Commit 396a1a58 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Paul Mackerras
Browse files

[POWERPC] Fix mmap of PCI resource with hack for X 



The powerpc version of pci_resource_to_user() and associated hooks
used by /proc/bus/pci and /sys/bus/pci mmap have been broken for some
time on machines that don't have a 1:1 mapping of devices (basically
on non-PowerMacs) and have PCI devices above 32 bits.

This attempts to fix it as well as possible.

The rule is supposed to be that pci_resource_to_user() always converts
the resources back into a BAR values since that's what the /proc
interface was supposed to deal with. However, for X to work on
platforms where PCI MMIO is not mapped 1:1, it became a habit of
platforms like powerpc to pass "fixed up" values there since X expects
to be able to use values from /proc/bus/pci/devices as offsets to mmap
of /dev/mem...

So we keep that contraption here, causing also /sys/*/resource to
expose fully absolute MMIO addresses instead of BAR values, which is
ugly, but should still work as long as those are only used to calculate
alignment within a page.

X is still broken when built 32 bits on machines where PCI MMIO can be
above 32-bit space unfortunately.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent f09b5ce0

arch/powerpc/kernel/pci_32.c

+32 −13
Original line number Diff line number Diff line
@@ -1544,7 +1544,7 @@ pci_resource_to_bus(struct pci_dev *pdev, struct resource *res) 




static struct resource *__pci_mmap_make_offset(struct pci_dev *dev,

					       unsigned long *offset,

					       resource_size_t *offset,

					       enum pci_mmap_state mmap_state)

{

	struct pci_controller *hose = pci_bus_to_hose(dev->bus->number);
@@ -1556,7 +1556,9 @@ static struct resource *__pci_mmap_make_offset(struct pci_dev *dev, 


	/* If memory, add on the PCI bridge address offset */

	if (mmap_state == pci_mmap_mem) {

#if 0 /* See comment in pci_resource_to_user() for why this is disabled */

		*offset += hose->pci_mem_offset;

#endif

		res_bit = IORESOURCE_MEM;

	} else {

		io_offset = hose->io_base_virt - (void __iomem *)_IO_BASE;
@@ -1624,9 +1626,6 @@ static pgprot_t __pci_mmap_set_pgprot(struct pci_dev *dev, struct resource *rp, 
	else

		prot |= _PAGE_GUARDED;



	printk("PCI map for %s:%llx, prot: %lx\n", pci_name(dev),

		(unsigned long long)rp->start, prot);



	return __pgprot(prot);

}
@@ -1695,7 +1694,7 @@ 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 offset = vma->vm_pgoff << PAGE_SHIFT;

	resource_size_t offset = vma->vm_pgoff << PAGE_SHIFT;

	struct resource *rp;

	int ret;
@@ -1808,22 +1807,42 @@ void pci_resource_to_user(const struct pci_dev *dev, int bar, 
			  resource_size_t *start, resource_size_t *end)

{

	struct pci_controller *hose = pci_bus_to_hose(dev->bus->number);

	unsigned long offset = 0;

	resource_size_t offset = 0;



	if (hose == NULL)

		return;



	if (rsrc->flags & IORESOURCE_IO)

		offset = (void __iomem *)_IO_BASE - hose->io_base_virt

			+ hose->io_base_phys;

		offset = (unsigned long)hose->io_base_virt - _IO_BASE;



	*start = rsrc->start + offset;

	*end = rsrc->end + offset;

	/* We pass a fully fixed up address to userland for MMIO instead of

	 * a BAR value because X is lame and expects to be able to use that

	 * to pass to /dev/mem !

	 *

	 * That means that we'll have potentially 64 bits values where some

	 * userland apps only expect 32 (like X itself since it thinks only

	 * Sparc has 64 bits MMIO) but if we don't do that, we break it on

	 * 32 bits CHRPs :-(

	 *

	 * Hopefully, the sysfs insterface is immune to that gunk. Once X

	 * has been fixed (and the fix spread enough), we can re-enable the

	 * 2 lines below and pass down a BAR value to userland. In that case

	 * we'll also have to re-enable the matching code in

	 * __pci_mmap_make_offset().

	 *

	 * BenH.

	 */

#if 0

	else if (rsrc->flags & IORESOURCE_MEM)

		offset = hose->pci_mem_offset;

#endif



	*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)

void __init pci_init_resource(struct resource *res, resource_size_t start,

			      resource_size_t end, int flags, char *name)

{

	res->start = start;

	res->end = end;

arch/powerpc/kernel/pci_64.c

+31 −11
Original line number Diff line number Diff line
@@ -682,7 +682,7 @@ int pci_proc_domain(struct pci_bus *bus) 
 * Returns negative error code on failure, zero on success.

 */

static struct resource *__pci_mmap_make_offset(struct pci_dev *dev,

					       unsigned long *offset,

					       resource_size_t *offset,

					       enum pci_mmap_state mmap_state)

{

	struct pci_controller *hose = pci_bus_to_host(dev->bus);
@@ -694,7 +694,9 @@ static struct resource *__pci_mmap_make_offset(struct pci_dev *dev, 


	/* If memory, add on the PCI bridge address offset */

	if (mmap_state == pci_mmap_mem) {

#if 0 /* See comment in pci_resource_to_user() for why this is disabled */

		*offset += hose->pci_mem_offset;

#endif

		res_bit = IORESOURCE_MEM;

	} else {

		io_offset = (unsigned long)hose->io_base_virt - pci_io_base;
@@ -762,9 +764,6 @@ static pgprot_t __pci_mmap_set_pgprot(struct pci_dev *dev, struct resource *rp, 
	else

		prot |= _PAGE_GUARDED;



	printk(KERN_DEBUG "PCI map for %s:%lx, prot: %lx\n", pci_name(dev), rp->start,

	       prot);



	return __pgprot(prot);

}
@@ -832,7 +831,7 @@ pgprot_t pci_phys_mem_access_prot(struct file *file, 
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 offset = vma->vm_pgoff << PAGE_SHIFT;

	resource_size_t offset = vma->vm_pgoff << PAGE_SHIFT;

	struct resource *rp;

	int ret;
@@ -1333,20 +1332,41 @@ 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)

			  resource_size_t *start, resource_size_t *end)

{

	struct pci_controller *hose = pci_bus_to_host(dev->bus);

	unsigned long offset = 0;

	resource_size_t 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;

		offset = (unsigned long)hose->io_base_virt - pci_io_base;



	/* We pass a fully fixed up address to userland for MMIO instead of

	 * a BAR value because X is lame and expects to be able to use that

	 * to pass to /dev/mem !

	 *

	 * That means that we'll have potentially 64 bits values where some

	 * userland apps only expect 32 (like X itself since it thinks only

	 * Sparc has 64 bits MMIO) but if we don't do that, we break it on

	 * 32 bits CHRPs :-(

	 *

	 * Hopefully, the sysfs insterface is immune to that gunk. Once X

	 * has been fixed (and the fix spread enough), we can re-enable the

	 * 2 lines below and pass down a BAR value to userland. In that case

	 * we'll also have to re-enable the matching code in

	 * __pci_mmap_make_offset().

	 *

	 * BenH.

	 */

#if 0

	else if (rsrc->flags & IORESOURCE_MEM)

		offset = hose->pci_mem_offset;

#endif



	*start = rsrc->start + offset;

	*end = rsrc->end + offset;

	*start = rsrc->start - offset;

	*end = rsrc->end - offset;

}



struct pci_controller* pci_find_hose_for_OF_device(struct device_node* node)

arch/ppc/kernel/pci.c

+32 −9
Original line number Diff line number Diff line
@@ -879,7 +879,7 @@ pci_resource_to_bus(struct pci_dev *pdev, struct resource *res) 




static struct resource *__pci_mmap_make_offset(struct pci_dev *dev,

					       unsigned long *offset,

					       resource_size_t *offset,

					       enum pci_mmap_state mmap_state)

{

	struct pci_controller *hose = pci_bus_to_hose(dev->bus->number);
@@ -891,7 +891,9 @@ static struct resource *__pci_mmap_make_offset(struct pci_dev *dev, 


	/* If memory, add on the PCI bridge address offset */

	if (mmap_state == pci_mmap_mem) {

#if 0 /* See comment in pci_resource_to_user() for why this is disabled */

		*offset += hose->pci_mem_offset;

#endif

		res_bit = IORESOURCE_MEM;

	} else {

		io_offset = hose->io_base_virt - ___IO_BASE;
@@ -1030,7 +1032,7 @@ 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 offset = vma->vm_pgoff << PAGE_SHIFT;

	resource_size_t offset = vma->vm_pgoff << PAGE_SHIFT;

	struct resource *rp;

	int ret;
@@ -1132,21 +1134,42 @@ void pci_resource_to_user(const struct pci_dev *dev, int bar, 
			  resource_size_t *start, resource_size_t *end)

{

	struct pci_controller *hose = pci_bus_to_hose(dev->bus->number);

	unsigned long offset = 0;

	resource_size_t offset = 0;



	if (hose == NULL)

		return;



	if (rsrc->flags & IORESOURCE_IO)

		offset = ___IO_BASE - hose->io_base_virt + hose->io_base_phys;

		offset = (unsigned long)hose->io_base_virt - _IO_BASE;



	/* We pass a fully fixed up address to userland for MMIO instead of

	 * a BAR value because X is lame and expects to be able to use that

	 * to pass to /dev/mem !

	 *

	 * That means that we'll have potentially 64 bits values where some

	 * userland apps only expect 32 (like X itself since it thinks only

	 * Sparc has 64 bits MMIO) but if we don't do that, we break it on

	 * 32 bits CHRPs :-(

	 *

	 * Hopefully, the sysfs insterface is immune to that gunk. Once X

	 * has been fixed (and the fix spread enough), we can re-enable the

	 * 2 lines below and pass down a BAR value to userland. In that case

	 * we'll also have to re-enable the matching code in

	 * __pci_mmap_make_offset().

	 *

	 * BenH.

	 */

#if 0

	else if (rsrc->flags & IORESOURCE_MEM)

		offset = hose->pci_mem_offset;

#endif



	*start = rsrc->start + offset;

	*end = rsrc->end + offset;

	*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)

void __init pci_init_resource(struct resource *res, resource_size_t start,

			      resource_size_t end, int flags, char *name)

{

	res->start = start;

	res->end = end;

include/asm-powerpc/pci-bridge.h

+2 −2
Original line number Diff line number Diff line
@@ -31,12 +31,12 @@ struct pci_controller { 
	int last_busno;



	void __iomem *io_base_virt;

	unsigned long io_base_phys;

	resource_size_t io_base_phys;



	/* Some machines have a non 1:1 mapping of

	 * the PCI memory space in the CPU bus space

	 */

	unsigned long pci_mem_offset;

	resource_size_t pci_mem_offset;

	unsigned long pci_io_size;



	struct pci_ops *ops;

include/asm-ppc/pci-bridge.h

+4 −4
Original line number Diff line number Diff line
@@ -20,8 +20,8 @@ extern unsigned long pci_bus_mem_base_phys(unsigned int bus); 
extern struct pci_controller* pcibios_alloc_controller(void);



/* Helper function for setting up resources */

extern void pci_init_resource(struct resource *res, unsigned long start,

			      unsigned long end, int flags, char *name);

extern void pci_init_resource(struct resource *res, resource_size_t start,

			      resource_size_t end, int flags, char *name);



/* Get the PCI host controller for a bus */

extern struct pci_controller* pci_bus_to_hose(int bus);
@@ -50,12 +50,12 @@ struct pci_controller { 
	int bus_offset;



	void __iomem *io_base_virt;

	unsigned long io_base_phys;

	resource_size_t io_base_phys;



	/* Some machines (PReP) have a non 1:1 mapping of

	 * the PCI memory space in the CPU bus space

	 */

	unsigned long pci_mem_offset;

	resource_size_t pci_mem_offset;



	struct pci_ops *ops;

	volatile unsigned int __iomem *cfg_addr;

CRA Git | Maintained and supported by SUSTech CRA and CCSE