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4b22c693e3
On CPUs which support the EBase WG (write gate) flag, the most significant bits of the exception base can be changed. Firmware running on a VP(E) using MIPS rproc may change EBase to point into the user segment where the firmware is located such that it can service interrupts. When control is transferred back to the kernel the EBase must be switched back into the kernel segment, such that the kernel's exception vectors are used. Similarly when vectored interrupts (vint) or vectored external interrupt controllers (veic) are enabled an exception vector is allocated from bootmem, and written to the EBase register. Due to the WG flag being clear, only bits 29:12 will be written. Asside from the rproc case above this is normally fine (as it will usually be a low allocation within the KSeg0 range, however when Enhanced Virtual Addressing (EVA) is enabled the allocation may be outside of the traditional KSeg0/KSeg1 address range, resulting in the wrong EBase being written. Correct both cases (configure_exception_vector() for the boot CPU, and per_cpu_trap_init() for secondary CPUs) to write EBase with the WG flag first if supported. On the Malta EVA configuration, KSeg0 is mapped to physical address 0, and memory is allocated from the KUSeg segment which is mapped to physical address 0x80000000, which physically aliases the RAM at 0. This only worked due to the exception base address aliasing the same underlying RAM that was written to & cache flushed, and due to flush_icache_range() going beyond the call of duty and flushing from the L2 cache too (due to the differing physical addresses). Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14150/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> |
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| .. | ||
| alchemy | ||
| ar7 | ||
| ath25 | ||
| ath79 | ||
| bcm47xx | ||
| bcm63xx | ||
| bmips | ||
| boot | ||
| cavium-octeon | ||
| cobalt | ||
| configs | ||
| dec | ||
| emma | ||
| fw | ||
| include | ||
| jazz | ||
| jz4740 | ||
| kernel | ||
| kvm | ||
| lantiq | ||
| lasat | ||
| lib | ||
| loongson32 | ||
| loongson64 | ||
| math-emu | ||
| mm | ||
| mti-malta | ||
| mti-sead3 | ||
| net | ||
| netlogic | ||
| oprofile | ||
| paravirt | ||
| pci | ||
| pic32 | ||
| pistachio | ||
| pmcs-msp71xx | ||
| pnx833x | ||
| power | ||
| ralink | ||
| rb532 | ||
| sgi-ip22 | ||
| sgi-ip27 | ||
| sgi-ip32 | ||
| sibyte | ||
| sni | ||
| txx9 | ||
| vdso | ||
| vr41xx | ||
| xilfpga | ||
| Kbuild | ||
| Kbuild.platforms | ||
| Kconfig | ||
| Kconfig.debug | ||
| Makefile | ||