From 45e576b1c3d0020607b8666c0247164e92c7d719 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Wed, 7 May 2008 09:22:59 +0200 Subject: [PATCH] [S390] guest page hinting light Use the existing arch_alloc_page/arch_free_page callbacks to do the guest page state transitions between stable and unused. Acked-by: Rik van Riel Signed-off-by: Martin Schwidefsky --- arch/s390/Kconfig | 7 ++++ arch/s390/mm/Makefile | 1 + arch/s390/mm/init.c | 3 ++ arch/s390/mm/page-states.c | 79 ++++++++++++++++++++++++++++++++++++++ include/asm-s390/page.h | 11 ++++++ include/asm-s390/system.h | 6 +++ 6 files changed, 107 insertions(+) create mode 100644 arch/s390/mm/page-states.c diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 29a7940f28..1d035082e7 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -430,6 +430,13 @@ config CMM_IUCV Select this option to enable the special message interface to the cooperative memory management. +config PAGE_STATES + bool "Unused page notification" + help + This enables the notification of unused pages to the + hypervisor. The ESSA instruction is used to do the states + changes between a page that has content and the unused state. + config VIRT_TIMER bool "Virtual CPU timer support" help diff --git a/arch/s390/mm/Makefile b/arch/s390/mm/Makefile index fb988a48a7..2a74581345 100644 --- a/arch/s390/mm/Makefile +++ b/arch/s390/mm/Makefile @@ -5,3 +5,4 @@ obj-y := init.o fault.o extmem.o mmap.o vmem.o pgtable.o obj-$(CONFIG_CMM) += cmm.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o +obj-$(CONFIG_PAGE_STATES) += page-states.o diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index fa31de6ae9..29f3a63806 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -126,6 +126,9 @@ void __init mem_init(void) /* clear the zero-page */ memset(empty_zero_page, 0, PAGE_SIZE); + /* Setup guest page hinting */ + cmma_init(); + /* this will put all low memory onto the freelists */ totalram_pages += free_all_bootmem(); diff --git a/arch/s390/mm/page-states.c b/arch/s390/mm/page-states.c new file mode 100644 index 0000000000..fc0ad73ffd --- /dev/null +++ b/arch/s390/mm/page-states.c @@ -0,0 +1,79 @@ +/* + * arch/s390/mm/page-states.c + * + * Copyright IBM Corp. 2008 + * + * Guest page hinting for unused pages. + * + * Author(s): Martin Schwidefsky + */ + +#include +#include +#include +#include +#include + +#define ESSA_SET_STABLE 1 +#define ESSA_SET_UNUSED 2 + +static int cmma_flag; + +static int __init cmma(char *str) +{ + char *parm; + parm = strstrip(str); + if (strcmp(parm, "yes") == 0 || strcmp(parm, "on") == 0) { + cmma_flag = 1; + return 1; + } + cmma_flag = 0; + if (strcmp(parm, "no") == 0 || strcmp(parm, "off") == 0) + return 1; + return 0; +} + +__setup("cmma=", cmma); + +void __init cmma_init(void) +{ + register unsigned long tmp asm("0") = 0; + register int rc asm("1") = -EOPNOTSUPP; + + if (!cmma_flag) + return; + asm volatile( + " .insn rrf,0xb9ab0000,%1,%1,0,0\n" + "0: la %0,0\n" + "1:\n" + EX_TABLE(0b,1b) + : "+&d" (rc), "+&d" (tmp)); + if (rc) + cmma_flag = 0; +} + +void arch_free_page(struct page *page, int order) +{ + int i, rc; + + if (!cmma_flag) + return; + for (i = 0; i < (1 << order); i++) + asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" + : "=&d" (rc) + : "a" ((page_to_pfn(page) + i) << PAGE_SHIFT), + "i" (ESSA_SET_UNUSED)); +} + +void arch_alloc_page(struct page *page, int order) +{ + int i, rc; + + if (!cmma_flag) + return; + for (i = 0; i < (1 << order); i++) + asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" + : "=&d" (rc) + : "a" ((page_to_pfn(page) + i) << PAGE_SHIFT), + "i" (ESSA_SET_STABLE)); +} diff --git a/include/asm-s390/page.h b/include/asm-s390/page.h index f0f4579eac..12fd9c4f0f 100644 --- a/include/asm-s390/page.h +++ b/include/asm-s390/page.h @@ -125,6 +125,17 @@ page_get_storage_key(unsigned long addr) return skey; } +#ifdef CONFIG_PAGE_STATES + +struct page; +void arch_free_page(struct page *page, int order); +void arch_alloc_page(struct page *page, int order); + +#define HAVE_ARCH_FREE_PAGE +#define HAVE_ARCH_ALLOC_PAGE + +#endif + #endif /* !__ASSEMBLY__ */ /* to align the pointer to the (next) page boundary */ diff --git a/include/asm-s390/system.h b/include/asm-s390/system.h index c819ae25a8..e0d4500d5f 100644 --- a/include/asm-s390/system.h +++ b/include/asm-s390/system.h @@ -116,6 +116,12 @@ extern void pfault_fini(void); #define pfault_fini() do { } while (0) #endif /* CONFIG_PFAULT */ +#ifdef CONFIG_PAGE_STATES +extern void cmma_init(void); +#else +static inline void cmma_init(void) { } +#endif + #define finish_arch_switch(prev) do { \ set_fs(current->thread.mm_segment); \ account_vtime(prev); \ -- 2.39.5