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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-13 02:50:23 +0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-13 02:50:23 +0400
commit6a84258e5f5bb8b9bd72e06a5837fa6fdacaf5c5 (patch)
tree3c4911a489c85e908b0ef3ed83d78264788f858c /Documentation
parentefefc6eb38d43b8e5daef482f575d767b002004e (diff)
parentf3e6f164c2389853432454c89b316a8ab7485e2f (diff)
downloadlinux-6a84258e5f5bb8b9bd72e06a5837fa6fdacaf5c5.tar.xz
Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6: (37 commits) PCI: merge almost all of pci_32.h and pci_64.h together PCI: X86: Introduce and enable PCI domain support PCI: Add 'nodomains' boot option, and pci_domains_supported global PCI: modify PCI bridge control ISA flag for clarity PCI: use _CRS for PCI resource allocation PCI: avoid P2P prefetch window for expansion ROMs PCI: skip ISA ioresource alignment on some systems PCI: remove transparent bridge sizing pci: write file size to inode on proc bus file write pci: use size stored in proc_dir_entry for proc bus files pci: implement "pci=noaer" PCI: fix IDE legacy mode resources MSI: Use correct data offset for 32-bit MSI in read_msi_msg() PCI: Fix incorrect argument order to list_add_tail() in PCI dynamic ID code PCI: i386: Compaq EVO N800c needs PCI bus renumbering PCI: Remove no longer correct documentation regarding MSI vector assignment PCI: re-enable onboard sound on "MSI K8T Neo2-FIR" PCI: quirk_vt82c586_acpi: Omit reading PCI revision ID PCI: quirk amd_8131_mmrbc: Omit reading pci revision ID cpqphp: Use PCI_CLASS_REVISION instead of PCI_REVISION_ID for read ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/DMA-API.txt3
-rw-r--r--Documentation/MSI-HOWTO.txt69
-rw-r--r--Documentation/kernel-parameters.txt8
3 files changed, 15 insertions, 65 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index cc7a8c39fb6f..b939ebb62871 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -68,6 +68,9 @@ size and dma_handle must all be the same as those passed into the
consistent allocate. cpu_addr must be the virtual address returned by
the consistent allocate.
+Note that unlike their sibling allocation calls, these routines
+may only be called with IRQs enabled.
+
Part Ib - Using small dma-coherent buffers
------------------------------------------
diff --git a/Documentation/MSI-HOWTO.txt b/Documentation/MSI-HOWTO.txt
index 0d8240774fca..a51f693c1541 100644
--- a/Documentation/MSI-HOWTO.txt
+++ b/Documentation/MSI-HOWTO.txt
@@ -241,68 +241,7 @@ address space of the MSI-X table/MSI-X PBA. Otherwise, the PCI subsystem
will fail enabling MSI-X on its hardware device when it calls the function
pci_enable_msix().
-5.3.2 Handling MSI-X allocation
-
-Determining the number of MSI-X vectors allocated to a function is
-dependent on the number of MSI capable devices and MSI-X capable
-devices populated in the system. The policy of allocating MSI-X
-vectors to a function is defined as the following:
-
-#of MSI-X vectors allocated to a function = (x - y)/z where
-
-x = The number of available PCI vector resources by the time
- the device driver calls pci_enable_msix(). The PCI vector
- resources is the sum of the number of unassigned vectors
- (new) and the number of released vectors when any MSI/MSI-X
- device driver switches its hardware device back to a legacy
- mode or is hot-removed. The number of unassigned vectors
- may exclude some vectors reserved, as defined in parameter
- NR_HP_RESERVED_VECTORS, for the case where the system is
- capable of supporting hot-add/hot-remove operations. Users
- may change the value defined in NR_HR_RESERVED_VECTORS to
- meet their specific needs.
-
-y = The number of MSI capable devices populated in the system.
- This policy ensures that each MSI capable device has its
- vector reserved to avoid the case where some MSI-X capable
- drivers may attempt to claim all available vector resources.
-
-z = The number of MSI-X capable devices populated in the system.
- This policy ensures that maximum (x - y) is distributed
- evenly among MSI-X capable devices.
-
-Note that the PCI subsystem scans y and z during a bus enumeration.
-When the PCI subsystem completes configuring MSI/MSI-X capability
-structure of a device as requested by its device driver, y/z is
-decremented accordingly.
-
-5.3.3 Handling MSI-X shortages
-
-For the case where fewer MSI-X vectors are allocated to a function
-than requested, the function pci_enable_msix() will return the
-maximum number of MSI-X vectors available to the caller. A device
-driver may re-send its request with fewer or equal vectors indicated
-in the return. For example, if a device driver requests 5 vectors, but
-the number of available vectors is 3 vectors, a value of 3 will be
-returned as a result of pci_enable_msix() call. A function could be
-designed for its driver to use only 3 MSI-X table entries as
-different combinations as ABC--, A-B-C, A--CB, etc. Note that this
-patch does not support multiple entries with the same vector. Such
-attempt by a device driver to use 5 MSI-X table entries with 3 vectors
-as ABBCC, AABCC, BCCBA, etc will result as a failure by the function
-pci_enable_msix(). Below are the reasons why supporting multiple
-entries with the same vector is an undesirable solution.
-
- - The PCI subsystem cannot determine the entry that
- generated the message to mask/unmask MSI while handling
- software driver ISR. Attempting to walk through all MSI-X
- table entries (2048 max) to mask/unmask any match vector
- is an undesirable solution.
-
- - Walking through all MSI-X table entries (2048 max) to handle
- SMP affinity of any match vector is an undesirable solution.
-
-5.3.4 API pci_enable_msix
+5.3.2 API pci_enable_msix
int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
@@ -339,7 +278,7 @@ a failure. This failure may be a result of duplicate entries
specified in second argument, or a result of no available vector,
or a result of failing to initialize MSI-X table entries.
-5.3.5 API pci_disable_msix
+5.3.3 API pci_disable_msix
void pci_disable_msix(struct pci_dev *dev)
@@ -349,7 +288,7 @@ always call free_irq() on all MSI-X vectors it has done request_irq()
on before calling this API. Failure to do so results in a BUG_ON() and
a device will be left with MSI-X enabled and leaks its vectors.
-5.3.6 MSI-X mode vs. legacy mode diagram
+5.3.4 MSI-X mode vs. legacy mode diagram
The below diagram shows the events which switch the interrupt
mode on the MSI-X capable device function between MSI-X mode and
@@ -407,7 +346,7 @@ between MSI mod MSI-X mode during a run-time.
MSI/MSI-X support requires support from both system hardware and
individual hardware device functions.
-5.5.1 System hardware support
+5.5.1 Required x86 hardware support
Since the target of MSI address is the local APIC CPU, enabling
MSI/MSI-X support in the Linux kernel is dependent on whether existing
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 912c57c2334e..9cbc82e37ed0 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -68,6 +68,7 @@ parameter is applicable:
PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
PARISC The PA-RISC architecture is enabled.
PCI PCI bus support is enabled.
+ PCIE PCI Express support is enabled.
PCMCIA The PCMCIA subsystem is enabled.
PNP Plug & Play support is enabled.
PPC PowerPC architecture is enabled.
@@ -1277,6 +1278,11 @@ and is between 256 and 4096 characters. It is defined in the file
Mechanism 1.
conf2 [X86-32] Force use of PCI Configuration
Mechanism 2.
+ noaer [PCIE] If the PCIEAER kernel config parameter is
+ enabled, this kernel boot option can be used to
+ disable the use of PCIE advanced error reporting.
+ nodomains [PCI] Disable support for multiple PCI
+ root domains (aka PCI segments, in ACPI-speak).
nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
Configuration
nomsi [MSI] If the PCI_MSI kernel config parameter is
@@ -1321,6 +1327,8 @@ and is between 256 and 4096 characters. It is defined in the file
IRQ routing is enabled.
noacpi [X86-32] Do not use ACPI for IRQ routing
or for PCI scanning.
+ use_crs [X86-32] Use _CRS for PCI resource
+ allocation.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
so this option is a temporary workaround