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authorDavid S. Miller <davem@davemloft.net>2010-11-30 20:15:58 -0800
committerDavid S. Miller <davem@davemloft.net>2010-11-30 20:15:58 -0800
commit595a251c0740785fd3c0d2156d78578c7479811e (patch)
tree513cee9d682b12c2c4e490f7e91422e82530c4b8 /arch/sparc/prom
parent12c7a35ee6a1c605e740733f2cbd5b5079f09f0f (diff)
downloadlinux-595a251c0740785fd3c0d2156d78578c7479811e.tar.gz
sparc: Write to prom console using indirect buffer.
sparc64 systems have a restriction in that passing in buffer addressses above 4GB to prom calls is not reliable. We end up violating this when we do prom console writes, because we use an on-stack buffer to translate '\n' into '\r\n'. So instead, do this translation into an intermediate buffer, which is in the kernel image and thus below 4GB, then pass that to the PROM console write calls. On the 32-bit side we don't have to deal with any of these issues, so the new prom_console_write_buf() uses the existing prom_nbputchar() implementation. However we can now mark those routines static. Since the 64-bit side completely uses new code we can delete the putchar bits as they are now completely unused. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/prom')
-rw-r--r--arch/sparc/prom/console_32.c14
-rw-r--r--arch/sparc/prom/console_64.c27
-rw-r--r--arch/sparc/prom/printf.c32
3 files changed, 48 insertions, 25 deletions
diff --git a/arch/sparc/prom/console_32.c b/arch/sparc/prom/console_32.c
index 157019e29fd4..48863108a44c 100644
--- a/arch/sparc/prom/console_32.c
+++ b/arch/sparc/prom/console_32.c
@@ -43,12 +43,14 @@ static int prom_nbputchar(const char *buf)
return i; /* Ugh, we could spin forever on unsupported proms ;( */
}
-/* Blocking version of put character routine above. */
-void prom_putchar(const char *buf)
+void prom_console_write_buf(const char *buf, int len)
{
- while (1) {
- int err = prom_nbputchar(buf);
- if (!err)
- break;
+ while (len) {
+ int n = prom_nbputchar(buf);
+ if (n)
+ continue;
+ len--;
+ buf++;
}
}
+
diff --git a/arch/sparc/prom/console_64.c b/arch/sparc/prom/console_64.c
index 0da88d10beff..ed39e75828bd 100644
--- a/arch/sparc/prom/console_64.c
+++ b/arch/sparc/prom/console_64.c
@@ -15,35 +15,34 @@
extern int prom_stdin, prom_stdout;
-/* Non blocking put character to console device, returns -1 if
- * unsuccessful.
- */
-static int prom_nbputchar(const char *buf)
+static int __prom_console_write_buf(const char *buf, int len)
{
unsigned long args[7];
+ int ret;
args[0] = (unsigned long) "write";
args[1] = 3;
args[2] = 1;
args[3] = (unsigned int) prom_stdout;
args[4] = (unsigned long) buf;
- args[5] = 1;
+ args[5] = (unsigned int) len;
args[6] = (unsigned long) -1;
p1275_cmd_direct(args);
- if (args[6] == 1)
- return 0;
- else
+ ret = (int) args[6];
+ if (ret < 0)
return -1;
+ return ret;
}
-/* Blocking version of put character routine above. */
-void prom_putchar(const char *buf)
+void prom_console_write_buf(const char *buf, int len)
{
- while (1) {
- int err = prom_nbputchar(buf);
- if (!err)
- break;
+ while (len) {
+ int n = __prom_console_write_buf(buf, len);
+ if (n < 0)
+ continue;
+ len -= n;
+ buf += len;
}
}
diff --git a/arch/sparc/prom/printf.c b/arch/sparc/prom/printf.c
index 24031971f806..d9682f06b3b0 100644
--- a/arch/sparc/prom/printf.c
+++ b/arch/sparc/prom/printf.c
@@ -15,23 +15,45 @@
#include <linux/kernel.h>
#include <linux/compiler.h>
+#include <linux/spinlock.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
+#define CONSOLE_WRITE_BUF_SIZE 1024
+
static char ppbuf[1024];
+static char console_write_buf[CONSOLE_WRITE_BUF_SIZE];
+static DEFINE_RAW_SPINLOCK(console_write_lock);
void notrace prom_write(const char *buf, unsigned int n)
{
+ unsigned int dest_len;
+ unsigned long flags;
+ char *dest;
+
+ dest = console_write_buf;
+ raw_spin_lock_irqsave(&console_write_lock, flags);
+
+ dest_len = 0;
while (n-- != 0) {
- char ch = *buf;
+ char ch = *buf++;
if (ch == '\n') {
- char tmp = '\r';
- prom_putchar(&tmp);
+ *dest++ = '\r';
+ dest_len++;
+ }
+ *dest++ = ch;
+ dest_len++;
+ if (dest_len >= CONSOLE_WRITE_BUF_SIZE - 1) {
+ prom_console_write_buf(console_write_buf, dest_len);
+ dest = console_write_buf;
+ dest_len = 0;
}
- prom_putchar(buf);
- buf++;
}
+ if (dest_len)
+ prom_console_write_buf(console_write_buf, dest_len);
+
+ raw_spin_unlock_irqrestore(&console_write_lock, flags);
}
void notrace prom_printf(const char *fmt, ...)