From aee3ad815dd291a7193ab01da0f1a30c84d00061 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Fri, 27 Jun 2008 16:56:57 -0600 Subject: PNP: replace pnp_resource_table with dynamically allocated resources PNP used to have a fixed-size pnp_resource_table for tracking the resources used by a device. This table often overflowed, so we've had to increase the table size, which wastes memory because most devices have very few resources. This patch replaces the table with a linked list of resources where the entries are allocated on demand. This removes messages like these: pnpacpi: exceeded the max number of IO resources 00:01: too many I/O port resources References: http://bugzilla.kernel.org/show_bug.cgi?id=9535 http://bugzilla.kernel.org/show_bug.cgi?id=9740 http://lkml.org/lkml/2007/11/30/110 This patch also changes the way PNP uses the IORESOURCE_UNSET, IORESOURCE_AUTO, and IORESOURCE_DISABLED flags. Prior to this patch, the pnp_resource_table entries used the flags like this: IORESOURCE_UNSET This table entry is unused and available for use. When this flag is set, we shouldn't look at anything else in the resource structure. This flag is set when a resource table entry is initialized. IORESOURCE_AUTO This resource was assigned automatically by pnp_assign_{io,mem,etc}(). This flag is set when a resource table entry is initialized and cleared whenever we discover a resource setting by reading an ISAPNP config register, parsing a PNPBIOS resource data stream, parsing an ACPI _CRS list, or interpreting a sysfs "set" command. Resources marked IORESOURCE_AUTO are reinitialized and marked as IORESOURCE_UNSET by pnp_clean_resource_table() in these cases: - before we attempt to assign resources automatically, - if we fail to assign resources automatically, - after disabling a device IORESOURCE_DISABLED Set by pnp_assign_{io,mem,etc}() when automatic assignment fails. Also set by PNPBIOS and PNPACPI for: - invalid IRQs or GSI registration failures - invalid DMA channels - I/O ports above 0x10000 - mem ranges with negative length After this patch, there is no pnp_resource_table, and the resource list entries use the flags like this: IORESOURCE_UNSET This flag is no longer used in PNP. Instead of keeping IORESOURCE_UNSET entries in the resource list, we remove entries from the list and free them. IORESOURCE_AUTO No change in meaning: it still means the resource was assigned automatically by pnp_assign_{port,mem,etc}(), but these functions now set the bit explicitly. We still "clean" a device's resource list in the same places, but rather than reinitializing IORESOURCE_AUTO entries, we just remove them from the list. Note that IORESOURCE_AUTO entries are always at the end of the list, so removing them doesn't reorder other list entries. This is because non-IORESOURCE_AUTO entries are added by the ISAPNP, PNPBIOS, or PNPACPI "get resources" methods and by the sysfs "set" command. In each of these cases, we completely free the resource list first. IORESOURCE_DISABLED In addition to the cases where we used to set this flag, ISAPNP now adds an IORESOURCE_DISABLED resource when it reads a configuration register with a "disabled" value. Signed-off-by: Bjorn Helgaas Signed-off-by: Len Brown Signed-off-by: Andi Kleen --- drivers/pnp/core.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) (limited to 'drivers/pnp/core.c') diff --git a/drivers/pnp/core.c b/drivers/pnp/core.c index 20771b7d4482..7182da92aec3 100644 --- a/drivers/pnp/core.c +++ b/drivers/pnp/core.c @@ -99,6 +99,21 @@ static void pnp_free_ids(struct pnp_dev *dev) } } +void pnp_free_resource(struct pnp_resource *pnp_res) +{ + list_del(&pnp_res->list); + kfree(pnp_res); +} + +void pnp_free_resources(struct pnp_dev *dev) +{ + struct pnp_resource *pnp_res, *tmp; + + list_for_each_entry_safe(pnp_res, tmp, &dev->resources, list) { + pnp_free_resource(pnp_res); + } +} + static void pnp_release_device(struct device *dmdev) { struct pnp_dev *dev = to_pnp_dev(dmdev); @@ -106,7 +121,7 @@ static void pnp_release_device(struct device *dmdev) pnp_free_option(dev->independent); pnp_free_option(dev->dependent); pnp_free_ids(dev); - kfree(dev->res); + pnp_free_resources(dev); kfree(dev); } @@ -119,12 +134,7 @@ struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *protocol, int id, char *pnpid if (!dev) return NULL; - dev->res = kzalloc(sizeof(struct pnp_resource_table), GFP_KERNEL); - if (!dev->res) { - kfree(dev); - return NULL; - } - + INIT_LIST_HEAD(&dev->resources); dev->protocol = protocol; dev->number = id; dev->dma_mask = DMA_24BIT_MASK; @@ -140,7 +150,6 @@ struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *protocol, int id, char *pnpid dev_id = pnp_add_id(dev, pnpid); if (!dev_id) { - kfree(dev->res); kfree(dev); return NULL; } -- cgit v1.2.3 From 1f32ca31e7409d37c1b25e5f81840fb184380cdf Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Fri, 27 Jun 2008 16:57:17 -0600 Subject: PNP: convert resource options to single linked list ISAPNP, PNPBIOS, and ACPI describe the "possible resource settings" of a device, i.e., the possibilities an OS bus driver has when it assigns I/O port, MMIO, and other resources to the device. PNP used to maintain this "possible resource setting" information in one independent option structure and a list of dependent option structures for each device. Each of these option structures had lists of I/O, memory, IRQ, and DMA resources, for example: dev independent options ind-io0 -> ind-io1 ... ind-mem0 -> ind-mem1 ... ... dependent option set 0 dep0-io0 -> dep0-io1 ... dep0-mem0 -> dep0-mem1 ... ... dependent option set 1 dep1-io0 -> dep1-io1 ... dep1-mem0 -> dep1-mem1 ... ... ... This data structure was designed for ISAPNP, where the OS configures device resource settings by writing directly to configuration registers. The OS can write the registers in arbitrary order much like it writes PCI BARs. However, for PNPBIOS and ACPI devices, the OS uses firmware interfaces that perform device configuration, and it is important to pass the desired settings to those interfaces in the correct order. The OS learns the correct order by using firmware interfaces that return the "current resource settings" and "possible resource settings," but the option structures above doesn't store the ordering information. This patch replaces the independent and dependent lists with a single list of options. For example, a device might have possible resource settings like this: dev options ind-io0 -> dep0-io0 -> dep1->io0 -> ind-io1 ... All the possible settings are in the same list, in the order they come from the firmware "possible resource settings" list. Each entry is tagged with an independent/dependent flag. Dependent entries also have a "set number" and an optional priority value. All dependent entries must be assigned from the same set. For example, the OS can use all the entries from dependent set 0, or all the entries from dependent set 1, but it cannot mix entries from set 0 with entries from set 1. Prior to this patch PNP didn't keep track of the order of this list, and it assigned all independent options first, then all dependent ones. Using the example above, that resulted in a "desired configuration" list like this: ind->io0 -> ind->io1 -> depN-io0 ... instead of the list the firmware expects, which looks like this: ind->io0 -> depN-io0 -> ind-io1 ... Signed-off-by: Bjorn Helgaas Signed-off-by: Andi Kleen Acked-by: Rene Herman Signed-off-by: Len Brown --- drivers/pnp/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/pnp/core.c') diff --git a/drivers/pnp/core.c b/drivers/pnp/core.c index 7182da92aec3..a411582bcd72 100644 --- a/drivers/pnp/core.c +++ b/drivers/pnp/core.c @@ -118,10 +118,9 @@ static void pnp_release_device(struct device *dmdev) { struct pnp_dev *dev = to_pnp_dev(dmdev); - pnp_free_option(dev->independent); - pnp_free_option(dev->dependent); pnp_free_ids(dev); pnp_free_resources(dev); + pnp_free_options(dev); kfree(dev); } @@ -135,6 +134,7 @@ struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *protocol, int id, char *pnpid return NULL; INIT_LIST_HEAD(&dev->resources); + INIT_LIST_HEAD(&dev->options); dev->protocol = protocol; dev->number = id; dev->dma_mask = DMA_24BIT_MASK; -- cgit v1.2.3