv-sbi.c | 51 ++++++++++++++++++++++++-
1 file changed, 49 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/earlycon-riscv-sbi.c b/drivers/tty/serial/earlycon-riscv-sbi.c
index 311a4f8..9033cca 100644
--- a/drivers/tty/serial/earlycon-riscv-sbi.c
+++ b/drivers/tty/serial/earlycon-riscv-sbi.c
@@ -9,6 +9,14 @@
#include <linux/init.h>
#include <linux/serial_core.h>
#include <asm/sbi.h>
+#include <asm/cove.h>
+#include <asm/covg_sbi.h>
+#include <linux/memblock.h>
+
+#ifdef CONFIG_RISCV_COVE_GUEST
+#define DBCN_BOUNCE_BUF_SIZE (PAGE_SIZE)
+static char dbcn_buf[DBCN_BOUNCE_BUF_SIZE] __aligned(PAGE_SIZE);
+#endif
#ifdef CONFIG_RISCV_SBI_V01
static void sbi_putc(struct uart_port *port, unsigned char c)
@@ -24,6 +32,33 @@ static void sbi_0_1_console_write(struct console *con,
}
#endif
+#ifdef CONFIG_RISCV_COVE_GUEST
+static void sbi_dbcn_console_write_cove(struct console *con, const char *s,
+ unsigned int n)
+{
+ phys_addr_t pa = __pa(dbcn_buf);
+ unsigned int off = 0;
+
+ while (off < n) {
+ const unsigned int rem = n - off;
+ const unsigned int size =
+ rem > DBCN_BOUNCE_BUF_SIZE ? DBCN_BOUNCE_BUF_SIZE : rem;
+
+ memcpy(dbcn_buf, &s[off], size);
+
+ sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE,
+#ifdef CONFIG_32BIT
+ size, pa, (u64)pa >> 32,
+#else
+ size, pa, 0,
+#endif
+ 0, 0, 0);
+
+ off += size;
+ }
+}
+#endif
+
static void sbi_dbcn_console_write(struct console *con,
const char *s, unsigned n)
{
@@ -45,14 +80,26 @@ static int __init early_sbi_setup(struct earlycon_device *device,
/* TODO: Check for SBI debug console (DBCN) extension */
if ((sbi_spec_version >= sbi_mk_version(1, 0)) &&
- (sbi_probe_extension(SBI_EXT_DBCN) > 0))
+ (sbi_probe_extension(SBI_EXT_DBCN) > 0)) {
+#ifdef CONFIG_RISCV_COVE_GUEST
+ if (is_cove_guest()) {
+ ret = sbi_covg_share_memory(__pa(dbcn_buf),
+ DBCN_BOUNCE_BUF_SIZE);
+ if (ret)
+ return ret;
+
+ device->con->write = sbi_dbcn_console_write_cove;
+ return 0;
+ }
+#endif
device->con->write = sbi_dbcn_console_write;
- else
+ } else {
#ifdef CONFIG_RISCV_SBI_V01
device->con->write = sbi_0_1_console_write;
#else
ret = -ENODEV;
#endif
+ }
return ret;
}
--
2.25.1
