Re: [PATCH V6 2/5] PCI: Adapt pci_register_io_range() for indirect-IO and PCI I/O translation

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Hi Rafael,

Could you kindly check the minor changes to drivers/acpi/pci_root.c? It would also be appreciated if you could review the ACPI-relevant parts in lib/extio.c, in [PATCH V5 5/5] LPC: Add the ACPI LPC support

Thanks,
John

On 24/01/2017 07:05, zhichang.yuan wrote:
After indirect-IO is introduced, system must can assigned indirect-IO devices
with logical I/O ranges which are different from those for PCI I/O devices.
Otherwise, I/O accessors can't identify whether the I/O port is for memory
mapped I/O or indirect-IO.
As current helper, pci_register_io_range(), is used for PCI I/O ranges
registration and translation, indirect-IO devices should also apply these
helpers to manage the I/O ranges. It will be easy to ensure the assigned
logical I/O ranges unique.
But for indirect-IO devices, there is no cpu address. The current
pci_register_io_range() can not work for this case.

This patch makes some changes on the pci_register_io_range() to support the
I/O range registration with device's fwnode also. After this, the indirect-IO
devices can register the device-local I/O range to system logical I/O and
easily perform the translation between device-local I/O range and sytem
logical I/O range.

Signed-off-by: zhichang.yuan <yuanzhichang@xxxxxxxxxxxxx>
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 drivers/acpi/pci_root.c | 12 +++++-------
 drivers/of/address.c    |  8 ++------
 drivers/pci/pci.c       | 44 ++++++++++++++++++++++++++++++++++++++++----
 include/linux/pci.h     |  7 +++++--
 4 files changed, 52 insertions(+), 19 deletions(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index bf601d4..6cadf05 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -730,7 +730,8 @@ static void acpi_pci_root_validate_resources(struct device *dev,
 	}
 }

-static void acpi_pci_root_remap_iospace(struct resource_entry *entry)
+static void acpi_pci_root_remap_iospace(struct fwnode_handle *node,
+					struct resource_entry *entry)
 {
 #ifdef PCI_IOBASE
 	struct resource *res = entry->res;
@@ -739,11 +740,7 @@ static void acpi_pci_root_remap_iospace(struct resource_entry *entry)
 	resource_size_t length = resource_size(res);
 	unsigned long port;

-	if (pci_register_io_range(cpu_addr, length))
-		goto err;
-
-	port = pci_address_to_pio(cpu_addr);
-	if (port == (unsigned long)-1)
+	if (pci_register_io_range(node, cpu_addr, length, &port))
 		goto err;

 	res->start = port;
@@ -781,7 +778,8 @@ int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
 	else {
 		resource_list_for_each_entry_safe(entry, tmp, list) {
 			if (entry->res->flags & IORESOURCE_IO)
-				acpi_pci_root_remap_iospace(entry);
+				acpi_pci_root_remap_iospace(&device->fwnode,
+							    entry);

 			if (entry->res->flags & IORESOURCE_DISABLED)
 				resource_list_destroy_entry(entry);
diff --git a/drivers/of/address.c b/drivers/of/address.c
index 02b2903..d85d228 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -2,6 +2,7 @@
 #define pr_fmt(fmt)	"OF: " fmt

 #include <linux/device.h>
+#include <linux/fwnode.h>
 #include <linux/io.h>
 #include <linux/ioport.h>
 #include <linux/module.h>
@@ -323,14 +324,9 @@ int of_pci_range_to_resource(struct of_pci_range *range,

 	if (res->flags & IORESOURCE_IO) {
 		unsigned long port;
-		err = pci_register_io_range(range->cpu_addr, range->size);
+		err = pci_register_io_range(&np->fwnode, range->cpu_addr, range->size, &port);
 		if (err)
 			goto invalid_range;
-		port = pci_address_to_pio(range->cpu_addr);
-		if (port == (unsigned long)-1) {
-			err = -EINVAL;
-			goto invalid_range;
-		}
 		res->start = port;
 	} else {
 		if ((sizeof(resource_size_t) < 8) &&
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index a881c0d..5289221 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3241,6 +3241,7 @@ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
 #ifdef PCI_IOBASE
 struct io_range {
 	struct list_head list;
+	struct fwnode_handle *node;
 	phys_addr_t start;
 	resource_size_t size;
 };
@@ -3253,7 +3254,8 @@ struct io_range {
  * 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 __weak pci_register_io_range(struct fwnode_handle *node, phys_addr_t addr,
+				 resource_size_t size, unsigned long *port)
 {
 	int err = 0;

@@ -3261,10 +3263,31 @@ int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
 	struct io_range *range;
 	resource_size_t allocated_size = 0;

+	/*
+	 * As indirect-IO which support multiple bus instances is introduced,
+	 * the input 'addr' is probably not page-aligned. If the PCI I/O
+	 * ranges are registered after indirect-IO, there is risk that the
+	 * start logical PIO assigned to PCI I/O is not page-aligned.
+	 * This will cause some I/O subranges are not remapped or overlapped
+	 * in pci_remap_iospace() handling.
+	 */
+	WARN_ON(addr != IO_RANGE_IOEXT && !(addr & PAGE_MASK));
+	/*
+	 * MMIO will call ioremap, it is better to align size with PAGE_SIZE,
+	 * then the return linux virtual PIO is page-aligned.
+	 */
+	if (size & PAGE_MASK)
+		size = PAGE_ALIGN(size);
+
 	/* 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) {
+		if (node == range->node)
+			goto end_register;
+
+		if (addr != IO_RANGE_IOEXT &&
+		    addr >= range->start &&
+		    addr + size <= range->start + size) {
 			/* range already registered, bail out */
 			goto end_register;
 		}
@@ -3290,6 +3313,7 @@ int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
 		goto end_register;
 	}

+	range->node = node;
 	range->start = addr;
 	range->size = size;

@@ -3297,6 +3321,14 @@ int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)

 end_register:
 	spin_unlock(&io_range_lock);
+
+	*port = allocated_size;
+#else
+	/*
+	 * powerpc and microblaze have their own registration,
+	 * just look up the value here
+	 */
+	*port = pci_address_to_pio(addr);
 #endif

 	return err;
@@ -3315,7 +3347,9 @@ phys_addr_t pci_pio_to_address(unsigned long pio)

 	spin_lock(&io_range_lock);
 	list_for_each_entry(range, &io_range_list, list) {
-		if (pio >= allocated_size && pio < allocated_size + range->size) {
+		if (range->start != IO_RANGE_IOEXT &&
+			pio >= allocated_size &&
+			pio < allocated_size + range->size) {
 			address = range->start + pio - allocated_size;
 			break;
 		}
@@ -3336,7 +3370,9 @@ unsigned long __weak pci_address_to_pio(phys_addr_t address)

 	spin_lock(&io_range_lock);
 	list_for_each_entry(res, &io_range_list, list) {
-		if (address >= res->start && address < res->start + res->size) {
+		if (res->start != IO_RANGE_IOEXT &&
+			address >= res->start &&
+			address < res->start + res->size) {
 			addr = address - res->start + offset;
 			break;
 		}
diff --git a/include/linux/pci.h b/include/linux/pci.h
index e2d1a12..8d91af8 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -34,6 +34,9 @@

 #include <linux/pci_ids.h>

+/* the macro below flags an invalid cpu address
+ * and is used by IO special hosts              */
+#define IO_RANGE_IOEXT (resource_size_t)(-1ull)
 /*
  * The PCI interface treats multi-function devices as independent
  * devices.  The slot/function address of each device is encoded
@@ -1197,8 +1200,8 @@ int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
 						  resource_size_t),
 			void *alignf_data);

-
-int pci_register_io_range(phys_addr_t addr, resource_size_t size);
+int pci_register_io_range(struct fwnode_handle *node, phys_addr_t addr,
+			  resource_size_t size, unsigned long *port);
 unsigned long pci_address_to_pio(phys_addr_t addr);
 phys_addr_t pci_pio_to_address(unsigned long pio);
 int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr);






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