Skip to content

Commit

Permalink
Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6
Browse files Browse the repository at this point in the history
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6: (169 commits)
  commit 78a596b
  Author: Adrian Bunk <bunk@stusta.de>
  Date:   Fri Mar 31 01:38:12 2006 -0800
  
      [PATCH] remove kernel/power/pm.c:pm_unregister()
      
      Since the last user is removed in -mm, we can now remove this long deprecated
      function.
      
      Signed-off-by: Adrian Bunk <bunk@stusta.de>
      Cc: Pavel Machek <pavel@ucw.cz>
      Signed-off-by: Andrew Morton <akpm@osdl.org>
      Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  
  commit 21440d3
  Author: David Brownell <david-b@pacbell.net>
  Date:   Sat Apr 1 10:21:52 2006 -0800
  
      [PATCH] dma doc updates
      
  ...
  • Loading branch information
Linus Torvalds committed Apr 15, 2006
2 parents 754a264 + 78a596b commit bcdc084
Show file tree
Hide file tree
Showing 12 changed files with 308 additions and 80 deletions.
49 changes: 36 additions & 13 deletions Documentation/DMA-API.txt
Original file line number Diff line number Diff line change
Expand Up @@ -33,7 +33,9 @@ pci_alloc_consistent(struct pci_dev *dev, size_t size,

Consistent memory is memory for which a write by either the device or
the processor can immediately be read by the processor or device
without having to worry about caching effects.
without having to worry about caching effects. (You may however need
to make sure to flush the processor's write buffers before telling
devices to read that memory.)

This routine allocates a region of <size> bytes of consistent memory.
it also returns a <dma_handle> which may be cast to an unsigned
Expand Down Expand Up @@ -304,12 +306,12 @@ dma address with dma_mapping_error(). A non zero return value means the mapping
could not be created and the driver should take appropriate action (eg
reduce current DMA mapping usage or delay and try again later).

int
dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction direction)
int
pci_map_sg(struct pci_dev *hwdev, struct scatterlist *sg,
int nents, int direction)
int
dma_map_sg(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction direction)
int
pci_map_sg(struct pci_dev *hwdev, struct scatterlist *sg,
int nents, int direction)

Maps a scatter gather list from the block layer.

Expand All @@ -327,12 +329,33 @@ critical that the driver do something, in the case of a block driver
aborting the request or even oopsing is better than doing nothing and
corrupting the filesystem.

void
dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
enum dma_data_direction direction)
void
pci_unmap_sg(struct pci_dev *hwdev, struct scatterlist *sg,
int nents, int direction)
With scatterlists, you use the resulting mapping like this:

int i, count = dma_map_sg(dev, sglist, nents, direction);
struct scatterlist *sg;

for (i = 0, sg = sglist; i < count; i++, sg++) {
hw_address[i] = sg_dma_address(sg);
hw_len[i] = sg_dma_len(sg);
}

where nents is the number of entries in the sglist.

The implementation is free to merge several consecutive sglist entries
into one (e.g. with an IOMMU, or if several pages just happen to be
physically contiguous) and returns the actual number of sg entries it
mapped them to. On failure 0, is returned.

Then you should loop count times (note: this can be less than nents times)
and use sg_dma_address() and sg_dma_len() macros where you previously
accessed sg->address and sg->length as shown above.

void
dma_unmap_sg(struct device *dev, struct scatterlist *sg,
int nhwentries, enum dma_data_direction direction)
void
pci_unmap_sg(struct pci_dev *hwdev, struct scatterlist *sg,
int nents, int direction)

unmap the previously mapped scatter/gather list. All the parameters
must be the same as those and passed in to the scatter/gather mapping
Expand Down
22 changes: 17 additions & 5 deletions Documentation/DMA-mapping.txt
Original file line number Diff line number Diff line change
Expand Up @@ -58,11 +58,15 @@ translating each of those pages back to a kernel address using
something like __va(). [ EDIT: Update this when we integrate
Gerd Knorr's generic code which does this. ]

This rule also means that you may not use kernel image addresses
(ie. items in the kernel's data/text/bss segment, or your driver's)
nor may you use kernel stack addresses for DMA. Both of these items
might be mapped somewhere entirely different than the rest of physical
memory.
This rule also means that you may use neither kernel image addresses
(items in data/text/bss segments), nor module image addresses, nor
stack addresses for DMA. These could all be mapped somewhere entirely
different than the rest of physical memory. Even if those classes of
memory could physically work with DMA, you'd need to ensure the I/O
buffers were cacheline-aligned. Without that, you'd see cacheline
sharing problems (data corruption) on CPUs with DMA-incoherent caches.
(The CPU could write to one word, DMA would write to a different one
in the same cache line, and one of them could be overwritten.)

Also, this means that you cannot take the return of a kmap()
call and DMA to/from that. This is similar to vmalloc().
Expand Down Expand Up @@ -284,6 +288,11 @@ There are two types of DMA mappings:

in order to get correct behavior on all platforms.

Also, on some platforms your driver may need to flush CPU write
buffers in much the same way as it needs to flush write buffers
found in PCI bridges (such as by reading a register's value
after writing it).

- Streaming DMA mappings which are usually mapped for one DMA transfer,
unmapped right after it (unless you use pci_dma_sync_* below) and for which
hardware can optimize for sequential accesses.
Expand All @@ -303,6 +312,9 @@ There are two types of DMA mappings:

Neither type of DMA mapping has alignment restrictions that come
from PCI, although some devices may have such restrictions.
Also, systems with caches that aren't DMA-coherent will work better
when the underlying buffers don't share cache lines with other data.


Using Consistent DMA mappings.

Expand Down
3 changes: 3 additions & 0 deletions arch/i386/pci/irq.c
Original file line number Diff line number Diff line change
Expand Up @@ -588,7 +588,10 @@ static __init int via_router_probe(struct irq_router *r,
case PCI_DEVICE_ID_VIA_82C596:
case PCI_DEVICE_ID_VIA_82C686:
case PCI_DEVICE_ID_VIA_8231:
case PCI_DEVICE_ID_VIA_8233A:
case PCI_DEVICE_ID_VIA_8235:
case PCI_DEVICE_ID_VIA_8237:
case PCI_DEVICE_ID_VIA_8237_SATA:
/* FIXME: add new ones for 8233/5 */
r->name = "VIA";
r->get = pirq_via_get;
Expand Down
3 changes: 0 additions & 3 deletions drivers/pci/hotplug/rpaphp_core.c
Original file line number Diff line number Diff line change
Expand Up @@ -360,9 +360,6 @@ static int __init rpaphp_init(void)
while ((dn = of_find_node_by_type(dn, "pci")))
rpaphp_add_slot(dn);

if (!num_slots)
return -ENODEV;

return 0;
}

Expand Down
227 changes: 198 additions & 29 deletions drivers/pci/msi.c
Original file line number Diff line number Diff line change
Expand Up @@ -504,6 +504,201 @@ void pci_scan_msi_device(struct pci_dev *dev)
nr_reserved_vectors++;
}

#ifdef CONFIG_PM
int pci_save_msi_state(struct pci_dev *dev)
{
int pos, i = 0;
u16 control;
struct pci_cap_saved_state *save_state;
u32 *cap;

pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
if (pos <= 0 || dev->no_msi)
return 0;

pci_read_config_word(dev, msi_control_reg(pos), &control);
if (!(control & PCI_MSI_FLAGS_ENABLE))
return 0;

save_state = kzalloc(sizeof(struct pci_cap_saved_state) + sizeof(u32) * 5,
GFP_KERNEL);
if (!save_state) {
printk(KERN_ERR "Out of memory in pci_save_msi_state\n");
return -ENOMEM;
}
cap = &save_state->data[0];

pci_read_config_dword(dev, pos, &cap[i++]);
control = cap[0] >> 16;
pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_LO, &cap[i++]);
if (control & PCI_MSI_FLAGS_64BIT) {
pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_HI, &cap[i++]);
pci_read_config_dword(dev, pos + PCI_MSI_DATA_64, &cap[i++]);
} else
pci_read_config_dword(dev, pos + PCI_MSI_DATA_32, &cap[i++]);
if (control & PCI_MSI_FLAGS_MASKBIT)
pci_read_config_dword(dev, pos + PCI_MSI_MASK_BIT, &cap[i++]);
disable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
save_state->cap_nr = PCI_CAP_ID_MSI;
pci_add_saved_cap(dev, save_state);
return 0;
}

void pci_restore_msi_state(struct pci_dev *dev)
{
int i = 0, pos;
u16 control;
struct pci_cap_saved_state *save_state;
u32 *cap;

save_state = pci_find_saved_cap(dev, PCI_CAP_ID_MSI);
pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
if (!save_state || pos <= 0)
return;
cap = &save_state->data[0];

control = cap[i++] >> 16;
pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_LO, cap[i++]);
if (control & PCI_MSI_FLAGS_64BIT) {
pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_HI, cap[i++]);
pci_write_config_dword(dev, pos + PCI_MSI_DATA_64, cap[i++]);
} else
pci_write_config_dword(dev, pos + PCI_MSI_DATA_32, cap[i++]);
if (control & PCI_MSI_FLAGS_MASKBIT)
pci_write_config_dword(dev, pos + PCI_MSI_MASK_BIT, cap[i++]);
pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
pci_remove_saved_cap(save_state);
kfree(save_state);
}

int pci_save_msix_state(struct pci_dev *dev)
{
int pos;
u16 control;
struct pci_cap_saved_state *save_state;

pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (pos <= 0 || dev->no_msi)
return 0;

pci_read_config_word(dev, msi_control_reg(pos), &control);
if (!(control & PCI_MSIX_FLAGS_ENABLE))
return 0;
save_state = kzalloc(sizeof(struct pci_cap_saved_state) + sizeof(u16),
GFP_KERNEL);
if (!save_state) {
printk(KERN_ERR "Out of memory in pci_save_msix_state\n");
return -ENOMEM;
}
*((u16 *)&save_state->data[0]) = control;

disable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
save_state->cap_nr = PCI_CAP_ID_MSIX;
pci_add_saved_cap(dev, save_state);
return 0;
}

void pci_restore_msix_state(struct pci_dev *dev)
{
u16 save;
int pos;
int vector, head, tail = 0;
void __iomem *base;
int j;
struct msg_address address;
struct msg_data data;
struct msi_desc *entry;
int temp;
struct pci_cap_saved_state *save_state;

save_state = pci_find_saved_cap(dev, PCI_CAP_ID_MSIX);
if (!save_state)
return;
save = *((u16 *)&save_state->data[0]);
pci_remove_saved_cap(save_state);
kfree(save_state);

pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (pos <= 0)
return;

/* route the table */
temp = dev->irq;
if (msi_lookup_vector(dev, PCI_CAP_ID_MSIX))
return;
vector = head = dev->irq;
while (head != tail) {
entry = msi_desc[vector];
base = entry->mask_base;
j = entry->msi_attrib.entry_nr;

msi_address_init(&address);
msi_data_init(&data, vector);

address.lo_address.value &= MSI_ADDRESS_DEST_ID_MASK;
address.lo_address.value |= entry->msi_attrib.current_cpu <<
MSI_TARGET_CPU_SHIFT;

writel(address.lo_address.value,
base + j * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
writel(address.hi_address,
base + j * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
writel(*(u32*)&data,
base + j * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_DATA_OFFSET);

tail = msi_desc[vector]->link.tail;
vector = tail;
}
dev->irq = temp;

pci_write_config_word(dev, msi_control_reg(pos), save);
enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
}
#endif

static void msi_register_init(struct pci_dev *dev, struct msi_desc *entry)
{
struct msg_address address;
struct msg_data data;
int pos, vector = dev->irq;
u16 control;

pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
pci_read_config_word(dev, msi_control_reg(pos), &control);
/* Configure MSI capability structure */
msi_address_init(&address);
msi_data_init(&data, vector);
entry->msi_attrib.current_cpu = ((address.lo_address.u.dest_id >>
MSI_TARGET_CPU_SHIFT) & MSI_TARGET_CPU_MASK);
pci_write_config_dword(dev, msi_lower_address_reg(pos),
address.lo_address.value);
if (is_64bit_address(control)) {
pci_write_config_dword(dev,
msi_upper_address_reg(pos), address.hi_address);
pci_write_config_word(dev,
msi_data_reg(pos, 1), *((u32*)&data));
} else
pci_write_config_word(dev,
msi_data_reg(pos, 0), *((u32*)&data));
if (entry->msi_attrib.maskbit) {
unsigned int maskbits, temp;
/* All MSIs are unmasked by default, Mask them all */
pci_read_config_dword(dev,
msi_mask_bits_reg(pos, is_64bit_address(control)),
&maskbits);
temp = (1 << multi_msi_capable(control));
temp = ((temp - 1) & ~temp);
maskbits |= temp;
pci_write_config_dword(dev,
msi_mask_bits_reg(pos, is_64bit_address(control)),
maskbits);
}
}

/**
* msi_capability_init - configure device's MSI capability structure
* @dev: pointer to the pci_dev data structure of MSI device function
Expand All @@ -516,8 +711,6 @@ void pci_scan_msi_device(struct pci_dev *dev)
static int msi_capability_init(struct pci_dev *dev)
{
struct msi_desc *entry;
struct msg_address address;
struct msg_data data;
int pos, vector;
u16 control;

Expand Down Expand Up @@ -549,33 +742,8 @@ static int msi_capability_init(struct pci_dev *dev)
/* Replace with MSI handler */
irq_handler_init(PCI_CAP_ID_MSI, vector, entry->msi_attrib.maskbit);
/* Configure MSI capability structure */
msi_address_init(&address);
msi_data_init(&data, vector);
entry->msi_attrib.current_cpu = ((address.lo_address.u.dest_id >>
MSI_TARGET_CPU_SHIFT) & MSI_TARGET_CPU_MASK);
pci_write_config_dword(dev, msi_lower_address_reg(pos),
address.lo_address.value);
if (is_64bit_address(control)) {
pci_write_config_dword(dev,
msi_upper_address_reg(pos), address.hi_address);
pci_write_config_word(dev,
msi_data_reg(pos, 1), *((u32*)&data));
} else
pci_write_config_word(dev,
msi_data_reg(pos, 0), *((u32*)&data));
if (entry->msi_attrib.maskbit) {
unsigned int maskbits, temp;
/* All MSIs are unmasked by default, Mask them all */
pci_read_config_dword(dev,
msi_mask_bits_reg(pos, is_64bit_address(control)),
&maskbits);
temp = (1 << multi_msi_capable(control));
temp = ((temp - 1) & ~temp);
maskbits |= temp;
pci_write_config_dword(dev,
msi_mask_bits_reg(pos, is_64bit_address(control)),
maskbits);
}
msi_register_init(dev, entry);

attach_msi_entry(entry, vector);
/* Set MSI enabled bits */
enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
Expand Down Expand Up @@ -731,6 +899,7 @@ int pci_enable_msi(struct pci_dev* dev)
vector_irq[dev->irq] = -1;
nr_released_vectors--;
spin_unlock_irqrestore(&msi_lock, flags);
msi_register_init(dev, msi_desc[dev->irq]);
enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
return 0;
}
Expand Down
Loading

0 comments on commit bcdc084

Please sign in to comment.