[PATCH 0/4] PCI legacy I/O port free driver (take5)

[PATCH 0/4] PCI legacy I/O port free driver (take5)

[Kenji Kaneshige]

Hi,

Here is an updated set of patches for PCI legacy I/O port free drivers,
which incorporate feedbacks. Summary of changes from the previous
version is as follows:

    - Use pci_enable_device_bars() approach instead of 'no_ioport'
      approach. Please see the header of patch 1/4 for specific.

    - Update Documentation/pci.txt

    - Changed e1000 driver to use pci_enable_device_bars() instead of
      'no_ioport'.

    - Changed lpfc driver to use pci_enable_device_bars() instead of
      'no_ioport'

Greg, could you consider applying those into your test tree?

Thanks,
Kenji Kaneshige

[PATCH 1/4] PCI legacy I/O port free driver (take5) - changes to generic PCI code

[Kenji Kaneshige]

This patch adds the following changes into generic PCI code especially
for PCI legacy free drivers.

    - Moved the following two things from pci_enable_device() into
      pci_enable_device_bars(). By this change, we can use
      pci_enable_device_bars() to enable only the specific regions.

          o Call pci_fixup_device() on the device
          o Set dev->is_enabled

    - Added new field 'bars_enabled' into struct pci_device to
      remember which BARs already enabled. This new field is
      initialized at pci_enable_device_bars() time and cleared
      at pci_disable_device() time.
 
    - Changed pci_request_regions()/pci_release_regions() to
      request/release only the regions which have already been
      enabled.

    - Added helper routine pci_select_bars() which makes proper mask
      of BARs from the specified resource type. This would be very
      helpful for users of pci_enable_device_bars().

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>

---
 drivers/pci/pci-driver.c |    3 ++-
 drivers/pci/pci.c        |   30 +++++++++++++++++++++++-------
 include/linux/pci.h      |   12 ++++++++++++
 3 files changed, 37 insertions(+), 8 deletions(-)

Index: linux-2.6.16-rc5-mm2/drivers/pci/pci-driver.c
===================================================================
--- linux-2.6.16-rc5-mm2.orig/drivers/pci/pci-driver.c	2006-03-07 13:45:33.000000000 +0900
+++ linux-2.6.16-rc5-mm2/drivers/pci/pci-driver.c	2006-03-07 13:45:39.000000000 +0900
@@ -294,7 +294,8 @@
 	pci_restore_state(pci_dev);
 	/* if the device was enabled before suspend, reenable */
 	if (pci_dev->is_enabled)
-		retval = pci_enable_device(pci_dev);
+		retval = pci_enable_device_bars(pci_dev,
+						pci_dev->bars_enabled);
 	/* if the device was busmaster before the suspend, make it busmaster again */
 	if (pci_dev->is_busmaster)
 		pci_set_master(pci_dev);
Index: linux-2.6.16-rc5-mm2/drivers/pci/pci.c
===================================================================
--- linux-2.6.16-rc5-mm2.orig/drivers/pci/pci.c	2006-03-07 13:45:33.000000000 +0900
+++ linux-2.6.16-rc5-mm2/drivers/pci/pci.c	2006-03-07 14:07:09.000000000 +0900
@@ -493,6 +493,9 @@
 	err = pcibios_enable_device(dev, bars);
 	if (err < 0)
 		return err;
+	pci_fixup_device(pci_fixup_enable, dev);
+	dev->is_enabled = 1;
+	dev->bars_enabled = bars;
 	return 0;
 }
 
@@ -510,8 +513,6 @@
 	int err = pci_enable_device_bars(dev, (1 << PCI_NUM_RESOURCES) - 1);
 	if (err)
 		return err;
-	pci_fixup_device(pci_fixup_enable, dev);
-	dev->is_enabled = 1;
 	return 0;
 }
 
@@ -546,6 +547,7 @@
 
 	pcibios_disable_device(dev);
 	dev->is_enabled = 0;
+	dev->bars_enabled = 0;
 }
 
 /**
@@ -628,6 +630,12 @@
 {
 	if (pci_resource_len(pdev, bar) == 0)
 		return;
+	if (!(pdev->bars_enabled & (1 << bar))) {
+		dev_warn(&pdev->dev,
+			 "Trying to release region #%d that is not enabled\n",
+			 bar + 1);
+		return;
+	}
 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
 		release_region(pci_resource_start(pdev, bar),
 				pci_resource_len(pdev, bar));
@@ -654,7 +662,12 @@
 {
 	if (pci_resource_len(pdev, bar) == 0)
 		return 0;
-		
+	if (!(pdev->bars_enabled & (1 << bar))) {
+		dev_warn(&pdev->dev,
+			 "Trying to request region #%d that is not enabled\n",
+			 bar + 1);
+		goto err_out;
+	}
 	if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
 		if (!request_region(pci_resource_start(pdev, bar),
 			    pci_resource_len(pdev, bar), res_name))
@@ -692,7 +705,8 @@
 	int i;
 	
 	for (i = 0; i < 6; i++)
-		pci_release_region(pdev, i);
+		if (pdev->bars_enabled & (1 << i))
+			pci_release_region(pdev, i);
 }
 
 /**
@@ -713,13 +727,15 @@
 	int i;
 	
 	for (i = 0; i < 6; i++)
-		if(pci_request_region(pdev, i, res_name))
-			goto err_out;
+		if (pdev->bars_enabled & (1 << i))
+			if(pci_request_region(pdev, i, res_name))
+				goto err_out;
 	return 0;
 
 err_out:
 	while(--i >= 0)
-		pci_release_region(pdev, i);
+		if (pdev->bars_enabled & (1 << i))
+			pci_release_region(pdev, i);
 		
 	return -EBUSY;
 }
Index: linux-2.6.16-rc5-mm2/include/linux/pci.h
===================================================================
--- linux-2.6.16-rc5-mm2.orig/include/linux/pci.h	2006-03-07 13:45:33.000000000 +0900
+++ linux-2.6.16-rc5-mm2/include/linux/pci.h	2006-03-07 13:45:39.000000000 +0900
@@ -169,6 +169,7 @@
 	struct bin_attribute *rom_attr; /* attribute descriptor for sysfs ROM entry */
 	int rom_attr_enabled;		/* has display of the rom attribute been enabled? */
 	struct bin_attribute *res_attr[DEVICE_COUNT_RESOURCE]; /* sysfs file for resources */
+	int	bars_enabled;		/* BARs enabled */
 };
 
 #define pci_dev_g(n) list_entry(n, struct pci_dev, global_list)
@@ -732,6 +733,17 @@
 }
 #endif /* HAVE_ARCH_PCI_RESOURCE_TO_USER */
 
+/*
+ * This helper routine makes bar mask from the type of resource.
+ */
+static inline int pci_select_bars(struct pci_dev *dev, unsigned long flags)
+{
+	int i, bars = 0;
+	for (i = 0; i < PCI_NUM_RESOURCES; i++)
+		if (pci_resource_flags(dev, i) & flags)
+			bars |= (1 << i);
+	return bars;
+}
 
 /*
  *  The world is not perfect and supplies us with broken PCI devices.

[PATCH 2/4] PCI legacy I/O port free driver (take5) - Update Documentation/pci.txt

[Kenji Kaneshige]

This patch adds the description about legacy I/O port free driver into
Documentation/pci.txt.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>

 Documentation/pci.txt |   67 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 67 insertions(+)

Index: linux-2.6.16-rc5-mm2/Documentation/pci.txt
===================================================================
--- linux-2.6.16-rc5-mm2.orig/Documentation/pci.txt	2006-03-07 14:06:50.000000000 +0900
+++ linux-2.6.16-rc5-mm2/Documentation/pci.txt	2006-03-07 14:07:21.000000000 +0900
@@ -269,3 +269,70 @@
 pci_find_device()		Superseded by pci_get_device()
 pci_find_subsys()		Superseded by pci_get_subsys()
 pci_find_slot()			Superseded by pci_get_slot()
+
+
+9. Legacy I/O port free driver
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Large servers may not be able to provide I/O port resources to all PCI
+devices. I/O Port space is only 64KB on Intel Architecture[1] and is
+likely also fragmented since the I/O base register of PCI-to-PCI
+bridge will usually be aligned to a 4KB boundary[2]. On such systems,
+pci_enable_device() and pci_request_regions() will fail when
+attempting to enable I/O Port regions that don't have I/O Port
+resources assigned.
+
+Fortunately, many PCI devices which request I/O Port resources also
+provide access to the same registers via MMIO BARs. These devices can
+be handled without using I/O port space and the drivers typically
+offer a CONFIG_ option to only use MMIO regions
+(e.g. CONFIG_TULIP_MMIO). PCI devices typically provide I/O port
+interface for legacy OSs and will work when I/O port resources are not
+assigned. The "PCI Local Bus Specification Revision 3.0" discusses
+this on p.44, "IMPLEMENTATION NOTE".
+
+If your PCI device driver doesn't need I/O port resources assigned to
+I/O Port BARs, you should use pci_enable_device_bars() instead of
+pci_enable_device() in order not to enable I/O port regions for the
+corresponding devices.
+
+[1] Some systems support 64KB I/O port space per PCI segment.
+[2] Some PCI-to-PCI bridges support optional 1KB aligned I/O base.
+
+
+10. MMIO Space and "Write Posting"
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Converting a driver from using I/O Port space to using MMIO space
+often requires some additional changes. Specifically, "write posting"
+needs to be handled. Most drivers (e.g. tg3, acenic, sym53c8xx_2)
+already do. I/O Port space guarantees write transactions reach the PCI
+device before the CPU can continue. Writes to MMIO space allow to CPU
+continue before the transaction reaches the PCI device. HW weenies
+call this "Write Posting" because the write completion is "posted" to
+the CPU before the transaction has reached it's destination.
+
+Thus, timing sensitive code should add readl() where the CPU is
+expected to wait before doing other work.  The classic "bit banging"
+sequence works fine for I/O Port space:
+
+	for (i=8; --i; val >>= 1) {
+		outb(val & 1, ioport_reg);	/* write bit */
+		udelay(10);
+	}
+
+The same sequence for MMIO space should be:
+
+	for (i=8; --i; val >>= 1) {
+		writeb(val & 1, mmio_reg);	/* write bit */
+		readb(safe_mmio_reg);		/* flush posted write */
+		udelay(10);
+	}
+
+It is important that "safe_mmio_reg" not have any side effects that
+interferes with the correct operation of the device.
+
+Another case to watch out for is when resetting a PCI device. Use PCI
+Configuration space reads to flush the writel(). This will gracefully
+handle the PCI master abort on all platforms if the PCI device is
+expected to not respond to a readl().  Most x86 platforms will allow
+MMIO reads to master abort (aka "Soft Fail") and return garbage
+(e.g. ~0). But many RISC platforms will crash (aka "Hard Fail").

[PATCH 3/4] PCI legacy I/O port free driver (take5) - Make Intel e1000 driver legacy I/O port free

[Kenji Kaneshige]

This patch makes Intel e1000 driver legacy I/O port free.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>

---
 drivers/net/e1000/e1000.h      |    6 +-
 drivers/net/e1000/e1000_main.c |  117 ++++++++++++++++++++++-------------------
 2 files changed, 68 insertions(+), 55 deletions(-)

Index: linux-2.6.16-rc5-mm2/drivers/net/e1000/e1000.h
===================================================================
--- linux-2.6.16-rc5-mm2.orig/drivers/net/e1000/e1000.h	2006-03-07 14:06:49.000000000 +0900
+++ linux-2.6.16-rc5-mm2/drivers/net/e1000/e1000.h	2006-03-07 14:07:21.000000000 +0900
@@ -77,8 +77,9 @@
 #define BAR_1		1
 #define BAR_5		5
 
-#define INTEL_E1000_ETHERNET_DEVICE(device_id) {\
-	PCI_DEVICE(PCI_VENDOR_ID_INTEL, device_id)}
+#define E1000_NO_IOPORT	(1 << 0)
+#define INTEL_E1000_ETHERNET_DEVICE(device_id, flags) {\
+	PCI_DEVICE(PCI_VENDOR_ID_INTEL, device_id), .driver_data = flags}
 
 struct e1000_adapter;
 
@@ -358,6 +359,7 @@
 #ifdef CONFIG_PCI_MSI
 	boolean_t have_msi;
 #endif
+	int bars;	/* BARs to be enabled */
 };
 
 
Index: linux-2.6.16-rc5-mm2/drivers/net/e1000/e1000_main.c
===================================================================
--- linux-2.6.16-rc5-mm2.orig/drivers/net/e1000/e1000_main.c	2006-03-07 14:06:49.000000000 +0900
+++ linux-2.6.16-rc5-mm2/drivers/net/e1000/e1000_main.c	2006-03-07 14:07:21.000000000 +0900
@@ -115,51 +115,51 @@
  *   {PCI_DEVICE(PCI_VENDOR_ID_INTEL, device_id)}
  */
 static struct pci_device_id e1000_pci_tbl[] = {
-	INTEL_E1000_ETHERNET_DEVICE(0x1000),
-	INTEL_E1000_ETHERNET_DEVICE(0x1001),
-	INTEL_E1000_ETHERNET_DEVICE(0x1004),
-	INTEL_E1000_ETHERNET_DEVICE(0x1008),
-	INTEL_E1000_ETHERNET_DEVICE(0x1009),
-	INTEL_E1000_ETHERNET_DEVICE(0x100C),
-	INTEL_E1000_ETHERNET_DEVICE(0x100D),
-	INTEL_E1000_ETHERNET_DEVICE(0x100E),
-	INTEL_E1000_ETHERNET_DEVICE(0x100F),
-	INTEL_E1000_ETHERNET_DEVICE(0x1010),
-	INTEL_E1000_ETHERNET_DEVICE(0x1011),
-	INTEL_E1000_ETHERNET_DEVICE(0x1012),
-	INTEL_E1000_ETHERNET_DEVICE(0x1013),
-	INTEL_E1000_ETHERNET_DEVICE(0x1014),
-	INTEL_E1000_ETHERNET_DEVICE(0x1015),
-	INTEL_E1000_ETHERNET_DEVICE(0x1016),
-	INTEL_E1000_ETHERNET_DEVICE(0x1017),
-	INTEL_E1000_ETHERNET_DEVICE(0x1018),
-	INTEL_E1000_ETHERNET_DEVICE(0x1019),
-	INTEL_E1000_ETHERNET_DEVICE(0x101A),
-	INTEL_E1000_ETHERNET_DEVICE(0x101D),
-	INTEL_E1000_ETHERNET_DEVICE(0x101E),
-	INTEL_E1000_ETHERNET_DEVICE(0x1026),
-	INTEL_E1000_ETHERNET_DEVICE(0x1027),
-	INTEL_E1000_ETHERNET_DEVICE(0x1028),
-	INTEL_E1000_ETHERNET_DEVICE(0x105E),
-	INTEL_E1000_ETHERNET_DEVICE(0x105F),
-	INTEL_E1000_ETHERNET_DEVICE(0x1060),
-	INTEL_E1000_ETHERNET_DEVICE(0x1075),
-	INTEL_E1000_ETHERNET_DEVICE(0x1076),
-	INTEL_E1000_ETHERNET_DEVICE(0x1077),
-	INTEL_E1000_ETHERNET_DEVICE(0x1078),
-	INTEL_E1000_ETHERNET_DEVICE(0x1079),
-	INTEL_E1000_ETHERNET_DEVICE(0x107A),
-	INTEL_E1000_ETHERNET_DEVICE(0x107B),
-	INTEL_E1000_ETHERNET_DEVICE(0x107C),
-	INTEL_E1000_ETHERNET_DEVICE(0x107D),
-	INTEL_E1000_ETHERNET_DEVICE(0x107E),
-	INTEL_E1000_ETHERNET_DEVICE(0x107F),
-	INTEL_E1000_ETHERNET_DEVICE(0x108A),
-	INTEL_E1000_ETHERNET_DEVICE(0x108B),
-	INTEL_E1000_ETHERNET_DEVICE(0x108C),
-	INTEL_E1000_ETHERNET_DEVICE(0x1099),
-	INTEL_E1000_ETHERNET_DEVICE(0x109A),
-	INTEL_E1000_ETHERNET_DEVICE(0x10B5),
+	INTEL_E1000_ETHERNET_DEVICE(0x1000, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x1001, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x1004, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x1008, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1009, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x100C, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x100D, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x100E, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x100F, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1010, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1011, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1012, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1013, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1014, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x1015, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1016, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1017, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1018, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1019, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x101A, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x101D, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x101E, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1026, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x1027, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x1028, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x105E, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x105F, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x1060, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x1075, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x1076, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1077, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1078, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x1079, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x107A, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x107B, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x107C, 0),
+	INTEL_E1000_ETHERNET_DEVICE(0x107D, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x107E, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x107F, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x108A, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x108B, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x108C, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x1099, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x109A, E1000_NO_IOPORT),
+	INTEL_E1000_ETHERNET_DEVICE(0x10B5, E1000_NO_IOPORT),
 	/* required last entry */
 	{0,}
 };
@@ -652,7 +652,14 @@
 	int i, err, pci_using_dac;
 	uint16_t eeprom_data;
 	uint16_t eeprom_apme_mask = E1000_EEPROM_APME;
-	if ((err = pci_enable_device(pdev)))
+	int bars;
+
+	if (ent->driver_data & E1000_NO_IOPORT)
+		bars = pci_select_bars(pdev, IORESOURCE_MEM);
+	else
+		bars = pci_select_bars(pdev, IORESOURCE_MEM | IORESOURCE_IO);
+
+	if ((err = pci_enable_device_bars(pdev, bars)))
 		return err;
 
 	if (!(err = pci_set_dma_mask(pdev, DMA_64BIT_MASK))) {
@@ -685,6 +692,7 @@
 	adapter->pdev = pdev;
 	adapter->hw.back = adapter;
 	adapter->msg_enable = (1 << debug) - 1;
+	adapter->bars = bars;
 
 	mmio_start = pci_resource_start(pdev, BAR_0);
 	mmio_len = pci_resource_len(pdev, BAR_0);
@@ -695,12 +703,15 @@
 		goto err_ioremap;
 	}
 
-	for (i = BAR_1; i <= BAR_5; i++) {
-		if (pci_resource_len(pdev, i) == 0)
-			continue;
-		if (pci_resource_flags(pdev, i) & IORESOURCE_IO) {
-			adapter->hw.io_base = pci_resource_start(pdev, i);
-			break;
+	if (!(ent->driver_data & E1000_NO_IOPORT)) {
+		for (i = BAR_1; i <= BAR_5; i++) {
+			if (pci_resource_len(pdev, i) == 0)
+				continue;
+			if (pci_resource_flags(pdev, i) & IORESOURCE_IO) {
+				adapter->hw.io_base =
+					pci_resource_start(pdev, i);
+				break;
+			}
 		}
 	}
 
@@ -4642,7 +4653,7 @@
 	if (retval)
 		DPRINTK(PROBE, ERR, "Error in setting power state\n");
 	e1000_pci_restore_state(adapter);
-	ret_val = pci_enable_device(pdev);
+	ret_val = pci_enable_device_bars(pdev, adapter->bars);
 	pci_set_master(pdev);
 
 	retval = pci_enable_wake(pdev, PCI_D3hot, 0);

[PATCH 4/4] PCI legacy I/O port free driver (take5) - Make Emulex lpfc driver legacy I/O port free

[Kenji Kaneshige]

This patch makes Emulex lpfc driver legacy I/O port free.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>

---
 drivers/scsi/lpfc/lpfc_init.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletion(-)

Index: linux-2.6.16-rc5-mm2/drivers/scsi/lpfc/lpfc_init.c
===================================================================
--- linux-2.6.16-rc5-mm2.orig/drivers/scsi/lpfc/lpfc_init.c	2006-03-07 14:06:48.000000000 +0900
+++ linux-2.6.16-rc5-mm2/drivers/scsi/lpfc/lpfc_init.c	2006-03-07 14:07:22.000000000 +0900
@@ -1391,8 +1391,9 @@
 	int error = -ENODEV, retval;
 	int i;
 	uint16_t iotag;
+	int bars = pci_select_bars(pdev, IORESOURCE_MEM);
 
-	if (pci_enable_device(pdev))
+	if (pci_enable_device_bars(pdev, bars))
 		goto out;
 	if (pci_request_regions(pdev, LPFC_DRIVER_NAME))
 		goto out_disable_device;