linux/arch/s390/include/asm/setup.h

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/*
* S390 version
* Copyright IBM Corp. 1999, 2010
*/
#ifndef _ASM_S390_SETUP_H
#define _ASM_S390_SETUP_H
#include <uapi/asm/setup.h>
#define PARMAREA 0x10400
#ifndef __ASSEMBLY__
#include <asm/lowcore.h>
#include <asm/types.h>
#ifndef CONFIG_64BIT
#define IPL_DEVICE (*(unsigned long *) (0x10404))
#define INITRD_START (*(unsigned long *) (0x1040C))
#define INITRD_SIZE (*(unsigned long *) (0x10414))
#define OLDMEM_BASE (*(unsigned long *) (0x1041C))
#define OLDMEM_SIZE (*(unsigned long *) (0x10424))
#else /* CONFIG_64BIT */
#define IPL_DEVICE (*(unsigned long *) (0x10400))
#define INITRD_START (*(unsigned long *) (0x10408))
#define INITRD_SIZE (*(unsigned long *) (0x10410))
#define OLDMEM_BASE (*(unsigned long *) (0x10418))
#define OLDMEM_SIZE (*(unsigned long *) (0x10420))
#endif /* CONFIG_64BIT */
#define COMMAND_LINE ((char *) (0x10480))
extern int memory_end_set;
extern unsigned long memory_end;
extern unsigned long max_physmem_end;
extern void detect_memory_memblock(void);
/*
* Machine features detected in head.S
*/
#define MACHINE_FLAG_VM (1UL << 0)
#define MACHINE_FLAG_IEEE (1UL << 1)
s390/mm: implement software dirty bits The s390 architecture is unique in respect to dirty page detection, it uses the change bit in the per-page storage key to track page modifications. All other architectures track dirty bits by means of page table entries. This property of s390 has caused numerous problems in the past, e.g. see git commit ef5d437f71afdf4a "mm: fix XFS oops due to dirty pages without buffers on s390". To avoid future issues in regard to per-page dirty bits convert s390 to a fault based software dirty bit detection mechanism. All user page table entries which are marked as clean will be hardware read-only, even if the pte is supposed to be writable. A write by the user process will trigger a protection fault which will cause the user pte to be marked as dirty and the hardware read-only bit is removed. With this change the dirty bit in the storage key is irrelevant for Linux as a host, but the storage key is still required for KVM guests. The effect is that page_test_and_clear_dirty and the related code can be removed. The referenced bit in the storage key is still used by the page_test_and_clear_young primitive to provide page age information. For page cache pages of mappings with mapping_cap_account_dirty there will not be any change in behavior as the dirty bit tracking already uses read-only ptes to control the amount of dirty pages. Only for swap cache pages and pages of mappings without mapping_cap_account_dirty there can be additional protection faults. To avoid an excessive number of additional faults the mk_pte primitive checks for PageDirty if the pgprot value allows for writes and pre-dirties the pte. That avoids all additional faults for tmpfs and shmem pages until these pages are added to the swap cache. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-11-07 20:17:37 +08:00
#define MACHINE_FLAG_CSP (1UL << 2)
#define MACHINE_FLAG_MVPG (1UL << 3)
#define MACHINE_FLAG_DIAG44 (1UL << 4)
#define MACHINE_FLAG_IDTE (1UL << 5)
#define MACHINE_FLAG_DIAG9C (1UL << 6)
#define MACHINE_FLAG_KVM (1UL << 8)
#define MACHINE_FLAG_ESOP (1UL << 9)
#define MACHINE_FLAG_EDAT1 (1UL << 10)
#define MACHINE_FLAG_EDAT2 (1UL << 11)
#define MACHINE_FLAG_LPAR (1UL << 12)
#define MACHINE_FLAG_LPP (1UL << 13)
#define MACHINE_FLAG_TOPOLOGY (1UL << 14)
#define MACHINE_FLAG_TE (1UL << 15)
#define MACHINE_FLAG_TLB_LC (1UL << 17)
#define MACHINE_IS_VM (S390_lowcore.machine_flags & MACHINE_FLAG_VM)
#define MACHINE_IS_KVM (S390_lowcore.machine_flags & MACHINE_FLAG_KVM)
#define MACHINE_IS_LPAR (S390_lowcore.machine_flags & MACHINE_FLAG_LPAR)
#define MACHINE_HAS_DIAG9C (S390_lowcore.machine_flags & MACHINE_FLAG_DIAG9C)
s390/mm: implement software dirty bits The s390 architecture is unique in respect to dirty page detection, it uses the change bit in the per-page storage key to track page modifications. All other architectures track dirty bits by means of page table entries. This property of s390 has caused numerous problems in the past, e.g. see git commit ef5d437f71afdf4a "mm: fix XFS oops due to dirty pages without buffers on s390". To avoid future issues in regard to per-page dirty bits convert s390 to a fault based software dirty bit detection mechanism. All user page table entries which are marked as clean will be hardware read-only, even if the pte is supposed to be writable. A write by the user process will trigger a protection fault which will cause the user pte to be marked as dirty and the hardware read-only bit is removed. With this change the dirty bit in the storage key is irrelevant for Linux as a host, but the storage key is still required for KVM guests. The effect is that page_test_and_clear_dirty and the related code can be removed. The referenced bit in the storage key is still used by the page_test_and_clear_young primitive to provide page age information. For page cache pages of mappings with mapping_cap_account_dirty there will not be any change in behavior as the dirty bit tracking already uses read-only ptes to control the amount of dirty pages. Only for swap cache pages and pages of mappings without mapping_cap_account_dirty there can be additional protection faults. To avoid an excessive number of additional faults the mk_pte primitive checks for PageDirty if the pgprot value allows for writes and pre-dirties the pte. That avoids all additional faults for tmpfs and shmem pages until these pages are added to the swap cache. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-11-07 20:17:37 +08:00
#define MACHINE_HAS_ESOP (S390_lowcore.machine_flags & MACHINE_FLAG_ESOP)
#define MACHINE_HAS_PFMF MACHINE_HAS_EDAT1
#define MACHINE_HAS_HPAGE MACHINE_HAS_EDAT1
#ifndef CONFIG_64BIT
#define MACHINE_HAS_IEEE (S390_lowcore.machine_flags & MACHINE_FLAG_IEEE)
#define MACHINE_HAS_CSP (S390_lowcore.machine_flags & MACHINE_FLAG_CSP)
#define MACHINE_HAS_IDTE (0)
#define MACHINE_HAS_DIAG44 (1)
#define MACHINE_HAS_MVPG (S390_lowcore.machine_flags & MACHINE_FLAG_MVPG)
#define MACHINE_HAS_EDAT1 (0)
#define MACHINE_HAS_EDAT2 (0)
#define MACHINE_HAS_LPP (0)
#define MACHINE_HAS_TOPOLOGY (0)
#define MACHINE_HAS_TE (0)
#define MACHINE_HAS_TLB_LC (0)
#else /* CONFIG_64BIT */
#define MACHINE_HAS_IEEE (1)
#define MACHINE_HAS_CSP (1)
#define MACHINE_HAS_IDTE (S390_lowcore.machine_flags & MACHINE_FLAG_IDTE)
#define MACHINE_HAS_DIAG44 (S390_lowcore.machine_flags & MACHINE_FLAG_DIAG44)
#define MACHINE_HAS_MVPG (1)
#define MACHINE_HAS_EDAT1 (S390_lowcore.machine_flags & MACHINE_FLAG_EDAT1)
#define MACHINE_HAS_EDAT2 (S390_lowcore.machine_flags & MACHINE_FLAG_EDAT2)
#define MACHINE_HAS_LPP (S390_lowcore.machine_flags & MACHINE_FLAG_LPP)
#define MACHINE_HAS_TOPOLOGY (S390_lowcore.machine_flags & MACHINE_FLAG_TOPOLOGY)
#define MACHINE_HAS_TE (S390_lowcore.machine_flags & MACHINE_FLAG_TE)
#define MACHINE_HAS_TLB_LC (S390_lowcore.machine_flags & MACHINE_FLAG_TLB_LC)
#endif /* CONFIG_64BIT */
/*
* Console mode. Override with conmode=
*/
extern unsigned int console_mode;
extern unsigned int console_devno;
extern unsigned int console_irq;
extern char vmhalt_cmd[];
extern char vmpoff_cmd[];
#define CONSOLE_IS_UNDEFINED (console_mode == 0)
#define CONSOLE_IS_SCLP (console_mode == 1)
#define CONSOLE_IS_3215 (console_mode == 2)
#define CONSOLE_IS_3270 (console_mode == 3)
#define SET_CONSOLE_SCLP do { console_mode = 1; } while (0)
#define SET_CONSOLE_3215 do { console_mode = 2; } while (0)
#define SET_CONSOLE_3270 do { console_mode = 3; } while (0)
#define NSS_NAME_SIZE 8
extern char kernel_nss_name[];
#ifdef CONFIG_PFAULT
extern int pfault_init(void);
extern void pfault_fini(void);
#else /* CONFIG_PFAULT */
#define pfault_init() ({-1;})
#define pfault_fini() do { } while (0)
#endif /* CONFIG_PFAULT */
extern void cmma_init(void);
extern void (*_machine_restart)(char *command);
extern void (*_machine_halt)(void);
extern void (*_machine_power_off)(void);
#else /* __ASSEMBLY__ */
#ifndef CONFIG_64BIT
#define IPL_DEVICE 0x10404
#define INITRD_START 0x1040C
#define INITRD_SIZE 0x10414
#define OLDMEM_BASE 0x1041C
#define OLDMEM_SIZE 0x10424
#else /* CONFIG_64BIT */
#define IPL_DEVICE 0x10400
#define INITRD_START 0x10408
#define INITRD_SIZE 0x10410
#define OLDMEM_BASE 0x10418
#define OLDMEM_SIZE 0x10420
#endif /* CONFIG_64BIT */
#define COMMAND_LINE 0x10480
#endif /* __ASSEMBLY__ */
#endif /* _ASM_S390_SETUP_H */