PCI: Move pci_rebar_bytes_to_size() and clean it up

Move pci_rebar_bytes_to_size() from include/linux/pci.h to rebar.c as it
does not look very trivial and is not expected to be performance critical.

Convert literals to use a newly added PCI_REBAR_MIN_SIZE define.

Also add kernel doc for the function as the function is exported.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michael J. Ruhl <mjruhl@habana.ai>
Link: https://patch.msgid.link/20251113180053.27944-3-ilpo.jarvinen@linux.intel.com

diff --git a/drivers/pci/rebar.c b/drivers/pci/rebar.c
index f6ed7e4893a77341bc4e5e5501dfbbac49a93f40..f29810fe0a5841b9ea341cd3e5073d5b66f20431 100644 (file)
--- a/drivers/pci/rebar.c
+++ b/drivers/pci/rebar.c
@@ -7,11 +7,34 @@
 #include <linux/errno.h>
 #include <linux/export.h>
 #include <linux/ioport.h>
+#include <linux/log2.h>
 #include <linux/pci.h>
+#include <linux/sizes.h>
 #include <linux/types.h>
 
 #include "pci.h"
 
+#define PCI_REBAR_MIN_SIZE     ((resource_size_t)SZ_1M)
+
+/**
+ * pci_rebar_bytes_to_size - Convert size in bytes to PCI BAR Size
+ * @bytes: size in bytes
+ *
+ * Convert size in bytes to encoded BAR Size in Resizable BAR Capability
+ * (PCIe r6.2, sec. 7.8.6.3).
+ *
+ * Return: encoded BAR Size as defined in the PCIe spec (0=1MB, 31=128TB)
+ */
+int pci_rebar_bytes_to_size(u64 bytes)
+{
+       int rebar_minsize = ilog2(PCI_REBAR_MIN_SIZE);
+
+       bytes = roundup_pow_of_two(bytes);
+
+       return max(ilog2(bytes), rebar_minsize) - rebar_minsize;
+}
+EXPORT_SYMBOL_GPL(pci_rebar_bytes_to_size);
+
 void pci_rebar_init(struct pci_dev *pdev)
 {
        pdev->rebar_cap = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 34ff295cd2e3fcf3014cb03f30133088996042d9..628dda63b9e09d38aa7eeeae67e98a6f6ef98a9e 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1419,17 +1419,13 @@ void pcibios_reset_secondary_bus(struct pci_dev *dev);
 void pci_update_resource(struct pci_dev *dev, int resno);
 int __must_check pci_assign_resource(struct pci_dev *dev, int i);
 int pci_release_resource(struct pci_dev *dev, int resno);
-static inline int pci_rebar_bytes_to_size(u64 bytes)
-{
-       bytes = roundup_pow_of_two(bytes);
-
-       /* Return BAR size as defined in the resizable BAR specification */
-       return max(ilog2(bytes), 20) - 20;
-}
 
+/* Resizable BAR related routines */
+int pci_rebar_bytes_to_size(u64 bytes);
 u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar);
 int __must_check pci_resize_resource(struct pci_dev *dev, int i, int size,
                                     int exclude_bars);
+
 int pci_select_bars(struct pci_dev *dev, unsigned long flags);
 bool pci_device_is_present(struct pci_dev *pdev);
 void pci_ignore_hotplug(struct pci_dev *dev);