arm64: trans_pgd: make trans_pgd_map_page generic

kexec is going to use a different allocator, so make
trans_pgd_map_page to accept allocator as an argument, and also
kexec is going to use a different map protection, so also pass
it via argument.

Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Matthias Brugger <mbrugger@suse.com>
Link: https://lore.kernel.org/r/20210125191923.1060122-5-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/include/asm/trans_pgd.h b/arch/arm64/include/asm/trans_pgd.h
index 23153c1..b46409b 100644 (file)
--- a/arch/arm64/include/asm/trans_pgd.h
+++ b/arch/arm64/include/asm/trans_pgd.h
@@ -12,10 +12,25 @@
 #include <linux/types.h>
 #include <asm/pgtable-types.h>
 
+/*
+ * trans_alloc_page
+ *     - Allocator that should return exactly one zeroed page, if this
+ *       allocator fails, trans_pgd_create_copy() and trans_pgd_map_page()
+ *       return -ENOMEM error.
+ *
+ * trans_alloc_arg
+ *     - Passed to trans_alloc_page as an argument
+ */
+
+struct trans_pgd_info {
+       void * (*trans_alloc_page)(void *arg);
+       void *trans_alloc_arg;
+};
+
 int trans_pgd_create_copy(pgd_t **dst_pgdp, unsigned long start,
                          unsigned long end);
 
-int trans_pgd_map_page(pgd_t *trans_pgd, void *page, unsigned long dst_addr,
-                      pgprot_t pgprot);
+int trans_pgd_map_page(struct trans_pgd_info *info, pgd_t *trans_pgd,
+                      void *page, unsigned long dst_addr, pgprot_t pgprot);
 
 #endif /* _ASM_TRANS_TABLE_H */

diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 4a38662..c173f28 100644 (file)
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -176,6 +176,11 @@ int arch_hibernation_header_restore(void *addr)
 }
 EXPORT_SYMBOL(arch_hibernation_header_restore);
 
+static void *hibernate_page_alloc(void *arg)
+{
+       return (void *)get_safe_page((gfp_t)(unsigned long)arg);
+}
+
 /*
  * Copies length bytes, starting at src_start into an new page,
  * perform cache maintenance, then maps it at the specified address low
@@ -192,6 +197,11 @@ static int create_safe_exec_page(void *src_start, size_t length,
                                 unsigned long dst_addr,
                                 phys_addr_t *phys_dst_addr)
 {
+       struct trans_pgd_info trans_info = {
+               .trans_alloc_page       = hibernate_page_alloc,
+               .trans_alloc_arg        = (void *)GFP_ATOMIC,
+       };
+
        void *page = (void *)get_safe_page(GFP_ATOMIC);
        pgd_t *trans_pgd;
        int rc;
@@ -206,7 +216,7 @@ static int create_safe_exec_page(void *src_start, size_t length,
        if (!trans_pgd)
                return -ENOMEM;
 
-       rc = trans_pgd_map_page(trans_pgd, page, dst_addr,
+       rc = trans_pgd_map_page(&trans_info, trans_pgd, page, dst_addr,
                                PAGE_KERNEL_EXEC);
        if (rc)
                return rc;

diff --git a/arch/arm64/mm/trans_pgd.c b/arch/arm64/mm/trans_pgd.c
index e048d1f..f28eceb 100644 (file)
--- a/arch/arm64/mm/trans_pgd.c
+++ b/arch/arm64/mm/trans_pgd.c
@@ -25,6 +25,11 @@
 #include <linux/mm.h>
 #include <linux/mmzone.h>
 
+static void *trans_alloc(struct trans_pgd_info *info)
+{
+       return info->trans_alloc_page(info->trans_alloc_arg);
+}
+
 static void _copy_pte(pte_t *dst_ptep, pte_t *src_ptep, unsigned long addr)
 {
        pte_t pte = READ_ONCE(*src_ptep);
@@ -201,9 +206,18 @@ int trans_pgd_create_copy(pgd_t **dst_pgdp, unsigned long start,
        return rc;
 }
 
-int trans_pgd_map_page(pgd_t *trans_pgd, void *page,
-                      unsigned long dst_addr,
-                      pgprot_t pgprot)
+/*
+ * Add map entry to trans_pgd for a base-size page at PTE level.
+ * info:       contains allocator and its argument
+ * trans_pgd:  page table in which new map is added.
+ * page:       page to be mapped.
+ * dst_addr:   new VA address for the page
+ * pgprot:     protection for the page.
+ *
+ * Returns 0 on success, and -ENOMEM on failure.
+ */
+int trans_pgd_map_page(struct trans_pgd_info *info, pgd_t *trans_pgd,
+                      void *page, unsigned long dst_addr, pgprot_t pgprot)
 {
        pgd_t *pgdp;
        p4d_t *p4dp;
@@ -213,7 +227,7 @@ int trans_pgd_map_page(pgd_t *trans_pgd, void *page,
 
        pgdp = pgd_offset_pgd(trans_pgd, dst_addr);
        if (pgd_none(READ_ONCE(*pgdp))) {
-               p4dp = (void *)get_safe_page(GFP_ATOMIC);
+               p4dp = trans_alloc(info);
                if (!pgdp)
                        return -ENOMEM;
                pgd_populate(&init_mm, pgdp, p4dp);
@@ -221,7 +235,7 @@ int trans_pgd_map_page(pgd_t *trans_pgd, void *page,
 
        p4dp = p4d_offset(pgdp, dst_addr);
        if (p4d_none(READ_ONCE(*p4dp))) {
-               pudp = (void *)get_safe_page(GFP_ATOMIC);
+               pudp = trans_alloc(info);
                if (!pudp)
                        return -ENOMEM;
                p4d_populate(&init_mm, p4dp, pudp);
@@ -229,7 +243,7 @@ int trans_pgd_map_page(pgd_t *trans_pgd, void *page,
 
        pudp = pud_offset(p4dp, dst_addr);
        if (pud_none(READ_ONCE(*pudp))) {
-               pmdp = (void *)get_safe_page(GFP_ATOMIC);
+               pmdp = trans_alloc(info);
                if (!pmdp)
                        return -ENOMEM;
                pud_populate(&init_mm, pudp, pmdp);
@@ -237,14 +251,14 @@ int trans_pgd_map_page(pgd_t *trans_pgd, void *page,
 
        pmdp = pmd_offset(pudp, dst_addr);
        if (pmd_none(READ_ONCE(*pmdp))) {
-               ptep = (void *)get_safe_page(GFP_ATOMIC);
+               ptep = trans_alloc(info);
                if (!ptep)
                        return -ENOMEM;
                pmd_populate_kernel(&init_mm, pmdp, ptep);
        }
 
        ptep = pte_offset_kernel(pmdp, dst_addr);
-       set_pte(ptep, pfn_pte(virt_to_pfn(page), PAGE_KERNEL_EXEC));
+       set_pte(ptep, pfn_pte(virt_to_pfn(page), pgprot));
 
        return 0;
 }