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

Commit Message

Zong Li March 9, 2020, 8:22 a.m. UTC

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 <[e-mail]>
---
 arch/riscv/Kconfig       |  3 +++
 arch/riscv/mm/pageattr.c | 13 +++++++++++++
 2 files changed, 16 insertions(+)

Patch

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));
+}