[POWERPC] 4xx: Fix 4xx flush_tlb_page()

On 4xx CPUs, the current implementation of flush_tlb_page() uses
a low level _tlbie() assembly function that only works for the
current PID. Thus, invalidations caused by, for example, a COW
fault triggered by get_user_pages() from a different context will
not work properly, causing among other things, gdb breakpoints
to fail.

This patch adds a "pid" argument to _tlbie() on 4xx processors,
and uses it to flush entries in the right context. FSL BookE
also gets the argument but it seems they don't need it (their
tlbivax form ignores the PID when invalidating according to the
document I have).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 8533de5..0ed2c7e 100644 (file)
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -288,7 +288,16 @@ _GLOBAL(_tlbia)
  */
 _GLOBAL(_tlbie)
 #if defined(CONFIG_40x)
+       /* We run the search with interrupts disabled because we have to change
+        * the PID and I don't want to preempt when that happens.
+        */
+       mfmsr   r5
+       mfspr   r6,SPRN_PID
+       wrteei  0
+       mtspr   SPRN_PID,r4
        tlbsx.  r3, 0, r3
+       mtspr   SPRN_PID,r6
+       wrtee   r5
        bne     10f
        sync
        /* There are only 64 TLB entries, so r3 < 64, which means bit 25 is clear.
@@ -297,23 +306,23 @@ _GLOBAL(_tlbie)
        tlbwe   r3, r3, TLB_TAG
        isync
 10:
+
 #elif defined(CONFIG_44x)
-       mfspr   r4,SPRN_MMUCR
-       mfspr   r5,SPRN_PID                     /* Get PID */
-       rlwimi  r4,r5,0,24,31                   /* Set TID */
+       mfspr   r5,SPRN_MMUCR
+       rlwimi  r5,r4,0,24,31                   /* Set TID */
 
        /* We have to run the search with interrupts disabled, even critical
         * and debug interrupts (in fact the only critical exceptions we have
         * are debug and machine check).  Otherwise  an interrupt which causes
         * a TLB miss can clobber the MMUCR between the mtspr and the tlbsx. */
-       mfmsr   r5
+       mfmsr   r4
        lis     r6,(MSR_EE|MSR_CE|MSR_ME|MSR_DE)@ha
        addi    r6,r6,(MSR_EE|MSR_CE|MSR_ME|MSR_DE)@l
-       andc    r6,r5,r6
+       andc    r6,r4,r6
        mtmsr   r6
-       mtspr   SPRN_MMUCR,r4
+       mtspr   SPRN_MMUCR,r5
        tlbsx.  r3, 0, r3
-       mtmsr   r5
+       mtmsr   r4
        bne     10f
        sync
        /* There are only 64 TLB entries, so r3 < 64,

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index a18fda3..8135da0 100644 (file)
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -309,7 +309,7 @@ good_area:
                                        set_bit(PG_arch_1, &page->flags);
                                }
                                pte_update(ptep, 0, _PAGE_HWEXEC);
-                               _tlbie(address);
+                               _tlbie(address, mm->context.id);
                                pte_unmap_unlock(ptep, ptl);
                                up_read(&mm->mmap_sem);
                                return 0;

diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index c94a64f..eb3a732 100644 (file)
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -61,12 +61,12 @@ extern unsigned long total_lowmem;
 #define mmu_mapin_ram()                (0UL)
 
 #elif defined(CONFIG_4xx)
-#define flush_HPTE(X, va, pg)  _tlbie(va)
+#define flush_HPTE(pid, va, pg)        _tlbie(va, pid)
 extern void MMU_init_hw(void);
 extern unsigned long mmu_mapin_ram(void);
 
 #elif defined(CONFIG_FSL_BOOKE)
-#define flush_HPTE(X, va, pg)  _tlbie(va)
+#define flush_HPTE(pid, va, pg)        _tlbie(va, pid)
 extern void MMU_init_hw(void);
 extern unsigned long mmu_mapin_ram(void);
 extern void adjust_total_lowmem(void);

diff --git a/arch/ppc/kernel/misc.S b/arch/ppc/kernel/misc.S
index a22e1f4..2b81e71 100644 (file)
--- a/arch/ppc/kernel/misc.S
+++ b/arch/ppc/kernel/misc.S
@@ -224,7 +224,16 @@ _GLOBAL(_tlbia)
  */
 _GLOBAL(_tlbie)
 #if defined(CONFIG_40x)
+       /* We run the search with interrupts disabled because we have to change
+        * the PID and I don't want to preempt when that happens.
+        */
+       mfmsr   r5
+       mfspr   r6,SPRN_PID
+       wrteei  0
+       mtspr   SPRN_PID,r4
        tlbsx.  r3, 0, r3
+       mtspr   SPRN_PID,r6
+       wrtee   r5
        bne     10f
        sync
        /* There are only 64 TLB entries, so r3 < 64, which means bit 25 is clear.
@@ -234,22 +243,21 @@ _GLOBAL(_tlbie)
        isync
 10:
 #elif defined(CONFIG_44x)
-       mfspr   r4,SPRN_MMUCR
-       mfspr   r5,SPRN_PID                     /* Get PID */
-       rlwimi  r4,r5,0,24,31                   /* Set TID */
+       mfspr   r5,SPRN_MMUCR
+       rlwimi  r5,r4,0,24,31                   /* Set TID */
 
        /* We have to run the search with interrupts disabled, even critical
         * and debug interrupts (in fact the only critical exceptions we have
         * are debug and machine check).  Otherwise  an interrupt which causes
         * a TLB miss can clobber the MMUCR between the mtspr and the tlbsx. */
-       mfmsr   r5
+       mfmsr   r4
        lis     r6,(MSR_EE|MSR_CE|MSR_ME|MSR_DE)@ha
        addi    r6,r6,(MSR_EE|MSR_CE|MSR_ME|MSR_DE)@l
-       andc    r6,r5,r6
+       andc    r6,r4,r6
        mtmsr   r6
-       mtspr   SPRN_MMUCR,r4
+       mtspr   SPRN_MMUCR,r5
        tlbsx.  r3, 0, r3
-       mtmsr   r5
+       mtmsr   r4
        bne     10f
        sync
        /* There are only 64 TLB entries, so r3 < 64,

diff --git a/arch/ppc/mm/fault.c b/arch/ppc/mm/fault.c
index 254c23b..36c0e75 100644 (file)
--- a/arch/ppc/mm/fault.c
+++ b/arch/ppc/mm/fault.c
@@ -227,7 +227,7 @@ good_area:
                                        set_bit(PG_arch_1, &page->flags);
                                }
                                pte_update(ptep, 0, _PAGE_HWEXEC);
-                               _tlbie(address);
+                               _tlbie(address, mm->context.id);
                                pte_unmap_unlock(ptep, ptl);
                                up_read(&mm->mmap_sem);
                                return 0;

diff --git a/arch/ppc/mm/mmu_decl.h b/arch/ppc/mm/mmu_decl.h
index 540f329..f1d4f21 100644 (file)
--- a/arch/ppc/mm/mmu_decl.h
+++ b/arch/ppc/mm/mmu_decl.h
@@ -54,12 +54,12 @@ extern unsigned int num_tlbcam_entries;
 #define mmu_mapin_ram()                (0UL)
 
 #elif defined(CONFIG_4xx)
-#define flush_HPTE(X, va, pg)  _tlbie(va)
+#define flush_HPTE(pid, va, pg)        _tlbie(va, pid)
 extern void MMU_init_hw(void);
 extern unsigned long mmu_mapin_ram(void);
 
 #elif defined(CONFIG_FSL_BOOKE)
-#define flush_HPTE(X, va, pg)  _tlbie(va)
+#define flush_HPTE(pid, va, pg)        _tlbie(va, pid)
 extern void MMU_init_hw(void);
 extern unsigned long mmu_mapin_ram(void);
 extern void adjust_total_lowmem(void);

diff --git a/arch/ppc/platforms/4xx/ebony.c b/arch/ppc/platforms/4xx/ebony.c
index 05d7184..453643a 100644 (file)
--- a/arch/ppc/platforms/4xx/ebony.c
+++ b/arch/ppc/platforms/4xx/ebony.c
@@ -236,7 +236,7 @@ ebony_early_serial_map(void)
        gen550_init(0, &port);
 
        /* Purge TLB entry added in head_44x.S for early serial access */
-       _tlbie(UART0_IO_BASE);
+       _tlbie(UART0_IO_BASE, 0);
 #endif
 
        port.membase = ioremap64(PPC440GP_UART1_ADDR, 8);

diff --git a/arch/ppc/platforms/4xx/ocotea.c b/arch/ppc/platforms/4xx/ocotea.c
index fd0f971..28a712c 100644 (file)
--- a/arch/ppc/platforms/4xx/ocotea.c
+++ b/arch/ppc/platforms/4xx/ocotea.c
@@ -259,7 +259,7 @@ ocotea_early_serial_map(void)
        gen550_init(0, &port);
 
        /* Purge TLB entry added in head_44x.S for early serial access */
-       _tlbie(UART0_IO_BASE);
+       _tlbie(UART0_IO_BASE, 0);
 #endif
 
        port.membase = ioremap64(PPC440GX_UART1_ADDR, 8);

diff --git a/arch/ppc/platforms/4xx/taishan.c b/arch/ppc/platforms/4xx/taishan.c
index 888c492..f6a0c66 100644 (file)
--- a/arch/ppc/platforms/4xx/taishan.c
+++ b/arch/ppc/platforms/4xx/taishan.c
@@ -316,7 +316,7 @@ taishan_early_serial_map(void)
        gen550_init(0, &port);
 
        /* Purge TLB entry added in head_44x.S for early serial access */
-       _tlbie(UART0_IO_BASE);
+       _tlbie(UART0_IO_BASE, 0);
 #endif
 
        port.membase = ioremap64(PPC440GX_UART1_ADDR, 8);

diff --git a/include/asm-powerpc/tlbflush.h b/include/asm-powerpc/tlbflush.h
index b6b036c..e7b4c0d 100644 (file)
--- a/include/asm-powerpc/tlbflush.h
+++ b/include/asm-powerpc/tlbflush.h
@@ -1,5 +1,6 @@
 #ifndef _ASM_POWERPC_TLBFLUSH_H
 #define _ASM_POWERPC_TLBFLUSH_H
+
 /*
  * TLB flushing:
  *
@@ -16,9 +17,6 @@
  */
 #ifdef __KERNEL__
 
-struct mm_struct;
-struct vm_area_struct;
-
 #if defined(CONFIG_4xx) || defined(CONFIG_8xx) || defined(CONFIG_FSL_BOOKE)
 /*
  * TLB flushing for software loaded TLB chips
@@ -28,7 +26,9 @@ struct vm_area_struct;
  * specific tlbie's
  */
 
-extern void _tlbie(unsigned long address);
+#include <linux/mm.h>
+
+extern void _tlbie(unsigned long address, unsigned int pid);
 
 #if defined(CONFIG_40x) || defined(CONFIG_8xx)
 #define _tlbia()       asm volatile ("tlbia; sync" : : : "memory")
@@ -44,13 +44,13 @@ static inline void flush_tlb_mm(struct mm_struct *mm)
 static inline void flush_tlb_page(struct vm_area_struct *vma,
                                  unsigned long vmaddr)
 {
-       _tlbie(vmaddr);
+       _tlbie(vmaddr, vma->vm_mm->context.id);
 }
 
 static inline void flush_tlb_page_nohash(struct vm_area_struct *vma,
                                         unsigned long vmaddr)
 {
-       _tlbie(vmaddr);
+       _tlbie(vmaddr, vma->vm_mm->context.id);
 }
 
 static inline void flush_tlb_range(struct vm_area_struct *vma,