[PATCH] Fix PCI mmap on ppc and ppc64

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

Hi Andrew !

This patch was discussed at length on linux-pci and so far, the last
iteration of it didn't raise any comment. It's effect is a nop on
architecture that don't define the new pci_resource_to_user() callback
anyway. It allows architecture like ppc who put weird things inside of
PCI resource structures to convert to some different value for user
visible ones. It also fixes mmap'ing of IO space on those archs.

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	2005-05-06
15:39:24.000000000 +1000
+++ linux-work/arch/ppc64/kernel/pci.c	2005-05-09 12:00:54.000000000
+1000
@@ -351,9 +351,12 @@
 		*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;
+		printk("offset: %lx, io_base_virt: %p, pci_io_base: %lx, io_offset: %
lx\n",
+		       *offset, hose->io_base_virt, pci_io_base, io_offset);
 		*offset += io_offset;
 		res_bit = IORESOURCE_IO;
+		printk(" -> offset: %lx\n", *offset);
 	}
 
 	/*
@@ -373,12 +376,15 @@
 			continue;
 
 		/* In the range of this resource? */
+		printk(" r%d: %lx -> %lx\n", i, rp->start, rp->end);
 		if (*offset < (rp->start & PAGE_MASK) || *offset > rp->end)
 			continue;
 
 		/* found it! construct the final physical address */
-		if (mmap_state == pci_mmap_io)
-			*offset += hose->io_base_phys - io_offset;
+		if (mmap_state == pci_mmap_io) {
+		       	*offset += hose->io_base_phys - io_offset;
+			printk(" result: %lx\n", *offset);
+		}
 		return rp;
 	}
 
@@ -941,4 +947,22 @@
 }
 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	2005-05-05
15:56:37.000000000 +1000
+++ linux-work/drivers/pci/pci-sysfs.c	2005-05-09 12:00:54.000000000
+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);
 }
@@ -301,8 +304,21 @@
 						       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	2005-05-09 12:00:54.000000000
+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	2005-05-09 12:00:54.000000000 +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	2005-05-09 12:00:54.000000000 +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	2005-05-09 12:00:55.000000000 +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	2005-05-09 12:00:55.000000000 +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	2005-05-02 10:48:08.000000000
+1000
+++ linux-work/arch/ppc/kernel/pci.c	2005-05-09 12:00:55.000000000 +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;
 	}
 
@@ -1739,6 +1739,23 @@
 	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)


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