On 30.04.14 22:03, Stuart Yoder wrote:
-----Original Message-----
From: Alexander Graf [mailto:ag...@suse.de]
Sent: Wednesday, April 30, 2014 2:56 PM
To: Yoder Stuart-B08248; b...@kernel.crashing.org; Wood Scott-B07421
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] powerpc: move epapr paravirt init of power_save to
an initcall
On 30.04.14 21:54, Stuart Yoder wrote:
From: Stuart Yoder <stuart.yo...@freescale.com>
some restructuring of epapr paravirt init resulted in
ppc_md.power_save being set, and then overwritten to
NULL during machine_init. This patch splits the
initialization of ppc_md.power_save out into a postcore
init call.
Signed-off-by: Stuart Yoder <stuart.yo...@freescale.com>
---
arch/powerpc/kernel/epapr_paravirt.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kernel/epapr_paravirt.c
b/arch/powerpc/kernel/epapr_paravirt.c
index 6300c13..c49b69c 100644
--- a/arch/powerpc/kernel/epapr_paravirt.c
+++ b/arch/powerpc/kernel/epapr_paravirt.c
@@ -52,11 +52,6 @@ static int __init early_init_dt_scan_epapr(unsigned
long node,
#endif
}
-#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
- if (of_get_flat_dt_prop(node, "has-idle", NULL))
- ppc_md.power_save = epapr_ev_idle;
-#endif
-
epapr_paravirt_enabled = true;
return 1;
@@ -69,3 +64,23 @@ int __init epapr_paravirt_early_init(void)
return 0;
}
+static int __init epapr_idle_init_dt_scan(unsigned long node,
+ const char *uname,
+ int depth, void *data)
+{
+#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
+ if (of_get_flat_dt_prop(node, "has-idle", NULL))
+ ppc_md.power_save = epapr_ev_idle;
+#endif
+ return 0;
+}
+
+static int __init epapr_idle_init(void)
+{
+ if (epapr_paravirt_enabled)
+ of_scan_flat_dt(epapr_idle_init_dt_scan, NULL);
Doesn't this scan all nodes? We only want to match on
/hypervisor/has-idle, no?
I cut/pasted from the approach the existing code in that file
took, but yes you're right we just need the one property.
Let me respin that to look at the hypervisor node only.
Yeah, the same commit that introduced the breakage on has-idle also
removed the explicit check for /hypervisor.
Laurentiu, was this change on purpose?
commit 4e21b94c9c644c43223878f4c848e852743e789c
Author: Laurentiu TUDOR <laurentiu.tu...@freescale.com>
Date: Wed Jul 3 17:13:15 2013 +0300
powerpc/85xx: Move ePAPR paravirt initialization earlier
At console init, when the kernel tries to flush the log buffer
the ePAPR byte-channel based console write fails silently,
losing the buffered messages.
This happens because The ePAPR para-virtualization init isn't
done early enough so that the hcall instruction to be set,
causing the byte-channel write hcall to be a nop.
To fix, change the ePAPR para-virt init to use early device
tree functions and move it in early init.
Signed-off-by: Laurentiu Tudor <laurentiu.tu...@freescale.com>
Signed-off-by: Scott Wood <scottw...@freescale.com>
[...]
diff --git a/arch/powerpc/kernel/epapr_paravirt.c
b/arch/powerpc/kernel/epapr_paravirt.c
index d44a571..6300c13 100644
--- a/arch/powerpc/kernel/epapr_paravirt.c
+++ b/arch/powerpc/kernel/epapr_paravirt.c
@@ -30,22 +30,20 @@ extern u32 epapr_ev_idle_start[];
bool epapr_paravirt_enabled;
-static int __init epapr_paravirt_init(void)
+static int __init early_init_dt_scan_epapr(unsigned long node,
+ const char *uname,
+ int depth, void *data)
{
- struct device_node *hyper_node;
const u32 *insts;
- int len, i;
+ unsigned long len;
+ int i;
- hyper_node = of_find_node_by_path("/hypervisor");
- if (!hyper_node)
- return -ENODEV;
-
- insts = of_get_property(hyper_node, "hcall-instructions", &len);
+ insts = of_get_flat_dt_prop(node, "hcall-instructions", &len);
if (!insts)
- return -ENODEV;
+ return 0;
if (len % 4 || len > (4 * 4))
- return -ENODEV;
+ return -1;
[...]
Alex
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