diff options
| -rw-r--r-- | drivers/bus/mvebu-mbus.c | 105 |
1 files changed, 89 insertions, 16 deletions
diff --git a/drivers/bus/mvebu-mbus.c b/drivers/bus/mvebu-mbus.c index a62c8ae253c3..fb9ec6221730 100644 --- a/drivers/bus/mvebu-mbus.c +++ b/drivers/bus/mvebu-mbus.c @@ -58,6 +58,7 @@ #include <linux/debugfs.h> #include <linux/log2.h> #include <linux/syscore_ops.h> +#include <linux/memblock.h> /* * DDR target is the same on all platforms. @@ -101,7 +102,9 @@ /* Relative to mbusbridge_base */ #define MBUS_BRIDGE_CTRL_OFF 0x0 +#define MBUS_BRIDGE_SIZE_MASK 0xffff0000 #define MBUS_BRIDGE_BASE_OFF 0x4 +#define MBUS_BRIDGE_BASE_MASK 0xffff0000 /* Maximum number of windows, for all known platforms */ #define MBUS_WINS_MAX 20 @@ -574,36 +577,106 @@ static unsigned int armada_xp_mbus_win_remap_offset(int win) return MVEBU_MBUS_NO_REMAP; } +/* + * Use the memblock information to find the MBus bridge hole in the + * physical address space. + */ +static void __init +mvebu_mbus_find_bridge_hole(uint64_t *start, uint64_t *end) +{ + struct memblock_region *r; + uint64_t s = 0; + + for_each_memblock(memory, r) { + /* + * This part of the memory is above 4 GB, so we don't + * care for the MBus bridge hole. + */ + if (r->base >= 0x100000000) + continue; + + /* + * The MBus bridge hole is at the end of the RAM under + * the 4 GB limit. + */ + if (r->base + r->size > s) + s = r->base + r->size; + } + + *start = s; + *end = 0x100000000; +} + static void __init mvebu_mbus_default_setup_cpu_target(struct mvebu_mbus_state *mbus) { int i; int cs; + uint64_t mbus_bridge_base, mbus_bridge_end; mvebu_mbus_dram_info.mbus_dram_target_id = TARGET_DDR; + mvebu_mbus_find_bridge_hole(&mbus_bridge_base, &mbus_bridge_end); + for (i = 0, cs = 0; i < 4; i++) { - u32 base = readl(mbus->sdramwins_base + DDR_BASE_CS_OFF(i)); - u32 size = readl(mbus->sdramwins_base + DDR_SIZE_CS_OFF(i)); + u64 base = readl(mbus->sdramwins_base + DDR_BASE_CS_OFF(i)); + u64 size = readl(mbus->sdramwins_base + DDR_SIZE_CS_OFF(i)); + u64 end; + struct mbus_dram_window *w; + + /* Ignore entries that are not enabled */ + if (!(size & DDR_SIZE_ENABLED)) + continue; /* - * We only take care of entries for which the chip - * select is enabled, and that don't have high base - * address bits set (devices can only access the first - * 32 bits of the memory). + * Ignore entries whose base address is above 2^32, + * since devices cannot DMA to such high addresses */ - if ((size & DDR_SIZE_ENABLED) && - !(base & DDR_BASE_CS_HIGH_MASK)) { - struct mbus_dram_window *w; + if (base & DDR_BASE_CS_HIGH_MASK) + continue; - w = &mvebu_mbus_dram_info.cs[cs++]; - w->cs_index = i; - w->mbus_attr = 0xf & ~(1 << i); - if (mbus->hw_io_coherency) - w->mbus_attr |= ATTR_HW_COHERENCY; - w->base = base & DDR_BASE_CS_LOW_MASK; - w->size = (size | ~DDR_SIZE_MASK) + 1; + base = base & DDR_BASE_CS_LOW_MASK; + size = (size | ~DDR_SIZE_MASK) + 1; + end = base + size; + + /* + * Adjust base/size of the current CS to make sure it + * doesn't overlap with the MBus bridge hole. This is + * particularly important for devices that do DMA from + * DRAM to a SRAM mapped in a MBus window, such as the + * CESA cryptographic engine. + */ + + /* + * The CS is fully enclosed inside the MBus bridge + * area, so ignore it. + */ + if (base >= mbus_bridge_base && end <= mbus_bridge_end) + continue; + + /* + * Beginning of CS overlaps with end of MBus, raise CS + * base address, and shrink its size. + */ + if (base >= mbus_bridge_base && end > mbus_bridge_end) { + size -= mbus_bridge_end - base; + base = mbus_bridge_end; } + + /* + * End of CS overlaps with beginning of MBus, shrink + * CS size. + */ + if (base < mbus_bridge_base && end > mbus_bridge_base) + size -= end - mbus_bridge_base; + + w = &mvebu_mbus_dram_info.cs[cs++]; + w->cs_index = i; + w->mbus_attr = 0xf & ~(1 << i); + if (mbus->hw_io_coherency) + w->mbus_attr |= ATTR_HW_COHERENCY; + w->base = base; + w->size = size; } mvebu_mbus_dram_info.num_cs = cs; } |