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| author | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2016-02-25 15:10:39 +0300 |
|---|---|---|
| committer | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2016-02-26 19:51:24 +0300 |
| commit | a4d7b75be034115d36b6a20db566eb8b11bacaf8 (patch) | |
| tree | 248751b330ad2cc41bca983987fa20cafbc80423 /drivers/tty | |
| parent | 5de738b3fbbd52a21850d5c1b6c1e5823db18b21 (diff) | |
| download | linux-a4d7b75be034115d36b6a20db566eb8b11bacaf8.tar.xz | |
hvc_xen: make early_printk work with HVM guests
Refactor the existing code in xen_raw_console_write to get the generic
early_printk console work with HVM guests.
Take the opportunity to replace the outb loop with a single outsb call
to reduce the number of vmexit.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/hvc/hvc_xen.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c index f34dec1d588a..71784950048f 100644 --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -605,6 +605,16 @@ static int xen_cons_init(void) } console_initcall(xen_cons_init); +#ifdef CONFIG_X86 +static void xen_hvm_early_write(uint32_t vtermno, const char *str, int len) +{ + if (xen_cpuid_base()) + outsb(0xe9, str, len); +} +#else +static void xen_hvm_early_write(uint32_t vtermno, const char *str, int len) { } +#endif + #ifdef CONFIG_EARLY_PRINTK static int __init xenboot_setup_console(struct console *console, char *string) { @@ -624,8 +634,10 @@ static void xenboot_write_console(struct console *console, const char *string, unsigned int linelen, off = 0; const char *pos; - if (!xen_pv_domain()) + if (!xen_pv_domain()) { + xen_hvm_early_write(0, string, len); return; + } dom0_write_console(0, string, len); @@ -661,17 +673,10 @@ void xen_raw_console_write(const char *str) if (xen_domain()) { rc = dom0_write_console(0, str, len); -#ifdef CONFIG_X86 - if (rc == -ENOSYS && xen_hvm_domain()) - goto outb_print; - - } else if (xen_cpuid_base()) { - int i; -outb_print: - for (i = 0; i < len; i++) - outb(str[i], 0xe9); -#endif + if (rc != -ENOSYS || !xen_hvm_domain()) + return; } + xen_hvm_early_write(0, str, len); } void xen_raw_printk(const char *fmt, ...) |