From: Tudor Laurentiu <laurentiu.tu...@freescale.com>
The ePAPR para-virtualization needs to happen very early
otherwise the bytechannel based console will silently
drop some of the early boot messages.
Before this patch, this is how the kernel log started:
-----------------------------------------------------
> Brought up 2 CPUs
> devtmpfs: initialized
> NET: Registered protocol family 16
[...]
-----------------------------------------------------
After the patch the early messages show up:
-----------------------------------------------------
> Using P5020 DS machine description
> MMU: Supported page sizes
> 4 KB as direct
> 4096 KB as direct
[...]
-----------------------------------------------------
At console init, the kernel tried to flush the log buffer.
Since the paravirt was not yet initialized the console write
function failed silently, thus losing the buffered messages.
Signed-off-by: Laurentiu Tudor <laurentiu.tu...@freescale.com>
---
arch/powerpc/include/asm/epapr_hcalls.h | 6 ++++++
arch/powerpc/kernel/epapr_paravirt.c | 3 +--
arch/powerpc/kernel/setup_32.c | 2 ++
arch/powerpc/kernel/setup_64.c | 3 +++
4 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/epapr_hcalls.h
b/arch/powerpc/include/asm/epapr_hcalls.h
index d3d6342..544176e 100644
--- a/arch/powerpc/include/asm/epapr_hcalls.h
+++ b/arch/powerpc/include/asm/epapr_hcalls.h
@@ -105,6 +105,12 @@
extern bool epapr_paravirt_enabled;
extern u32 epapr_hypercall_start[];
+#ifdef CONFIG_EPAPR_PARAVIRT
+int __init epapr_paravirt_init(void);
+#else
+static inline int epapr_paravirt_init(void) { return 0; }
+#endif
+
/*
* We use "uintptr_t" to define a register because it's guaranteed to be a
* 32-bit integer on a 32-bit platform, and a 64-bit integer on a 64-bit
diff --git a/arch/powerpc/kernel/epapr_paravirt.c
b/arch/powerpc/kernel/epapr_paravirt.c
index f3eab85..9848713 100644
--- a/arch/powerpc/kernel/epapr_paravirt.c
+++ b/arch/powerpc/kernel/epapr_paravirt.c
@@ -28,7 +28,7 @@ extern u32 epapr_ev_idle_start[];
bool epapr_paravirt_enabled;
-static int __init epapr_paravirt_init(void)
+int __init epapr_paravirt_init(void)
{
struct device_node *hyper_node;
const u32 *insts;
@@ -58,4 +58,3 @@ static int __init epapr_paravirt_init(void)
return 0;
}
-early_initcall(epapr_paravirt_init);
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index a8f54ec..1464655 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -38,6 +38,7 @@
#include <asm/serial.h>
#include <asm/udbg.h>
#include <asm/mmu_context.h>
+#include <asm/epapr_hcalls.h>
#include "setup.h"
@@ -327,4 +328,5 @@ void __init setup_arch(char **cmdline_p)
/* Initialize the MMU context management stuff */
mmu_context_init();
+ epapr_paravirt_init();
}
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 6da881b..ce092ac 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -66,6 +66,7 @@
#include <asm/code-patching.h>
#include <asm/kvm_ppc.h>
#include <asm/hugetlb.h>
+#include <asm/epapr_hcalls.h>
#include "setup.h"
@@ -599,6 +600,8 @@ void __init setup_arch(char **cmdline_p)
/* Initialize the MMU context management stuff */
mmu_context_init();
+ epapr_paravirt_init();
+
kvm_linear_init();
/* Interrupt code needs to be 64K-aligned */
--
1.7.6.5
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