Merge tag 'nios2_updates_for_v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/dinguyen/linux

Pull nios2 updates fromDinh Nguyen:

- Use strscpy() and simply setup_cpuinfo()

- Remove conflicting mappings when flushing tlb entries

- Force update_mmu_cache on spurious pagefaults

* tag 'nios2_updates_for_v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/dinguyen/linux:
nios2: Replace strcpy() with strscpy() and simplify setup_cpuinfo()
nios2: do not introduce conflicting mappings when flushing tlb entries
nios2: force update_mmu_cache on spurious tlb-permission--related pagefaults

arch/nios2/include/asm/pgtable.h

···
 #define update_mmu_cache(vma, addr, ptep) \
 	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
 
+static inline int pte_same(pte_t pte_a, pte_t pte_b);
+
+#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
+static inline int ptep_set_access_flags(struct vm_area_struct *vma,
+					unsigned long address, pte_t *ptep,
+					pte_t entry, int dirty)
+{
+	if (!pte_same(*ptep, entry))
+		set_ptes(vma->vm_mm, address, ptep, entry, 1);
+	/*
+	 * update_mmu_cache will unconditionally execute, handling both
+	 * the case that the PTE changed and the spurious fault case.
+	 */
+	return true;
+}
+
 #endif /* _ASM_NIOS2_PGTABLE_H */

arch/nios2/kernel/cpuinfo.c

···
 	cpuinfo.cpu_clock_freq = fcpu(cpu, "clock-frequency");
 
 	str = of_get_property(cpu, "altr,implementation", &len);
-	if (str)
-		strscpy(cpuinfo.cpu_impl, str, sizeof(cpuinfo.cpu_impl));
-	else
-		strcpy(cpuinfo.cpu_impl, "<unknown>");
+	strscpy(cpuinfo.cpu_impl, str ?: "<unknown>");
 
 	cpuinfo.has_div = of_property_read_bool(cpu, "altr,has-div");
 	cpuinfo.has_mul = of_property_read_bool(cpu, "altr,has-mul");

arch/nios2/mm/tlb.c

···
 		if (((pteaddr >> 2) & 0xfffff) != (addr >> PAGE_SHIFT))
 			continue;
 
+		tlbmisc = RDCTL(CTL_TLBMISC);
 		pr_debug("Flush entry by writing way=%dl pid=%ld\n",
-			 way, (pid_misc >> TLBMISC_PID_SHIFT));
+			 way, ((tlbmisc >> TLBMISC_PID_SHIFT) & TLBMISC_PID_MASK));
 
-		tlbmisc = TLBMISC_WE | (way << TLBMISC_WAY_SHIFT);
+		tlbmisc = TLBMISC_WE | (way << TLBMISC_WAY_SHIFT) | (tlbmisc & TLBMISC_PID);
 		WRCTL(CTL_TLBMISC, tlbmisc);
 		WRCTL(CTL_PTEADDR, pteaddr_invalid(addr));
 		WRCTL(CTL_TLBACC, 0);
···
 			if (pid != mmu_pid)
 				continue;
 
-			tlbmisc = TLBMISC_WE | (way << TLBMISC_WAY_SHIFT);
+			tlbmisc = TLBMISC_WE | (way << TLBMISC_WAY_SHIFT) |
+				  (pid << TLBMISC_PID_SHIFT);
 			WRCTL(CTL_TLBMISC, tlbmisc);
 			WRCTL(CTL_TLBACC, 0);
 		}
···
 	/* remember pid/way until we return */
 	get_misc_and_pid(&org_misc, &pid_misc);
 
-	/* Start at way 0, way is auto-incremented after each TLBACC write */
-	WRCTL(CTL_TLBMISC, TLBMISC_WE);
-
 	/* Map each TLB entry to physcal address 0 with no-access and a
 	   bad ptbase */
 	for (line = 0; line < cpuinfo.tlb_num_lines; line++) {
 		WRCTL(CTL_PTEADDR, pteaddr_invalid(addr));
-		for (way = 0; way < cpuinfo.tlb_num_ways; way++)
+		for (way = 0; way < cpuinfo.tlb_num_ways; way++) {
+			// Code such as replace_tlb_one_pid assumes that no duplicate entries exist
+			// for a single address across ways, so also use way as a dummy PID
+			WRCTL(CTL_TLBMISC, TLBMISC_WE | (way << TLBMISC_WAY_SHIFT) |
+					   (way << TLBMISC_PID_SHIFT));
 			WRCTL(CTL_TLBACC, 0);
+		}
 
 		addr += PAGE_SIZE;
 	}