We used to use the same memory layout and size for a couple of boards and thus we just hardcoding IOC aperture start and size.
Now when we're getting more boards with more memory on board we need to have an ability to set IOC so it matches real DDR layout and size.
Even though it is not really a must but for simplicity we assume IOC covers all the DDR we have, that gives us a chance to not bother where DMA buffers are allocated - any part of DDR is OK.
Signed-off-by: Alexey Brodkin abrodkin@synopsys.com --- arch/arc/lib/cache.c | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-)
diff --git a/arch/arc/lib/cache.c b/arch/arc/lib/cache.c index f1436bf19992..cbae27e9fcec 100644 --- a/arch/arc/lib/cache.c +++ b/arch/arc/lib/cache.c @@ -8,6 +8,7 @@ #include <common.h> #include <linux/compiler.h> #include <linux/kernel.h> +#include <linux/log2.h> #include <asm/arcregs.h> #include <asm/cache.h>
@@ -215,17 +216,33 @@ void cache_init(void) read_decode_cache_bcr_arcv2();
if (ioc_exists) { + /* IOC Aperture start is equal to DDR start */ + unsigned int ap_base = CONFIG_SYS_SDRAM_BASE; + /* IOC Aperture size is equal to DDR size */ + long ap_size = CONFIG_SYS_SDRAM_SIZE; + flush_dcache_all(); invalidate_dcache_all();
- /* IO coherency base - 0x8z */ - write_aux_reg(ARC_AUX_IO_COH_AP0_BASE, 0x80000); - /* IO coherency aperture size - 512Mb: 0x8z-0xAz */ - write_aux_reg(ARC_AUX_IO_COH_AP0_SIZE, 0x11); - /* Enable partial writes */ + if (!is_power_of_2(ap_size) || ap_size < 4096) + panic("IOC Aperture size must be power of 2 and bigger 4Kib"); + + /* + * IOC Aperture size decoded as 2 ^ (SIZE + 2) KB, + * so setting 0x11 implies 512M, 0x12 implies 1G... + */ + write_aux_reg(ARC_AUX_IO_COH_AP0_SIZE, + order_base_2(ap_size/1024) - 2); + + + /* IOC Aperture start must be aligned to the size of the aperture */ + if (ap_base % ap_size != 0) + panic("IOC Aperture start must be aligned to the size of the aperture"); + + write_aux_reg(ARC_AUX_IO_COH_AP0_BASE, ap_base >> 12); write_aux_reg(ARC_AUX_IO_COH_PARTIAL, 1); - /* Enable IO coherency */ write_aux_reg(ARC_AUX_IO_COH_ENABLE, 1); + } #endif }