[PATCH 1/2] drm/msm: update iommu support

From: Stephane Viau
Date: Tue Jun 17 2014 - 10:33:39 EST


Iommu support is slightly modified in order to make sure
that MDP iommu is properly cleaned up if a probe deferral is
requested. Before this change, IOMMU faults would occur if the
probe failed (-EPROBE_DEFER).

Signed-off-by: Stephane Viau <sviau@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c | 22 +++++++++++++++++-----
drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h | 1 +
drivers/gpu/drm/msm/msm_gem.c | 6 ++++++
drivers/gpu/drm/msm/msm_iommu.c | 21 +++++++++++++++++++--
drivers/gpu/drm/msm/msm_mmu.h | 1 +
5 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
index ee8446c..47b3eb0 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
@@ -20,6 +20,10 @@
#include "msm_mmu.h"
#include "mdp5_kms.h"

+static const char *iommu_ports[] = {
+ "mdp_0",
+};
+
static struct mdp5_platform_config *mdp5_get_config(struct platform_device *dev);

static int mdp5_hw_init(struct msm_kms *kms)
@@ -104,6 +108,12 @@ static void mdp5_preclose(struct msm_kms *kms, struct drm_file *file)
static void mdp5_destroy(struct msm_kms *kms)
{
struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
+ struct msm_mmu *mmu = mdp5_kms->mmu;
+
+ if (mmu) {
+ mmu->funcs->detach(mmu, iommu_ports, ARRAY_SIZE(iommu_ports));
+ mmu->funcs->destroy(mmu);
+ }
kfree(mdp5_kms);
}

@@ -216,10 +226,6 @@ fail:
return ret;
}

-static const char *iommu_ports[] = {
- "mdp_0",
-};
-
static int get_clk(struct platform_device *pdev, struct clk **clkp,
const char *name)
{
@@ -307,17 +313,23 @@ struct msm_kms *mdp5_kms_init(struct drm_device *dev)
mmu = msm_iommu_new(dev, config->iommu);
if (IS_ERR(mmu)) {
ret = PTR_ERR(mmu);
+ dev_err(dev->dev, "failed to init iommu: %d\n", ret);
goto fail;
}
+
ret = mmu->funcs->attach(mmu, iommu_ports,
ARRAY_SIZE(iommu_ports));
- if (ret)
+ if (ret) {
+ dev_err(dev->dev, "failed to attach iommu: %d\n", ret);
+ mmu->funcs->destroy(mmu);
goto fail;
+ }
} else {
dev_info(dev->dev, "no iommu, fallback to phys "
"contig buffers for scanout\n");
mmu = NULL;
}
+ mdp5_kms->mmu = mmu;

mdp5_kms->id = msm_register_mmu(dev, mmu);
if (mdp5_kms->id < 0) {
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
index c8b1a25..6e981b6 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
@@ -33,6 +33,7 @@ struct mdp5_kms {

/* mapper-id used to request GEM buffer mapped for scanout: */
int id;
+ struct msm_mmu *mmu;

/* for tracking smp allocation amongst pipes: */
mdp5_smp_state_t smp_state;
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index bb8026d..690d7e7 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -278,6 +278,7 @@ int msm_gem_get_iova_locked(struct drm_gem_object *obj, int id,
uint32_t *iova)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
+ struct drm_device *dev = obj->dev;
int ret = 0;

if (!msm_obj->domain[id].iova) {
@@ -285,6 +286,11 @@ int msm_gem_get_iova_locked(struct drm_gem_object *obj, int id,
struct msm_mmu *mmu = priv->mmus[id];
struct page **pages = get_pages(obj);

+ if (!mmu) {
+ dev_err(dev->dev, "null MMU pointer\n");
+ return -EINVAL;
+ }
+
if (IS_ERR(pages))
return PTR_ERR(pages);

diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index 92b7459..198b2fe 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -28,7 +28,7 @@ static int msm_fault_handler(struct iommu_domain *iommu, struct device *dev,
unsigned long iova, int flags, void *arg)
{
DBG("*** fault: iova=%08lx, flags=%d", iova, flags);
- return 0;
+ return -ENOSYS;
}

static int msm_iommu_attach(struct msm_mmu *mmu, const char **names, int cnt)
@@ -40,8 +40,10 @@ static int msm_iommu_attach(struct msm_mmu *mmu, const char **names, int cnt)
for (i = 0; i < cnt; i++) {
struct device *msm_iommu_get_ctx(const char *ctx_name);
struct device *ctx = msm_iommu_get_ctx(names[i]);
- if (IS_ERR_OR_NULL(ctx))
+ if (IS_ERR_OR_NULL(ctx)) {
+ dev_warn(dev->dev, "couldn't get %s context", names[i]);
continue;
+ }
ret = iommu_attach_device(iommu->domain, ctx);
if (ret) {
dev_warn(dev->dev, "could not attach iommu to %s", names[i]);
@@ -52,6 +54,20 @@ static int msm_iommu_attach(struct msm_mmu *mmu, const char **names, int cnt)
return 0;
}

+static void msm_iommu_detach(struct msm_mmu *mmu, const char **names, int cnt)
+{
+ struct msm_iommu *iommu = to_msm_iommu(mmu);
+ int i;
+
+ for (i = 0; i < cnt; i++) {
+ struct device *msm_iommu_get_ctx(const char *ctx_name);
+ struct device *ctx = msm_iommu_get_ctx(names[i]);
+ if (IS_ERR_OR_NULL(ctx))
+ continue;
+ iommu_detach_device(iommu->domain, ctx);
+ }
+}
+
static int msm_iommu_map(struct msm_mmu *mmu, uint32_t iova,
struct sg_table *sgt, unsigned len, int prot)
{
@@ -127,6 +143,7 @@ static void msm_iommu_destroy(struct msm_mmu *mmu)

static const struct msm_mmu_funcs funcs = {
.attach = msm_iommu_attach,
+ .detach = msm_iommu_detach,
.map = msm_iommu_map,
.unmap = msm_iommu_unmap,
.destroy = msm_iommu_destroy,
diff --git a/drivers/gpu/drm/msm/msm_mmu.h b/drivers/gpu/drm/msm/msm_mmu.h
index 0303244..21da6d1 100644
--- a/drivers/gpu/drm/msm/msm_mmu.h
+++ b/drivers/gpu/drm/msm/msm_mmu.h
@@ -22,6 +22,7 @@

struct msm_mmu_funcs {
int (*attach)(struct msm_mmu *mmu, const char **names, int cnt);
+ void (*detach)(struct msm_mmu *mmu, const char **names, int cnt);
int (*map)(struct msm_mmu *mmu, uint32_t iova, struct sg_table *sgt,
unsigned len, int prot);
int (*unmap)(struct msm_mmu *mmu, uint32_t iova, struct sg_table *sgt,
--
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