Commit 10a0ef39 authored by Ivan Kokshaysky's avatar Ivan Kokshaysky Committed by Jesse Barnes
Browse files

PCI/alpha: pci sysfs resources 

This closes http://bugzilla.kernel.org/show_bug.cgi?id=10893


which is a showstopper for X development on alpha.

The generic HAVE_PCI_MMAP code (drivers/pci-sysfs.c) is not
very useful since we have to deal with three different types
of MMIO address spaces: sparse and dense mappings for old
ev4/ev5 machines and "normal" 1:1 MMIO space (bwx) for ev56 and
later.
Also "write combine" mappings are meaningless on alpha - roughly
speaking, alpha does write combining, IO reordering and other
optimizations by default, unless user splits IO accesses
with memory barriers.

I think the cleanest way to deal with resource files on alpha
is to convert the default no-op pci_create_resource_files() and
pci_remove_resource_files() for !HAVE_PCI_MMAP case into __weak
functions and override them with alpha specific ones.

Another alpha hook is needed for "legacy_" resource files
to handle sparse addressing (pci_adjust_legacy_attr).

With the "standard" resourceN files on ev56/ev6 libpciaccess
works "out of the box". Handling of resourceN_sparse/resourceN_dense
files on older machines obviously requires some userland work.

Sparse/dense stuff has been tested on sx164 (pca56/pyxis, normally
uses bwx IO) with the kernel hacked into "cia compatible" mode.

Signed-off-by: default avatarIvan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent ea741551

arch/alpha/include/asm/pci.h

+14 −0
Original line number Diff line number Diff line
@@ -273,4 +273,18 @@ struct pci_dev *alpha_gendev_to_pci(struct device *dev); 


extern struct pci_dev *isa_bridge;



extern int pci_legacy_read(struct pci_bus *bus, loff_t port, u32 *val,

			   size_t count);

extern int pci_legacy_write(struct pci_bus *bus, loff_t port, u32 val,

			    size_t count);

extern int pci_mmap_legacy_page_range(struct pci_bus *bus,

				      struct vm_area_struct *vma,

				      enum pci_mmap_state mmap_state);

extern void pci_adjust_legacy_attr(struct pci_bus *bus,

				   enum pci_mmap_state mmap_type);

#define HAVE_PCI_LEGACY	1



extern int pci_create_resource_files(struct pci_dev *dev);

extern void pci_remove_resource_files(struct pci_dev *dev);



#endif /* __ALPHA_PCI_H */

arch/alpha/kernel/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ obj-y := entry.o traps.o process.o init_task.o osf_sys.o irq.o \ 


obj-$(CONFIG_VGA_HOSE)	+= console.o

obj-$(CONFIG_SMP)	+= smp.o

obj-$(CONFIG_PCI)	+= pci.o pci_iommu.o

obj-$(CONFIG_PCI)	+= pci.o pci_iommu.o pci-sysfs.o

obj-$(CONFIG_SRM_ENV)	+= srm_env.o

obj-$(CONFIG_MODULES)	+= module.o

arch/alpha/kernel/pci-sysfs.c

0 → 100644
+366 −0
Original line number Diff line number Diff line 
/*

 * arch/alpha/kernel/pci-sysfs.c

 *

 * Copyright (C) 2009 Ivan Kokshaysky

 *

 * Alpha PCI resource files.

 *

 * Loosely based on generic HAVE_PCI_MMAP implementation in

 * drivers/pci/pci-sysfs.c

 */



#include <linux/sched.h>

#include <linux/pci.h>



static int hose_mmap_page_range(struct pci_controller *hose,

				struct vm_area_struct *vma,

				enum pci_mmap_state mmap_type, int sparse)

{

	unsigned long base;



	if (mmap_type == pci_mmap_mem)

		base = sparse ? hose->sparse_mem_base : hose->dense_mem_base;

	else

		base = sparse ? hose->sparse_io_base : hose->dense_io_base;



	vma->vm_pgoff += base >> PAGE_SHIFT;

	vma->vm_flags |= (VM_IO | VM_RESERVED);



	return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,

				  vma->vm_end - vma->vm_start,

				  vma->vm_page_prot);

}



static int __pci_mmap_fits(struct pci_dev *pdev, int num,

			   struct vm_area_struct *vma, int sparse)

{

	unsigned long nr, start, size;

	int shift = sparse ? 5 : 0;



	nr = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;

	start = vma->vm_pgoff;

	size = ((pci_resource_len(pdev, num) - 1) >> (PAGE_SHIFT - shift)) + 1;



	if (start < size && size - start >= nr)

		return 1;

	WARN(1, "process \"%s\" tried to map%s 0x%08lx-0x%08lx on %s BAR %d "

		"(size 0x%08lx)\n",

		current->comm, sparse ? " sparse" : "", start, start + nr,

		pci_name(pdev), num, size);

	return 0;

}



/**

 * pci_mmap_resource - map a PCI resource into user memory space

 * @kobj: kobject for mapping

 * @attr: struct bin_attribute for the file being mapped

 * @vma: struct vm_area_struct passed into the mmap

 * @sparse: address space type

 *

 * Use the bus mapping routines to map a PCI resource into userspace.

 */

static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,

			     struct vm_area_struct *vma, int sparse)

{

	struct pci_dev *pdev = to_pci_dev(container_of(kobj,

						       struct device, kobj));

	struct resource *res = (struct resource *)attr->private;

	enum pci_mmap_state mmap_type;

	struct pci_bus_region bar;

	int i;



	for (i = 0; i < PCI_ROM_RESOURCE; i++)

		if (res == &pdev->resource[i])

			break;

	if (i >= PCI_ROM_RESOURCE)

		return -ENODEV;



	if (!__pci_mmap_fits(pdev, i, vma, sparse))

		return -EINVAL;



	if (iomem_is_exclusive(res->start))

		return -EINVAL;



	pcibios_resource_to_bus(pdev, &bar, res);

	vma->vm_pgoff += bar.start >> (PAGE_SHIFT - (sparse ? 5 : 0));

	mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;



	return hose_mmap_page_range(pdev->sysdata, vma, mmap_type, sparse);

}



static int pci_mmap_resource_sparse(struct kobject *kobj,

				    struct bin_attribute *attr,

				    struct vm_area_struct *vma)

{

	return pci_mmap_resource(kobj, attr, vma, 1);

}



static int pci_mmap_resource_dense(struct kobject *kobj,

				   struct bin_attribute *attr,

				   struct vm_area_struct *vma)

{

	return pci_mmap_resource(kobj, attr, vma, 0);

}



/**

 * pci_remove_resource_files - cleanup resource files

 * @dev: dev to cleanup

 *

 * If we created resource files for @dev, remove them from sysfs and

 * free their resources.

 */

void pci_remove_resource_files(struct pci_dev *pdev)

{

	int i;



	for (i = 0; i < PCI_ROM_RESOURCE; i++) {

		struct bin_attribute *res_attr;



		res_attr = pdev->res_attr[i];

		if (res_attr) {

			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);

			kfree(res_attr);

		}



		res_attr = pdev->res_attr_wc[i];

		if (res_attr) {

			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);

			kfree(res_attr);

		}

	}

}



static int sparse_mem_mmap_fits(struct pci_dev *pdev, int num)

{

	struct pci_bus_region bar;

	struct pci_controller *hose = pdev->sysdata;

	long dense_offset;

	unsigned long sparse_size;



	pcibios_resource_to_bus(pdev, &bar, &pdev->resource[num]);



	/* All core logic chips have 4G sparse address space, except

	   CIA which has 16G (see xxx_SPARSE_MEM and xxx_DENSE_MEM

	   definitions in asm/core_xxx.h files). This corresponds

	   to 128M or 512M of the bus space. */

	dense_offset = (long)(hose->dense_mem_base - hose->sparse_mem_base);

	sparse_size = dense_offset >= 0x400000000UL ? 0x20000000 : 0x8000000;



	return bar.end < sparse_size;

}



static int pci_create_one_attr(struct pci_dev *pdev, int num, char *name,

			       char *suffix, struct bin_attribute *res_attr,

			       unsigned long sparse)

{

	size_t size = pci_resource_len(pdev, num);



	sprintf(name, "resource%d%s", num, suffix);

	res_attr->mmap = sparse ? pci_mmap_resource_sparse :

				  pci_mmap_resource_dense;

	res_attr->attr.name = name;

	res_attr->attr.mode = S_IRUSR | S_IWUSR;

	res_attr->size = sparse ? size << 5 : size;

	res_attr->private = &pdev->resource[num];

	return sysfs_create_bin_file(&pdev->dev.kobj, res_attr);

}



static int pci_create_attr(struct pci_dev *pdev, int num)

{

	/* allocate attribute structure, piggyback attribute name */

	int retval, nlen1, nlen2 = 0, res_count = 1;

	unsigned long sparse_base, dense_base;

	struct bin_attribute *attr;

	struct pci_controller *hose = pdev->sysdata;

	char *suffix, *attr_name;



	suffix = "";	/* Assume bwx machine, normal resourceN files. */

	nlen1 = 10;



	if (pdev->resource[num].flags & IORESOURCE_MEM) {

		sparse_base = hose->sparse_mem_base;

		dense_base = hose->dense_mem_base;

		if (sparse_base && !sparse_mem_mmap_fits(pdev, num)) {

			sparse_base = 0;

			suffix = "_dense";

			nlen1 = 16;	/* resourceN_dense */

		}

	} else {

		sparse_base = hose->sparse_io_base;

		dense_base = hose->dense_io_base;

	}



	if (sparse_base) {

		suffix = "_sparse";

		nlen1 = 17;

		if (dense_base) {

			nlen2 = 16;	/* resourceN_dense */

			res_count = 2;

		}

	}



	attr = kzalloc(sizeof(*attr) * res_count + nlen1 + nlen2, GFP_ATOMIC);

	if (!attr)

		return -ENOMEM;



	/* Create bwx, sparse or single dense file */

	attr_name = (char *)(attr + res_count);

	pdev->res_attr[num] = attr;

	retval = pci_create_one_attr(pdev, num, attr_name, suffix, attr,

				     sparse_base);

	if (retval || res_count == 1)

		return retval;



	/* Create dense file */

	attr_name += nlen1;

	attr++;

	pdev->res_attr_wc[num] = attr;

	return pci_create_one_attr(pdev, num, attr_name, "_dense", attr, 0);

}



/**

 * pci_create_resource_files - create resource files in sysfs for @dev

 * @dev: dev in question

 *

 * Walk the resources in @dev creating files for each resource available.

 */

int pci_create_resource_files(struct pci_dev *pdev)

{

	int i;

	int retval;



	/* Expose the PCI resources from this device as files */

	for (i = 0; i < PCI_ROM_RESOURCE; i++) {



		/* skip empty resources */

		if (!pci_resource_len(pdev, i))

			continue;



		retval = pci_create_attr(pdev, i);

		if (retval) {

			pci_remove_resource_files(pdev);

			return retval;

		}

	}

	return 0;

}



/* Legacy I/O bus mapping stuff. */



static int __legacy_mmap_fits(struct pci_controller *hose,

			      struct vm_area_struct *vma,

			      unsigned long res_size, int sparse)

{

	unsigned long nr, start, size;



	nr = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;

	start = vma->vm_pgoff;

	size = ((res_size - 1) >> PAGE_SHIFT) + 1;



	if (start < size && size - start >= nr)

		return 1;

	WARN(1, "process \"%s\" tried to map%s 0x%08lx-0x%08lx on hose %d "

		"(size 0x%08lx)\n",

		current->comm, sparse ? " sparse" : "", start, start + nr,

		hose->index, size);

	return 0;

}



static inline int has_sparse(struct pci_controller *hose,

			     enum pci_mmap_state mmap_type)

{

	unsigned long base;



	base = (mmap_type == pci_mmap_mem) ? hose->sparse_mem_base :

					     hose->sparse_io_base;



	return base != 0;

}



int pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma,

			       enum pci_mmap_state mmap_type)

{

	struct pci_controller *hose = bus->sysdata;

	int sparse = has_sparse(hose, mmap_type);

	unsigned long res_size;



	res_size = (mmap_type == pci_mmap_mem) ? bus->legacy_mem->size :

						 bus->legacy_io->size;

	if (!__legacy_mmap_fits(hose, vma, res_size, sparse))

		return -EINVAL;



	return hose_mmap_page_range(hose, vma, mmap_type, sparse);

}



/**

 * pci_adjust_legacy_attr - adjustment of legacy file attributes

 * @b: bus to create files under

 * @mmap_type: I/O port or memory

 *

 * Adjust file name and size for sparse mappings.

 */

void pci_adjust_legacy_attr(struct pci_bus *bus, enum pci_mmap_state mmap_type)

{

	struct pci_controller *hose = bus->sysdata;



	if (!has_sparse(hose, mmap_type))

		return;



	if (mmap_type == pci_mmap_mem) {

		bus->legacy_mem->attr.name = "legacy_mem_sparse";

		bus->legacy_mem->size <<= 5;

	} else {

		bus->legacy_io->attr.name = "legacy_io_sparse";

		bus->legacy_io->size <<= 5;

	}

	return;

}



/* Legacy I/O bus read/write functions */

int pci_legacy_read(struct pci_bus *bus, loff_t port, u32 *val, size_t size)

{

	struct pci_controller *hose = bus->sysdata;



	port += hose->io_space->start;



	switch(size) {

	case 1:

		*((u8 *)val) = inb(port);

		return 1;

	case 2:

		if (port & 1)

			return -EINVAL;

		*((u16 *)val) = inw(port);

		return 2;

	case 4:

		if (port & 3)

			return -EINVAL;

		*((u32 *)val) = inl(port);

		return 4;

	}

	return -EINVAL;

}



int pci_legacy_write(struct pci_bus *bus, loff_t port, u32 val, size_t size)

{

	struct pci_controller *hose = bus->sysdata;



	port += hose->io_space->start;



	switch(size) {

	case 1:

		outb(port, val);

		return 1;

	case 2:

		if (port & 1)

			return -EINVAL;

		outw(port, val);

		return 2;

	case 4:

		if (port & 3)

			return -EINVAL;

		outl(port, val);

		return 4;

	}

	return -EINVAL;

}

drivers/pci/pci-sysfs.c

+17 −2
Original line number Diff line number Diff line
@@ -492,6 +492,19 @@ pci_mmap_legacy_io(struct kobject *kobj, struct bin_attribute *attr, 
        return pci_mmap_legacy_page_range(bus, vma, pci_mmap_io);

}



/**

 * pci_adjust_legacy_attr - adjustment of legacy file attributes

 * @b: bus to create files under

 * @mmap_type: I/O port or memory

 *

 * Stub implementation. Can be overridden by arch if necessary.

 */

void __weak

pci_adjust_legacy_attr(struct pci_bus *b, enum pci_mmap_state mmap_type)

{

	return;

}



/**

 * pci_create_legacy_files - create legacy I/O port and memory files

 * @b: bus to create files under
@@ -518,6 +531,7 @@ void pci_create_legacy_files(struct pci_bus *b) 
	b->legacy_io->read = pci_read_legacy_io;

	b->legacy_io->write = pci_write_legacy_io;

	b->legacy_io->mmap = pci_mmap_legacy_io;

	pci_adjust_legacy_attr(b, pci_mmap_io);

	error = device_create_bin_file(&b->dev, b->legacy_io);

	if (error)

		goto legacy_io_err;
@@ -528,6 +542,7 @@ void pci_create_legacy_files(struct pci_bus *b) 
	b->legacy_mem->size = 1024*1024;

	b->legacy_mem->attr.mode = S_IRUSR | S_IWUSR;

	b->legacy_mem->mmap = pci_mmap_legacy_mem;

	pci_adjust_legacy_attr(b, pci_mmap_mem);

	error = device_create_bin_file(&b->dev, b->legacy_mem);

	if (error)

		goto legacy_mem_err;
@@ -719,8 +734,8 @@ static int pci_create_resource_files(struct pci_dev *pdev) 
	return 0;

}

#else /* !HAVE_PCI_MMAP */

static inline int pci_create_resource_files(struct pci_dev *dev) { return 0; }

static inline void pci_remove_resource_files(struct pci_dev *dev) { return; }

int __weak pci_create_resource_files(struct pci_dev *dev) { return 0; }

void __weak pci_remove_resource_files(struct pci_dev *dev) { return; }

#endif /* HAVE_PCI_MMAP */



/**

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