diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index efc7aa7a067099f6bacdb860cde13f2d876030a8..d5c27d947c2e31fdf89c0c1f1770afc01220ae4a 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2994,7 +2994,30 @@
See header of drivers/block/paride/pcd.c.
See also Documentation/blockdev/paride.txt.
- pci=option[,option...] [PCI] various PCI subsystem options:
+ pci=option[,option...] [PCI] various PCI subsystem options.
+
+ Some options herein operate on a specific device
+ or a set of devices (<pci_dev>). These are
+ specified in one of the following formats:
+
+ [<domain>:]<bus>:<dev>.<func>[/<dev>.<func>]*
+ pci:<vendor>:<device>[:<subvendor>:<subdevice>]
+
+ Note: the first format specifies a PCI
+ bus/device/function address which may change
+ if new hardware is inserted, if motherboard
+ firmware changes, or due to changes caused
+ by other kernel parameters. If the
+ domain is left unspecified, it is
+ taken to be zero. Optionally, a path
+ to a device through multiple device/function
+ addresses can be specified after the base
+ address (this is more robust against
+ renumbering issues). The second format
+ selects devices using IDs from the
+ configuration space which may match multiple
+ devices in the system.
+
earlydump [X86] dump PCI config space before the kernel
changes anything
off [X86] don't probe for the PCI bus
@@ -3123,11 +3146,10 @@
window. The default value is 64 megabytes.
resource_alignment=
Format:
- [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...]
- [<order of align>@]pci:<vendor>:<device>\
- [:<subvendor>:<subdevice>][; ...]
+ [<order of align>@]<pci_dev>[; ...]
Specifies alignment and device to reassign
- aligned memory resources.
+ aligned memory resources. How to
+ specify the device is described above.
If <order of align> is not specified,
PAGE_SIZE is used as alignment.
PCI-PCI bridge can be specified, if resource
@@ -3170,6 +3192,15 @@
Adding the window is slightly risky (it may
conflict with unreported devices), so this
taints the kernel.
+ disable_acs_redir=<pci_dev>[; ...]
+ Specify one or more PCI devices (in the format
+ specified above) separated by semicolons.
+ Each device specified will have the PCI ACS
+ redirect capabilities forced off which will
+ allow P2P traffic between devices through
+ bridges without forcing it upstream. Note:
+ this removes isolation between devices and
+ may put more devices in an IOMMU group.
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
Management.
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 0306fa44653ae0716b90bd4ab89a5622ba5f0710..f68217abc1efe4ed6996ee60d242aec8c5a76eb7 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -190,6 +190,168 @@ void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
#endif
+/**
+ * pci_dev_str_match_path - test if a path string matches a device
+ * @dev: the PCI device to test
+ * @p: string to match the device against
+ * @endptr: pointer to the string after the match
+ *
+ * Test if a string (typically from a kernel parameter) formatted as a
+ * path of device/function addresses matches a PCI device. The string must
+ * be of the form:
+ *
+ * [<domain>:]<bus>:<device>.<func>[/<device>.<func>]*
+ *
+ * A path for a device can be obtained using 'lspci -t'. Using a path
+ * is more robust against bus renumbering than using only a single bus,
+ * device and function address.
+ *
+ * Returns 1 if the string matches the device, 0 if it does not and
+ * a negative error code if it fails to parse the string.
+ */
+static int pci_dev_str_match_path(struct pci_dev *dev, const char *path,
+ const char **endptr)
+{
+ int ret;
+ int seg, bus, slot, func;
+ char *wpath, *p;
+ char end;
+
+ *endptr = strchrnul(path, ';');
+
+ wpath = kmemdup_nul(path, *endptr - path, GFP_KERNEL);
+ if (!wpath)
+ return -ENOMEM;
+
+ while (1) {
+ p = strrchr(wpath, '/');
+ if (!p)
+ break;
+ ret = sscanf(p, "/%x.%x%c", &slot, &func, &end);
+ if (ret != 2) {
+ ret = -EINVAL;
+ goto free_and_exit;
+ }
+
+ if (dev->devfn != PCI_DEVFN(slot, func)) {
+ ret = 0;
+ goto free_and_exit;
+ }
+
+ /*
+ * Note: we don't need to get a reference to the upstream
+ * bridge because we hold a reference to the top level
+ * device which should hold a reference to the bridge,
+ * and so on.
+ */
+ dev = pci_upstream_bridge(dev);
+ if (!dev) {
+ ret = 0;
+ goto free_and_exit;
+ }
+
+ *p = 0;
+ }
+
+ ret = sscanf(wpath, "%x:%x:%x.%x%c", &seg, &bus, &slot,
+ &func, &end);
+ if (ret != 4) {
+ seg = 0;
+ ret = sscanf(wpath, "%x:%x.%x%c", &bus, &slot, &func, &end);
+ if (ret != 3) {
+ ret = -EINVAL;
+ goto free_and_exit;
+ }
+ }
+
+ ret = (seg == pci_domain_nr(dev->bus) &&
+ bus == dev->bus->number &&
+ dev->devfn == PCI_DEVFN(slot, func));
+
+free_and_exit:
+ kfree(wpath);
+ return ret;
+}
+
+/**
+ * pci_dev_str_match - test if a string matches a device
+ * @dev: the PCI device to test
+ * @p: string to match the device against
+ * @endptr: pointer to the string after the match
+ *
+ * Test if a string (typically from a kernel parameter) matches a specified
+ * PCI device. The string may be of one of the following formats:
+ *
+ * [<domain>:]<bus>:<device>.<func>[/<device>.<func>]*
+ * pci:<vendor>:<device>[:<subvendor>:<subdevice>]
+ *
+ * The first format specifies a PCI bus/device/function address which
+ * may change if new hardware is inserted, if motherboard firmware changes,
+ * or due to changes caused in kernel parameters. If the domain is
+ * left unspecified, it is taken to be 0. In order to be robust against
+ * bus renumbering issues, a path of PCI device/function numbers may be used
+ * to address the specific device. The path for a device can be determined
+ * through the use of 'lspci -t'.
+ *
+ * The second format matches devices using IDs in the configuration
+ * space which may match multiple devices in the system. A value of 0
+ * for any field will match all devices. (Note: this differs from
+ * in-kernel code that uses PCI_ANY_ID which is ~0; this is for
+ * legacy reasons and convenience so users don't have to specify
+ * FFFFFFFFs on the command line.)
+ *
+ * Returns 1 if the string matches the device, 0 if it does not and
+ * a negative error code if the string cannot be parsed.
+ */
+static int pci_dev_str_match(struct pci_dev *dev, const char *p,
+ const char **endptr)
+{
+ int ret;
+ int count;
+ unsigned short vendor, device, subsystem_vendor, subsystem_device;
+
+ if (strncmp(p, "pci:", 4) == 0) {
+ /* PCI vendor/device (subvendor/subdevice) IDs are specified */
+ p += 4;
+ ret = sscanf(p, "%hx:%hx:%hx:%hx%n", &vendor, &device,
+ &subsystem_vendor, &subsystem_device, &count);
+ if (ret != 4) {
+ ret = sscanf(p, "%hx:%hx%n", &vendor, &device, &count);
+ if (ret != 2)
+ return -EINVAL;
+
+ subsystem_vendor = 0;
+ subsystem_device = 0;
+ }
+
+ p += count;
+
+ if ((!vendor || vendor == dev->vendor) &&
+ (!device || device == dev->device) &&
+ (!subsystem_vendor ||
+ subsystem_vendor == dev->subsystem_vendor) &&
+ (!subsystem_device ||
+ subsystem_device == dev->subsystem_device))
+ goto found;
+ } else {
+ /*
+ * PCI Bus, Device, Function IDs are specified
+ * (optionally, may include a path of devfns following it)
+ */
+ ret = pci_dev_str_match_path(dev, p, &p);
+ if (ret < 0)
+ return ret;
+ else if (ret)
+ goto found;
+ }
+
+ *endptr = p;
+ return 0;
+
+found:
+ *endptr = p;
+ return 1;
+}
static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
u8 pos, int cap, int *ttl)
@@ -2829,6 +2991,66 @@ void pci_request_acs(void)
pci_acs_enable = 1;
}
+static const char *disable_acs_redir_param;
+
+/**
+ * pci_disable_acs_redir - disable ACS redirect capabilities
+ * @dev: the PCI device
+ *
+ * For only devices specified in the disable_acs_redir parameter.
+ */
+static void pci_disable_acs_redir(struct pci_dev *dev)
+{
+ int ret = 0;
+ const char *p;
+ int pos;
+ u16 ctrl;
+
+ if (!disable_acs_redir_param)
+ return;
+
+ p = disable_acs_redir_param;
+ while (*p) {
+ ret = pci_dev_str_match(dev, p, &p);
+ if (ret < 0) {
+ pr_info_once("PCI: Can't parse disable_acs_redir parameter: %s\n",
+ disable_acs_redir_param);
+
+ break;
+ } else if (ret == 1) {
+ /* Found a match */
+ break;
+ }
+
+ if (*p != ';' && *p != ',') {
+ /* End of param or invalid format */
+ break;
+ }
+ p++;
+ }
+
+ if (ret != 1)
+ return;
+
+ if (!pci_dev_specific_disable_acs_redir(dev))
+ return;
+
+ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
+ if (!pos) {
+ pci_warn(dev, "cannot disable ACS redirect for this hardware as it does not have ACS capabilities\n");
+ return;
+ }
+
+ pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
+
+ /* P2P Request & Completion Redirect */
+ ctrl &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_EC);
+
+ pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
+
+ pci_info(dev, "disabled ACS redirect\n");
+}
+
/**
* pci_std_enable_acs - enable ACS on devices using standard ACS capabilites
* @dev: the PCI device
@@ -2868,12 +3090,22 @@ static void pci_std_enable_acs(struct pci_dev *dev)
void pci_enable_acs(struct pci_dev *dev)
{
if (!pci_acs_enable)
- return;
+ goto disable_acs_redir;
if (!pci_dev_specific_enable_acs(dev))
- return;
+ goto disable_acs_redir;
pci_std_enable_acs(dev);
+
+disable_acs_redir:
+ /*
+ * Note: pci_disable_acs_redir() must be called even if ACS was not
+ * enabled by the kernel because it may have been enabled by
+ * platform firmware. So if we are told to disable it, we should
+ * always disable it after setting the kernel's default
+ * preferences.
+ */
+ pci_disable_acs_redir(dev);
}
static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags)
@@ -5514,10 +5746,10 @@ static DEFINE_SPINLOCK(resource_alignment_lock);
static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
bool *resize)
{
- int seg, bus, slot, func, align_order, count;
- unsigned short vendor, device, subsystem_vendor, subsystem_device;
+ int align_order, count;
resource_size_t align = pcibios_default_alignment();
- char *p;
+ const char *p;
+ int ret;
spin_lock(&resource_alignment_lock);
p = resource_alignment_param;
@@ -5537,58 +5769,21 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
} else {
align_order = -1;
}
- if (strncmp(p, "pci:", 4) == 0) {
- /* PCI vendor/device (subvendor/subdevice) ids are specified */
- p += 4;
- if (sscanf(p, "%hx:%hx:%hx:%hx%n",
- &vendor, &device, &subsystem_vendor, &subsystem_device, &count) != 4) {
- if (sscanf(p, "%hx:%hx%n", &vendor, &device, &count) != 2) {
- printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: pci:%s\n",
- p);
- break;
- }
- subsystem_vendor = subsystem_device = 0;
- }
- p += count;
- if ((!vendor || (vendor == dev->vendor)) &&
- (!device || (device == dev->device)) &&
- (!subsystem_vendor || (subsystem_vendor == dev->subsystem_vendor)) &&
- (!subsystem_device || (subsystem_device == dev->subsystem_device))) {
- *resize = true;
- if (align_order == -1)
- align = PAGE_SIZE;
- else
- align = 1 << align_order;
- /* Found */
- break;
- }
- }
- else {
- if (sscanf(p, "%x:%x:%x.%x%n",
- &seg, &bus, &slot, &func, &count) != 4) {
- seg = 0;
- if (sscanf(p, "%x:%x.%x%n",
- &bus, &slot, &func, &count) != 3) {
- /* Invalid format */
- printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: %s\n",
- p);
- break;
- }
- }
- p += count;
- if (seg == pci_domain_nr(dev->bus) &&
- bus == dev->bus->number &&
- slot == PCI_SLOT(dev->devfn) &&
- func == PCI_FUNC(dev->devfn)) {
- *resize = true;
- if (align_order == -1)
- align = PAGE_SIZE;
- else
- align = 1 << align_order;
- /* Found */
- break;
- }
+
+ ret = pci_dev_str_match(dev, p, &p);
+ if (ret == 1) {
+ *resize = true;
+ if (align_order == -1)
+ align = PAGE_SIZE;
+ else
+ align = 1 << align_order;
+ break;
+ } else if (ret < 0) {
+ pr_err("PCI: Can't parse resource_alignment parameter: %s\n",
+ p);
+ break;
}
+
if (*p != ';' && *p != ',') {
/* End of param or invalid format */
break;
@@ -5901,6 +6096,8 @@ static int __init pci_setup(char *str)
pcie_bus_config = PCIE_BUS_PEER2PEER;
} else if (!strncmp(str, "pcie_scan_all", 13)) {
pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
+ } else if (!strncmp(str, "disable_acs_redir=", 18)) {
+ disable_acs_redir_param = str + 18;
} else {
printk(KERN_ERR "PCI: Unknown option `%s'\n",
str);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index ccb0537d5d8943edef1c2f5b4aead7603d02b52d..8907ceb8823377049b29c6f49292b6fd68d09eec 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -400,6 +400,25 @@ static inline resource_size_t pci_resource_alignment(struct pci_dev *dev,
}
void pci_enable_acs(struct pci_dev *dev);
+#ifdef CONFIG_PCI_QUIRKS
+int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags);
+int pci_dev_specific_enable_acs(struct pci_dev *dev);
+int pci_dev_specific_disable_acs_redir(struct pci_dev *dev);
+#else
+static inline int pci_dev_specific_acs_enabled(struct pci_dev *dev,
+ u16 acs_flags)
+{
+ return -ENOTTY;
+}
+static inline int pci_dev_specific_enable_acs(struct pci_dev *dev)
+{
+ return -ENOTTY;
+}
+static inline int pci_dev_specific_disable_acs_redir(struct pci_dev *dev)
+{
+ return -ENOTTY;
+}
+#endif
/* PCI error reporting and recovery */
void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service);
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 2c6d987c271fba3ae77dd2d15840a0422c60103b..eb57d8b610fef4b1f29d1fcc9e1505c89130a0e4 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4555,27 +4555,79 @@ static int pci_quirk_enable_intel_spt_pch_acs(struct pci_dev *dev)
return 0;
}
-static const struct pci_dev_enable_acs {
+static int pci_quirk_disable_intel_spt_pch_acs_redir(struct pci_dev *dev)
+{
+ int pos;
+ u32 cap, ctrl;
+
+ if (!pci_quirk_intel_spt_pch_acs_match(dev))
+ return -ENOTTY;
+
+ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
+ if (!pos)
+ return -ENOTTY;
+
+ pci_read_config_dword(dev, pos + PCI_ACS_CAP, &cap);
+ pci_read_config_dword(dev, pos + INTEL_SPT_ACS_CTRL, &ctrl);
+
+ ctrl &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_EC);
+
+ pci_write_config_dword(dev, pos + INTEL_SPT_ACS_CTRL, ctrl);
+
+ pci_info(dev, "Intel SPT PCH root port workaround: disabled ACS redirect\n");
+
+ return 0;
+}
+
+static const struct pci_dev_acs_ops {
u16 vendor;
u16 device;
int (*enable_acs)(struct pci_dev *dev);
-} pci_dev_enable_acs[] = {
- { PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_quirk_enable_intel_pch_acs },
- { PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_quirk_enable_intel_spt_pch_acs },
- { 0 }
+ int (*disable_acs_redir)(struct pci_dev *dev);
+} pci_dev_acs_ops[] = {
+ { PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
+ .enable_acs = pci_quirk_enable_intel_pch_acs,
+ },
+ { PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
+ .enable_acs = pci_quirk_enable_intel_spt_pch_acs,
+ .disable_acs_redir = pci_quirk_disable_intel_spt_pch_acs_redir,
+ },
};
int pci_dev_specific_enable_acs(struct pci_dev *dev)
{
- const struct pci_dev_enable_acs *i;
- int ret;
+ const struct pci_dev_acs_ops *p;
+ int i, ret;
+
+ for (i = 0; i < ARRAY_SIZE(pci_dev_acs_ops); i++) {
+ p = &pci_dev_acs_ops[i];
+ if ((p->vendor == dev->vendor ||
+ p->vendor == (u16)PCI_ANY_ID) &&
+ (p->device == dev->device ||
+ p->device == (u16)PCI_ANY_ID) &&
+ p->enable_acs) {
+ ret = p->enable_acs(dev);
+ if (ret >= 0)
+ return ret;
+ }
+ }
- for (i = pci_dev_enable_acs; i->enable_acs; i++) {
- if ((i->vendor == dev->vendor ||
- i->vendor == (u16)PCI_ANY_ID) &&
- (i->device == dev->device ||
- i->device == (u16)PCI_ANY_ID)) {
- ret = i->enable_acs(dev);
+ return -ENOTTY;
+}
+
+int pci_dev_specific_disable_acs_redir(struct pci_dev *dev)
+{
+ const struct pci_dev_acs_ops *p;
+ int i, ret;
+
+ for (i = 0; i < ARRAY_SIZE(pci_dev_acs_ops); i++) {
+ p = &pci_dev_acs_ops[i];
+ if ((p->vendor == dev->vendor ||
+ p->vendor == (u16)PCI_ANY_ID) &&
+ (p->device == dev->device ||
+ p->device == (u16)PCI_ANY_ID) &&
+ p->disable_acs_redir) {
+ ret = p->disable_acs_redir(dev);
if (ret >= 0)
return ret;
}
diff --git a/include/linux/pci.h b/include/linux/pci.h
index b37f2734f9a21fda57575c9652b8e04b0ecf4ad3..3dd5b871b895d06cd6c2d5fed730cd0f9ef83cf5 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1890,20 +1890,9 @@ enum pci_fixup_pass {
#ifdef CONFIG_PCI_QUIRKS
void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev);
-int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags);
-int pci_dev_specific_enable_acs(struct pci_dev *dev);
#else
static inline void pci_fixup_device(enum pci_fixup_pass pass,
struct pci_dev *dev) { }
-static inline int pci_dev_specific_acs_enabled(struct pci_dev *dev,
- u16 acs_flags)
-{
- return -ENOTTY;
-}
-static inline int pci_dev_specific_enable_acs(struct pci_dev *dev)
-{
- return -ENOTTY;
-}
#endif
void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen);