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authorStefan Roese <sr@denx.de>2016-09-15 07:37:31 +0200
committerVinod Koul <vinod.koul@intel.com>2016-09-15 21:13:59 +0530
commit77ff7a706f014a56d38f07acf220f381a8fe0fd8 (patch)
tree060c52eedaba57d63912fc10e89bdefbfcb8ded1 /drivers/dma/mv_xor.c
parent434cec62a6d73b8c8080cd992bc97a564fdd5a5a (diff)
downloadlinux-77ff7a706f014a56d38f07acf220f381a8fe0fd8.tar.bz2
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 <sr@denx.de> Cc: Gregory CLEMENT <gregory.clement@free-electrons.com> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: Marcin Wojtas <mw@semihalf.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/mv_xor.c')
-rw-r--r--drivers/dma/mv_xor.c95
1 files changed, 94 insertions, 1 deletions
diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index f4c9f98ec35e..ff4a094cd582 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));
}