Hej,
On Tue, Oct 29, 2024 at 12:48:46PM +0530, Sughosh Ganu wrote:
The LMB module is typically used for managing the platform's RAM memory. RAM memory gets added to the module's memory map, and subsequently allocated through various LMB API's.
The IOMMU driver for the apple platforms also uses the LMB API's for allocating device virtual addresses(VA). These addresses are different from the RAM addresses, and cannot be added to the RAM memory map. Add a separate instance of LMB memory map for the device VA's, which gets managed by the IOMMU driver. Use lmb_push() and lmb_pop() functions to set-up the relevant lmb instance.
thanks, this fixes the initial brokenness when setting up dma mappings but I still see SError due to translation fault. I don't have time right now to look into it so it could be unrelated to the iommu.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org
drivers/iommu/apple_dart.c | 67 +++++++++++++++++++++++++++++++++++++- include/lmb.h | 2 ++ lib/lmb.c | 1 - 3 files changed, 68 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/apple_dart.c b/drivers/iommu/apple_dart.c index 611ac7cd6de..55f60287b0e 100644 --- a/drivers/iommu/apple_dart.c +++ b/drivers/iommu/apple_dart.c @@ -3,6 +3,7 @@
- Copyright (C) 2021 Mark Kettenis kettenis@openbsd.org
*/
+#include <alist.h> #include <cpu_func.h> #include <dm.h> #include <iommu.h> @@ -70,6 +71,8 @@
struct apple_dart_priv { void *base;
- struct lmb apple_dart_lmb;
- struct lmb ram_lmb; u64 *l1, *l2; int bypass, shift;
@@ -87,6 +90,56 @@ struct apple_dart_priv { void (*flush_tlb)(struct apple_dart_priv *priv); };
+static int apple_dart_lmb_init(struct apple_dart_priv *priv) +{
- bool ret;
- struct lmb *almb = &priv->apple_dart_lmb;
- ret = alist_init(&almb->free_mem, sizeof(struct lmb_region),
(uint)LMB_ALIST_INITIAL_SIZE);- if (!ret) {
log_debug("Unable to initialise the list for LMB free memory\n");return -ENOMEM;- }
- ret = alist_init(&almb->used_mem, sizeof(struct lmb_region),
(uint)LMB_ALIST_INITIAL_SIZE);- if (!ret) {
log_debug("Unable to initialise the list for LMB used memory\n");return -ENOMEM;- }
- return 0;
+}
+static void apple_dart_lmb_uninit(struct apple_dart_priv *priv) +{
- struct lmb *almb = &priv->apple_dart_lmb;
- alist_uninit(&almb->free_mem);
- alist_uninit(&almb->used_mem);
+}
+static void apple_dart_lmb_setup(struct apple_dart_priv *priv) +{
- struct lmb *almb = &priv->apple_dart_lmb;
- struct lmb *rlmb = &priv->ram_lmb;
- lmb_push(rlmb);
- lmb_pop(almb);
This doesn't look look like a good solution to me. We're conflating two different concepts into the global lmb. This looks error prone to me. I was looking into adding iomb_* entry points into the lmb points which take a pointer.
Janne