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Subject[PATCH v4 4/7] x86/mm: Introduce __set_memory_prot()
For use in the 32bit arch_add_memory() to set the pgprot type of the
memory to add.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
---
arch/x86/include/asm/set_memory.h | 1 +
arch/x86/mm/pat/set_memory.c | 13 +++++++++++++
2 files changed, 14 insertions(+)

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)
{
/*
--
2.20.1
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