[v4,4/7] x86/mm: Introduce __set_memory_prot()

Commit Message

Logan Gunthorpe March 6, 2020, 5:08 p.m. UTC

For use in the 32bit arch_add_memory() to set the pgprot type of the
memory to add.

Cc: Thomas Gleixner <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: "H. Peter Anvin" <[e-mail]>
Cc: [e-mail]
Cc: Dave Hansen <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Signed-off-by: Logan Gunthorpe <[e-mail]>
Reviewed-by: Dan Williams <[e-mail]>
---
 arch/x86/include/asm/set_memory.h |  1 +
 arch/x86/mm/pat/set_memory.c      | 13 +++++++++++++
 2 files changed, 14 insertions(+)

Patch

diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index 64c3dce374e5..034358da4837 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -34,6 +34,7 @@ 
  * The caller is required to take care of these.
  */
 
+int __set_memory_prot(unsigned long addr, int numpages, pgprot_t prot);
 int _set_memory_uc(unsigned long addr, int numpages);
 int _set_memory_wc(unsigned long addr, int numpages);
 int _set_memory_wt(unsigned long addr, int numpages);
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index c4aedd00c1ba..a7b14dffeb0b 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -1792,6 +1792,19 @@  static inline int cpa_clear_pages_array(struct page **pages, int numpages,
 		CPA_PAGES_ARRAY, pages);
 }
 
+/*
+ * _set_memory_prot is an internal helper for callers that have been passed
+ * a pgprot_t value from upper layers and a reservation has already been taken.
+ * If you want to set the pgprot to a specific page protocol, use the
+ * set_memory_xx() functions.
+ */
+int __set_memory_prot(unsigned long addr, int numpages, pgprot_t prot)
+{
+	return change_page_attr_set_clr(&addr, numpages, prot,
+					__pgprot(~pgprot_val(prot)), 0, 0,
+					NULL);
+}
+
 int _set_memory_uc(unsigned long addr, int numpages)
 {
 	/*