platform/x86/intel/pmt: allow user offset for PMT callbacks

Usage of the telem sysfs file allows for partial reads at an offset.
The current callback method returns the buffer starting from offset 0
only.

Include the requested offset in the callback and update the necessary
address calculations with the offset.

Note: offset addition is moved from the caller to the local usage. For
non-callback usage this is unchanged behavior.

Fixes: e92affc74cd8 ("platform/x86/intel/vsec: Add PMT read callbacks")
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Michael J. Ruhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/platform/x86/intel/pmt/class.c b/drivers/platform/x86/intel/pmt/class.c
index 7680474c4f96..375695cc0d60 100644
--- a/drivers/platform/x86/intel/pmt/class.c
+++ b/drivers/platform/x86/intel/pmt/class.c
@@ -59,10 +59,12 @@ pmt_memcpy64_fromio(void *to, const u64 __iomem *from, size_t count)
 }
 
 int pmt_telem_read_mmio(struct pci_dev *pdev, struct pmt_callbacks *cb, u32 guid, void *buf,
-			void __iomem *addr, u32 count)
+			void __iomem *addr, loff_t off, u32 count)
 {
 	if (cb && cb->read_telem)
-		return cb->read_telem(pdev, guid, buf, count);
+		return cb->read_telem(pdev, guid, buf, off, count);
+
+	addr += off;
 
 	if (guid == GUID_SPR_PUNIT)
 		/* PUNIT on SPR only supports aligned 64-bit read */
@@ -96,7 +98,7 @@ intel_pmt_read(struct file *filp, struct kobject *kobj,
 		count = entry->size - off;
 
 	count = pmt_telem_read_mmio(entry->ep->pcidev, entry->cb, entry->header.guid, buf,
-				    entry->base + off, count);
+				    entry->base, off, count);
 
 	return count;
 }