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Merge tag 'iommu-updates-v3.8' of git://git.kernel.org/pub/scm/linux/…

…kernel/git/joro/iommu

Pull IOMMU updates from Joerg Roedel:
 "A few new features this merge-window.  The most important one is
  probably, that dma-debug now warns if a dma-handle is not checked with
  dma_mapping_error by the device driver.  This requires minor changes
  to some architectures which make use of dma-debug.  Most of these
  changes have the respective Acks by the Arch-Maintainers.

  Besides that there are updates to the AMD IOMMU driver for refactor
  the IOMMU-Groups support and to make sure it does not trigger a
  hardware erratum.

  The OMAP changes (for which I pulled in a branch from Tony Lindgren's
  tree) have a conflict in linux-next with the arm-soc tree.  The
  conflict is in the file arch/arm/mach-omap2/clock44xx_data.c which is
  deleted in the arm-soc tree.  It is safe to delete the file too so
  solve the conflict.  Similar changes are done in the arm-soc tree in
  the common clock framework migration.  A missing hunk from the patch
  in the IOMMU tree will be submitted as a seperate patch when the
  merge-window is closed."

* tag 'iommu-updates-v3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (29 commits)
  ARM: dma-mapping: support debug_dma_mapping_error
  ARM: OMAP4: hwmod data: ipu and dsp to use parent clocks instead of leaf clocks
  iommu/omap: Adapt to runtime pm
  iommu/omap: Migrate to hwmod framework
  iommu/omap: Keep mmu enabled when requested
  iommu/omap: Remove redundant clock handling on ISR
  iommu/amd: Remove obsolete comment
  iommu/amd: Don't use 512GB pages
  iommu/tegra: smmu: Move bus_set_iommu after probe for multi arch
  iommu/tegra: gart: Move bus_set_iommu after probe for multi arch
  iommu/tegra: smmu: Remove unnecessary PTC/TLB flush all
  tile: dma_debug: add debug_dma_mapping_error support
  sh: dma_debug: add debug_dma_mapping_error support
  powerpc: dma_debug: add debug_dma_mapping_error support
  mips: dma_debug: add debug_dma_mapping_error support
  microblaze: dma-mapping: support debug_dma_mapping_error
  ia64: dma_debug: add debug_dma_mapping_error support
  c6x: dma_debug: add debug_dma_mapping_error support
  ARM64: dma_debug: add debug_dma_mapping_error support
  intel-iommu: Prevent devices with RMRRs from being placed into SI Domain
  ...
  • Loading branch information...
torvalds committed Dec 20, 2012
2 parents 6491d4d + 9c6ecf6 commit 787314c35fbb97e02823a1b8eb8cfa58f366cd49
@@ -468,11 +468,46 @@ To map a single region, you do:
size_t size = buffer->len;
dma_handle = dma_map_single(dev, addr, size, direction);
+ if (dma_mapping_error(dma_handle)) {
+ /*
+ * reduce current DMA mapping usage,
+ * delay and try again later or
+ * reset driver.
+ */
+ goto map_error_handling;
+ }
and to unmap it:
dma_unmap_single(dev, dma_handle, size, direction);
+You should call dma_mapping_error() as dma_map_single() could fail and return
+error. Not all dma implementations support dma_mapping_error() interface.
+However, it is a good practice to call dma_mapping_error() interface, which
+will invoke the generic mapping error check interface. Doing so will ensure
+that the mapping code will work correctly on all dma implementations without
+any dependency on the specifics of the underlying implementation. Using the
+returned address without checking for errors could result in failures ranging
+from panics to silent data corruption. Couple of example of incorrect ways to
+check for errors that make assumptions about the underlying dma implementation
+are as follows and these are applicable to dma_map_page() as well.
+
+Incorrect example 1:
+ dma_addr_t dma_handle;
+
+ dma_handle = dma_map_single(dev, addr, size, direction);
+ if ((dma_handle & 0xffff != 0) || (dma_handle >= 0x1000000)) {
+ goto map_error;
+ }
+
+Incorrect example 2:
+ dma_addr_t dma_handle;
+
+ dma_handle = dma_map_single(dev, addr, size, direction);
+ if (dma_handle == DMA_ERROR_CODE) {
+ goto map_error;
+ }
+
You should call dma_unmap_single when the DMA activity is finished, e.g.
from the interrupt which told you that the DMA transfer is done.
@@ -489,13 +524,27 @@ Specifically:
size_t size = buffer->len;
dma_handle = dma_map_page(dev, page, offset, size, direction);
+ if (dma_mapping_error(dma_handle)) {
+ /*
+ * reduce current DMA mapping usage,
+ * delay and try again later or
+ * reset driver.
+ */
+ goto map_error_handling;
+ }
...
dma_unmap_page(dev, dma_handle, size, direction);
Here, "offset" means byte offset within the given page.
+You should call dma_mapping_error() as dma_map_page() could fail and return
+error as outlined under the dma_map_single() discussion.
+
+You should call dma_unmap_page when the DMA activity is finished, e.g.
+from the interrupt which told you that the DMA transfer is done.
+
With scatterlists, you map a region gathered from several regions by:
int i, count = dma_map_sg(dev, sglist, nents, direction);
@@ -578,6 +627,14 @@ to use the dma_sync_*() interfaces.
dma_addr_t mapping;
mapping = dma_map_single(cp->dev, buffer, len, DMA_FROM_DEVICE);
+ if (dma_mapping_error(dma_handle)) {
+ /*
+ * reduce current DMA mapping usage,
+ * delay and try again later or
+ * reset driver.
+ */
+ goto map_error_handling;
+ }
cp->rx_buf = buffer;
cp->rx_len = len;
@@ -658,6 +715,75 @@ failure can be determined by:
* delay and try again later or
* reset driver.
*/
+ goto map_error_handling;
+ }
+
+- unmap pages that are already mapped, when mapping error occurs in the middle
+ of a multiple page mapping attempt. These example are applicable to
+ dma_map_page() as well.
+
+Example 1:
+ dma_addr_t dma_handle1;
+ dma_addr_t dma_handle2;
+
+ dma_handle1 = dma_map_single(dev, addr, size, direction);
+ if (dma_mapping_error(dev, dma_handle1)) {
+ /*
+ * reduce current DMA mapping usage,
+ * delay and try again later or
+ * reset driver.
+ */
+ goto map_error_handling1;
+ }
+ dma_handle2 = dma_map_single(dev, addr, size, direction);
+ if (dma_mapping_error(dev, dma_handle2)) {
+ /*
+ * reduce current DMA mapping usage,
+ * delay and try again later or
+ * reset driver.
+ */
+ goto map_error_handling2;
+ }
+
+ ...
+
+ map_error_handling2:
+ dma_unmap_single(dma_handle1);
+ map_error_handling1:
+
+Example 2: (if buffers are allocated a loop, unmap all mapped buffers when
+ mapping error is detected in the middle)
+
+ dma_addr_t dma_addr;
+ dma_addr_t array[DMA_BUFFERS];
+ int save_index = 0;
+
+ for (i = 0; i < DMA_BUFFERS; i++) {
+
+ ...
+
+ dma_addr = dma_map_single(dev, addr, size, direction);
+ if (dma_mapping_error(dev, dma_addr)) {
+ /*
+ * reduce current DMA mapping usage,
+ * delay and try again later or
+ * reset driver.
+ */
+ goto map_error_handling;
+ }
+ array[i].dma_addr = dma_addr;
+ save_index++;
+ }
+
+ ...
+
+ map_error_handling:
+
+ for (i = 0; i < save_index; i++) {
+
+ ...
+
+ dma_unmap_single(array[i].dma_addr);
}
Networking drivers must call dev_kfree_skb to free the socket buffer
View
@@ -678,3 +678,15 @@ out of dma_debug_entries. These entries are preallocated at boot. The number
of preallocated entries is defined per architecture. If it is too low for you
boot with 'dma_debug_entries=<your_desired_number>' to overwrite the
architectural default.
+
+void debug_dmap_mapping_error(struct device *dev, dma_addr_t dma_addr);
+
+dma-debug interface debug_dma_mapping_error() to debug drivers that fail
+to check dma mapping errors on addresses returned by dma_map_single() and
+dma_map_page() interfaces. This interface clears a flag set by
+debug_dma_map_page() to indicate that dma_mapping_error() has been called by
+the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
+this flag is still set, prints warning message that includes call trace that
+leads up to the unmap. This interface can be called from dma_mapping_error()
+routines to enable dma mapping error check debugging.
+
@@ -91,6 +91,7 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
*/
static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
+ debug_dma_mapping_error(dev, dma_addr);
return dma_addr == DMA_ERROR_CODE;
}
@@ -226,7 +226,7 @@ static struct platform_device omap3isp_device = {
};
static struct omap_iommu_arch_data omap3_isp_iommu = {
- .name = "isp",
+ .name = "mmu_isp",
};
int omap3_init_camera(struct isp_platform_data *pdata)
@@ -12,153 +12,60 @@
#include <linux/module.h>
#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/slab.h>
#include <linux/platform_data/iommu-omap.h>
+#include <plat/omap_hwmod.h>
+#include <plat/omap_device.h>
-#include "soc.h"
-#include "common.h"
-
-struct iommu_device {
- resource_size_t base;
- int irq;
- struct iommu_platform_data pdata;
- struct resource res[2];
-};
-static struct iommu_device *devices;
-static int num_iommu_devices;
-
-#ifdef CONFIG_ARCH_OMAP3
-static struct iommu_device omap3_devices[] = {
- {
- .base = 0x480bd400,
- .irq = 24 + OMAP_INTC_START,
- .pdata = {
- .name = "isp",
- .nr_tlb_entries = 8,
- .clk_name = "cam_ick",
- .da_start = 0x0,
- .da_end = 0xFFFFF000,
- },
- },
-#if defined(CONFIG_OMAP_IOMMU_IVA2)
- {
- .base = 0x5d000000,
- .irq = 28 + OMAP_INTC_START,
- .pdata = {
- .name = "iva2",
- .nr_tlb_entries = 32,
- .clk_name = "iva2_ck",
- .da_start = 0x11000000,
- .da_end = 0xFFFFF000,
- },
- },
-#endif
-};
-#define NR_OMAP3_IOMMU_DEVICES ARRAY_SIZE(omap3_devices)
-static struct platform_device *omap3_iommu_pdev[NR_OMAP3_IOMMU_DEVICES];
-#else
-#define omap3_devices NULL
-#define NR_OMAP3_IOMMU_DEVICES 0
-#define omap3_iommu_pdev NULL
-#endif
-
-#ifdef CONFIG_ARCH_OMAP4
-static struct iommu_device omap4_devices[] = {
- {
- .base = OMAP4_MMU1_BASE,
- .irq = 100 + OMAP44XX_IRQ_GIC_START,
- .pdata = {
- .name = "ducati",
- .nr_tlb_entries = 32,
- .clk_name = "ipu_fck",
- .da_start = 0x0,
- .da_end = 0xFFFFF000,
- },
- },
- {
- .base = OMAP4_MMU2_BASE,
- .irq = 28 + OMAP44XX_IRQ_GIC_START,
- .pdata = {
- .name = "tesla",
- .nr_tlb_entries = 32,
- .clk_name = "dsp_fck",
- .da_start = 0x0,
- .da_end = 0xFFFFF000,
- },
- },
-};
-#define NR_OMAP4_IOMMU_DEVICES ARRAY_SIZE(omap4_devices)
-static struct platform_device *omap4_iommu_pdev[NR_OMAP4_IOMMU_DEVICES];
-#else
-#define omap4_devices NULL
-#define NR_OMAP4_IOMMU_DEVICES 0
-#define omap4_iommu_pdev NULL
-#endif
-
-static struct platform_device **omap_iommu_pdev;
-
-static int __init omap_iommu_init(void)
+static int __init omap_iommu_dev_init(struct omap_hwmod *oh, void *unused)
{
- int i, err;
- struct resource res[] = {
- { .flags = IORESOURCE_MEM },
- { .flags = IORESOURCE_IRQ },
- };
+ struct platform_device *pdev;
+ struct iommu_platform_data *pdata;
+ struct omap_mmu_dev_attr *a = (struct omap_mmu_dev_attr *)oh->dev_attr;
+ static int i;
+
+ pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ pdata->name = oh->name;
+ pdata->nr_tlb_entries = a->nr_tlb_entries;
+ pdata->da_start = a->da_start;
+ pdata->da_end = a->da_end;
+
+ if (oh->rst_lines_cnt == 1) {
+ pdata->reset_name = oh->rst_lines->name;
+ pdata->assert_reset = omap_device_assert_hardreset;
+ pdata->deassert_reset = omap_device_deassert_hardreset;
+ }
- if (cpu_is_omap34xx()) {
- devices = omap3_devices;
- omap_iommu_pdev = omap3_iommu_pdev;
- num_iommu_devices = NR_OMAP3_IOMMU_DEVICES;
- } else if (cpu_is_omap44xx()) {
- devices = omap4_devices;
- omap_iommu_pdev = omap4_iommu_pdev;
- num_iommu_devices = NR_OMAP4_IOMMU_DEVICES;
- } else
- return -ENODEV;
+ pdev = omap_device_build("omap-iommu", i, oh, pdata, sizeof(*pdata),
+ NULL, 0, 0);
- for (i = 0; i < num_iommu_devices; i++) {
- struct platform_device *pdev;
- const struct iommu_device *d = &devices[i];
+ kfree(pdata);
- pdev = platform_device_alloc("omap-iommu", i);
- if (!pdev) {
- err = -ENOMEM;
- goto err_out;
- }
+ if (IS_ERR(pdev)) {
+ pr_err("%s: device build err: %ld\n", __func__, PTR_ERR(pdev));
+ return PTR_ERR(pdev);
+ }
- res[0].start = d->base;
- res[0].end = d->base + MMU_REG_SIZE - 1;
- res[1].start = res[1].end = d->irq;
+ i++;
- err = platform_device_add_resources(pdev, res,
- ARRAY_SIZE(res));
- if (err)
- goto err_out;
- err = platform_device_add_data(pdev, &d->pdata,
- sizeof(d->pdata));
- if (err)
- goto err_out;
- err = platform_device_add(pdev);
- if (err)
- goto err_out;
- omap_iommu_pdev[i] = pdev;
- }
return 0;
+}
-err_out:
- while (i--)
- platform_device_put(omap_iommu_pdev[i]);
- return err;
+static int __init omap_iommu_init(void)
+{
+ return omap_hwmod_for_each_by_class("mmu", omap_iommu_dev_init, NULL);
}
/* must be ready before omap3isp is probed */
subsys_initcall(omap_iommu_init);
static void __exit omap_iommu_exit(void)
{
- int i;
-
- for (i = 0; i < num_iommu_devices; i++)
- platform_device_unregister(omap_iommu_pdev[i]);
+ /* Do nothing */
}
module_exit(omap_iommu_exit);
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