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.
Signed-off-by: Alex Elder <[email protected]>
---
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
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.
Reviewed-by: Bjorn Andersson <[email protected]>
Regards,
Bjorn
> Signed-off-by: Alex Elder <[email protected]>
> ---
> 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
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Alex,
Minor comment.
On 4/25/2018 8:18 AM, 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.
>
> Signed-off-by: Alex Elder <[email protected]>
> ---
> 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;
> +
We have a null pointer check for __smem here since it is called by
external clients. This case should probably never happen though.
> + 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);
Thanks,
Chris
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
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 <[email protected]>
>
> Regards,
> Bjorn
>
>> Signed-off-by: Alex Elder <[email protected]>
>> ---
>> 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
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
>> the body of a message to [email protected]
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
On 04/25/2018 06:29 PM, Chris Lew wrote:
> Hi Alex,
>
> Minor comment.
>
> On 4/25/2018 8:18 AM, 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.
>>
>> Signed-off-by: Alex Elder <[email protected]>
>> ---
>> 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;
>> +
>
> We have a null pointer check for __smem here since it is called by
> external clients. This case should probably never happen though.
I think you're suggesting that we should verify __smem is non-null first?
I'll make a few statements about that.
- This function can only be called with a pointer that was returned by
qcom_smem_get(). That function won't return a valid pointer unless
__smem was non-null.
- The only other way __smem would be null is if this were called after
qcom_smem_remove(), which is erroneous.
- I think putting a null pointer check suggests that it's a condition
that might be expected to occur. If anything, I'd put an assertion
in there (e.g. BUG_ON(!__smem)) but I don't think it's warranted.
I do understand why you suggest this--and it's a relatively harmless
check. But I think it's better without it.
-Alex
>> + 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);
>
> Thanks,
> Chris
>