| Message ID | 20200304133847.103881-1-d.c.ddcc@gmail.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [v2] fpga: dfl: afu: support debug access to memory-mapped afu regions | expand |
On Wed, Mar 04, 2020 at 08:38:47AM -0500, Dominic Chen wrote: > Allow debug access to memory-mapped regions using e.g. gdb. > > Signed-off-by: Dominic Chen <d.c.ddcc@gmail.com> > --- > drivers/fpga/dfl-afu-main.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c > index 02baa6a227c0..ec9dbd3d51b8 100644 > --- a/drivers/fpga/dfl-afu-main.c > +++ b/drivers/fpga/dfl-afu-main.c > @@ -459,6 +459,12 @@ static long afu_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > return -EINVAL; > } > > +static const struct vm_operations_struct afu_vma_ops = { > +#ifdef CONFIG_HAVE_IOREMAP_PROT > + .access = generic_access_phys, > +#endif /* CONFIG_HAVE_IOREMAP_PROT */ I remember there were issues in the past with modules and this, are those resolved? > +}; > + > static int afu_mmap(struct file *filp, struct vm_area_struct *vma) > { > struct platform_device *pdev = filp->private_data; > @@ -488,6 +494,9 @@ static int afu_mmap(struct file *filp, struct vm_area_struct *vma) > !(region.flags & DFL_PORT_REGION_WRITE)) > return -EPERM; > > + // Support debug access to the mapping Please use kernel style comments /* */ checkpatch.pl should catch this. > + vma->vm_ops = &afu_vma_ops; > + > vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); > > return remap_pfn_range(vma, vma->vm_start, > -- > 2.17.1 > Thanks, Moritz
On 3/4/2020 10:09 PM, Moritz Fischer wrote: >> +static const struct vm_operations_struct afu_vma_ops = { >> +#ifdef CONFIG_HAVE_IOREMAP_PROT >> + .access = generic_access_phys, >> +#endif /* CONFIG_HAVE_IOREMAP_PROT */ > I remember there were issues in the past with modules and this, are > those resolved? Are you referring to the `generic_access_phys` symbol not being exported? It looks like it became available to GPL modules starting with kernel v3.12. >> static int afu_mmap(struct file *filp, struct vm_area_struct *vma) >> { >> struct platform_device *pdev = filp->private_data; >> @@ -488,6 +494,9 @@ static int afu_mmap(struct file *filp, struct vm_area_struct *vma) >> !(region.flags & DFL_PORT_REGION_WRITE)) >> return -EPERM; >> >> + // Support debug access to the mapping > Please use kernel style comments /* */ checkpatch.pl should catch this. Hmm, I did run checkpatch.pl, though it contains `$allow_c99_comments = 1`. I'll send out v3 to fix this. Thanks, Dominic
diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c index 02baa6a227c0..ec9dbd3d51b8 100644 --- a/drivers/fpga/dfl-afu-main.c +++ b/drivers/fpga/dfl-afu-main.c @@ -459,6 +459,12 @@ static long afu_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return -EINVAL; } +static const struct vm_operations_struct afu_vma_ops = { +#ifdef CONFIG_HAVE_IOREMAP_PROT + .access = generic_access_phys, +#endif /* CONFIG_HAVE_IOREMAP_PROT */ +}; + static int afu_mmap(struct file *filp, struct vm_area_struct *vma) { struct platform_device *pdev = filp->private_data; @@ -488,6 +494,9 @@ static int afu_mmap(struct file *filp, struct vm_area_struct *vma) !(region.flags & DFL_PORT_REGION_WRITE)) return -EPERM; + // Support debug access to the mapping + vma->vm_ops = &afu_vma_ops; + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); return remap_pfn_range(vma, vma->vm_start,
Allow debug access to memory-mapped regions using e.g. gdb. Signed-off-by: Dominic Chen <d.c.ddcc@gmail.com> --- drivers/fpga/dfl-afu-main.c | 9 +++++++++ 1 file changed, 9 insertions(+)