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powerpc/85xx: Move ePAPR paravirt initialization earlier

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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.Tudor@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
This commit is contained in:
Laurentiu TUDOR 2013-07-03 17:13:15 +03:00 committed by Scott Wood
parent f31dd9443a
commit 4e21b94c9c
4 changed files with 28 additions and 13 deletions
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6
arch/powerpc/include/asm/epapr_hcalls.h
View File

@ -105,6 +105,12 @@
extern bool epapr_paravirt_enabled;
extern u32 epapr_hypercall_start[];
#ifdef CONFIG_EPAPR_PARAVIRT
int __init epapr_paravirt_early_init(void);
#else
static inline int epapr_paravirt_early_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

28
arch/powerpc/kernel/epapr_paravirt.c
View File

@ -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;
for (i = 0; i < (len / 4); i++) {
patch_instruction(epapr_hypercall_start + i, insts[i]);
@ -55,13 +53,19 @@ static int __init epapr_paravirt_init(void)
}
#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
if (of_get_property(hyper_node, "has-idle", NULL))
if (of_get_flat_dt_prop(node, "has-idle", NULL))
ppc_md.power_save = epapr_ev_idle;
#endif
epapr_paravirt_enabled = true;
return 1;
}
int __init epapr_paravirt_early_init(void)
{
of_scan_flat_dt(early_init_dt_scan_epapr, NULL);
return 0;
}
early_initcall(epapr_paravirt_init);

4
arch/powerpc/kernel/setup_32.c
View File

@ -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"
@ -128,6 +129,8 @@ notrace void __init machine_init(u64 dt_ptr)
/* Do some early initialization based on the flat device tree */
early_init_devtree(__va(dt_ptr));
epapr_paravirt_early_init();
early_init_mmu();
probe_machine();
@ -326,5 +329,4 @@ void __init setup_arch(char **cmdline_p)
/* Initialize the MMU context management stuff */
mmu_context_init();
}

3
arch/powerpc/kernel/setup_64.c
View File

@ -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"
@ -215,6 +216,8 @@ void __init early_setup(unsigned long dt_ptr)
*/
early_init_devtree(__va(dt_ptr));
epapr_paravirt_early_init();
/* Now we know the logical id of our boot cpu, setup the paca. */
setup_paca(&paca[boot_cpuid]);
fixup_boot_paca();