[RFC PATCH V2 15/38] riscv: s64ilp32: Add asid support

[guoren at kernel.org]

From: Guo Ren <guoren at linux.alibaba.com>

The s32ilp32 uses 9 bits as asid_bits because of the xlen=32
limitation of CSR. The xlen of s64ilp32 is 64 bits in width, and
the SATP CSR format is the same for Sv32, Sv39, Sv48, and Sv57. So
this patch makes asid mechanism support s64ilp32 with maximum
num_asids.

Signed-off-by: Guo Ren <guoren at linux.alibaba.com>
Signed-off-by: Guo Ren <guoren at kernel.org>
---
 arch/riscv/include/asm/tlbflush.h |  2 +-
 arch/riscv/mm/context.c           | 16 ++++++++++------
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h
index a09196f8de68..6793c3f835a0 100644
--- a/arch/riscv/include/asm/tlbflush.h
+++ b/arch/riscv/include/asm/tlbflush.h
@@ -12,7 +12,7 @@
 #include <asm/errata_list.h>
 
 #ifdef CONFIG_MMU
-extern unsigned long asid_mask;
+extern xlen_t asid_mask;
 
 static inline void local_flush_tlb_all(void)
 {
diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c
index 12e22e7330e7..9eab9aa87dc6 100644
--- a/arch/riscv/mm/context.c
+++ b/arch/riscv/mm/context.c
@@ -20,9 +20,9 @@
 
 DEFINE_STATIC_KEY_FALSE(use_asid_allocator);
 
-static unsigned long asid_bits;
+static xlen_t asid_bits;
 static unsigned long num_asids;
-unsigned long asid_mask;
+xlen_t asid_mask;
 
 static atomic_long_t current_version;
 
@@ -227,14 +227,18 @@ static inline void set_mm(struct mm_struct *prev,
 
 static int __init asids_init(void)
 {
-	unsigned long old;
+	xlen_t old;
 
 	/* Figure-out number of ASID bits in HW */
 	old = csr_read(CSR_SATP);
 	asid_bits = old | (SATP_ASID_MASK << SATP_ASID_SHIFT);
 	csr_write(CSR_SATP, asid_bits);
 	asid_bits = (csr_read(CSR_SATP) >> SATP_ASID_SHIFT)  & SATP_ASID_MASK;
-	asid_bits = fls_long(asid_bits);
+#if __riscv_xlen == 64
+	asid_bits = fls64(asid_bits);
+#else
+	asid_bits = fls(asid_bits);
+#endif
 	csr_write(CSR_SATP, old);
 
 	/*
@@ -267,9 +271,9 @@ static int __init asids_init(void)
 		static_branch_enable(&use_asid_allocator);
 
 		pr_info("ASID allocator using %lu bits (%lu entries)\n",
-			asid_bits, num_asids);
+			(ulong)asid_bits, num_asids);
 	} else {
-		pr_info("ASID allocator disabled (%lu bits)\n", asid_bits);
+		pr_info("ASID allocator disabled (%lu bits)\n", (ulong)asid_bits);
 	}
 
 	return 0;
-- 
2.36.1