Re: [PATCH] ppc/ppc64: Fix pci mmap via sysfs

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Sun, 2005-06-26 at 18:57 -0700, Andrew Morton wrote:
> Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
> >
> > Hi !
> > 
> > This implement the change to /proc and sysfs PCI mmap functions that we
> > discussed a while ago, that is adding an arch optional
> > pci_resource_to_user() to allow munging on the exposed value of PCI
> > resources to userland and thus hiding kernel internal values. It also
> > implements using of that callback to sanitize exposed values on ppc an
> > ppc64, thus fixing mmap of PCI devices via /proc and sysfs.
> > 
> 
> You sure you want all those printks in there?

One quilt ref later ... :)

Hi !

This implement the change to /proc and sysfs PCI mmap functions that we
discussed a while ago, that is adding an arch optional
pci_resource_to_user() to allow munging on the exposed value of PCI
resources to userland and thus hiding kernel internal values. It also
implements using of that callback to sanitize exposed values on ppc an
ppc64, thus fixing mmap of PCI devices via /proc and sysfs.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Index: linux-work/arch/ppc64/kernel/pci.c
===================================================================
--- linux-work.orig/arch/ppc64/kernel/pci.c	2005-06-25
09:22:56.000000000 +1000
+++ linux-work/arch/ppc64/kernel/pci.c	2005-06-27 12:09:58.000000000
+1000
@@ -351,7 +351,7 @@
 		*offset += hose->pci_mem_offset;
 		res_bit = IORESOURCE_MEM;
 	} else {
-		io_offset = (unsigned long)hose->io_base_virt;
+		io_offset = (unsigned long)hose->io_base_virt - pci_io_base;
 		*offset += io_offset;
 		res_bit = IORESOURCE_IO;
 	}
@@ -378,7 +378,7 @@
 
 		/* found it! construct the final physical address */
 		if (mmap_state == pci_mmap_io)
-			*offset += hose->io_base_phys - io_offset;
+		       	*offset += hose->io_base_phys - io_offset;
 		return rp;
 	}
 
@@ -416,9 +416,6 @@
 	else
 		prot |= _PAGE_GUARDED;
 
-	printk("PCI map for %s:%lx, prot: %lx\n", pci_name(dev), rp->start,
-	       prot);
-
 	return __pgprot(prot);
 }
 
@@ -944,4 +941,22 @@
 }
 EXPORT_SYMBOL(pci_read_irq_line);
 
+void pci_resource_to_user(const struct pci_dev *dev, int bar,
+			  const struct resource *rsrc,
+			  u64 *start, u64 *end)
+{
+	struct pci_controller *hose = pci_bus_to_host(dev->bus);
+	unsigned long offset = 0;
+
+	if (hose == NULL)
+		return;
+
+	if (rsrc->flags & IORESOURCE_IO)
+		offset = pci_io_base - (unsigned long)hose->io_base_virt +
+			hose->io_base_phys;
+
+	*start = rsrc->start + offset;
+	*end = rsrc->end + offset;
+}
+
 #endif /* CONFIG_PPC_MULTIPLATFORM */
Index: linux-work/drivers/pci/pci-sysfs.c
===================================================================
--- linux-work.orig/drivers/pci/pci-sysfs.c	2005-06-25
09:22:57.000000000 +1000
+++ linux-work/drivers/pci/pci-sysfs.c	2005-06-27 11:28:21.000000000
+1000
@@ -60,15 +60,18 @@
 	char * str = buf;
 	int i;
 	int max = 7;
+	u64 start, end;
 
 	if (pci_dev->subordinate)
 		max = DEVICE_COUNT_RESOURCE;
 
 	for (i = 0; i < max; i++) {
-		str += sprintf(str,"0x%016lx 0x%016lx 0x%016lx\n",
-			       pci_resource_start(pci_dev,i),
-			       pci_resource_end(pci_dev,i),
-			       pci_resource_flags(pci_dev,i));
+		struct resource *res =  &pci_dev->resource[i];
+		pci_resource_to_user(pci_dev, i, res, &start, &end);
+		str += sprintf(str,"0x%016llx 0x%016llx 0x%016llx\n",
+			       (unsigned long long)start,
+			       (unsigned long long)end,
+			       (unsigned long long)res->flags);
 	}
 	return (str - buf);
 }
@@ -313,8 +316,21 @@
 						       struct device, kobj));
 	struct resource *res = (struct resource *)attr->private;
 	enum pci_mmap_state mmap_type;
+	u64 start, end;
+	int i;
 
-	vma->vm_pgoff += res->start >> PAGE_SHIFT;
+	for (i = 0; i < PCI_ROM_RESOURCE; i++)
+		if (res == &pdev->resource[i])
+			break;
+	if (i >= PCI_ROM_RESOURCE)
+		return -ENODEV;
+
+	/* pci_mmap_page_range() expects the same kind of entry as coming
+	 * from /proc/bus/pci/ which is a "user visible" value. If this is
+	 * different from the resource itself, arch will do necessary fixup.
+	 */
+	pci_resource_to_user(pdev, i, res, &start, &end);
+	vma->vm_pgoff += start >> PAGE_SHIFT;
 	mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
 
 	return pci_mmap_page_range(pdev, vma, mmap_type, 0);
Index: linux-work/include/asm-ppc64/pci.h
===================================================================
--- linux-work.orig/include/asm-ppc64/pci.h	2005-05-02
10:50:01.000000000 +1000
+++ linux-work/include/asm-ppc64/pci.h	2005-06-27 11:28:21.000000000
+1000
@@ -135,6 +135,11 @@
 					 unsigned long offset,
 					 unsigned long size,
 					 pgprot_t prot);
+#define HAVE_ARCH_PCI_RESOURCE_TO_USER
+extern void pci_resource_to_user(const struct pci_dev *dev, int bar,
+				 const struct resource *rsrc,
+				 u64 *start, u64 *end);
+
 
 
 #endif	/* __KERNEL__ */
Index: linux-work/drivers/pci/proc.c
===================================================================
--- linux-work.orig/drivers/pci/proc.c	2005-05-05 15:56:37.000000000
+1000
+++ linux-work/drivers/pci/proc.c	2005-06-27 11:28:21.000000000 +1000
@@ -355,14 +355,20 @@
 			dev->device,
 			dev->irq);
 	/* Here should be 7 and not PCI_NUM_RESOURCES as we need to preserve
compatibility */
-	for(i=0; i<7; i++)
+	for(i=0; i<7; i++) {
+		u64 start, end;
+		pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
 		seq_printf(m, LONG_FORMAT,
-			dev->resource[i].start |
+			((unsigned long)start) |
 			(dev->resource[i].flags & PCI_REGION_FLAG_MASK));
-	for(i=0; i<7; i++)
+	}
+	for(i=0; i<7; i++) {
+		u64 start, end;
+		pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
 		seq_printf(m, LONG_FORMAT,
 			dev->resource[i].start < dev->resource[i].end ?
-			dev->resource[i].end - dev->resource[i].start + 1 : 0);
+			(unsigned long)(end - start) + 1 : 0);
+	}
 	seq_putc(m, '\t');
 	if (drv)
 		seq_printf(m, "%s", drv->name);
Index: linux-work/drivers/pci/pci.c
===================================================================
--- linux-work.orig/drivers/pci/pci.c	2005-05-05 15:56:37.000000000
+1000
+++ linux-work/drivers/pci/pci.c	2005-06-27 11:28:21.000000000 +1000
@@ -759,7 +759,7 @@
 	return 0;
 }
 #endif
-     
+
 static int __devinit pci_init(void)
 {
 	struct pci_dev *dev = NULL;
Index: linux-work/include/linux/pci.h
===================================================================
--- linux-work.orig/include/linux/pci.h	2005-05-05 15:56:38.000000000
+1000
+++ linux-work/include/linux/pci.h	2005-06-27 11:28:21.000000000 +1000
@@ -1016,6 +1016,21 @@
 #define pci_pretty_name(dev) ""
 #endif
 
+
+/* Some archs don't want to expose struct resource to userland as-is
+ * in sysfs and /proc
+ */
+#ifndef HAVE_ARCH_PCI_RESOURCE_TO_USER
+static void pci_resource_to_user(const struct pci_dev *dev, int bar,
+				 const struct resource *rsrc,
+				 u64 *start, u64 *end)
+{
+	*start = rsrc->start;
+	*end = rsrc->end;
+}
+#endif /* HAVE_ARCH_PCI_RESOURCE_TO_USER */
+
+
 /*
  *  The world is not perfect and supplies us with broken PCI devices.
  *  For at least a part of these bugs we need a work-around, so both
Index: linux-work/include/asm-ppc/pci.h
===================================================================
--- linux-work.orig/include/asm-ppc/pci.h	2005-05-02 10:49:57.000000000
+1000
+++ linux-work/include/asm-ppc/pci.h	2005-06-27 11:28:21.000000000 +1000
@@ -103,6 +103,12 @@
 					 unsigned long size,
 					 pgprot_t prot);
 
+#define HAVE_ARCH_PCI_RESOURCE_TO_USER
+extern void pci_resource_to_user(const struct pci_dev *dev, int bar,
+				 const struct resource *rsrc,
+				 u64 *start, u64 *end);
+
+
 #endif	/* __KERNEL__ */
 
 #endif /* __PPC_PCI_H */
Index: linux-work/arch/ppc/kernel/pci.c
===================================================================
--- linux-work.orig/arch/ppc/kernel/pci.c	2005-06-25 09:22:56.000000000
+1000
+++ linux-work/arch/ppc/kernel/pci.c	2005-06-27 12:09:30.000000000 +1000
@@ -1495,7 +1495,7 @@
 		*offset += hose->pci_mem_offset;
 		res_bit = IORESOURCE_MEM;
 	} else {
-		io_offset = (unsigned long)hose->io_base_virt;
+		io_offset = hose->io_base_virt - ___IO_BASE;
 		*offset += io_offset;
 		res_bit = IORESOURCE_IO;
 	}
@@ -1522,7 +1522,7 @@
 
 		/* found it! construct the final physical address */
 		if (mmap_state == pci_mmap_io)
-			*offset += hose->io_base_phys - _IO_BASE;
+			*offset += hose->io_base_phys - io_offset;
 		return rp;
 	}
 
@@ -1560,9 +1560,6 @@
 	else
 		prot |= _PAGE_GUARDED;
 
-	printk("PCI map for %s:%lx, prot: %lx\n", pci_name(dev), rp->start,
-	       prot);
-
 	return __pgprot(prot);
 }
 
@@ -1739,6 +1736,23 @@
 	return result;
 }
 
+void pci_resource_to_user(const struct pci_dev *dev, int bar,
+			  const struct resource *rsrc,
+			  u64 *start, u64 *end)
+{
+	struct pci_controller *hose = pci_bus_to_hose(dev->bus->number);
+	unsigned long offset = 0;
+
+	if (hose == NULL)
+		return;
+
+	if (rsrc->flags & IORESOURCE_IO)
+		offset = ___IO_BASE - hose->io_base_virt + hose->io_base_phys;
+
+	*start = rsrc->start + offset;
+	*end = rsrc->end + offset;
+}
+
 void __init
 pci_init_resource(struct resource *res, unsigned long start, unsigned
long end,
 		  int flags, char *name)