From 77ff7a706f014a56d38f07acf220f381a8fe0fd8 Mon Sep 17 00:00:00 2001 From: Stefan Roese Date: Thu, 15 Sep 2016 07:37:31 +0200 Subject: [PATCH] dmaengine: mv_xor: Add support for IO (PCIe) src/dst areas To enable the access to a specific area, the MVEBU XOR controllers needs to have this area enabled / mapped via an address window. Right now, only the DRAM memory area is enabled via such memory windows. So using this driver to DMA to / from a e.g. PCIe memory region is currently not supported. This patch now adds support for such PCIe / IO regions by checking if the src / dst address is located in an IO memory area in contrast to being located in DRAM. This is done by using the newly introduced MBus function mvebu_mbus_get_io_win_info(). If the src / dst address is located in such an IO area, a new address window is created in the XOR DMA controller. Enabling the controller to access this area. Signed-off-by: Stefan Roese Cc: Gregory CLEMENT Cc: Thomas Petazzoni Cc: Marcin Wojtas Cc: Arnd Bergmann Cc: Andrew Lunn Cc: Vinod Koul Signed-off-by: Vinod Koul --- drivers/dma/mv_xor.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++- drivers/dma/mv_xor.h | 7 ++++ 2 files changed, 101 insertions(+), 1 deletion(-) diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c index f4c9f98..ff4a094 100644 --- a/drivers/dma/mv_xor.c +++ b/drivers/dma/mv_xor.c @@ -470,12 +470,90 @@ static int mv_xor_alloc_chan_resources(struct dma_chan *chan) return mv_chan->slots_allocated ? : -ENOMEM; } +/* + * Check if source or destination is an PCIe/IO address (non-SDRAM) and add + * a new MBus window if necessary. Use a cache for these check so that + * the MMIO mapped registers don't have to be accessed for this check + * to speed up this process. + */ +static int mv_xor_add_io_win(struct mv_xor_chan *mv_chan, u32 addr) +{ + struct mv_xor_device *xordev = mv_chan->xordev; + void __iomem *base = mv_chan->mmr_high_base; + u32 win_enable; + u32 size; + u8 target, attr; + int ret; + int i; + + /* Nothing needs to get done for the Armada 3700 */ + if (xordev->xor_type == XOR_ARMADA_37XX) + return 0; + + /* + * Loop over the cached windows to check, if the requested area + * is already mapped. If this the case, nothing needs to be done + * and we can return. + */ + for (i = 0; i < WINDOW_COUNT; i++) { + if (addr >= xordev->win_start[i] && + addr <= xordev->win_end[i]) { + /* Window is already mapped */ + return 0; + } + } + + /* + * The window is not mapped, so we need to create the new mapping + */ + + /* If no IO window is found that addr has to be located in SDRAM */ + ret = mvebu_mbus_get_io_win_info(addr, &size, &target, &attr); + if (ret < 0) + return 0; + + /* + * Mask the base addr 'addr' according to 'size' read back from the + * MBus window. Otherwise we might end up with an address located + * somewhere in the middle of this area here. + */ + size -= 1; + addr &= ~size; + + /* + * Reading one of both enabled register is enough, as they are always + * programmed to the identical values + */ + win_enable = readl(base + WINDOW_BAR_ENABLE(0)); + + /* Set 'i' to the first free window to write the new values to */ + i = ffs(~win_enable) - 1; + if (i >= WINDOW_COUNT) + return -ENOMEM; + + writel((addr & 0xffff0000) | (attr << 8) | target, + base + WINDOW_BASE(i)); + writel(size & 0xffff0000, base + WINDOW_SIZE(i)); + + /* Fill the caching variables for later use */ + xordev->win_start[i] = addr; + xordev->win_end[i] = addr + size; + + win_enable |= (1 << i); + win_enable |= 3 << (16 + (2 * i)); + writel(win_enable, base + WINDOW_BAR_ENABLE(0)); + writel(win_enable, base + WINDOW_BAR_ENABLE(1)); + + return 0; +} + static struct dma_async_tx_descriptor * mv_xor_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src, unsigned int src_cnt, size_t len, unsigned long flags) { struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan); struct mv_xor_desc_slot *sw_desc; + int ret; if (unlikely(len < MV_XOR_MIN_BYTE_COUNT)) return NULL; @@ -486,6 +564,11 @@ mv_xor_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src, "%s src_cnt: %d len: %zu dest %pad flags: %ld\n", __func__, src_cnt, len, &dest, flags); + /* Check if a new window needs to get added for 'dest' */ + ret = mv_xor_add_io_win(mv_chan, dest); + if (ret) + return NULL; + sw_desc = mv_chan_alloc_slot(mv_chan); if (sw_desc) { sw_desc->type = DMA_XOR; @@ -493,8 +576,13 @@ mv_xor_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src, mv_desc_init(sw_desc, dest, len, flags); if (mv_chan->op_in_desc == XOR_MODE_IN_DESC) mv_desc_set_mode(sw_desc); - while (src_cnt--) + while (src_cnt--) { + /* Check if a new window needs to get added for 'src' */ + ret = mv_xor_add_io_win(mv_chan, src[src_cnt]); + if (ret) + return NULL; mv_desc_set_src_addr(sw_desc, src_cnt, src[src_cnt]); + } } dev_dbg(mv_chan_to_devp(mv_chan), @@ -959,6 +1047,7 @@ mv_xor_channel_add(struct mv_xor_device *xordev, mv_chan->op_in_desc = XOR_MODE_IN_DESC; dma_dev = &mv_chan->dmadev; + mv_chan->xordev = xordev; /* * These source and destination dummy buffers are used to implement @@ -1086,6 +1175,10 @@ mv_xor_conf_mbus_windows(struct mv_xor_device *xordev, dram->mbus_dram_target_id, base + WINDOW_BASE(i)); writel((cs->size - 1) & 0xffff0000, base + WINDOW_SIZE(i)); + /* Fill the caching variables for later use */ + xordev->win_start[i] = cs->base; + xordev->win_end[i] = cs->base + cs->size - 1; + win_enable |= (1 << i); win_enable |= 3 << (16 + (2 * i)); } diff --git a/drivers/dma/mv_xor.h b/drivers/dma/mv_xor.h index bf56e08..88eeab2 100644 --- a/drivers/dma/mv_xor.h +++ b/drivers/dma/mv_xor.h @@ -80,12 +80,17 @@ #define WINDOW_BAR_ENABLE(chan) (0x40 + ((chan) << 2)) #define WINDOW_OVERRIDE_CTRL(chan) (0xA0 + ((chan) << 2)) +#define WINDOW_COUNT 8 + struct mv_xor_device { void __iomem *xor_base; void __iomem *xor_high_base; struct clk *clk; struct mv_xor_chan *channels[MV_XOR_MAX_CHANNELS]; int xor_type; + + u32 win_start[WINDOW_COUNT]; + u32 win_end[WINDOW_COUNT]; }; /** @@ -127,6 +132,8 @@ struct mv_xor_chan { char dummy_dst[MV_XOR_MIN_BYTE_COUNT]; dma_addr_t dummy_src_addr, dummy_dst_addr; u32 saved_config_reg, saved_int_mask_reg; + + struct mv_xor_device *xordev; }; /** -- 2.7.4