svn commit: r203528 - head/sys/dev/pci

[Alexander Motin]

Author: mav
Date: Fri Feb  5 17:18:48 2010
New Revision: 203528
URL: http://svn.freebsd.org/changeset/base/203528

Log:
  Add pci_get|set_max_read_req() helper functions to control maximum PCIe
  read request size.
  
  Reviewed by:	jhb@

Modified:
  head/sys/dev/pci/pci.c
  head/sys/dev/pci/pcivar.h

Modified: head/sys/dev/pci/pci.c
==============================================================================
--- head/sys/dev/pci/pci.c	Fri Feb  5 16:41:19 2010	(r203527)
+++ head/sys/dev/pci/pci.c	Fri Feb  5 17:18:48 2010	(r203528)
@@ -1626,6 +1626,40 @@ pci_ht_map_msi(device_t dev, uint64_t ad
 	}
 }
 
+int
+pci_get_max_read_req(device_t dev)
+{
+	int cap;
+	uint16_t val;
+
+	if (pci_find_extcap(dev, PCIY_EXPRESS, &cap) != 0)
+		return (0);
+	val = pci_read_config(dev, cap + PCIR_EXPRESS_DEVICE_CTL, 2);
+	val &= PCIM_EXP_CTL_MAX_READ_REQUEST;
+	val >>= 12;
+	return (1 << (val + 7));
+}
+
+int
+pci_set_max_read_req(device_t dev, int size)
+{
+	int cap;
+	uint16_t val;
+
+	if (pci_find_extcap(dev, PCIY_EXPRESS, &cap) != 0)
+		return (0);
+	if (size < 128)
+		size = 128;
+	if (size > 4096)
+		size = 4096;
+	size = (1 << (fls(size) - 1));
+	val = pci_read_config(dev, cap + PCIR_EXPRESS_DEVICE_CTL, 2);
+	val &= ~PCIM_EXP_CTL_MAX_READ_REQUEST;
+	val |= (fls(size) - 8) << 12;
+	pci_write_config(dev, cap + PCIR_EXPRESS_DEVICE_CTL, val, 2);
+	return (size);
+}
+
 /*
  * Support for MSI message signalled interrupts.
  */

Modified: head/sys/dev/pci/pcivar.h
==============================================================================
--- head/sys/dev/pci/pcivar.h	Fri Feb  5 16:41:19 2010	(r203527)
+++ head/sys/dev/pci/pcivar.h	Fri Feb  5 17:18:48 2010	(r203528)
@@ -458,6 +458,9 @@ int	pci_msi_device_blacklisted(device_t 
 
 void	pci_ht_map_msi(device_t dev, uint64_t addr);
 
+int	pci_get_max_read_req(device_t dev);
+int	pci_set_max_read_req(device_t dev, int size);
+
 #endif	/* _SYS_BUS_H_ */
 
 /*