Re: [PATCH V7 03/11] pci, of: Move the PCI I/O space management to PCI core code.

From: Tomasz Nowicki
Date: Wed May 11 2016 - 03:37:12 EST


On 10.05.2016 19:59, Rafael J. Wysocki wrote:
On Tue, May 10, 2016 at 5:19 PM, Tomasz Nowicki <tn@xxxxxxxxxxxx> wrote:
No functional changes in this patch.

PCI I/O space mapping code does not depend on OF, therefore it can be
moved to PCI core code. This way we will be able to use it
e.g. in ACPI PCI code.

Suggested-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
CC: Arnd Bergmann <arnd@xxxxxxxx>
CC: Liviu Dudau <Liviu.Dudau@xxxxxxx>
---
drivers/of/address.c | 116 +--------------------------------------------
drivers/pci/pci.c | 115 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/of_address.h | 9 ----
include/linux/pci.h | 5 ++
4 files changed, 121 insertions(+), 124 deletions(-)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 91a469d..0a553c0 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -4,6 +4,7 @@
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/of_address.h>
+#include <linux/pci.h>
#include <linux/pci_regs.h>
#include <linux/sizes.h>
#include <linux/slab.h>
@@ -673,121 +674,6 @@ const __be32 *of_get_address(struct device_node *dev, int index, u64 *size,
}
EXPORT_SYMBOL(of_get_address);

-#ifdef PCI_IOBASE
-struct io_range {
- struct list_head list;
- phys_addr_t start;
- resource_size_t size;
-};
-
-static LIST_HEAD(io_range_list);
-static DEFINE_SPINLOCK(io_range_lock);
-#endif
-
-/*
- * Record the PCI IO range (expressed as CPU physical address + size).
- * Return a negative value if an error has occured, zero otherwise
- */
-int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
-{
- int err = 0;
-
-#ifdef PCI_IOBASE
- struct io_range *range;
- resource_size_t allocated_size = 0;
-
- /* check if the range hasn't been previously recorded */
- spin_lock(&io_range_lock);
- list_for_each_entry(range, &io_range_list, list) {
- if (addr >= range->start && addr + size <= range->start + size) {
- /* range already registered, bail out */
- goto end_register;
- }
- allocated_size += range->size;
- }
-
- /* range not registed yet, check for available space */
- if (allocated_size + size - 1 > IO_SPACE_LIMIT) {
- /* if it's too big check if 64K space can be reserved */
- if (allocated_size + SZ_64K - 1 > IO_SPACE_LIMIT) {
- err = -E2BIG;
- goto end_register;
- }
-
- size = SZ_64K;
- pr_warn("Requested IO range too big, new size set to 64K\n");
- }
-
- /* add the range to the list */
- range = kzalloc(sizeof(*range), GFP_ATOMIC);
- if (!range) {
- err = -ENOMEM;
- goto end_register;
- }
-
- range->start = addr;
- range->size = size;
-
- list_add_tail(&range->list, &io_range_list);
-
-end_register:
- spin_unlock(&io_range_lock);
-#endif
-
- return err;
-}
-
-phys_addr_t pci_pio_to_address(unsigned long pio)
-{
- phys_addr_t address = (phys_addr_t)OF_BAD_ADDR;
-
-#ifdef PCI_IOBASE
- struct io_range *range;
- resource_size_t allocated_size = 0;
-
- if (pio > IO_SPACE_LIMIT)
- return address;
-
- spin_lock(&io_range_lock);
- list_for_each_entry(range, &io_range_list, list) {
- if (pio >= allocated_size && pio < allocated_size + range->size) {
- address = range->start + pio - allocated_size;
- break;
- }
- allocated_size += range->size;
- }
- spin_unlock(&io_range_lock);
-#endif
-
- return address;
-}
-
-unsigned long __weak pci_address_to_pio(phys_addr_t address)
-{
-#ifdef PCI_IOBASE
- struct io_range *res;
- resource_size_t offset = 0;
- unsigned long addr = -1;
-
- spin_lock(&io_range_lock);
- list_for_each_entry(res, &io_range_list, list) {
- if (address >= res->start && address < res->start + res->size) {
- addr = address - res->start + offset;
- break;
- }
- offset += res->size;
- }
- spin_unlock(&io_range_lock);
-
- return addr;
-#else
- if (address > IO_SPACE_LIMIT)
- return (unsigned long)-1;
-
- return (unsigned long) address;
-#endif
-}
-
static int __of_address_to_resource(struct device_node *dev,
const __be32 *addrp, u64 size, unsigned int flags,
const char *name, struct resource *r)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 25e0327..bc0c914 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3021,6 +3021,121 @@ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
}
EXPORT_SYMBOL(pci_request_regions_exclusive);

+#ifdef PCI_IOBASE
+struct io_range {
+ struct list_head list;
+ phys_addr_t start;
+ resource_size_t size;
+};
+
+static LIST_HEAD(io_range_list);
+static DEFINE_SPINLOCK(io_range_lock);
+#endif
+
+/*
+ * Record the PCI IO range (expressed as CPU physical address + size).
+ * Return a negative value if an error has occured, zero otherwise
+ */
+int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
+{
+ int err = 0;
+
+#ifdef PCI_IOBASE

I understand that this moves code around, but those in-function
#ifdefs aren't nice. Any chance to get rid of them but putting whole
functions under the #ifdef?


This is a __weak implementation, so assuming I would move #ifdef out of function I need to provide another empty __weak stub. I do not know which solution is more ugly. In any case we can do that cleanup separately.

Tomasz