[MIPS] MT: Improved multithreading support.

    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 68 insertions, 17 deletions

diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
index a865f2394cb0..9dca099ba16b 100644
--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -32,13 +32,35 @@ extern void build_tlb_refill_handler(void);
                                      "nop; nop; nop; nop; nop; nop;\n\t" \
                                      ".set reorder\n\t")
 
+/* Atomicity and interruptability */
+#ifdef CONFIG_MIPS_MT_SMTC
+
+#include <asm/smtc.h>
+#include <asm/mipsmtregs.h>
+
+#define ENTER_CRITICAL(flags) \
+        { \
+        unsigned int mvpflags; \
+        local_irq_save(flags);\
+        mvpflags = dvpe()
+#define EXIT_CRITICAL(flags) \
+        evpe(mvpflags); \
+        local_irq_restore(flags); \
+        }
+#else
+
+#define ENTER_CRITICAL(flags) local_irq_save(flags)
+#define EXIT_CRITICAL(flags) local_irq_restore(flags)
+
+#endif /* CONFIG_MIPS_MT_SMTC */
+
 void local_flush_tlb_all(void)
 {
         unsigned long flags;
         unsigned long old_ctx;
         int entry;
 
-        local_irq_save(flags);
+        ENTER_CRITICAL(flags);
         /* Save old context and create impossible VPN2 value */
         old_ctx = read_c0_entryhi();
         write_c0_entrylo0(0);
@@ -57,7 +79,7 @@ void local_flush_tlb_all(void)
         }
         tlbw_use_hazard();
         write_c0_entryhi(old_ctx);
-        local_irq_restore(flags);
+        EXIT_CRITICAL(flags);
 }
 
 /* All entries common to a mm share an asid.  To effectively flush
@@ -87,6 +109,7 @@ void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
                 unsigned long flags;
                 int size;
 
+                ENTER_CRITICAL(flags);
                 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
                 size = (size + 1) >> 1;
                 local_irq_save(flags);
@@ -120,7 +143,7 @@ void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
                 } else {
                         drop_mmu_context(mm, cpu);
                 }
-                local_irq_restore(flags);
+                EXIT_CRITICAL(flags);
         }
 }
 
@@ -129,9 +152,9 @@ void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
         unsigned long flags;
         int size;
 
+        ENTER_CRITICAL(flags);
         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
         size = (size + 1) >> 1;
-        local_irq_save(flags);
         if (size <= current_cpu_data.tlbsize / 2) {
                 int pid = read_c0_entryhi();
 
@@ -162,7 +185,7 @@ void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
         } else {
                 local_flush_tlb_all();
         }
-        local_irq_restore(flags);
+        EXIT_CRITICAL(flags);
 }
 
 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
@@ -175,7 +198,7 @@ void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 
                 newpid = cpu_asid(cpu, vma->vm_mm);
                 page &= (PAGE_MASK << 1);
-                local_irq_save(flags);
+                ENTER_CRITICAL(flags);
                 oldpid = read_c0_entryhi();
                 write_c0_entryhi(page | newpid);
                 mtc0_tlbw_hazard();
@@ -194,7 +217,7 @@ void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 
         finish:
                 write_c0_entryhi(oldpid);
-                local_irq_restore(flags);
+                EXIT_CRITICAL(flags);
         }
 }
 
@@ -207,7 +230,7 @@ void local_flush_tlb_one(unsigned long page)
         unsigned long flags;
         int oldpid, idx;
 
-        local_irq_save(flags);
+        ENTER_CRITICAL(flags);
         oldpid = read_c0_entryhi();
         page &= (PAGE_MASK << 1);
         write_c0_entryhi(page);
@@ -226,7 +249,7 @@ void local_flush_tlb_one(unsigned long page)
         }
         write_c0_entryhi(oldpid);
 
-        local_irq_restore(flags);
+        EXIT_CRITICAL(flags);
 }
 
 /*
@@ -249,7 +272,7 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
         if (current->active_mm != vma->vm_mm)
                 return;
 
-        local_irq_save(flags);
+        ENTER_CRITICAL(flags);
 
         pid = read_c0_entryhi() & ASID_MASK;
         address &= (PAGE_MASK << 1);
@@ -277,7 +300,7 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
         else
                 tlb_write_indexed();
         tlbw_use_hazard();
-        local_irq_restore(flags);
+        EXIT_CRITICAL(flags);
 }
 
 #if 0
@@ -291,7 +314,7 @@ static void r4k_update_mmu_cache_hwbug(struct vm_area_struct * vma,
         pte_t *ptep;
         int idx;
 
-        local_irq_save(flags);
+        ENTER_CRITICAL(flags);
         address &= (PAGE_MASK << 1);
         asid = read_c0_entryhi() & ASID_MASK;
         write_c0_entryhi(address | asid);
@@ -310,7 +333,7 @@ static void r4k_update_mmu_cache_hwbug(struct vm_area_struct * vma,
         else
                 tlb_write_indexed();
         tlbw_use_hazard();
-        local_irq_restore(flags);
+        EXIT_CRITICAL(flags);
 }
 #endif
 
@@ -322,7 +345,7 @@ void __init add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
         unsigned long old_pagemask;
         unsigned long old_ctx;
 
-        local_irq_save(flags);
+        ENTER_CRITICAL(flags);
         /* Save old context and create impossible VPN2 value */
         old_ctx = read_c0_entryhi();
         old_pagemask = read_c0_pagemask();
@@ -342,7 +365,7 @@ void __init add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
         BARRIER;
         write_c0_pagemask(old_pagemask);
         local_flush_tlb_all();
-        local_irq_restore(flags);
+        EXIT_CRITICAL(flags);
 }
 
 /*
@@ -362,7 +385,7 @@ __init int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
         unsigned long old_pagemask;
         unsigned long old_ctx;
 
-        local_irq_save(flags);
+        ENTER_CRITICAL(flags);
         /* Save old context and create impossible VPN2 value */
         old_ctx = read_c0_entryhi();
         old_pagemask = read_c0_pagemask();
@@ -386,10 +409,11 @@ __init int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
         write_c0_entryhi(old_ctx);
         write_c0_pagemask(old_pagemask);
 out:
-        local_irq_restore(flags);
+        EXIT_CRITICAL(flags);
         return ret;
 }
 
+extern void __init sanitize_tlb_entries(void);
 static void __init probe_tlb(unsigned long config)
 {
         struct cpuinfo_mips *c = &current_cpu_data;
@@ -402,6 +426,14 @@ static void __init probe_tlb(unsigned long config)
          */
         if ((c->processor_id & 0xff0000) == PRID_COMP_LEGACY)
                 return;
+#ifdef CONFIG_MIPS_MT_SMTC
+        /*
+         * If TLB is shared in SMTC system, total size already
+         * has been calculated and written into cpu_data tlbsize
+         */
+        if((smtc_status & SMTC_TLB_SHARED) == SMTC_TLB_SHARED)
+                return;
+#endif /* CONFIG_MIPS_MT_SMTC */
 
         reg = read_c0_config1();
         if (!((config >> 7) & 3))
@@ -410,6 +442,15 @@ static void __init probe_tlb(unsigned long config)
         c->tlbsize = ((reg >> 25) & 0x3f) + 1;
 }
 
+static int __initdata ntlb = 0;
+static int __init set_ntlb(char *str)
+{
+        get_option(&str, &ntlb);
+        return 1;
+}
+
+__setup("ntlb=", set_ntlb);
+
 void __init tlb_init(void)
 {
         unsigned int config = read_c0_config();
@@ -432,5 +473,15 @@ void __init tlb_init(void)
 
         /* Did I tell you that ARC SUCKS?  */
 
+        if (ntlb) {
+                if (ntlb > 1 && ntlb <= current_cpu_data.tlbsize) {
+                        int wired = current_cpu_data.tlbsize - ntlb;
+                        write_c0_wired(wired);
+                        write_c0_index(wired-1);
+                        printk ("Restricting TLB to %d entries\n", ntlb);
+                } else
+                        printk("Ignoring invalid argument ntlb=%d\n", ntlb);
+        }
+
         build_tlb_refill_handler();
 }