[PATCH v2 3/9] riscv: add ARCH_SUPPORTS_DEBUG_PAGEALLOC support

Zong Li
2020-03-09T08:22:50Z

ARCH_SUPPORTS_DEBUG_PAGEALLOC provides a hook to map and unmap
pages for debugging purposes. Implement the __kernel_map_pages
functions to fill the poison pattern.

Signed-off-by: Zong Li <zong.li@sifive.com>
---
arch/riscv/Kconfig | 3 +++
arch/riscv/mm/pageattr.c | 13 +++++++++++++
2 files changed, 16 insertions(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 07bf1a7c0dd2..f524d7e60648 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -132,6 +132,9 @@ config ARCH_SELECT_MEMORY_MODEL
config ARCH_WANT_GENERAL_HUGETLB
def_bool y

+config ARCH_SUPPORTS_DEBUG_PAGEALLOC
+ def_bool y
+
config SYS_SUPPORTS_HUGETLBFS
def_bool y

diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
index 7be6cd67e2ef..728759eb530a 100644
--- a/arch/riscv/mm/pageattr.c
+++ b/arch/riscv/mm/pageattr.c
@@ -172,3 +172,16 @@ int set_direct_map_default_noflush(struct page *page)

return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
}
+
+void __kernel_map_pages(struct page *page, int numpages, int enable)
+{
+ if (!debug_pagealloc_enabled())
+ return;
+
+ if (enable)
+ __set_memory((unsigned long)page_address(page), numpages,
+ __pgprot(_PAGE_PRESENT), __pgprot(0));
+ else
+ __set_memory((unsigned long)page_address(page), numpages,
+ __pgprot(0), __pgprot(_PAGE_PRESENT));
+}
--
2.25.1