[PATCH v9 3/3] riscv: mm: support Svnapot in huge vmap

[panqinglin2020 at iscas.ac.cn]

From: Qinglin Pan <panqinglin2020 at iscas.ac.cn>

As HAVE_ARCH_HUGE_VMAP and HAVE_ARCH_HUGE_VMALLOC is supported, we can
implement arch_vmap_pte_range_map_size and arch_vmap_pte_supported_shift
for Svnapot to support huge vmap about napot size.

It can be tested by huge vmap used in pci driver. Huge vmalloc with svnapot
can be tested by changing test_vmalloc module like [1], and probe this
module to run fix_size_alloc_test with use_huge true.

[1]https://github.com/RV-VM/linux-vm-support/commit/33f4ee399c36d355c412ebe5334ca46fd727f8f5

Signed-off-by: Qinglin Pan <panqinglin2020 at iscas.ac.cn>
Reviewed-by: Andrew Jones <ajones at ventanamicro.com>

diff --git a/arch/riscv/include/asm/vmalloc.h b/arch/riscv/include/asm/vmalloc.h
index 48da5371f1e9..6f7447d563ab 100644
--- a/arch/riscv/include/asm/vmalloc.h
+++ b/arch/riscv/include/asm/vmalloc.h
@@ -17,6 +17,65 @@ static inline bool arch_vmap_pmd_supported(pgprot_t prot)
 	return true;
 }
 
-#endif
+#ifdef CONFIG_RISCV_ISA_SVNAPOT
+#include <linux/pgtable.h>
 
+#define arch_vmap_pte_range_map_size arch_vmap_pte_range_map_size
+static inline unsigned long arch_vmap_pte_range_map_size(unsigned long addr, unsigned long end,
+							 u64 pfn, unsigned int max_page_shift)
+{
+	unsigned long size, order;
+	unsigned long map_size = PAGE_SIZE;
+
+	if (!has_svnapot())
+		return map_size;
+
+	for_each_napot_order_rev(order) {
+		if (napot_cont_shift(order) > max_page_shift)
+			continue;
+
+		size = napot_cont_size(order);
+		if (end - addr < size)
+			continue;
+
+		if (!IS_ALIGNED(addr, size))
+			continue;
+
+		if (!IS_ALIGNED(PFN_PHYS(pfn), size))
+			continue;
+
+		map_size = size;
+		break;
+	}
+
+	return map_size;
+}
+
+#define arch_vmap_pte_supported_shift arch_vmap_pte_supported_shift
+static inline int arch_vmap_pte_supported_shift(unsigned long size)
+{
+	int shift = PAGE_SHIFT;
+	unsigned long order;
+
+	if (!has_svnapot())
+		return shift;
+
+	WARN_ON_ONCE(size >= PMD_SIZE);
+
+	for_each_napot_order_rev(order) {
+		if (napot_cont_size(order) > size)
+			continue;
+
+		if (!IS_ALIGNED(size, napot_cont_size(order)))
+			continue;
+
+		shift = napot_cont_shift(order);
+		break;
+	}
+
+	return shift;
+}
+
+#endif /* CONFIG_RISCV_ISA_SVNAPOT */
+#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
 #endif /* _ASM_RISCV_VMALLOC_H */
-- 
2.37.4