Hi Andi, I don't see this patch being applied in any of the tree yet. Resending this incase you guys might have missed it. I assume this will go through the ACPI tree. The need for this patch was explained in http://marc.info/?l=linux-kernel&m=121441818818598&w=2 The v2 patch was discussed in http://marc.info/?l=linux-acpi&m=121433339619175&w=2 I then sent a incremental patch on top of v2 to fix some conditions and handle the change in the e820_search_gap interface. In this v3 patch, i have folded the incremental fix into the v2 patch. Please apply this. Thanks, Alok -- acpi based pci gap calculation - v3 From: Alok N Kataria <akataria@xxxxxxxxxx> Evaluates the _CRS object under PCI0 looking for producer resources. Then searches the e820 memory space for a gap within these producer resources. Allows us to find a gap for the unclaimed pci resources or MMIO resources for hotplug devices within the BIOS allowed pci regions. v1->v2: Some changes in the print strings. Also note the prototype for e820_search_gap has changed in this iteration, but the return value is ignored while calling it over here. v2->v3: Pass the pci producer resources end_addr (got from _CRS) to the e820_search_gap function. We limit the search only within the producer region's address space. Also add a condition to check if the resource lies in the 32bit address range. Signed-off-by: Alok N Kataria <akataria@xxxxxxxxxx> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Len Brown <lenb@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> --- arch/x86/pci/acpi.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 80 insertions(+), 0 deletions(-) diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c index 19af069..fff2c42 100644 --- a/arch/x86/pci/acpi.c +++ b/arch/x86/pci/acpi.c @@ -4,6 +4,7 @@ #include <linux/irq.h> #include <linux/dmi.h> #include <asm/numa.h> +#include <asm/e820.h> #include "pci.h" struct pci_root_info { @@ -14,6 +15,11 @@ struct pci_root_info { int busnum; }; +struct gap_info { + unsigned long gapstart; + unsigned long gapsize; +}; + static acpi_status resource_to_addr(struct acpi_resource *resource, struct acpi_resource_address64 *addr) @@ -110,6 +116,78 @@ adjust_transparent_bridge_resources(struct pci_bus *bus) } } +static acpi_status search_gap(struct acpi_resource *resource, void *data) +{ + struct acpi_resource_address64 addr; + acpi_status status; + struct gap_info *gap = data; + unsigned long long start_addr, end_addr; + + status = resource_to_addr(resource, &addr); + if (ACPI_SUCCESS(status) && + addr.resource_type == ACPI_MEMORY_RANGE && + addr.address_length > gap->gapsize) { + start_addr = addr.minimum + addr.translation_offset; + /* + * We want space only in the 32bit address range + */ + if (start_addr < UINT_MAX) { + end_addr = start_addr + addr.address_length; + e820_search_gap(&gap->gapstart, &gap->gapsize, + start_addr, end_addr); + } + } + + return AE_OK; +} + +/* + * Search for a hole in the 32 bit address space for PCI to assign MMIO + * resources, for hotplug or unconfigured resources. + * We query the CRS object of the PCI root device to look for possible producer + * resources in the tree and consider these while calulating the start address + * for this hole. + */ +static void pci_setup_gap(acpi_handle *handle) +{ + struct gap_info gap; + acpi_status status; + + gap.gapstart = 0; + gap.gapsize = 0x400000; + + status = acpi_walk_resources(handle, METHOD_NAME__CRS, + search_gap, &gap); + + if (ACPI_SUCCESS(status)) { + unsigned long round; + + if (!gap.gapstart) { + printk(KERN_ERR "ACPI: Warning: Cannot find a gap " + "in the 32bit address range for PCI\n" + "ACPI: PCI devices may collide with " + "hotpluggable memory address range\n"); + } + /* + * Round the gapstart, uses the same logic as in + * e820_gap_setup + */ + round = 0x100000; + while ((gap.gapsize >> 4) > round) + round += round; + /* Fun with two's complement */ + pci_mem_start = (gap.gapstart + round) & -round; + + printk(KERN_INFO "ACPI: PCI resources should " + "start at %lx (gap: %lx:%lx)\n", + pci_mem_start, gap.gapstart, gap.gapsize); + } else { + printk(KERN_ERR "ACPI: Error while searching for gap in " + "the 32bit address range for PCI\n"); + } +} + + static void get_current_resources(struct acpi_device *device, int busnum, int domain, struct pci_bus *bus) @@ -220,6 +298,8 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_device *device, int do if (bus && (pci_probe & PCI_USE__CRS)) get_current_resources(device, busnum, domain, bus); + + pci_setup_gap(device->handle); return bus; } -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
