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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-02-08 14:27:21 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-02-10 14:39:08 +1100 |
| commit | 5b11abfdb572bf9284e596dd198ac2aaf95b6616 (patch) | |
| tree | 1d7852201544d29c6757cd27f131bb31d29d74ed | |
| parent | d87bf76679bd37593ae4a3133f5da9395a4963ac (diff) | |
| download | linux-5b11abfdb572bf9284e596dd198ac2aaf95b6616.tar.bz2 | |
powerpc/pci: mmap anonymous memory when legacy_mem doesn't exist
The new legacy_mem file in sysfs is causing problems with X on machines
that don't support legacy memory access. The way I initially implemented
it, we would fail with -ENXIO when trying to mmap it, thus exposing to
X that we do support the API but there is no legacy memory.
Unfortunately, X poor error handling is causing it to fail to start when
it gets this error.
This implements a workaround hack that instead maps anonymous memory
instead (using shmem if VM_SHARED is set, just like /dev/zero does).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| -rw-r--r-- | arch/powerpc/kernel/pci-common.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c index 19b12d2cbb4b..0f4181272311 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -561,8 +561,21 @@ int pci_mmap_legacy_page_range(struct pci_bus *bus, (unsigned long long)(offset + size - 1)); if (mmap_state == pci_mmap_mem) { - if ((offset + size) > hose->isa_mem_size) - return -ENXIO; + /* Hack alert ! + * + * Because X is lame and can fail starting if it gets an error trying + * to mmap legacy_mem (instead of just moving on without legacy memory + * access) we fake it here by giving it anonymous memory, effectively + * behaving just like /dev/zero + */ + if ((offset + size) > hose->isa_mem_size) { + printk(KERN_DEBUG + "Process %s (pid:%d) mapped non-existing PCI legacy memory for 0%04x:%02x\n", + current->comm, current->pid, pci_domain_nr(bus), bus->number); + if (vma->vm_flags & VM_SHARED) + return shmem_zero_setup(vma); + return 0; + } offset += hose->isa_mem_phys; } else { unsigned long io_offset = (unsigned long)hose->io_base_virt - _IO_BASE; |