--- /dev/null
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+Date: Mon, 15 Dec 2025 01:45:07 +0100
+Subject: Revert "MIPS: mm: kmalloc tlb_vpn array to avoid stack overflow"
+
+This reverts commit 63a93d1cd6077d79735f804f5a4957bfb240280c.
+---
+ arch/mips/mm/tlb-r4k.c | 18 ++----------------
+ 1 file changed, 2 insertions(+), 16 deletions(-)
+
+--- a/arch/mips/mm/tlb-r4k.c
++++ b/arch/mips/mm/tlb-r4k.c
+@@ -12,7 +12,6 @@
+ #include <linux/init.h>
+ #include <linux/sched.h>
+ #include <linux/smp.h>
+-#include <linux/memblock.h>
+ #include <linux/mm.h>
+ #include <linux/hugetlb.h>
+ #include <linux/export.h>
+@@ -523,26 +522,17 @@ static int r4k_vpn_cmp(const void *a, co
+ * Initialise all TLB entries with unique values that do not clash with
+ * what we have been handed over and what we'll be using ourselves.
+ */
+-static void __ref r4k_tlb_uniquify(void)
++static void r4k_tlb_uniquify(void)
+ {
++ unsigned long tlb_vpns[1 << MIPS_CONF1_TLBS_SIZE];
+ int tlbsize = current_cpu_data.tlbsize;
+- bool use_slab = slab_is_available();
+ int start = num_wired_entries();
+- phys_addr_t tlb_vpn_size;
+- unsigned long *tlb_vpns;
+ unsigned long vpn_mask;
+ int cnt, ent, idx, i;
+
+ vpn_mask = GENMASK(cpu_vmbits - 1, 13);
+ vpn_mask |= IS_ENABLED(CONFIG_64BIT) ? 3ULL << 62 : 1 << 31;
+
+- tlb_vpn_size = tlbsize * sizeof(*tlb_vpns);
+- tlb_vpns = (use_slab ?
+- kmalloc(tlb_vpn_size, GFP_KERNEL) :
+- memblock_alloc_raw(tlb_vpn_size, sizeof(*tlb_vpns)));
+- if (WARN_ON(!tlb_vpns))
+- return; /* Pray local_flush_tlb_all() is good enough. */
+-
+ htw_stop();
+
+ for (i = start, cnt = 0; i < tlbsize; i++, cnt++) {
+@@ -595,10 +585,6 @@ static void __ref r4k_tlb_uniquify(void)
+ tlbw_use_hazard();
+ htw_start();
+ flush_micro_tlb();
+- if (use_slab)
+- kfree(tlb_vpns);
+- else
+- memblock_free(tlb_vpns, tlb_vpn_size);
+ }
+
+ /*
--- /dev/null
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+Date: Mon, 15 Dec 2025 01:45:20 +0100
+Subject: Revert "MIPS: mm: Prevent a TLB shutdown on initial uniquification"
+
+This reverts commit 135178e90aa43ad949534e1d6e376c4034942caa.
+---
+ arch/mips/mm/tlb-r4k.c | 100 +++++++++++++++--------------------------
+ 1 file changed, 37 insertions(+), 63 deletions(-)
+
+--- a/arch/mips/mm/tlb-r4k.c
++++ b/arch/mips/mm/tlb-r4k.c
+@@ -15,7 +15,6 @@
+ #include <linux/mm.h>
+ #include <linux/hugetlb.h>
+ #include <linux/export.h>
+-#include <linux/sort.h>
+
+ #include <asm/cpu.h>
+ #include <asm/cpu-type.h>
+@@ -509,79 +508,55 @@ static int __init set_ntlb(char *str)
+
+ __setup("ntlb=", set_ntlb);
+
+-
+-/* Comparison function for EntryHi VPN fields. */
+-static int r4k_vpn_cmp(const void *a, const void *b)
+-{
+- long v = *(unsigned long *)a - *(unsigned long *)b;
+- int s = sizeof(long) > sizeof(int) ? sizeof(long) * 8 - 1: 0;
+- return s ? (v != 0) | v >> s : v;
+-}
+-
+-/*
+- * Initialise all TLB entries with unique values that do not clash with
+- * what we have been handed over and what we'll be using ourselves.
+- */
++/* Initialise all TLB entries with unique values */
+ static void r4k_tlb_uniquify(void)
+ {
+- unsigned long tlb_vpns[1 << MIPS_CONF1_TLBS_SIZE];
+- int tlbsize = current_cpu_data.tlbsize;
+- int start = num_wired_entries();
+- unsigned long vpn_mask;
+- int cnt, ent, idx, i;
+-
+- vpn_mask = GENMASK(cpu_vmbits - 1, 13);
+- vpn_mask |= IS_ENABLED(CONFIG_64BIT) ? 3ULL << 62 : 1 << 31;
++ int entry = num_wired_entries();
+
+ htw_stop();
++ write_c0_entrylo0(0);
++ write_c0_entrylo1(0);
+
+- for (i = start, cnt = 0; i < tlbsize; i++, cnt++) {
+- unsigned long vpn;
++ while (entry < current_cpu_data.tlbsize) {
++ unsigned long asid_mask = cpu_asid_mask(¤t_cpu_data);
++ unsigned long asid = 0;
++ int idx;
+
+- write_c0_index(i);
+- mtc0_tlbr_hazard();
+- tlb_read();
+- tlb_read_hazard();
+- vpn = read_c0_entryhi();
+- vpn &= vpn_mask & PAGE_MASK;
+- tlb_vpns[cnt] = vpn;
++ /* Skip wired MMID to make ginvt_mmid work */
++ if (cpu_has_mmid)
++ asid = MMID_KERNEL_WIRED + 1;
+
+- /* Prevent any large pages from overlapping regular ones. */
+- write_c0_pagemask(read_c0_pagemask() & PM_DEFAULT_MASK);
++ /* Check for match before using UNIQUE_ENTRYHI */
++ do {
++ if (cpu_has_mmid) {
++ write_c0_memorymapid(asid);
++ write_c0_entryhi(UNIQUE_ENTRYHI(entry));
++ } else {
++ write_c0_entryhi(UNIQUE_ENTRYHI(entry) | asid);
++ }
++ mtc0_tlbw_hazard();
++ tlb_probe();
++ tlb_probe_hazard();
++ idx = read_c0_index();
++ /* No match or match is on current entry */
++ if (idx < 0 || idx == entry)
++ break;
++ /*
++ * If we hit a match, we need to try again with
++ * a different ASID.
++ */
++ asid++;
++ } while (asid < asid_mask);
++
++ if (idx >= 0 && idx != entry)
++ panic("Unable to uniquify TLB entry %d", idx);
++
++ write_c0_index(entry);
+ mtc0_tlbw_hazard();
+ tlb_write_indexed();
+- tlbw_use_hazard();
++ entry++;
+ }
+
+- sort(tlb_vpns, cnt, sizeof(tlb_vpns[0]), r4k_vpn_cmp, NULL);
+-
+- write_c0_pagemask(PM_DEFAULT_MASK);
+- write_c0_entrylo0(0);
+- write_c0_entrylo1(0);
+-
+- idx = 0;
+- ent = tlbsize;
+- for (i = start; i < tlbsize; i++)
+- while (1) {
+- unsigned long entryhi, vpn;
+-
+- entryhi = UNIQUE_ENTRYHI(ent);
+- vpn = entryhi & vpn_mask & PAGE_MASK;
+-
+- if (idx >= cnt || vpn < tlb_vpns[idx]) {
+- write_c0_entryhi(entryhi);
+- write_c0_index(i);
+- mtc0_tlbw_hazard();
+- tlb_write_indexed();
+- ent++;
+- break;
+- } else if (vpn == tlb_vpns[idx]) {
+- ent++;
+- } else {
+- idx++;
+- }
+- }
+-
+ tlbw_use_hazard();
+ htw_start();
+ flush_micro_tlb();
+@@ -627,7 +602,6 @@ static void r4k_tlb_configure(void)
+
+ /* From this point on the ARC firmware is dead. */
+ r4k_tlb_uniquify();
+- local_flush_tlb_all();
+
+ /* Did I tell you that ARC SUCKS? */
+ }
projects / openwrt / openwrt.git / commitdiff