| Message ID | 20180425151820.25595-1-elder@linaro.org |
|---|---|
| State | Accepted |
| Commit | 6d361c1db7b69fddf5748cf212169ab57bb13a6e |
| Headers | show |
| Series | soc: qcom: smem: introduce qcom_smem_virt_to_phys() | expand |
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 <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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org 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 <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; > + 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 -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org 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 <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; >> + > > 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 > -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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
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 <elder@linaro.org> --- drivers/soc/qcom/smem.c | 27 +++++++++++++++++++++++++++ include/linux/soc/qcom/smem.h | 2 ++ 2 files changed, 29 insertions(+) -- 2.14.1 -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html