i.MX6Q arm_dcache_invalidate() bug?

andrewtrotman — Wed, 11 Sep 2013 02:36:24 GMT

According to "ARM® Architecture Reference Manual ARMv7-A and ARMv7-R edition", section "B4.1.19 CCSIDR, Cache Size ID Registers, VMSA", NumSets is in bits 13-27. The source code that is shipped with the i.MX6Q Platform SDK uses 0x13 not 13. Is this a bug or am I missing something? The Freescale code is listed below

Thanks

Andrew.

void arm_dcache_invalidate()

{

uint32_t csid; // Cache Size ID

uint32_t wayset; // wayset parameter

int num_sets; // number of sets

int num_ways; // number of ways

_ARM_MRC(15, 1, csid, 0, 0, 0); // Read Cache Size ID

// Fill number of sets and number of ways from csid register This walues are decremented by 1

num_ways = (csid >> 0x03) & 0x3FFu; //((csid& csid_ASSOCIATIVITY_MASK) >> csid_ASSOCIATIVITY_SHIFT)

// Invalidation all lines (all Sets in all ways)

while (num_ways >= 0)

{

num_sets = (csid >> 0x13) & 0x7FFFu; //((csid & csid_NUMSETS_MASK) >> csid_NUMSETS_SHIFT)

while (num_sets >= 0 )

{

wayset = (num_sets << 5u) | (num_ways << 30u); //(num_sets << SETWAY_SET_SHIFT) | (num_sets << 3SETWAY_WAY_SHIFT)

// invalidate line if we know set and way

_ARM_MCR(15, 0, wayset, 7, 6, 2);

num_sets--;

}

num_ways--;

}

// All Cache, Branch predictor and TLB maintenance operations before followed instruction complete

_ARM_DSB();

}

Re: i.MX6Q arm_dcache_invalidate() bug?

JerryFan — Wed, 11 Sep 2013 05:20:34 GMT

Nice catch, Andrew. Yes, it is a bug which was fixed in SDK_RELEASE_V1.1.

Re: i.MX6Q arm_dcache_invalidate() bug?

andrewtrotman — Wed, 11 Sep 2013 07:46:30 GMT

Thanks for the confirmation. I've noticed that the same bug also appears in arm_dcache_flush(). Is it fixed there too?

Re: i.MX6Q arm_dcache_invalidate() bug?

JerryFan — Wed, 11 Sep 2013 07:49:45 GMT

Yes, the bug in arm_dcache_flush had also been fixed.

Re: i.MX6Q arm_dcache_invalidate() bug?

andrewtrotman — Wed, 11 Sep 2013 08:15:12 GMT

Thanks. I'll update to the new version.

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i.MX6Q arm_dcache_invalidate() bug?

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Re: i.MX6Q arm_dcache_invalidate() bug?

Re: i.MX6Q arm_dcache_invalidate() bug?

Re: i.MX6Q arm_dcache_invalidate() bug?