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a51324c430
Rework the way physical pages are set no-dat / dat: The old way is: - Rely on that all pages are initially marked "dat" - Allocate page tables for the kernel mapping - Enable dat - Walk the whole kernel mapping and set PG_arch_1 bit in all struct pages that belong to pages of kernel page tables - Walk all struct pages and test and clear the PG_arch_1 bit. If the bit is not set, set the page state to no-dat - For all subsequent page table allocations, set the page state to dat (remove the no-dat state) on allocation time Change this rather complex logic to a simpler approach: - Set the whole physical memory (all pages) to "no-dat" - Explicitly set those page table pages to "dat" which are part of the kernel image (e.g. swapper_pg_dir) - For all subsequent page table allocations, set the page state to dat (remove the no-dat state) on allocation time In result the code is simpler, and this also allows to get rid of one odd usage of the PG_arch_1 bit. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
33 lines
678 B
C
33 lines
678 B
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright IBM Corp. 2008
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*
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* Guest page hinting for unused pages.
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*
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* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
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*/
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#include <linux/mm.h>
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#include <asm/page-states.h>
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#include <asm/sections.h>
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#include <asm/page.h>
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int __bootdata_preserved(cmma_flag);
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void arch_free_page(struct page *page, int order)
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{
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if (!cmma_flag)
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return;
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__set_page_unused(page_to_virt(page), 1UL << order);
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}
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void arch_alloc_page(struct page *page, int order)
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{
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if (!cmma_flag)
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return;
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if (cmma_flag < 2)
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__set_page_stable_dat(page_to_virt(page), 1UL << order);
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else
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__set_page_stable_nodat(page_to_virt(page), 1UL << order);
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}
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