[PATCH net-next 3/4] net: ipa: define IMEM memory region for IPA
From: Alex Elder
Date: Fri May 01 2020 - 17:46:41 EST
Define a region of IMEM memory available for use by IPA in the
platform configuration data. Initialize it from ipa_mem_init().
The memory must be mapped for access through an SMMU.
Signed-off-by: Alex Elder <elder@xxxxxxxxxx>
---
drivers/net/ipa/ipa.h | 5 ++
drivers/net/ipa/ipa_data-sc7180.c | 2 +
drivers/net/ipa/ipa_data-sdm845.c | 2 +
drivers/net/ipa/ipa_data.h | 6 ++-
drivers/net/ipa/ipa_mem.c | 84 +++++++++++++++++++++++++++++++
5 files changed, 98 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ipa/ipa.h b/drivers/net/ipa/ipa.h
index 23fb29889e5a..32f6dfafdb05 100644
--- a/drivers/net/ipa/ipa.h
+++ b/drivers/net/ipa/ipa.h
@@ -47,6 +47,8 @@ struct ipa_interrupt;
* @mem_offset: Offset from @mem_virt used for access to IPA memory
* @mem_size: Total size (bytes) of memory at @mem_virt
* @mem: Array of IPA-local memory region descriptors
+ * @imem_iova: I/O virtual address of IPA region in IMEM
+ * @imem_size; Size of IMEM region
* @zero_addr: DMA address of preallocated zero-filled memory
* @zero_virt: Virtual address of preallocated zero-filled memory
* @zero_size: Size (bytes) of preallocated zero-filled memory
@@ -88,6 +90,9 @@ struct ipa {
u32 mem_size;
const struct ipa_mem *mem;
+ unsigned long imem_iova;
+ size_t imem_size;
+
dma_addr_t zero_addr;
void *zero_virt;
size_t zero_size;
diff --git a/drivers/net/ipa/ipa_data-sc7180.c b/drivers/net/ipa/ipa_data-sc7180.c
index f97e7e4e61c1..e9007d151c68 100644
--- a/drivers/net/ipa/ipa_data-sc7180.c
+++ b/drivers/net/ipa/ipa_data-sc7180.c
@@ -299,6 +299,8 @@ static const struct ipa_mem ipa_mem_local_data[] = {
static struct ipa_mem_data ipa_mem_data = {
.local_count = ARRAY_SIZE(ipa_mem_local_data),
.local = ipa_mem_local_data,
+ .imem_addr = 0x146a8000,
+ .imem_size = 0x00002000,
};
/* Configuration data for the SC7180 SoC. */
diff --git a/drivers/net/ipa/ipa_data-sdm845.c b/drivers/net/ipa/ipa_data-sdm845.c
index c55507e94559..c0e207085550 100644
--- a/drivers/net/ipa/ipa_data-sdm845.c
+++ b/drivers/net/ipa/ipa_data-sdm845.c
@@ -321,6 +321,8 @@ static const struct ipa_mem ipa_mem_local_data[] = {
static struct ipa_mem_data ipa_mem_data = {
.local_count = ARRAY_SIZE(ipa_mem_local_data),
.local = ipa_mem_local_data,
+ .imem_addr = 0x146bd000,
+ .imem_size = 0x00002000,
};
/* Configuration data for the SDM845 SoC. */
diff --git a/drivers/net/ipa/ipa_data.h b/drivers/net/ipa/ipa_data.h
index 51d8e5a6f23a..69957af56ccd 100644
--- a/drivers/net/ipa/ipa_data.h
+++ b/drivers/net/ipa/ipa_data.h
@@ -245,13 +245,17 @@ struct ipa_resource_data {
};
/**
- * struct ipa_mem - IPA-local memory region description
+ * struct ipa_mem - description of IPA memory regions
* @local_count: number of regions defined in the local[] array
* @local: array of IPA-local memory region descriptors
+ * @imem_addr: physical address of IPA region within IMEM
+ * @imem_size: size in bytes of IPA IMEM region
*/
struct ipa_mem_data {
u32 local_count;
const struct ipa_mem *local;
+ u32 imem_addr;
+ u32 imem_size;
};
/**
diff --git a/drivers/net/ipa/ipa_mem.c b/drivers/net/ipa/ipa_mem.c
index fb4de2a12796..3c0916597fe1 100644
--- a/drivers/net/ipa/ipa_mem.c
+++ b/drivers/net/ipa/ipa_mem.c
@@ -8,6 +8,7 @@
#include <linux/bitfield.h>
#include <linux/bug.h>
#include <linux/dma-mapping.h>
+#include <linux/iommu.h>
#include <linux/io.h>
#include "ipa.h"
@@ -266,6 +267,79 @@ int ipa_mem_zero_modem(struct ipa *ipa)
return 0;
}
+/**
+ * ipa_imem_init() - Initialize IMEM memory used by the IPA
+ * @ipa: IPA pointer
+ * @addr: Physical address of the IPA region in IMEM
+ * @size: Size (bytes) of the IPA region in IMEM
+ *
+ * IMEM is a block of shared memory separate from system DRAM, and
+ * a portion of this memory is available for the IPA to use. The
+ * modem accesses this memory directly, but the IPA accesses it
+ * via the IOMMU, using the AP's credentials.
+ *
+ * If this region exists (size > 0) we map it for read/write access
+ * through the IOMMU using the IPA device.
+ *
+ * Note: @addr and @size are not guaranteed to be page-aligned.
+ */
+static int ipa_imem_init(struct ipa *ipa, unsigned long addr, size_t size)
+{
+ struct device *dev = &ipa->pdev->dev;
+ struct iommu_domain *domain;
+ unsigned long iova;
+ phys_addr_t phys;
+ int ret;
+
+ if (!size)
+ return 0; /* IMEM memory not used */
+
+ domain = iommu_get_domain_for_dev(dev);
+ if (!domain) {
+ dev_err(dev, "no IOMMU domain found for IMEM\n");
+ return -EINVAL;
+ }
+
+ /* Align the address down and the size up to page boundaries */
+ phys = addr & PAGE_MASK;
+ size = PAGE_ALIGN(size + addr - phys);
+ iova = phys; /* We just want a direct mapping */
+
+ ret = iommu_map(domain, iova, phys, size, IOMMU_READ | IOMMU_WRITE);
+ if (ret)
+ return ret;
+
+ ipa->imem_iova = iova;
+ ipa->imem_size = size;
+
+ return 0;
+}
+
+static void ipa_imem_exit(struct ipa *ipa)
+{
+ struct iommu_domain *domain;
+ struct device *dev;
+
+ if (!ipa->imem_size)
+ return;
+
+ dev = &ipa->pdev->dev;
+ domain = iommu_get_domain_for_dev(dev);
+ if (domain) {
+ size_t size;
+
+ size = iommu_unmap(domain, ipa->imem_iova, ipa->imem_size);
+ if (size != ipa->imem_size)
+ dev_warn(dev, "unmapped %zu IMEM bytes, expected %lu\n",
+ size, ipa->imem_size);
+ } else {
+ dev_err(dev, "couldn't get IPA IOMMU domain for IMEM\n");
+ }
+
+ ipa->imem_size = 0;
+ ipa->imem_iova = 0;
+}
+
/* Perform memory region-related initialization */
int ipa_mem_init(struct ipa *ipa, const struct ipa_mem_data *mem_data)
{
@@ -305,11 +379,21 @@ int ipa_mem_init(struct ipa *ipa, const struct ipa_mem_data *mem_data)
/* The ipa->mem[] array is indexed by enum ipa_mem_id values */
ipa->mem = mem_data->local;
+ ret = ipa_imem_init(ipa, mem_data->imem_addr, mem_data->imem_size);
+ if (ret)
+ goto err_unmap;
+
return 0;
+
+err_unmap:
+ memunmap(ipa->mem_virt);
+
+ return ret;
}
/* Inverse of ipa_mem_init() */
void ipa_mem_exit(struct ipa *ipa)
{
+ ipa_imem_exit(ipa);
memunmap(ipa->mem_virt);
}
--
2.20.1