| Message ID | 20200723073744.13400-15-krzk@kernel.org (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | memory: Cleanup, improve and compile test memory drivers | expand |
On Thu, Jul 23, 2020 at 9:39 AM Krzysztof Kozlowski <krzk@kernel.org> wrote: > > Cast pointer to iomem memory properly to fix sparse warning: > > drivers/memory/ti-emif-pm.c:251:38: warning: incorrect type in argument 1 (different address spaces) > drivers/memory/ti-emif-pm.c:251:38: expected void const volatile [noderef] __iomem *addr > drivers/memory/ti-emif-pm.c:251:38: got void * > > Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> > --- > drivers/memory/ti-emif-pm.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/memory/ti-emif-pm.c b/drivers/memory/ti-emif-pm.c > index 9c90f815ad3a..6c747c1e98cb 100644 > --- a/drivers/memory/ti-emif-pm.c > +++ b/drivers/memory/ti-emif-pm.c > @@ -248,7 +248,7 @@ MODULE_DEVICE_TABLE(of, ti_emif_of_match); > static int ti_emif_resume(struct device *dev) > { > unsigned long tmp = > - __raw_readl((void *)emif_instance->ti_emif_sram_virt); > + __raw_readl((void __iomem *)emif_instance->ti_emif_sram_virt); > Maybe this shouldn't even be __raw_readl(), but instead READ_ONCE()? The other accesses in this file don't use MMIO wrappers either but just treat it as a pointer. The effect would be the same though. Arnd
On Thu, Jul 23, 2020 at 10:48:19AM +0200, Arnd Bergmann wrote: > On Thu, Jul 23, 2020 at 9:39 AM Krzysztof Kozlowski <krzk@kernel.org> wrote: > > > > Cast pointer to iomem memory properly to fix sparse warning: > > > > drivers/memory/ti-emif-pm.c:251:38: warning: incorrect type in argument 1 (different address spaces) > > drivers/memory/ti-emif-pm.c:251:38: expected void const volatile [noderef] __iomem *addr > > drivers/memory/ti-emif-pm.c:251:38: got void * > > > > Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> > > --- > > drivers/memory/ti-emif-pm.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/memory/ti-emif-pm.c b/drivers/memory/ti-emif-pm.c > > index 9c90f815ad3a..6c747c1e98cb 100644 > > --- a/drivers/memory/ti-emif-pm.c > > +++ b/drivers/memory/ti-emif-pm.c > > @@ -248,7 +248,7 @@ MODULE_DEVICE_TABLE(of, ti_emif_of_match); > > static int ti_emif_resume(struct device *dev) > > { > > unsigned long tmp = > > - __raw_readl((void *)emif_instance->ti_emif_sram_virt); > > + __raw_readl((void __iomem *)emif_instance->ti_emif_sram_virt); > > > > Maybe this shouldn't even be __raw_readl(), but instead READ_ONCE()? Won't readl() be enough? Indeed it looks problematic. > > The other accesses in this file don't use MMIO wrappers either but just treat > it as a pointer. The effect would be the same though. I think all the reads and writes are with readl() and writel(). Best regards, Krzysztof
On Thu, Jul 23, 2020 at 11:02 AM Krzysztof Kozlowski <krzk@kernel.org> wrote: > On Thu, Jul 23, 2020 at 10:48:19AM +0200, Arnd Bergmann wrote: > > On Thu, Jul 23, 2020 at 9:39 AM Krzysztof Kozlowski <krzk@kernel.org> wrote: > > > > > > Cast pointer to iomem memory properly to fix sparse warning: > > > > > > drivers/memory/ti-emif-pm.c:251:38: warning: incorrect type in argument 1 (different address spaces) > > > drivers/memory/ti-emif-pm.c:251:38: expected void const volatile [noderef] __iomem *addr > > > drivers/memory/ti-emif-pm.c:251:38: got void * > > > > > > Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> > > > --- > > > drivers/memory/ti-emif-pm.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/memory/ti-emif-pm.c b/drivers/memory/ti-emif-pm.c > > > index 9c90f815ad3a..6c747c1e98cb 100644 > > > --- a/drivers/memory/ti-emif-pm.c > > > +++ b/drivers/memory/ti-emif-pm.c > > > @@ -248,7 +248,7 @@ MODULE_DEVICE_TABLE(of, ti_emif_of_match); > > > static int ti_emif_resume(struct device *dev) > > > { > > > unsigned long tmp = > > > - __raw_readl((void *)emif_instance->ti_emif_sram_virt); > > > + __raw_readl((void __iomem *)emif_instance->ti_emif_sram_virt); > > > > > > > Maybe this shouldn't even be __raw_readl(), but instead READ_ONCE()? > > Won't readl() be enough? Indeed it looks problematic. readl() won't work on big-endian kernels, since this is a byte comparison. > > The other accesses in this file don't use MMIO wrappers either but just treat > > it as a pointer. The effect would be the same though. > > I think all the reads and writes are with readl() and writel(). I actually see only one other access: copy_addr = sram_exec_copy(emif_data->sram_pool_code, (void *)emif_data->ti_emif_sram_virt, &ti_emif_sram, ti_emif_sram_sz); and this one ends up in a memcpy() that does not perform any byte swapping or barriers. Arnd
On Thu, Jul 23, 2020 at 11:14:02AM +0200, Arnd Bergmann wrote: > On Thu, Jul 23, 2020 at 11:02 AM Krzysztof Kozlowski <krzk@kernel.org> wrote: > > On Thu, Jul 23, 2020 at 10:48:19AM +0200, Arnd Bergmann wrote: > > > On Thu, Jul 23, 2020 at 9:39 AM Krzysztof Kozlowski <krzk@kernel.org> wrote: > > > > > > > > Cast pointer to iomem memory properly to fix sparse warning: > > > > > > > > drivers/memory/ti-emif-pm.c:251:38: warning: incorrect type in argument 1 (different address spaces) > > > > drivers/memory/ti-emif-pm.c:251:38: expected void const volatile [noderef] __iomem *addr > > > > drivers/memory/ti-emif-pm.c:251:38: got void * > > > > > > > > Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> > > > > --- > > > > drivers/memory/ti-emif-pm.c | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/memory/ti-emif-pm.c b/drivers/memory/ti-emif-pm.c > > > > index 9c90f815ad3a..6c747c1e98cb 100644 > > > > --- a/drivers/memory/ti-emif-pm.c > > > > +++ b/drivers/memory/ti-emif-pm.c > > > > @@ -248,7 +248,7 @@ MODULE_DEVICE_TABLE(of, ti_emif_of_match); > > > > static int ti_emif_resume(struct device *dev) > > > > { > > > > unsigned long tmp = > > > > - __raw_readl((void *)emif_instance->ti_emif_sram_virt); > > > > + __raw_readl((void __iomem *)emif_instance->ti_emif_sram_virt); > > > > > > > > > > Maybe this shouldn't even be __raw_readl(), but instead READ_ONCE()? > > > > Won't readl() be enough? Indeed it looks problematic. > > readl() won't work on big-endian kernels, since this is a byte comparison. Ah, right. > > > > The other accesses in this file don't use MMIO wrappers either but just treat > > > it as a pointer. The effect would be the same though. > > > > I think all the reads and writes are with readl() and writel(). > > I actually see only one other access: > > copy_addr = sram_exec_copy(emif_data->sram_pool_code, > (void *)emif_data->ti_emif_sram_virt, > &ti_emif_sram, ti_emif_sram_sz); > > and this one ends up in a memcpy() that does not perform any byte > swapping or barriers. At least the barrier would come through mutex in sram_exec_copy() and later spin locks for page table manipulation. Anyway, I do not have the HW to test the changes or to confirm whether this is real issue. I guess the driver author/owner should follow up on this report. Best regards, Krzysztof
diff --git a/drivers/memory/ti-emif-pm.c b/drivers/memory/ti-emif-pm.c index 9c90f815ad3a..6c747c1e98cb 100644 --- a/drivers/memory/ti-emif-pm.c +++ b/drivers/memory/ti-emif-pm.c @@ -248,7 +248,7 @@ MODULE_DEVICE_TABLE(of, ti_emif_of_match); static int ti_emif_resume(struct device *dev) { unsigned long tmp = - __raw_readl((void *)emif_instance->ti_emif_sram_virt); + __raw_readl((void __iomem *)emif_instance->ti_emif_sram_virt); /* * Check to see if what we are copying is already present in the
Cast pointer to iomem memory properly to fix sparse warning: drivers/memory/ti-emif-pm.c:251:38: warning: incorrect type in argument 1 (different address spaces) drivers/memory/ti-emif-pm.c:251:38: expected void const volatile [noderef] __iomem *addr drivers/memory/ti-emif-pm.c:251:38: got void * Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> --- drivers/memory/ti-emif-pm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)