Commit 2154e0b3 authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Heiko Carstens
Browse files

s390/mm: allocate Absolute Lowcore Area in decompressor 



Move Absolute Lowcore Area allocation to the decompressor.
As result, get_abs_lowcore() and put_abs_lowcore() access
brackets become really straight and do not require complex
execution context analysis and LAP and interrupts tackling.

Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 8e9205d2

arch/s390/boot/boot.h

+2 −0
Original line number Diff line number Diff line
@@ -66,5 +66,7 @@ extern unsigned char _compressed_end[]; 
extern struct vmlinux_info _vmlinux_info;

#define vmlinux _vmlinux_info



#define __abs_lowcore_pa(x)	(((unsigned long)(x) - __abs_lowcore) % sizeof(struct lowcore))



#endif /* __ASSEMBLY__ */

#endif /* BOOT_BOOT_H */

arch/s390/boot/vmem.c

+6 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include <asm/sections.h>

#include <asm/mem_detect.h>

#include <asm/maccess.h>

#include <asm/abs_lowcore.h>

#include "decompressor.h"

#include "boot.h"
@@ -29,6 +30,7 @@ unsigned long __bootdata(pgalloc_low); 
enum populate_mode {

	POPULATE_NONE,

	POPULATE_ONE2ONE,

	POPULATE_ABS_LOWCORE,

};



static void boot_check_oom(void)
@@ -102,6 +104,8 @@ static unsigned long _pa(unsigned long addr, enum populate_mode mode) 
		return -1;

	case POPULATE_ONE2ONE:

		return addr;

	case POPULATE_ABS_LOWCORE:

		return __abs_lowcore_pa(addr);

	default:

		return -1;

	}
@@ -271,6 +275,8 @@ void setup_vmem(unsigned long online_end, unsigned long asce_limit) 
	pgtable_populate_begin(online_end);

	pgtable_populate(0, sizeof(struct lowcore), POPULATE_ONE2ONE);

	pgtable_populate(0, online_end, POPULATE_ONE2ONE);

	pgtable_populate(__abs_lowcore, __abs_lowcore + sizeof(struct lowcore),

			 POPULATE_ABS_LOWCORE);

	pgtable_populate(__memcpy_real_area, __memcpy_real_area + PAGE_SIZE,

			 POPULATE_NONE);

	memcpy_real_ptep = __virt_to_kpte(__memcpy_real_area);

arch/s390/include/asm/abs_lowcore.h

+13 −3
Original line number Diff line number Diff line
@@ -7,11 +7,21 @@ 
#define ABS_LOWCORE_MAP_SIZE	(NR_CPUS * sizeof(struct lowcore))



extern unsigned long __abs_lowcore;

extern bool abs_lowcore_mapped;



struct lowcore *get_abs_lowcore(unsigned long *flags);

void put_abs_lowcore(struct lowcore *lc, unsigned long flags);

int abs_lowcore_map(int cpu, struct lowcore *lc, bool alloc);

void abs_lowcore_unmap(int cpu);



static inline struct lowcore *get_abs_lowcore(void)

{

	int cpu;



	cpu = get_cpu();

	return ((struct lowcore *)__abs_lowcore) + cpu;

}



static inline void put_abs_lowcore(struct lowcore *lc)

{

	put_cpu();

}



#endif /* _ASM_S390_ABS_LOWCORE_H */

arch/s390/kernel/abs_lowcore.c

+0 −49
Original line number Diff line number Diff line
@@ -3,12 +3,7 @@ 
#include <linux/pgtable.h>

#include <asm/abs_lowcore.h>



#define ABS_LOWCORE_UNMAPPED	1

#define ABS_LOWCORE_LAP_ON	2

#define ABS_LOWCORE_IRQS_ON	4



unsigned long __bootdata_preserved(__abs_lowcore);

bool __ro_after_init abs_lowcore_mapped;



int abs_lowcore_map(int cpu, struct lowcore *lc, bool alloc)

{
@@ -49,47 +44,3 @@ void abs_lowcore_unmap(int cpu) 
		addr += PAGE_SIZE;

	}

}
 


struct lowcore *get_abs_lowcore(unsigned long *flags)

{

	unsigned long irq_flags;

	union ctlreg0 cr0;

	int cpu;



	*flags = 0;

	cpu = get_cpu();

	if (abs_lowcore_mapped) {

		return ((struct lowcore *)__abs_lowcore) + cpu;

	} else {

		if (cpu != 0)

			panic("Invalid unmapped absolute lowcore access\n");

		local_irq_save(irq_flags);

		if (!irqs_disabled_flags(irq_flags))

			*flags |= ABS_LOWCORE_IRQS_ON;

		__ctl_store(cr0.val, 0, 0);

		if (cr0.lap) {

			*flags |= ABS_LOWCORE_LAP_ON;

			__ctl_clear_bit(0, 28);

		}

		*flags |= ABS_LOWCORE_UNMAPPED;

		return lowcore_ptr[0];

	}

}



void put_abs_lowcore(struct lowcore *lc, unsigned long flags)

{

	if (abs_lowcore_mapped) {

		if (flags)

			panic("Invalid mapped absolute lowcore release\n");

	} else {

		if (smp_processor_id() != 0)

			panic("Invalid mapped absolute lowcore access\n");

		if (!(flags & ABS_LOWCORE_UNMAPPED))

			panic("Invalid unmapped absolute lowcore release\n");

		if (flags & ABS_LOWCORE_LAP_ON)

			__ctl_set_bit(0, 28);

		if (flags & ABS_LOWCORE_IRQS_ON)

			local_irq_enable();

	}

	put_cpu();

}

arch/s390/kernel/ipl.c

+2 −3
Original line number Diff line number Diff line
@@ -1986,15 +1986,14 @@ static void dump_reipl_run(struct shutdown_trigger *trigger) 
{

	unsigned long ipib = (unsigned long) reipl_block_actual;

	struct lowcore *abs_lc;

	unsigned long flags;

	unsigned int csum;



	csum = (__force unsigned int)

	       csum_partial(reipl_block_actual, reipl_block_actual->hdr.len, 0);

	abs_lc = get_abs_lowcore(&flags);

	abs_lc = get_abs_lowcore();

	abs_lc->ipib = ipib;

	abs_lc->ipib_checksum = csum;

	put_abs_lowcore(abs_lc, flags);

	put_abs_lowcore(abs_lc);

	dump_run(trigger);

}