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Commit 4e21b94c authored by Laurentiu TUDOR's avatar Laurentiu TUDOR Committed by Scott Wood
Browse files

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: default avatarLaurentiu Tudor <Laurentiu.Tudor@freescale.com>
Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
parent f31dd944

arch/powerpc/include/asm/epapr_hcalls.h

+6 −0
Original line number Diff line number Diff line
@@ -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

arch/powerpc/kernel/epapr_paravirt.c

+16 −12
Original line number Diff line number Diff line
@@ -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);

arch/powerpc/kernel/setup_32.c

+3 −1
Original line number Diff line number Diff line
@@ -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();



}

arch/powerpc/kernel/setup_64.c

+3 −0
Original line number Diff line number Diff line
@@ -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();