tidspbridge driver uses a block of memory denominated SHared Memory
to store info & communicate with DSP, this SHM needs to be physically
contiguous and non-cacheable, to achieve the latter the driver ioremaps
the memory reserved to be SHM, this will trigger a warning if the
memory is under kernel control (because it creates another set of
mapping attributes, for the same memory area).
For now this can be avoided if a portion of memory (6MB) is left out
of kernel control (using bootarg attribute mem=) where tidspbridge
driver can make use of the memory and ioremap it without above
restriction.
Parameter has precedence over memblock allocator for shared memory.
i.e.: on a system with 256MB
set 'bootargs mem=250M ...'
cat /proc/iomem
...
80000000-8f9fffff : System RAM
So driver needs to be installed with:
insmod bridgedriver.ko phys_mempool_base=0x8FA00000
Same rationale applies for the menuconfig option.
Signed-off-by: Omar Ramirez Luna <omar.ramirez@xxxxxx>
---
Code to allocate dspbridge memblock needs to be disabled since
it will be wasting 6MB.
arch/arm/mach-omap2/dsp.c | 2 +-
drivers/staging/tidspbridge/Kconfig | 10 ++++++++++
drivers/staging/tidspbridge/rmgr/drv_interface.c | 15 ++++++++++++++-
3 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-omap2/dsp.c b/arch/arm/mach-omap2/dsp.c
index 6feeeae..0a4ba2f 100644
--- a/arch/arm/mach-omap2/dsp.c
+++ b/arch/arm/mach-omap2/dsp.c
@@ -45,7 +45,7 @@ static int __init omap_dsp_init(void)
int err = -ENOMEM;
struct omap_dsp_platform_data *pdata = &omap_dsp_pdata;
- pdata->phys_mempool_base = omap_dsp_get_mempool_base();
+ pdata->phys_mempool_base = CONFIG_TIDSPBRIDGE_MEMPOOL_BASE;
if (pdata->phys_mempool_base) {
pdata->phys_mempool_size = CONFIG_TIDSPBRIDGE_MEMPOOL_SIZE;
diff --git a/drivers/staging/tidspbridge/Kconfig b/drivers/staging/tidspbridge/Kconfig
index 93de4f2..1214cbc 100644
--- a/drivers/staging/tidspbridge/Kconfig
+++ b/drivers/staging/tidspbridge/Kconfig
@@ -23,6 +23,16 @@ config TIDSPBRIDGE_DVFS
performance and power consumption to the current processing
requirements.
+config TIDSPBRIDGE_MEMPOOL_BASE
+ hex "Physical memory pool base (Addr)"
+ depends on TIDSPBRIDGE
+ default 0
+ help
+ Use this address as the start of the shared memory block, it is assumed
+ that this address is outside kernel control and configured by tweaking
+ mem= in bootargs. BASE + SIZE should fit in the system RAM address
+ space.
+
config TIDSPBRIDGE_MEMPOOL_SIZE
hex "Physical memory pool size (Byte)"
depends on TIDSPBRIDGE
diff --git a/drivers/staging/tidspbridge/rmgr/drv_interface.c b/drivers/staging/tidspbridge/rmgr/drv_interface.c
index 1981e46..4533605 100644
--- a/drivers/staging/tidspbridge/rmgr/drv_interface.c
+++ b/drivers/staging/tidspbridge/rmgr/drv_interface.c
@@ -86,6 +86,7 @@ static s32 driver_major;
static char *base_img;
char *iva_img;
static s32 shm_size = 0x500000; /* 5 MB */
+static unsigned int phys_mempool_base;
static int tc_wordswapon; /* Default value is always false */
#ifdef CONFIG_TIDSPBRIDGE_RECOVERY
#define REC_TIMEOUT 5000 /*recovery timeout in msecs */
@@ -132,6 +133,9 @@ MODULE_PARM_DESC(shm_size, "shm size, default = 4 MB, minimum = 64 KB");
module_param(tc_wordswapon, int, 0);
MODULE_PARM_DESC(tc_wordswapon, "TC Word Swap Option. default = 0");
+module_param(phys_mempool_base, uint, 0);
+MODULE_PARM_DESC(phys_mempool_base, "Physical Address base for SHM");
+
MODULE_AUTHOR("Texas Instruments");
MODULE_LICENSE("GPL");
MODULE_VERSION(DSPBRIDGE_VERSION);
@@ -298,7 +302,16 @@ static int omap3_bridge_startup(struct platform_device *pdev)
}
dev_dbg(bridge, "%s: requested shm_size = 0x%x\n", __func__, shm_size);
- phys_membase = pdata->phys_mempool_base;
+ if (phys_mempool_base) {
+ /* Out of kernel SHM */
+ phys_membase = phys_mempool_base;
+ } else if (pdata->phys_mempool_base) {
+ /* Memblock allocator for SHM */
+ phys_membase = pdata->phys_mempool_base;
+ } else {
+ pr_err("%s: couldn't get SHM physical address\n", __func__);
+ goto err3;
+ }
phys_memsize = pdata->phys_mempool_size;
if (phys_membase > 0 && phys_memsize > 0)
mem_ext_phys_pool_init(phys_membase, phys_memsize);
--
1.7.1
--
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