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[PATCH] Revert "MIPS: mm: tlbex: Use cpu_has_mips_r2_exec_hazard for the

To: linux-mips@linux-mips.org, ralf@linux-mips.org
Subject: [PATCH] Revert "MIPS: mm: tlbex: Use cpu_has_mips_r2_exec_hazard for the EHB instruction"
From: David Daney <ddaney.cavm@gmail.com>
Date: Mon, 23 Feb 2015 14:52:54 -0800
Cc: linux-kernel@vger.kernel.org, Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>, Markos Chandras <markos.chandras@imgtec.com>, David Daney <david.daney@cavium.com>
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From: David Daney <david.daney@cavium.com>

This reverts commit 77f3ee59ee7cfe19e0ee48d9a990c7967fbfcbed.

There are two problems:

1) It breaks OCTEON, which will now crash in early boot with:

  Kernel panic - not syncing: No TLB refill handler yet (CPU type: 80)

2) The logic is broken.

The meaning of cpu_has_mips_r2_exec_hazard is that the EHB instruction
is required.  The offending patch attempts (and fails) to change the
meaning to be that EHB is part of the ISA.

Signed-off-by: David Daney <david.daney@cavium.com>
---
 arch/mips/mm/tlbex.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index d75ff73..ff8d99c 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -501,7 +501,7 @@ static void build_tlb_write_entry(u32 **p, struct 
uasm_label **l,
        case tlb_indexed: tlbw = uasm_i_tlbwi; break;
        }
 
-       if (cpu_has_mips_r2_exec_hazard) {
+       if (cpu_has_mips_r2) {
                /*
                 * The architecture spec says an ehb is required here,
                 * but a number of cores do not have the hazard and
@@ -1953,7 +1953,7 @@ static void build_r4000_tlb_load_handler(void)
 
                switch (current_cpu_type()) {
                default:
-                       if (cpu_has_mips_r2_exec_hazard) {
+                       if (cpu_has_mips_r2) {
                                uasm_i_ehb(&p);
 
                case CPU_CAVIUM_OCTEON:
@@ -2020,7 +2020,7 @@ static void build_r4000_tlb_load_handler(void)
 
                switch (current_cpu_type()) {
                default:
-                       if (cpu_has_mips_r2_exec_hazard) {
+                       if (cpu_has_mips_r2) {
                                uasm_i_ehb(&p);
 
                case CPU_CAVIUM_OCTEON:
-- 
1.7.11.7


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