[source] lantiq: fix pci issue if mem kernel parameter is used

[LEDE Commits]

mkresin pushed a commit to source.git, branch master:
https://git.lede-project.org/07bc0d60898d812f3c5793d4c020e748342176b2

commit 07bc0d60898d812f3c5793d4c020e748342176b2
Author: Eddi De Pieri <eddi at depieri.net>
AuthorDate: Tue Nov 8 17:38:03 2016 +0100

    lantiq: fix pci issue if mem kernel parameter is used
    
    As specified by e0229a16b0001c08e6c2611fa0bb9814507fced4 if the VR9
    based router provides FXS ports and they should enabled then the
    following must added to the kernel command line:
    
      mem=[TOTALMEMSIZE-2M] vpe1_load_addr=ADDRESS vpe1_mem=2M
    
    By adding mem= parameter a pci device stop working correctly. The
    pci-lantiq.c module use get_num_physpages() to compute dynamically the
    memory amount of the board.
    
    The mem= make the module to compute in the wrong way the BAR11MASK, so
    in this situation the mask is misaligned with the dma area that the
    hardware expects.
    
    This patch is a port of what legacy ifxmips_pci.c does.
    
    Signed-off-by: Eddi De Pieri <eddi at depieri.net>
---
 .../0154-lantiq-pci-bar11mask-fix.patch            | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/target/linux/lantiq/patches-4.4/0154-lantiq-pci-bar11mask-fix.patch b/target/linux/lantiq/patches-4.4/0154-lantiq-pci-bar11mask-fix.patch
new file mode 100644
index 0000000..0f564c4
--- /dev/null
+++ b/target/linux/lantiq/patches-4.4/0154-lantiq-pci-bar11mask-fix.patch
@@ -0,0 +1,22 @@
+--- a/arch/mips/pci/pci-lantiq.c
++++ b/arch/mips/pci/pci-lantiq.c
+@@ -62,6 +62,8 @@
+ #define ltq_pci_cfg_w32(x, y)	ltq_w32((x), ltq_pci_mapped_cfg + (y))
+ #define ltq_pci_cfg_r32(x)	ltq_r32(ltq_pci_mapped_cfg + (x))
+ 
++extern u32 max_low_pfn;
++
+ __iomem void *ltq_pci_mapped_cfg;
+ static __iomem void *ltq_pci_membase;
+ 
+@@ -87,8 +89,8 @@
+ 	u32 mem, bar11mask;
+ 
+ 	/* BAR11MASK value depends on available memory on system. */
+-	mem = get_num_physpages() * PAGE_SIZE;
+-	bar11mask = (0x0ffffff0 & ~((1 << (fls(mem) - 1)) - 1)) | 8;
++	mem = max_low_pfn << PAGE_SHIFT;
++	bar11mask = ((-roundup_pow_of_two(mem)) & 0x0F000000) | 8;
+ 
+ 	return bar11mask;
+ }