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| author |   Scott Wood <scottwood@freescale.com> | 2015-07-18 14:24:58 -0500 |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2015-08-07 23:00:01 -0500 |
| commit | c60232029aee84f69da0e74aa6f6d249edbbc80b (patch) | |
| tree | f56c5b4928f84e47a308a8d4adf664d0d34e4839 /arch/powerpc/kernel/exceptions-64e.S | |
| parent | powerpc/booke64: Move mb() to __set_pte_at() with kernel-addr test (diff) | |
| download | linux-dev-c60232029aee84f69da0e74aa6f6d249edbbc80b.tar.xz linux-dev-c60232029aee84f69da0e74aa6f6d249edbbc80b.zip | |
powerpc/fsl: Force coherent memory on e500mc derivatives
In CoreNet systems it is not allowed to mix M and non-M mappings to the
same memory, and coherent DMA accesses are considered to be M mappings
for this purpose. Ignoring this has been observed to cause hard
lockups in non-SMP kernels on e6500.
Furthermore, e6500 implements the LRAT (logical to real address table)
which allows KVM guests to control the WIMGE bits. This means that
KVM cannot force the M bit on the way it usually does, so the guest had
better set it itself.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64e.S')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64e.S | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index 3e68d1c69718..f3bd5e747ed8 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -1313,11 +1313,14 @@ skpinv: addi r6,r6,1 /* Increment */ sync isync -/* The mapping only needs to be cache-coherent on SMP */ -#ifdef CONFIG_SMP -#define M_IF_SMP MAS2_M +/* + * The mapping only needs to be cache-coherent on SMP, except on + * Freescale e500mc derivatives where it's also needed for coherent DMA. + */ +#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC) +#define M_IF_NEEDED MAS2_M #else -#define M_IF_SMP 0 +#define M_IF_NEEDED 0 #endif /* 6. Setup KERNELBASE mapping in TLB[0] @@ -1332,7 +1335,7 @@ skpinv: addi r6,r6,1 /* Increment */ ori r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_1GB))@l mtspr SPRN_MAS1,r6 - LOAD_REG_IMMEDIATE(r6, PAGE_OFFSET | M_IF_SMP) + LOAD_REG_IMMEDIATE(r6, PAGE_OFFSET | M_IF_NEEDED) mtspr SPRN_MAS2,r6 rlwinm r5,r5,0,0,25 |