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SubjectRe: [PATCH] soc: qcom: smem: introduce qcom_smem_virt_to_phys()
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On 04/25/2018 06:14 PM, Bjorn Andersson wrote:
> On Wed 25 Apr 08:18 PDT 2018, Alex Elder wrote:
>
>> Create function qcom_smem_virt_to_phys(), which returns the physical
>> address corresponding to a given SMEM item's virtual address. This
>> feature is required for a driver that will soon be out for review.
>>
>
> It might be wise to turn the aux_base in smem_region into a phys_addr_t
> and then mask that with AUX_BASE_MASK before comparing with the entry's
> aux_base in qcom_smem_get_global(). But this will work fine until the
> day someone places smem above 4GB.

I thought of that but went for this for now, because it made for a
nice, concise change. I agree with you though.

Thanks a lot for the quick review.

-Alex

> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
>
> Regards,
> Bjorn
>
>> Signed-off-by: Alex Elder <elder@linaro.org>
>> ---
>> drivers/soc/qcom/smem.c | 27 +++++++++++++++++++++++++++
>> include/linux/soc/qcom/smem.h | 2 ++
>> 2 files changed, 29 insertions(+)
>>
>> diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
>> index 7d9a43da5084..70b2ee80d6bd 100644
>> --- a/drivers/soc/qcom/smem.c
>> +++ b/drivers/soc/qcom/smem.c
>> @@ -655,6 +655,33 @@ int qcom_smem_get_free_space(unsigned host)
>> }
>> EXPORT_SYMBOL(qcom_smem_get_free_space);
>>
>> +/**
>> + * qcom_smem_virt_to_phys() - return the physical address associated
>> + * with an smem item pointer (previously returned by qcom_smem_get()
>> + * @p: the virtual address to convert
>> + *
>> + * Returns 0 if the pointer provided is not within any smem region.
>> + */
>> +phys_addr_t qcom_smem_virt_to_phys(void *p)
>> +{
>> + unsigned i;
>> +
>> + for (i = 0; i < __smem->num_regions; i++) {
>> + struct smem_region *region = &__smem->regions[i];
>> +
>> + if (p < region->virt_base)
>> + continue;
>> + if (p < region->virt_base + region->size) {
>> + u64 offset = p - region->virt_base;
>> +
>> + return (phys_addr_t)region->aux_base + offset;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL(qcom_smem_virt_to_phys);
>> +
>> static int qcom_smem_get_sbl_version(struct qcom_smem *smem)
>> {
>> struct smem_header *header;
>> diff --git a/include/linux/soc/qcom/smem.h b/include/linux/soc/qcom/smem.h
>> index c1657ed27b30..86e1b358688a 100644
>> --- a/include/linux/soc/qcom/smem.h
>> +++ b/include/linux/soc/qcom/smem.h
>> @@ -9,4 +9,6 @@ void *qcom_smem_get(unsigned host, unsigned item, size_t *size);
>>
>> int qcom_smem_get_free_space(unsigned host);
>>
>> +phys_addr_t qcom_smem_virt_to_phys(void *p);
>> +
>> #endif
>> --
>> 2.14.1
>>
>> --
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