diff options
Diffstat (limited to 'drivers/bus')
| -rw-r--r-- | drivers/bus/mvebu-mbus.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/drivers/bus/mvebu-mbus.c b/drivers/bus/mvebu-mbus.c index 6f047dcb94c2..c43c3d2baf73 100644 --- a/drivers/bus/mvebu-mbus.c +++ b/drivers/bus/mvebu-mbus.c @@ -57,6 +57,7 @@ #include <linux/of_address.h> #include <linux/debugfs.h> #include <linux/log2.h> +#include <linux/memblock.h> #include <linux/syscore_ops.h> /* @@ -152,13 +153,39 @@ struct mvebu_mbus_state { static struct mvebu_mbus_state mbus_state; +/* + * We provide two variants of the mv_mbus_dram_info() function: + * + * - The normal one, where the described DRAM ranges may overlap with + * the I/O windows, but for which the DRAM ranges are guaranteed to + * have a power of two size. Such ranges are suitable for the DMA + * masters that only DMA between the RAM and the device, which is + * actually all devices except the crypto engines. + * + * - The 'nooverlap' one, where the described DRAM ranges are + * guaranteed to not overlap with the I/O windows, but for which the + * DRAM ranges will not have power of two sizes. They will only be + * aligned on a 64 KB boundary, and have a size multiple of 64 + * KB. Such ranges are suitable for the DMA masters that DMA between + * the crypto SRAM (which is mapped through an I/O window) and a + * device. This is the case for the crypto engines. + */ + static struct mbus_dram_target_info mvebu_mbus_dram_info; +static struct mbus_dram_target_info mvebu_mbus_dram_info_nooverlap; + const struct mbus_dram_target_info *mv_mbus_dram_info(void) { return &mvebu_mbus_dram_info; } EXPORT_SYMBOL_GPL(mv_mbus_dram_info); +const struct mbus_dram_target_info *mv_mbus_dram_info_nooverlap(void) +{ + return &mvebu_mbus_dram_info_nooverlap; +} +EXPORT_SYMBOL_GPL(mv_mbus_dram_info_nooverlap); + /* Checks whether the given window has remap capability */ static bool mvebu_mbus_window_is_remappable(struct mvebu_mbus_state *mbus, const int win) @@ -576,6 +603,95 @@ 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 >= 0x100000000ULL) + 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 = 0x100000000ULL; +} + +/* + * This function fills in the mvebu_mbus_dram_info_nooverlap data + * structure, by looking at the mvebu_mbus_dram_info data, and + * removing the parts of it that overlap with I/O windows. + */ +static void __init +mvebu_mbus_setup_cpu_target_nooverlap(struct mvebu_mbus_state *mbus) +{ + uint64_t mbus_bridge_base, mbus_bridge_end; + int cs_nooverlap = 0; + int i; + + mvebu_mbus_find_bridge_hole(&mbus_bridge_base, &mbus_bridge_end); + + for (i = 0; i < mvebu_mbus_dram_info.num_cs; i++) { + struct mbus_dram_window *w; + u64 base, size, end; + + w = &mvebu_mbus_dram_info.cs[i]; + base = w->base; + size = w->size; + end = base + size; + + /* + * 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_nooverlap.cs[cs_nooverlap++]; + 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_nooverlap.mbus_dram_target_id = TARGET_DDR; + mvebu_mbus_dram_info_nooverlap.num_cs = cs_nooverlap; +} + static void __init mvebu_mbus_default_setup_cpu_target(struct mvebu_mbus_state *mbus) { @@ -964,6 +1080,7 @@ static int __init mvebu_mbus_common_init(struct mvebu_mbus_state *mbus, mvebu_mbus_disable_window(mbus, win); mbus->soc->setup_cpu_target(mbus); + mvebu_mbus_setup_cpu_target_nooverlap(mbus); if (is_coherent) writel(UNIT_SYNC_BARRIER_ALL, |