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authorNicholas Johnson <nicholas.johnson-opensource@outlook.com.au>2019-05-07 14:51:24 -0500
committerBjorn Helgaas <bhelgaas@google.com>2019-05-07 15:53:08 -0500
commit0d6076184aecb97cc583bc7f9e125518d6c24404 (patch)
treebf8862b9b703c75613a5554c90a39eab15ae00ba /drivers/pci
parent113fb03ed1d4c1877cc8817e500867616b222380 (diff)
downloadlinux-0d6076184aecb97cc583bc7f9e125518d6c24404.tar.bz2
PCI: Cleanup setup-bus.c comments and whitespace
Cleanup comments, kernel-doc, coding style. No functional changes intended; comment and whitespace changes only. Link: https://lore.kernel.org/lkml/PS2P216MB06427E290A68CDB921FB4B2980250@PS2P216MB0642.KORP216.PROD.OUTLOOK.COM Signed-off-by: Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au> [bhelgaas: tidy related things throughout the file] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/setup-bus.c496
1 files changed, 249 insertions, 247 deletions
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index ec44a0f3a7ac..6728144308c0 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -49,17 +49,15 @@ static void free_list(struct list_head *head)
}
/**
- * add_to_list() - add a new resource tracker to the list
+ * add_to_list() - Add a new resource tracker to the list
* @head: Head of the list
- * @dev: device corresponding to which the resource
- * belongs
- * @res: The resource to be tracked
- * @add_size: additional size to be optionally added
- * to the resource
+ * @dev: Device to which the resource belongs
+ * @res: Resource to be tracked
+ * @add_size: Additional size to be optionally added to the resource
*/
-static int add_to_list(struct list_head *head,
- struct pci_dev *dev, struct resource *res,
- resource_size_t add_size, resource_size_t min_align)
+static int add_to_list(struct list_head *head, struct pci_dev *dev,
+ struct resource *res, resource_size_t add_size,
+ resource_size_t min_align)
{
struct pci_dev_resource *tmp;
@@ -80,8 +78,7 @@ static int add_to_list(struct list_head *head,
return 0;
}
-static void remove_from_list(struct list_head *head,
- struct resource *res)
+static void remove_from_list(struct list_head *head, struct resource *res)
{
struct pci_dev_resource *dev_res, *tmp;
@@ -158,7 +155,7 @@ static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
tmp->res = r;
tmp->dev = dev;
- /* fallback is smallest one or list is empty*/
+ /* Fallback is smallest one or list is empty */
n = head;
list_for_each_entry(dev_res, head, list) {
resource_size_t align;
@@ -171,21 +168,20 @@ static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
break;
}
}
- /* Insert it just before n*/
+ /* Insert it just before n */
list_add_tail(&tmp->list, n);
}
}
-static void __dev_sort_resources(struct pci_dev *dev,
- struct list_head *head)
+static void __dev_sort_resources(struct pci_dev *dev, struct list_head *head)
{
u16 class = dev->class >> 8;
- /* Don't touch classless devices or host bridges or ioapics. */
+ /* Don't touch classless devices or host bridges or IOAPICs */
if (class == PCI_CLASS_NOT_DEFINED || class == PCI_CLASS_BRIDGE_HOST)
return;
- /* Don't touch ioapic devices already enabled by firmware */
+ /* Don't touch IOAPIC devices already enabled by firmware */
if (class == PCI_CLASS_SYSTEM_PIC) {
u16 command;
pci_read_config_word(dev, PCI_COMMAND, &command);
@@ -204,19 +200,18 @@ static inline void reset_resource(struct resource *res)
}
/**
- * reassign_resources_sorted() - satisfy any additional resource requests
+ * reassign_resources_sorted() - Satisfy any additional resource requests
*
- * @realloc_head : head of the list tracking requests requiring additional
- * resources
- * @head : head of the list tracking requests with allocated
- * resources
+ * @realloc_head: Head of the list tracking requests requiring
+ * additional resources
+ * @head: Head of the list tracking requests with allocated
+ * resources
*
- * Walk through each element of the realloc_head and try to procure
- * additional resources for the element, provided the element
- * is in the head list.
+ * Walk through each element of the realloc_head and try to procure additional
+ * resources for the element, provided the element is in the head list.
*/
static void reassign_resources_sorted(struct list_head *realloc_head,
- struct list_head *head)
+ struct list_head *head)
{
struct resource *res;
struct pci_dev_resource *add_res, *tmp;
@@ -228,18 +223,18 @@ static void reassign_resources_sorted(struct list_head *realloc_head,
bool found_match = false;
res = add_res->res;
- /* skip resource that has been reset */
+ /* Skip resource that has been reset */
if (!res->flags)
goto out;
- /* skip this resource if not found in head list */
+ /* Skip this resource if not found in head list */
list_for_each_entry(dev_res, head, list) {
if (dev_res->res == res) {
found_match = true;
break;
}
}
- if (!found_match)/* just skip */
+ if (!found_match) /* Just skip */
continue;
idx = res - &add_res->dev->resource[0];
@@ -267,14 +262,14 @@ out:
}
/**
- * assign_requested_resources_sorted() - satisfy resource requests
+ * assign_requested_resources_sorted() - Satisfy resource requests
*
- * @head : head of the list tracking requests for resources
- * @fail_head : head of the list tracking requests that could
- * not be allocated
+ * @head: Head of the list tracking requests for resources
+ * @fail_head: Head of the list tracking requests that could not be
+ * allocated
*
- * Satisfy resource requests of each element in the list. Add
- * requests that could not satisfied to the failed_list.
+ * Satisfy resource requests of each element in the list. Add requests that
+ * could not be satisfied to the failed_list.
*/
static void assign_requested_resources_sorted(struct list_head *head,
struct list_head *fail_head)
@@ -290,8 +285,9 @@ static void assign_requested_resources_sorted(struct list_head *head,
pci_assign_resource(dev_res->dev, idx)) {
if (fail_head) {
/*
- * if the failed res is for ROM BAR, and it will
- * be enabled later, don't add it to the list
+ * If the failed resource is a ROM BAR and
+ * it will be enabled later, don't add it
+ * to the list.
*/
if (!((idx == PCI_ROM_RESOURCE) &&
(!(res->flags & IORESOURCE_ROM_ENABLE))))
@@ -310,15 +306,14 @@ static unsigned long pci_fail_res_type_mask(struct list_head *fail_head)
struct pci_dev_resource *fail_res;
unsigned long mask = 0;
- /* check failed type */
+ /* Check failed type */
list_for_each_entry(fail_res, fail_head, list)
mask |= fail_res->flags;
/*
- * one pref failed resource will set IORESOURCE_MEM,
- * as we can allocate pref in non-pref range.
- * Will release all assigned non-pref sibling resources
- * according to that bit.
+ * One pref failed resource will set IORESOURCE_MEM, as we can
+ * allocate pref in non-pref range. Will release all assigned
+ * non-pref sibling resources according to that bit.
*/
return mask & (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH);
}
@@ -328,11 +323,11 @@ static bool pci_need_to_release(unsigned long mask, struct resource *res)
if (res->flags & IORESOURCE_IO)
return !!(mask & IORESOURCE_IO);
- /* check pref at first */
+ /* Check pref at first */
if (res->flags & IORESOURCE_PREFETCH) {
if (mask & IORESOURCE_PREFETCH)
return true;
- /* count pref if its parent is non-pref */
+ /* Count pref if its parent is non-pref */
else if ((mask & IORESOURCE_MEM) &&
!(res->parent->flags & IORESOURCE_PREFETCH))
return true;
@@ -343,33 +338,33 @@ static bool pci_need_to_release(unsigned long mask, struct resource *res)
if (res->flags & IORESOURCE_MEM)
return !!(mask & IORESOURCE_MEM);
- return false; /* should not get here */
+ return false; /* Should not get here */
}
static void __assign_resources_sorted(struct list_head *head,
- struct list_head *realloc_head,
- struct list_head *fail_head)
+ struct list_head *realloc_head,
+ struct list_head *fail_head)
{
/*
- * Should not assign requested resources at first.
- * they could be adjacent, so later reassign can not reallocate
- * them one by one in parent resource window.
- * Try to assign requested + add_size at beginning
- * if could do that, could get out early.
- * if could not do that, we still try to assign requested at first,
- * then try to reassign add_size for some resources.
+ * Should not assign requested resources at first. They could be
+ * adjacent, so later reassign can not reallocate them one by one in
+ * parent resource window.
+ *
+ * Try to assign requested + add_size at beginning. If could do that,
+ * could get out early. If could not do that, we still try to assign
+ * requested at first, then try to reassign add_size for some resources.
*
* Separate three resource type checking if we need to release
* assigned resource after requested + add_size try.
- * 1. if there is io port assign fail, will release assigned
- * io port.
- * 2. if there is pref mmio assign fail, release assigned
- * pref mmio.
- * if assigned pref mmio's parent is non-pref mmio and there
- * is non-pref mmio assign fail, will release that assigned
- * pref mmio.
- * 3. if there is non-pref mmio assign fail or pref mmio
- * assigned fail, will release assigned non-pref mmio.
+ *
+ * 1. If IO port assignment fails, will release assigned IO
+ * port.
+ * 2. If pref MMIO assignment fails, release assigned pref
+ * MMIO. If assigned pref MMIO's parent is non-pref MMIO
+ * and non-pref MMIO assignment fails, will release that
+ * assigned pref MMIO.
+ * 3. If non-pref MMIO assignment fails or pref MMIO
+ * assignment fails, will release assigned non-pref MMIO.
*/
LIST_HEAD(save_head);
LIST_HEAD(local_fail_head);
@@ -398,7 +393,7 @@ static void __assign_resources_sorted(struct list_head *head,
/*
* There are two kinds of additional resources in the list:
* 1. bridge resource -- IORESOURCE_STARTALIGN
- * 2. SR-IOV resource -- IORESOURCE_SIZEALIGN
+ * 2. SR-IOV resource -- IORESOURCE_SIZEALIGN
* Here just fix the additional alignment for bridge
*/
if (!(dev_res->res->flags & IORESOURCE_STARTALIGN))
@@ -407,10 +402,10 @@ static void __assign_resources_sorted(struct list_head *head,
add_align = get_res_add_align(realloc_head, dev_res->res);
/*
- * The "head" list is sorted by the alignment to make sure
- * resources with bigger alignment will be assigned first.
- * After we change the alignment of a dev_res in "head" list,
- * we need to reorder the list by alignment to make it
+ * The "head" list is sorted by alignment so resources with
+ * bigger alignment will be assigned first. After we
+ * change the alignment of a dev_res in "head" list, we
+ * need to reorder the list by alignment to make it
* consistent.
*/
if (add_align > dev_res->res->start) {
@@ -435,7 +430,7 @@ static void __assign_resources_sorted(struct list_head *head,
/* Try updated head list with add_size added */
assign_requested_resources_sorted(head, &local_fail_head);
- /* all assigned with add_size ? */
+ /* All assigned with add_size? */
if (list_empty(&local_fail_head)) {
/* Remove head list from realloc_head list */
list_for_each_entry(dev_res, head, list)
@@ -445,13 +440,13 @@ static void __assign_resources_sorted(struct list_head *head,
return;
}
- /* check failed type */
+ /* Check failed type */
fail_type = pci_fail_res_type_mask(&local_fail_head);
- /* remove not need to be released assigned res from head list etc */
+ /* Remove not need to be released assigned res from head list etc */
list_for_each_entry_safe(dev_res, tmp_res, head, list)
if (dev_res->res->parent &&
!pci_need_to_release(fail_type, dev_res->res)) {
- /* remove it from realloc_head list */
+ /* Remove it from realloc_head list */
remove_from_list(realloc_head, dev_res->res);
remove_from_list(&save_head, dev_res->res);
list_del(&dev_res->list);
@@ -477,16 +472,15 @@ requested_and_reassign:
/* Satisfy the must-have resource requests */
assign_requested_resources_sorted(head, fail_head);
- /* Try to satisfy any additional optional resource
- requests */
+ /* Try to satisfy any additional optional resource requests */
if (realloc_head)
reassign_resources_sorted(realloc_head, head);
free_list(head);
}
static void pdev_assign_resources_sorted(struct pci_dev *dev,
- struct list_head *add_head,
- struct list_head *fail_head)
+ struct list_head *add_head,
+ struct list_head *fail_head)
{
LIST_HEAD(head);
@@ -563,17 +557,19 @@ void pci_setup_cardbus(struct pci_bus *bus)
}
EXPORT_SYMBOL(pci_setup_cardbus);
-/* Initialize bridges with base/limit values we have collected.
- PCI-to-PCI Bridge Architecture Specification rev. 1.1 (1998)
- requires that if there is no I/O ports or memory behind the
- bridge, corresponding range must be turned off by writing base
- value greater than limit to the bridge's base/limit registers.
-
- Note: care must be taken when updating I/O base/limit registers
- of bridges which support 32-bit I/O. This update requires two
- config space writes, so it's quite possible that an I/O window of
- the bridge will have some undesirable address (e.g. 0) after the
- first write. Ditto 64-bit prefetchable MMIO. */
+/*
+ * Initialize bridges with base/limit values we have collected. PCI-to-PCI
+ * Bridge Architecture Specification rev. 1.1 (1998) requires that if there
+ * are no I/O ports or memory behind the bridge, the corresponding range
+ * must be turned off by writing base value greater than limit to the
+ * bridge's base/limit registers.
+ *
+ * Note: care must be taken when updating I/O base/limit registers of
+ * bridges which support 32-bit I/O. This update requires two config space
+ * writes, so it's quite possible that an I/O window of the bridge will
+ * have some undesirable address (e.g. 0) after the first write. Ditto
+ * 64-bit prefetchable MMIO.
+ */
static void pci_setup_bridge_io(struct pci_dev *bridge)
{
struct resource *res;
@@ -587,7 +583,7 @@ static void pci_setup_bridge_io(struct pci_dev *bridge)
if (bridge->io_window_1k)
io_mask = PCI_IO_1K_RANGE_MASK;
- /* Set up the top and bottom of the PCI I/O segment for this bus. */
+ /* Set up the top and bottom of the PCI I/O segment for this bus */
res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0];
pcibios_resource_to_bus(bridge->bus, &region, res);
if (res->flags & IORESOURCE_IO) {
@@ -595,19 +591,19 @@ static void pci_setup_bridge_io(struct pci_dev *bridge)
io_base_lo = (region.start >> 8) & io_mask;
io_limit_lo = (region.end >> 8) & io_mask;
l = ((u16) io_limit_lo << 8) | io_base_lo;
- /* Set up upper 16 bits of I/O base/limit. */
+ /* Set up upper 16 bits of I/O base/limit */
io_upper16 = (region.end & 0xffff0000) | (region.start >> 16);
pci_info(bridge, " bridge window %pR\n", res);
} else {
- /* Clear upper 16 bits of I/O base/limit. */
+ /* Clear upper 16 bits of I/O base/limit */
io_upper16 = 0;
l = 0x00f0;
}
- /* Temporarily disable the I/O range before updating PCI_IO_BASE. */
+ /* Temporarily disable the I/O range before updating PCI_IO_BASE */
pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, 0x0000ffff);
- /* Update lower 16 bits of I/O base/limit. */
+ /* Update lower 16 bits of I/O base/limit */
pci_write_config_word(bridge, PCI_IO_BASE, l);
- /* Update upper 16 bits of I/O base/limit. */
+ /* Update upper 16 bits of I/O base/limit */
pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, io_upper16);
}
@@ -617,7 +613,7 @@ static void pci_setup_bridge_mmio(struct pci_dev *bridge)
struct pci_bus_region region;
u32 l;
- /* Set up the top and bottom of the PCI Memory segment for this bus. */
+ /* Set up the top and bottom of the PCI Memory segment for this bus */
res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1];
pcibios_resource_to_bus(bridge->bus, &region, res);
if (res->flags & IORESOURCE_MEM) {
@@ -636,12 +632,14 @@ static void pci_setup_bridge_mmio_pref(struct pci_dev *bridge)
struct pci_bus_region region;
u32 l, bu, lu;
- /* Clear out the upper 32 bits of PREF limit.
- If PCI_PREF_BASE_UPPER32 was non-zero, this temporarily
- disables PREF range, which is ok. */
+ /*
+ * Clear out the upper 32 bits of PREF limit. If
+ * PCI_PREF_BASE_UPPER32 was non-zero, this temporarily disables
+ * PREF range, which is ok.
+ */
pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0);
- /* Set up PREF base/limit. */
+ /* Set up PREF base/limit */
bu = lu = 0;
res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2];
pcibios_resource_to_bus(bridge->bus, &region, res);
@@ -658,7 +656,7 @@ static void pci_setup_bridge_mmio_pref(struct pci_dev *bridge)
}
pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);
- /* Set the upper 32 bits of PREF base & limit. */
+ /* Set the upper 32 bits of PREF base & limit */
pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu);
pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu);
}
@@ -702,13 +700,13 @@ int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
return 0;
if (pci_claim_resource(bridge, i) == 0)
- return 0; /* claimed the window */
+ return 0; /* Claimed the window */
if ((bridge->class >> 8) != PCI_CLASS_BRIDGE_PCI)
return 0;
if (!pci_bus_clip_resource(bridge, i))
- return -EINVAL; /* clipping didn't change anything */
+ return -EINVAL; /* Clipping didn't change anything */
switch (i - PCI_BRIDGE_RESOURCES) {
case 0:
@@ -725,14 +723,16 @@ int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
}
if (pci_claim_resource(bridge, i) == 0)
- return 0; /* claimed a smaller window */
+ return 0; /* Claimed a smaller window */
return -EINVAL;
}
-/* Check whether the bridge supports optional I/O and
- prefetchable memory ranges. If not, the respective
- base/limit registers must be read-only and read as 0. */
+/*
+ * Check whether the bridge supports optional I/O and prefetchable memory
+ * ranges. If not, the respective base/limit registers must be read-only
+ * and read as 0.
+ */
static void pci_bridge_check_ranges(struct pci_bus *bus)
{
struct pci_dev *bridge = bus->self;
@@ -752,12 +752,14 @@ static void pci_bridge_check_ranges(struct pci_bus *bus)
}
}
-/* Helper function for sizing routines: find first available
- bus resource of a given type. Note: we intentionally skip
- the bus resources which have already been assigned (that is,
- have non-NULL parent resource). */
+/*
+ * Helper function for sizing routines: find first available bus resource
+ * of a given type. Note: we intentionally skip the bus resources which
+ * have already been assigned (that is, have non-NULL parent resource).
+ */
static struct resource *find_free_bus_resource(struct pci_bus *bus,
- unsigned long type_mask, unsigned long type)
+ unsigned long type_mask,
+ unsigned long type)
{
int i;
struct resource *r;
@@ -772,19 +774,21 @@ static struct resource *find_free_bus_resource(struct pci_bus *bus,
}
static resource_size_t calculate_iosize(resource_size_t size,
- resource_size_t min_size,
- resource_size_t size1,
- resource_size_t add_size,
- resource_size_t children_add_size,
- resource_size_t old_size,
- resource_size_t align)
+ resource_size_t min_size,
+ resource_size_t size1,
+ resource_size_t add_size,
+ resource_size_t children_add_size,
+ resource_size_t old_size,
+ resource_size_t align)
{
if (size < min_size)
size = min_size;
if (old_size == 1)
old_size = 0;
- /* To be fixed in 2.5: we should have sort of HAVE_ISA
- flag in the struct pci_bus. */
+ /*
+ * To be fixed in 2.5: we should have sort of HAVE_ISA flag in the
+ * struct pci_bus.
+ */
#if defined(CONFIG_ISA) || defined(CONFIG_EISA)
size = (size & 0xff) + ((size & ~0xffUL) << 2);
#endif
@@ -797,11 +801,11 @@ static resource_size_t calculate_iosize(resource_size_t size,
}
static resource_size_t calculate_memsize(resource_size_t size,
- resource_size_t min_size,
- resource_size_t add_size,
- resource_size_t children_add_size,
- resource_size_t old_size,
- resource_size_t align)
+ resource_size_t min_size,
+ resource_size_t add_size,
+ resource_size_t children_add_size,
+ resource_size_t old_size,
+ resource_size_t align)
{
if (size < min_size)
size = min_size;
@@ -824,8 +828,7 @@ resource_size_t __weak pcibios_window_alignment(struct pci_bus *bus,
#define PCI_P2P_DEFAULT_IO_ALIGN 0x1000 /* 4KiB */
#define PCI_P2P_DEFAULT_IO_ALIGN_1K 0x400 /* 1KiB */
-static resource_size_t window_alignment(struct pci_bus *bus,
- unsigned long type)
+static resource_size_t window_alignment(struct pci_bus *bus, unsigned long type)
{
resource_size_t align = 1, arch_align;
@@ -833,8 +836,8 @@ static resource_size_t window_alignment(struct pci_bus *bus,
align = PCI_P2P_DEFAULT_MEM_ALIGN;
else if (type & IORESOURCE_IO) {
/*
- * Per spec, I/O windows are 4K-aligned, but some
- * bridges have an extension to support 1K alignment.
+ * Per spec, I/O windows are 4K-aligned, but some bridges have
+ * an extension to support 1K alignment.
*/
if (bus->self->io_window_1k)
align = PCI_P2P_DEFAULT_IO_ALIGN_1K;
@@ -847,20 +850,21 @@ static resource_size_t window_alignment(struct pci_bus *bus,
}
/**
- * pbus_size_io() - size the io window of a given bus
+ * pbus_size_io() - Size the I/O window of a given bus
*
- * @bus : the bus
- * @min_size : the minimum io window that must to be allocated
- * @add_size : additional optional io window
- * @realloc_head : track the additional io window on this list
+ * @bus: The bus
+ * @min_size: The minimum I/O window that must be allocated
+ * @add_size: Additional optional I/O window
+ * @realloc_head: Track the additional I/O window on this list
*
- * Sizing the IO windows of the PCI-PCI bridge is trivial,
- * since these windows have 1K or 4K granularity and the IO ranges
- * of non-bridge PCI devices are limited to 256 bytes.
- * We must be careful with the ISA aliasing though.
+ * Sizing the I/O windows of the PCI-PCI bridge is trivial, since these
+ * windows have 1K or 4K granularity and the I/O ranges of non-bridge PCI
+ * devices are limited to 256 bytes. We must be careful with the ISA
+ * aliasing though.
*/
static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
- resource_size_t add_size, struct list_head *realloc_head)
+ resource_size_t add_size,
+ struct list_head *realloc_head)
{
struct pci_dev *dev;
struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO,
@@ -947,33 +951,33 @@ static inline resource_size_t calculate_mem_align(resource_size_t *aligns,
}
/**
- * pbus_size_mem() - size the memory window of a given bus
+ * pbus_size_mem() - Size the memory window of a given bus
*
- * @bus : the bus
- * @mask: mask the resource flag, then compare it with type
- * @type: the type of free resource from bridge
- * @type2: second match type
- * @type3: third match type
- * @min_size : the minimum memory window that must to be allocated
- * @add_size : additional optional memory window
- * @realloc_head : track the additional memory window on this list
+ * @bus: The bus
+ * @mask: Mask the resource flag, then compare it with type
+ * @type: The type of free resource from bridge
+ * @type2: Second match type
+ * @type3: Third match type
+ * @min_size: The minimum memory window that must be allocated
+ * @add_size: Additional optional memory window
+ * @realloc_head: Track the additional memory window on this list
*
- * Calculate the size of the bus and minimal alignment which
- * guarantees that all child resources fit in this size.
+ * Calculate the size of the bus and minimal alignment which guarantees
+ * that all child resources fit in this size.
*
- * Returns -ENOSPC if there's no available bus resource of the desired type.
- * Otherwise, sets the bus resource start/end to indicate the required
- * size, adds things to realloc_head (if supplied), and returns 0.
+ * Return -ENOSPC if there's no available bus resource of the desired
+ * type. Otherwise, set the bus resource start/end to indicate the
+ * required size, add things to realloc_head (if supplied), and return 0.
*/
static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
unsigned long type, unsigned long type2,
- unsigned long type3,
- resource_size_t min_size, resource_size_t add_size,
+ unsigned long type3, resource_size_t min_size,
+ resource_size_t add_size,
struct list_head *realloc_head)
{
struct pci_dev *dev;
resource_size_t min_align, align, size, size0, size1;
- resource_size_t aligns[18]; /* Alignments from 1Mb to 128Gb */
+ resource_size_t aligns[18]; /* Alignments from 1MB to 128GB */
int order, max_order;
struct resource *b_res = find_free_bus_resource(bus,
mask | IORESOURCE_PREFETCH, type);
@@ -1002,12 +1006,12 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
continue;
r_size = resource_size(r);
#ifdef CONFIG_PCI_IOV
- /* put SRIOV requested res to the optional list */
+ /* Put SRIOV requested res to the optional list */
if (realloc_head && i >= PCI_IOV_RESOURCES &&
i <= PCI_IOV_RESOURCE_END) {
add_align = max(pci_resource_alignment(dev, r), add_align);
r->end = r->start - 1;
- add_to_list(realloc_head, dev, r, r_size, 0/* don't care */);
+ add_to_list(realloc_head, dev, r, r_size, 0 /* Don't care */);
children_add_size += r_size;
continue;
}
@@ -1029,8 +1033,10 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
continue;
}
size += max(r_size, align);
- /* Exclude ranges with size > align from
- calculation of the alignment. */
+ /*
+ * Exclude ranges with size > align from calculation of
+ * the alignment.
+ */
if (r_size <= align)
aligns[order] += align;
if (order > max_order)
@@ -1081,7 +1087,7 @@ unsigned long pci_cardbus_resource_alignment(struct resource *res)
}
static void pci_bus_size_cardbus(struct pci_bus *bus,
- struct list_head *realloc_head)
+ struct list_head *realloc_head)
{
struct pci_dev *bridge = bus->self;
struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
@@ -1091,8 +1097,8 @@ static void pci_bus_size_cardbus(struct pci_bus *bus,
if (b_res[0].parent)
goto handle_b_res_1;
/*
- * Reserve some resources for CardBus. We reserve
- * a fixed amount of bus space for CardBus bridges.
+ * Reserve some resources for CardBus. We reserve a fixed amount
+ * of bus space for CardBus bridges.
*/
b_res[0].start = pci_cardbus_io_size;
b_res[0].end = b_res[0].start + pci_cardbus_io_size - 1;
@@ -1116,7 +1122,7 @@ handle_b_res_1:
}
handle_b_res_2:
- /* MEM1 must not be pref mmio */
+ /* MEM1 must not be pref MMIO */
pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM1) {
ctrl &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
@@ -1124,10 +1130,7 @@ handle_b_res_2:
pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
}
- /*
- * Check whether prefetchable memory is supported
- * by this bridge.
- */
+ /* Check whether prefetchable memory is supported by this bridge. */
pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
if (!(ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0)) {
ctrl |= PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
@@ -1138,9 +1141,8 @@ handle_b_res_2:
if (b_res[2].parent)
goto handle_b_res_3;
/*
- * If we have prefetchable memory support, allocate
- * two regions. Otherwise, allocate one region of
- * twice the size.
+ * If we have prefetchable memory support, allocate two regions.
+ * Otherwise, allocate one region of twice the size.
*/
if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
b_res[2].start = pci_cardbus_mem_size;
@@ -1153,7 +1155,7 @@ handle_b_res_2:
pci_cardbus_mem_size, pci_cardbus_mem_size);
}
- /* reduce that to half */
+ /* Reduce that to half */
b_res_3_size = pci_cardbus_mem_size;
}
@@ -1204,7 +1206,7 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
switch (bus->self->hdr_type) {
case PCI_HEADER_TYPE_CARDBUS:
- /* don't size cardbuses yet. */
+ /* Don't size CardBuses yet */
break;
case PCI_HEADER_TYPE_BRIDGE:
@@ -1271,18 +1273,17 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
/*
* Compute the size required to put everything else in the
- * non-prefetchable window. This includes:
+ * non-prefetchable window. This includes:
*
* - all non-prefetchable resources
* - 32-bit prefetchable resources if there's a 64-bit
* prefetchable window or no prefetchable window at all
- * - 64-bit prefetchable resources if there's no
- * prefetchable window at all
+ * - 64-bit prefetchable resources if there's no prefetchable
+ * window at all
*
- * Note that the strategy in __pci_assign_resource() must
- * match that used here. Specifically, we cannot put a
- * 32-bit prefetchable resource in a 64-bit prefetchable
- * window.
+ * Note that the strategy in __pci_assign_resource() must match
+ * that used here. Specifically, we cannot put a 32-bit
+ * prefetchable resource in a 64-bit prefetchable window.
*/
pbus_size_mem(bus, mask, IORESOURCE_MEM, type2, type3,
realloc_head ? 0 : additional_mem_size,
@@ -1315,8 +1316,8 @@ static void assign_fixed_resource_on_bus(struct pci_bus *b, struct resource *r)
}
/*
- * Try to assign any resources marked as IORESOURCE_PCI_FIXED, as they
- * are skipped by pbus_assign_resources_sorted().
+ * Try to assign any resources marked as IORESOURCE_PCI_FIXED, as they are
+ * skipped by pbus_assign_resources_sorted().
*/
static void pdev_assign_fixed_resources(struct pci_dev *dev)
{
@@ -1427,10 +1428,9 @@ static void pci_bus_allocate_resources(struct pci_bus *b)
struct pci_bus *child;
/*
- * Carry out a depth-first search on the PCI bus
- * tree to allocate bridge apertures. Read the
- * programmed bridge bases and recursively claim
- * the respective bridge resources.
+ * Carry out a depth-first search on the PCI bus tree to allocate
+ * bridge apertures. Read the programmed bridge bases and
+ * recursively claim the respective bridge resources.
*/
if (b->self) {
pci_read_bridge_bases(b);
@@ -1484,7 +1484,7 @@ static void __pci_bridge_assign_resources(const struct pci_dev *bridge,
IORESOURCE_MEM_64)
static void pci_bridge_release_resources(struct pci_bus *bus,
- unsigned long type)
+ unsigned long type)
{
struct pci_dev *dev = bus->self;
struct resource *r;
@@ -1495,16 +1495,14 @@ static void pci_bridge_release_resources(struct pci_bus *bus,
b_res = &dev->resource[PCI_BRIDGE_RESOURCES];
/*
- * 1. if there is io port assign fail, will release bridge
- * io port.
- * 2. if there is non pref mmio assign fail, release bridge
- * nonpref mmio.
- * 3. if there is 64bit pref mmio assign fail, and bridge pref
- * is 64bit, release bridge pref mmio.
- * 4. if there is pref mmio assign fail, and bridge pref is
- * 32bit mmio, release bridge pref mmio
- * 5. if there is pref mmio assign fail, and bridge pref is not
- * assigned, release bridge nonpref mmio.
+ * 1. If IO port assignment fails, release bridge IO port.
+ * 2. If non pref MMIO assignment fails, release bridge nonpref MMIO.
+ * 3. If 64bit pref MMIO assignment fails, and bridge pref is 64bit,
+ * release bridge pref MMIO.
+ * 4. If pref MMIO assignment fails, and bridge pref is 32bit,
+ * release bridge pref MMIO.
+ * 5. If pref MMIO assignment fails, and bridge pref is not
+ * assigned, release bridge nonpref MMIO.
*/
if (type & IORESOURCE_IO)
idx = 0;
@@ -1524,25 +1522,22 @@ static void pci_bridge_release_resources(struct pci_bus *bus,
if (!r->parent)
return;
- /*
- * if there are children under that, we should release them
- * all
- */
+ /* If there are children, release them all */
release_child_resources(r);
if (!release_resource(r)) {
type = old_flags = r->flags & PCI_RES_TYPE_MASK;
pci_printk(KERN_DEBUG, dev, "resource %d %pR released\n",
PCI_BRIDGE_RESOURCES + idx, r);
- /* keep the old size */
+ /* Keep the old size */
r->end = resource_size(r) - 1;
r->start = 0;
r->flags = 0;
- /* avoiding touch the one without PREF */
+ /* Avoiding touch the one without PREF */
if (type & IORESOURCE_PREFETCH)
type = IORESOURCE_PREFETCH;
__pci_setup_bridge(bus, type);
- /* for next child res under same bridge */
+ /* For next child res under same bridge */
r->flags = old_flags;
}
}
@@ -1551,9 +1546,10 @@ enum release_type {
leaf_only,
whole_subtree,
};
+
/*
- * try to release pci bridge resources that is from leaf bridge,
- * so we can allocate big new one later
+ * Try to release PCI bridge resources from leaf bridge, so we can allocate
+ * a larger window later.
*/
static void pci_bus_release_bridge_resources(struct pci_bus *bus,
unsigned long type,
@@ -1678,7 +1674,7 @@ static int iov_resources_unassigned(struct pci_dev *dev, void *data)
pcibios_resource_to_bus(dev->bus, &region, r);
if (!region.start) {
*unassigned = true;
- return 1; /* return early from pci_walk_bus() */
+ return 1; /* Return early from pci_walk_bus() */
}
}
@@ -1686,7 +1682,7 @@ static int iov_resources_unassigned(struct pci_dev *dev, void *data)
}
static enum enable_type pci_realloc_detect(struct pci_bus *bus,
- enum enable_type enable_local)
+ enum enable_type enable_local)
{
bool unassigned = false;
@@ -1701,21 +1697,21 @@ static enum enable_type pci_realloc_detect(struct pci_bus *bus,
}
#else
static enum enable_type pci_realloc_detect(struct pci_bus *bus,
- enum enable_type enable_local)
+ enum enable_type enable_local)
{
return enable_local;
}
#endif
/*
- * first try will not touch pci bridge res
- * second and later try will clear small leaf bridge res
- * will stop till to the max depth if can not find good one
+ * First try will not touch PCI bridge res.
+ * Second and later try will clear small leaf bridge res.
+ * Will stop till to the max depth if can not find good one.
*/
void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
{
- LIST_HEAD(realloc_head); /* list of resources that
- want additional resources */
+ LIST_HEAD(realloc_head);
+ /* List of resources that want additional resources */
struct list_head *add_list = NULL;
int tried_times = 0;
enum release_type rel_type = leaf_only;
@@ -1724,7 +1720,7 @@ void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
int pci_try_num = 1;
enum enable_type enable_local;
- /* don't realloc if asked to do so */
+ /* Don't realloc if asked to do so */
enable_local = pci_realloc_detect(bus, pci_realloc_enable);
if (pci_realloc_enabled(enable_local)) {
int max_depth = pci_bus_get_depth(bus);
@@ -1737,13 +1733,14 @@ void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
again:
/*
- * last try will use add_list, otherwise will try good to have as
- * must have, so can realloc parent bridge resource
+ * Last try will use add_list, otherwise will try good to have as must
+ * have, so can realloc parent bridge resource
*/
if (tried_times + 1 == pci_try_num)
add_list = &realloc_head;
- /* Depth first, calculate sizes and alignments of all
- subordinate buses. */
+ /*
+ * Depth first, calculate sizes and alignments of all subordinate buses.
+ */
__pci_bus_size_bridges(bus, add_list);
/* Depth last, allocate resources and update the hardware. */
@@ -1752,7 +1749,7 @@ again:
BUG_ON(!list_empty(add_list));
tried_times++;
- /* any device complain? */
+ /* Any device complain? */
if (list_empty(&fail_head))
goto dump;
@@ -1769,20 +1766,20 @@ again:
dev_printk(KERN_DEBUG, &bus->dev,
"No. %d try to assign unassigned res\n", tried_times + 1);
- /* third times and later will not check if it is leaf */
+ /* Third times and later will not check if it is leaf */
if ((tried_times + 1) > 2)
rel_type = whole_subtree;
/*
* Try to release leaf bridge's resources that doesn't fit resource of
- * child device under that bridge
+ * child device under that bridge.
*/
list_for_each_entry(fail_res, &fail_head, list)
pci_bus_release_bridge_resources(fail_res->dev->bus,
fail_res->flags & PCI_RES_TYPE_MASK,
rel_type);
- /* restore size and flags */
+ /* Restore size and flags */
list_for_each_entry(fail_res, &fail_head, list) {
struct resource *res = fail_res->res;
@@ -1797,7 +1794,7 @@ again:
goto again;
dump:
- /* dump the resource on buses */
+ /* Dump the resource on buses */
pci_bus_dump_resources(bus);
}
@@ -1808,14 +1805,15 @@ void __init pci_assign_unassigned_resources(void)
list_for_each_entry(root_bus, &pci_root_buses, node) {
pci_assign_unassigned_root_bus_resources(root_bus);
- /* Make sure the root bridge has a companion ACPI device: */
+ /* Make sure the root bridge has a companion ACPI device */
if (ACPI_HANDLE(root_bus->bridge))
acpi_ioapic_add(ACPI_HANDLE(root_bus->bridge));
}
}
static void extend_bridge_window(struct pci_dev *bridge, struct resource *res,
- struct list_head *add_list, resource_size_t available)
+ struct list_head *add_list,
+ resource_size_t available)
{
struct pci_dev_resource *dev_res;
@@ -1839,8 +1837,10 @@ static void extend_bridge_window(struct pci_dev *bridge, struct resource *res,
}
static void pci_bus_distribute_available_resources(struct pci_bus *bus,
- struct list_head *add_list, resource_size_t available_io,
- resource_size_t available_mmio, resource_size_t available_mmio_pref)
+ struct list_head *add_list,
+ resource_size_t available_io,
+ resource_size_t available_mmio,
+ resource_size_t available_mmio_pref)
{
resource_size_t remaining_io, remaining_mmio, remaining_mmio_pref;
unsigned int normal_bridges = 0, hotplug_bridges = 0;
@@ -1864,7 +1864,7 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
/*
* Calculate the total amount of extra resource space we can
- * pass to bridges below this one. This is basically the
+ * pass to bridges below this one. This is basically the
* extra space reduced by the minimal required space for the
* non-hotplug bridges.
*/
@@ -1874,7 +1874,7 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
/*
* Calculate how many hotplug bridges and normal bridges there
- * are on this bus. We will distribute the additional available
+ * are on this bus. We will distribute the additional available
* resources between hotplug bridges.
*/
for_each_pci_bridge(dev, bus) {
@@ -1909,8 +1909,8 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
/*
* There is only one bridge on the bus so it gets all available
- * resources which it can then distribute to the possible
- * hotplug bridges below.
+ * resources which it can then distribute to the possible hotplug
+ * bridges below.
*/
if (hotplug_bridges + normal_bridges == 1) {
dev = list_first_entry(&bus->devices, struct pci_dev, bus_list);
@@ -1961,9 +1961,8 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
}
}
-static void
-pci_bridge_distribute_available_resources(struct pci_dev *bridge,
- struct list_head *add_list)
+static void pci_bridge_distribute_available_resources(struct pci_dev *bridge,
+ struct list_head *add_list)
{
resource_size_t available_io, available_mmio, available_mmio_pref;
const struct resource *res;
@@ -1980,14 +1979,17 @@ pci_bridge_distribute_available_resources(struct pci_dev *bridge,
available_mmio_pref = resource_size(res);
pci_bus_distribute_available_resources(bridge->subordinate,
- add_list, available_io, available_mmio, available_mmio_pref);
+ add_list, available_io,
+ available_mmio,
+ available_mmio_pref);
}
void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
{
struct pci_bus *parent = bridge->subordinate;
- LIST_HEAD(add_list); /* list of resources that
- want additional resources */
+ /* List of resources that want additional resources */
+ LIST_HEAD(add_list);
+
int tried_times = 0;
LIST_HEAD(fail_head);
struct pci_dev_resource *fail_res;
@@ -1997,9 +1999,9 @@ again:
__pci_bus_size_bridges(parent, &add_list);
/*
- * Distribute remaining resources (if any) equally between
- * hotplug bridges below. This makes it possible to extend the
- * hierarchy later without running out of resources.
+ * Distribute remaining resources (if any) equally between hotplug
+ * bridges below. This makes it possible to extend the hierarchy
+ * later without running out of resources.
*/
pci_bridge_distribute_available_resources(bridge, &add_list);
@@ -2011,7 +2013,7 @@ again:
goto enable_all;
if (tried_times >= 2) {
- /* still fail, don't need to try more */
+ /* Still fail, don't need to try more */
free_list(&fail_head);
goto enable_all;
}
@@ -2020,15 +2022,15 @@ again:
tried_times + 1);
/*
- * Try to release leaf bridge's resources that doesn't fit resource of
- * child device under that bridge
+ * Try to release leaf bridge's resources that aren't big enough
+ * to contain child device resources.
*/
list_for_each_entry(fail_res, &fail_head, list)
pci_bus_release_bridge_resources(fail_res->dev->bus,
fail_res->flags & PCI_RES_TYPE_MASK,
whole_subtree);
- /* restore size and flags */
+ /* Restore size and flags */
list_for_each_entry(fail_res, &fail_head, list) {
struct resource *res = fail_res->res;
@@ -2107,7 +2109,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
}
list_for_each_entry(dev_res, &saved, list) {
- /* Skip the bridge we just assigned resources for. */
+ /* Skip the bridge we just assigned resources for */
if (bridge == dev_res->dev)
continue;
@@ -2119,7 +2121,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
return 0;
cleanup:
- /* restore size and flags */
+ /* Restore size and flags */
list_for_each_entry(dev_res, &failed, list) {
struct resource *res = dev_res->res;
@@ -2151,8 +2153,8 @@ cleanup:
void pci_assign_unassigned_bus_resources(struct pci_bus *bus)
{
struct pci_dev *dev;
- LIST_HEAD(add_list); /* list of resources that
- want additional resources */
+ /* List of resources that want additional resources */
+ LIST_HEAD(add_list);
down_read(&pci_bus_sem);
for_each_pci_bridge(dev, bus)