From 5c0d72b1b35fd0dad7dd70a114df068eadcc1b16 Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Tue, 22 Jun 2010 14:00:12 +0200 Subject: [PATCH] microblaze: Remove PER_CPU(KM) variable There is a way howto remove Kernel Mode variable. It is easier to parse UMS bit in MSR to find out if I come from kernel or user space. Loading MSR content should be in one cycle and loading PER_CPU variable depends on memory state. Signed-off-by: Michal Simek --- arch/microblaze/kernel/entry.S | 43 ++++++++++++++++------------------ 1 file changed, 20 insertions(+), 23 deletions(-) diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S index f5fe220954b0..9a98f70e4c30 100644 --- a/arch/microblaze/kernel/entry.S +++ b/arch/microblaze/kernel/entry.S @@ -275,9 +275,12 @@ C_ENTRY(_user_exception): addi r14, r14, 4 /* return address is 4 byte after call */ swi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* Save r11 */ - lwi r11, r0, TOPHYS(PER_CPU(KM));/* See if already in kernel mode.*/ - beqi r11, 1f; /* Jump ahead if coming from user */ -/* Kernel-mode state save. */ + mfs r11, rmsr + nop + andi r11, r11, MSR_UMS + bnei r11, 1f + +/* Kernel-mode state save - kernel execve */ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/ tophys(r1,r11); swi r11, r1, (PT_R1-PT_SIZE); /* Save original SP. */ @@ -307,8 +310,6 @@ C_ENTRY(_user_exception): swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); swi r11, r1, PTO+PT_R1; /* Store user SP. */ - addi r11, r0, 1; - swi r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode. */ 2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* Save away the syscall number. */ swi r12, r1, PTO+PT_R0; @@ -423,7 +424,6 @@ C_ENTRY(ret_from_trap): /* Finally, return to user state. */ 1: - swi r0, r0, PER_CPU(KM); /* Now officially in user state. */ swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */ VM_OFF; tophys(r1,r1); @@ -511,8 +511,10 @@ C_ENTRY(sys_rt_sigreturn_wrapper): enable_irq; \ set_ee; \ /* See if already in kernel mode.*/ \ - lwi r11, r0, TOPHYS(PER_CPU(KM)); \ - beqi r11, 1f; /* Jump ahead if coming from user */\ + mfs r11, rmsr; \ + nop; \ + andi r11, r11, MSR_UMS; \ + bnei r11, 1f; \ /* Kernel-mode state save. */ \ /* Reload kernel stack-ptr. */ \ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); \ @@ -544,8 +546,6 @@ C_ENTRY(sys_rt_sigreturn_wrapper): swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */ \ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); \ swi r11, r1, PTO+PT_R1; /* Store user SP. */ \ - addi r11, r0, 1; \ - swi r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode.*/\ 2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); \ /* Save away the syscall number. */ \ swi r0, r1, PTO+PT_R0; \ @@ -686,7 +686,7 @@ C_ENTRY(ret_from_exc): add r6, r0, r0; /* Arg 2: sigset_t *oldset */ /* Finally, return to user state. */ -1: swi r0, r0, PER_CPU(KM); /* Now officially in user state. */ +1: swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */ VM_OFF; tophys(r1,r1); @@ -724,8 +724,10 @@ C_ENTRY(_interrupt): swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) swi r11, r0, TOPHYS(PER_CPU(R11_SAVE)); /* MS: See if already in kernel mode. */ - lwi r11, r0, TOPHYS(PER_CPU(KM)); - beqi r11, 1f; /* MS: Jump ahead if coming from user */ + mfs r11, rmsr + nop + andi r11, r11, MSR_UMS + bnei r11, 1f /* Kernel-mode state save. */ or r11, r1, r0 @@ -761,10 +763,6 @@ C_ENTRY(_interrupt): swi r0, r1, PTO + PT_MODE; lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); swi r11, r1, PTO+PT_R1; - /* setup kernel mode to KM */ - addi r11, r0, 1; - swi r11, r0, TOPHYS(PER_CPU(KM)); - 2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); swi r0, r1, PTO + PT_R0; @@ -803,7 +801,6 @@ ret_from_irq: no_intr_resched: /* Disable interrupts, we are now committed to the state restore */ disable_irq - swi r0, r0, PER_CPU(KM); /* MS: Now officially in user state. */ swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); VM_OFF; tophys(r1,r1); @@ -858,8 +855,10 @@ C_ENTRY(_debug_exception): set_bip; /*equalize initial state for all possible entries*/ clear_eip; enable_irq; - lwi r11, r0, TOPHYS(PER_CPU(KM));/* See if already in kernel mode.*/ - beqi r11, 1f; /* Jump ahead if coming from user */ + mfs r11, rmsr + nop + andi r11, r11, MSR_UMS + bnei r11, 1f /* Kernel-mode state save. */ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/ tophys(r1,r11); @@ -887,8 +886,6 @@ C_ENTRY(_debug_exception): swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); swi r11, r1, PTO+PT_R1; /* Store user SP. */ - addi r11, r0, 1; - swi r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode. */ 2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* Save away the syscall number. */ swi r0, r1, PTO+PT_R0; @@ -944,7 +941,7 @@ dbtrap_call: rtbd r11, 0; /* Finally, return to user state. */ -1: swi r0, r0, PER_CPU(KM); /* Now officially in user state. */ +1: swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */ VM_OFF; tophys(r1,r1); -- 2.39.5