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[Xen-changelog] Fix mmapping of PCI resources from userspace.



# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID 1184286a2ee6c8a8d7e564bc533941e702d54ebb
# Parent  9c9a3bb878c2c1c9cc932cbc90335ad701b0e009
Fix mmapping of PCI resources from userspace.

Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>

diff -r 9c9a3bb878c2 -r 1184286a2ee6 
linux-2.6-xen-sparse/arch/xen/i386/pci/Makefile
--- a/linux-2.6-xen-sparse/arch/xen/i386/pci/Makefile   Wed Sep 14 17:06:37 2005
+++ b/linux-2.6-xen-sparse/arch/xen/i386/pci/Makefile   Wed Sep 14 17:54:43 2005
@@ -2,7 +2,7 @@
 
 CFLAGS += -Iarch/$(XENARCH)/pci
 
-c-obj-y                                := i386.o
+obj-y                          := i386.o
 
 #c-obj-$(CONFIG_PCI_BIOS)              += pcbios.o
 c-obj-$(CONFIG_PCI_MMCONFIG)   += mmconfig.o
diff -r 9c9a3bb878c2 -r 1184286a2ee6 
linux-2.6-xen-sparse/arch/xen/kernel/devmem.c
--- a/linux-2.6-xen-sparse/arch/xen/kernel/devmem.c     Wed Sep 14 17:06:37 2005
+++ b/linux-2.6-xen-sparse/arch/xen/kernel/devmem.c     Wed Sep 14 17:54:43 2005
@@ -27,7 +27,7 @@
 #include <asm/uaccess.h>
 #include <asm/io.h>
 
-static inline int uncached_access(struct file *file, unsigned long addr)
+static inline int uncached_access(struct file *file)
 {
         if (file->f_flags & O_SYNC)
                 return 1;
@@ -90,10 +90,9 @@
 
 static int mmap_mem(struct file * file, struct vm_area_struct * vma)
 {
-       unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
        int uncached;
 
-       uncached = uncached_access(file, offset);
+       uncached = uncached_access(file);
        if (uncached)
                vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
@@ -106,8 +105,9 @@
        if (uncached)
                vma->vm_flags |= VM_IO;
 
-       if (io_remap_page_range(vma, vma->vm_start, offset, 
-                               vma->vm_end-vma->vm_start, vma->vm_page_prot))
+       if (direct_remap_pfn_range(vma->vm_mm, vma->vm_start, vma->vm_pgoff,
+                                  vma->vm_end - vma->vm_start,
+                                  vma->vm_page_prot, DOMID_IO))
                return -EAGAIN;
 
        return 0;
diff -r 9c9a3bb878c2 -r 1184286a2ee6 
linux-2.6-xen-sparse/arch/xen/x86_64/pci/Makefile
--- a/linux-2.6-xen-sparse/arch/xen/x86_64/pci/Makefile Wed Sep 14 17:06:37 2005
+++ b/linux-2.6-xen-sparse/arch/xen/x86_64/pci/Makefile Wed Sep 14 17:54:43 2005
@@ -8,7 +8,7 @@
 
 CFLAGS += -Iarch/i386/pci
 
-c-i386-obj-y           := i386.o
+c-xen-obj-y            := i386.o
 c-i386-obj-y           += fixup.o
 c-i386-obj-$(CONFIG_ACPI_PCI)  += acpi.o
 c-i386-obj-y                   += legacy.o common.o
diff -r 9c9a3bb878c2 -r 1184286a2ee6 
linux-2.6-xen-sparse/arch/xen/i386/pci/i386.c
--- /dev/null   Wed Sep 14 17:06:37 2005
+++ b/linux-2.6-xen-sparse/arch/xen/i386/pci/i386.c     Wed Sep 14 17:54:43 2005
@@ -0,0 +1,304 @@
+/*
+ *     Low-Level PCI Access for i386 machines
+ *
+ * Copyright 1993, 1994 Drew Eckhardt
+ *      Visionary Computing
+ *      (Unix and Linux consulting and custom programming)
+ *      Drew@xxxxxxxxxxxx
+ *      +1 (303) 786-7975
+ *
+ * Drew's work was sponsored by:
+ *     iX Multiuser Multitasking Magazine
+ *     Hannover, Germany
+ *     hm@xxxxx
+ *
+ * Copyright 1997--2000 Martin Mares <mj@xxxxxx>
+ *
+ * For more information, please consult the following manuals (look at
+ * http://www.pcisig.com/ for how to get them):
+ *
+ * PCI BIOS Specification
+ * PCI Local Bus Specification
+ * PCI to PCI Bridge Specification
+ * PCI System Design Guide
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/errno.h>
+
+#include "pci.h"
+
+/*
+ * We need to avoid collisions with `mirrored' VGA ports
+ * and other strange ISA hardware, so we always want the
+ * addresses to be allocated in the 0x000-0x0ff region
+ * modulo 0x400.
+ *
+ * Why? Because some silly external IO cards only decode
+ * the low 10 bits of the IO address. The 0x00-0xff region
+ * is reserved for motherboard devices that decode all 16
+ * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
+ * but we want to try to avoid allocating at 0x2900-0x2bff
+ * which might have be mirrored at 0x0100-0x03ff..
+ */
+void
+pcibios_align_resource(void *data, struct resource *res,
+                      unsigned long size, unsigned long align)
+{
+       if (res->flags & IORESOURCE_IO) {
+               unsigned long start = res->start;
+
+               if (start & 0x300) {
+                       start = (start + 0x3ff) & ~0x3ff;
+                       res->start = start;
+               }
+       }
+}
+
+
+/*
+ *  Handle resources of PCI devices.  If the world were perfect, we could
+ *  just allocate all the resource regions and do nothing more.  It isn't.
+ *  On the other hand, we cannot just re-allocate all devices, as it would
+ *  require us to know lots of host bridge internals.  So we attempt to
+ *  keep as much of the original configuration as possible, but tweak it
+ *  when it's found to be wrong.
+ *
+ *  Known BIOS problems we have to work around:
+ *     - I/O or memory regions not configured
+ *     - regions configured, but not enabled in the command register
+ *     - bogus I/O addresses above 64K used
+ *     - expansion ROMs left enabled (this may sound harmless, but given
+ *       the fact the PCI specs explicitly allow address decoders to be
+ *       shared between expansion ROMs and other resource regions, it's
+ *       at least dangerous)
+ *
+ *  Our solution:
+ *     (1) Allocate resources for all buses behind PCI-to-PCI bridges.
+ *         This gives us fixed barriers on where we can allocate.
+ *     (2) Allocate resources for all enabled devices.  If there is
+ *         a collision, just mark the resource as unallocated. Also
+ *         disable expansion ROMs during this step.
+ *     (3) Try to allocate resources for disabled devices.  If the
+ *         resources were assigned correctly, everything goes well,
+ *         if they weren't, they won't disturb allocation of other
+ *         resources.
+ *     (4) Assign new addresses to resources which were either
+ *         not configured at all or misconfigured.  If explicitly
+ *         requested by the user, configure expansion ROM address
+ *         as well.
+ */
+
+static void __init pcibios_allocate_bus_resources(struct list_head *bus_list)
+{
+       struct pci_bus *bus;
+       struct pci_dev *dev;
+       int idx;
+       struct resource *r, *pr;
+
+       /* Depth-First Search on bus tree */
+       list_for_each_entry(bus, bus_list, node) {
+               if ((dev = bus->self)) {
+                       for (idx = PCI_BRIDGE_RESOURCES; idx < 
PCI_NUM_RESOURCES; idx++) {
+                               r = &dev->resource[idx];
+                               if (!r->start)
+                                       continue;
+                               pr = pci_find_parent_resource(dev, r);
+                               if (!pr || request_resource(pr, r) < 0)
+                                       printk(KERN_ERR "PCI: Cannot allocate 
resource region %d of bridge %s\n", idx, pci_name(dev));
+                       }
+               }
+               pcibios_allocate_bus_resources(&bus->children);
+       }
+}
+
+static void __init pcibios_allocate_resources(int pass)
+{
+       struct pci_dev *dev = NULL;
+       int idx, disabled;
+       u16 command;
+       struct resource *r, *pr;
+
+       for_each_pci_dev(dev) {
+               pci_read_config_word(dev, PCI_COMMAND, &command);
+               for(idx = 0; idx < 6; idx++) {
+                       r = &dev->resource[idx];
+                       if (r->parent)          /* Already allocated */
+                               continue;
+                       if (!r->start)          /* Address not assigned at all 
*/
+                               continue;
+                       if (r->flags & IORESOURCE_IO)
+                               disabled = !(command & PCI_COMMAND_IO);
+                       else
+                               disabled = !(command & PCI_COMMAND_MEMORY);
+                       if (pass == disabled) {
+                               DBG("PCI: Resource %08lx-%08lx (f=%lx, d=%d, 
p=%d)\n",
+                                   r->start, r->end, r->flags, disabled, pass);
+                               pr = pci_find_parent_resource(dev, r);
+                               if (!pr || request_resource(pr, r) < 0) {
+                                       printk(KERN_ERR "PCI: Cannot allocate 
resource region %d of device %s\n", idx, pci_name(dev));
+                                       /* We'll assign a new address later */
+                                       r->end -= r->start;
+                                       r->start = 0;
+                               }
+                       }
+               }
+               if (!pass) {
+                       r = &dev->resource[PCI_ROM_RESOURCE];
+                       if (r->flags & IORESOURCE_ROM_ENABLE) {
+                               /* Turn the ROM off, leave the resource region, 
but keep it unregistered. */
+                               u32 reg;
+                               DBG("PCI: Switching off ROM of %s\n", 
pci_name(dev));
+                               r->flags &= ~IORESOURCE_ROM_ENABLE;
+                               pci_read_config_dword(dev, dev->rom_base_reg, 
&reg);
+                               pci_write_config_dword(dev, dev->rom_base_reg, 
reg & ~PCI_ROM_ADDRESS_ENABLE);
+                       }
+               }
+       }
+}
+
+static int __init pcibios_assign_resources(void)
+{
+       struct pci_dev *dev = NULL;
+       int idx;
+       struct resource *r;
+
+       for_each_pci_dev(dev) {
+               int class = dev->class >> 8;
+
+               /* Don't touch classless devices and host bridges */
+               if (!class || class == PCI_CLASS_BRIDGE_HOST)
+                       continue;
+
+               for(idx=0; idx<6; idx++) {
+                       r = &dev->resource[idx];
+
+                       /*
+                        *  Don't touch IDE controllers and I/O ports of video 
cards!
+                        */
+                       if ((class == PCI_CLASS_STORAGE_IDE && idx < 4) ||
+                           (class == PCI_CLASS_DISPLAY_VGA && (r->flags & 
IORESOURCE_IO)))
+                               continue;
+
+                       /*
+                        *  We shall assign a new address to this resource, 
either because
+                        *  the BIOS forgot to do so or because we have decided 
the old
+                        *  address was unusable for some reason.
+                        */
+                       if (!r->start && r->end)
+                               pci_assign_resource(dev, idx);
+               }
+
+               if (pci_probe & PCI_ASSIGN_ROMS) {
+                       r = &dev->resource[PCI_ROM_RESOURCE];
+                       r->end -= r->start;
+                       r->start = 0;
+                       if (r->end)
+                               pci_assign_resource(dev, PCI_ROM_RESOURCE);
+               }
+       }
+       return 0;
+}
+
+void __init pcibios_resource_survey(void)
+{
+       DBG("PCI: Allocating resources\n");
+       pcibios_allocate_bus_resources(&pci_root_buses);
+       pcibios_allocate_resources(0);
+       pcibios_allocate_resources(1);
+}
+
+/**
+ * called in fs_initcall (one below subsys_initcall),
+ * give a chance for motherboard reserve resources
+ */
+fs_initcall(pcibios_assign_resources);
+
+int pcibios_enable_resources(struct pci_dev *dev, int mask)
+{
+       u16 cmd, old_cmd;
+       int idx;
+       struct resource *r;
+
+       pci_read_config_word(dev, PCI_COMMAND, &cmd);
+       old_cmd = cmd;
+       for(idx=0; idx<6; idx++) {
+               /* Only set up the requested stuff */
+               if (!(mask & (1<<idx)))
+                       continue;
+
+               r = &dev->resource[idx];
+               if (!r->start && r->end) {
+                       printk(KERN_ERR "PCI: Device %s not available because 
of resource collisions\n", pci_name(dev));
+                       return -EINVAL;
+               }
+               if (r->flags & IORESOURCE_IO)
+                       cmd |= PCI_COMMAND_IO;
+               if (r->flags & IORESOURCE_MEM)
+                       cmd |= PCI_COMMAND_MEMORY;
+       }
+       if (dev->resource[PCI_ROM_RESOURCE].start)
+               cmd |= PCI_COMMAND_MEMORY;
+       if (cmd != old_cmd) {
+               printk("PCI: Enabling device %s (%04x -> %04x)\n", 
pci_name(dev), old_cmd, cmd);
+               pci_write_config_word(dev, PCI_COMMAND, cmd);
+       }
+       return 0;
+}
+
+/*
+ *  If we set up a device for bus mastering, we need to check the latency
+ *  timer as certain crappy BIOSes forget to set it properly.
+ */
+unsigned int pcibios_max_latency = 255;
+
+void pcibios_set_master(struct pci_dev *dev)
+{
+       u8 lat;
+       pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
+       if (lat < 16)
+               lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
+       else if (lat > pcibios_max_latency)
+               lat = pcibios_max_latency;
+       else
+               return;
+       printk(KERN_DEBUG "PCI: Setting latency timer of device %s to %d\n", 
pci_name(dev), lat);
+       pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
+}
+
+int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
+                       enum pci_mmap_state mmap_state, int write_combine)
+{
+       unsigned long prot;
+
+       /* I/O space cannot be accessed via normal processor loads and
+        * stores on this platform.
+        */
+       if (mmap_state == pci_mmap_io)
+               return -EINVAL;
+
+       /* Leave vm_pgoff as-is, the PCI space address is the physical
+        * address on this platform.
+        */
+       vma->vm_flags |= (VM_SHM | VM_LOCKED | VM_IO);
+
+       prot = pgprot_val(vma->vm_page_prot);
+       if (boot_cpu_data.x86 > 3)
+               prot |= _PAGE_PCD | _PAGE_PWT;
+       vma->vm_page_prot = __pgprot(prot);
+
+       /* Write-combine setting is ignored, it is changed via the mtrr
+        * interfaces on this platform.
+        */
+       if (direct_remap_pfn_range(vma->vm_mm, vma->vm_start, vma->vm_pgoff,
+                                  vma->vm_end - vma->vm_start,
+                                  vma->vm_page_prot, DOMID_IO))
+               return -EAGAIN;
+
+       return 0;
+}

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