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-rw-r--r--sys-kernel/boest-v5.0.15/raspberrypi/0134-vchiq_2835_arm-Implement-a-DMA-pool-for-small-bulk-t.patch126
1 files changed, 126 insertions, 0 deletions
diff --git a/sys-kernel/boest-v5.0.15/raspberrypi/0134-vchiq_2835_arm-Implement-a-DMA-pool-for-small-bulk-t.patch b/sys-kernel/boest-v5.0.15/raspberrypi/0134-vchiq_2835_arm-Implement-a-DMA-pool-for-small-bulk-t.patch
new file mode 100644
index 00000000..20e513e0
--- /dev/null
+++ b/sys-kernel/boest-v5.0.15/raspberrypi/0134-vchiq_2835_arm-Implement-a-DMA-pool-for-small-bulk-t.patch
@@ -0,0 +1,126 @@
+From f490ba0e24dfb09db88e947d07c89650e5e5885a Mon Sep 17 00:00:00 2001
+From: detule <ogjoneski@gmail.com>
+Date: Tue, 2 Oct 2018 04:10:08 -0400
+Subject: [PATCH 134/194] vchiq_2835_arm: Implement a DMA pool for small bulk
+ transfers (#2699)
+
+During a bulk transfer we request a DMA allocation to hold the
+scatter-gather list. Most of the time, this allocation is small
+(<< PAGE_SIZE), however it can be requested at a high enough frequency
+to cause fragmentation and/or stress the CMA allocator (think time
+spent in compaction here, or during allocations elsewhere).
+
+Implement a pool to serve up small DMA allocations, falling back
+to a coherent allocation if the request is greater than
+VCHIQ_DMA_POOL_SIZE.
+
+Signed-off-by: Oliver Gjoneski <ogjoneski@gmail.com>
+---
+ .../interface/vchiq_arm/vchiq_2835_arm.c | 38 ++++++++++++++++---
+ 1 file changed, 33 insertions(+), 5 deletions(-)
+
+diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
+index dd4898861b83..300e8cb5fbbc 100644
+--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
++++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
+@@ -37,6 +37,7 @@
+ #include <linux/interrupt.h>
+ #include <linux/pagemap.h>
+ #include <linux/dma-mapping.h>
++#include <linux/dmapool.h>
+ #include <linux/io.h>
+ #include <linux/platform_device.h>
+ #include <linux/uaccess.h>
+@@ -58,6 +59,8 @@
+ #define BELL0 0x00
+ #define BELL2 0x08
+
++#define VCHIQ_DMA_POOL_SIZE PAGE_SIZE
++
+ struct vchiq_2835_state {
+ int inited;
+ struct vchiq_arm_state arm_state;
+@@ -67,6 +70,7 @@ struct vchiq_pagelist_info {
+ struct pagelist *pagelist;
+ size_t pagelist_buffer_size;
+ dma_addr_t dma_addr;
++ bool is_from_pool;
+ enum dma_data_direction dma_dir;
+ unsigned int num_pages;
+ unsigned int pages_need_release;
+@@ -87,6 +91,7 @@ static void __iomem *g_regs;
+ * of 32.
+ */
+ static unsigned int g_cache_line_size = 32;
++static struct dma_pool *g_dma_pool;
+ static unsigned int g_fragments_size;
+ static char *g_fragments_base;
+ static char *g_free_fragments;
+@@ -193,6 +198,14 @@ int vchiq_platform_init(struct platform_device *pdev, struct vchiq_state *state)
+ }
+
+ g_dev = dev;
++ g_dma_pool = dmam_pool_create("vchiq_scatter_pool", dev,
++ VCHIQ_DMA_POOL_SIZE, g_cache_line_size,
++ 0);
++ if (!g_dma_pool) {
++ dev_err(dev, "failed to create dma pool");
++ return -ENOMEM;
++ }
++
+ vchiq_log_info(vchiq_arm_log_level,
+ "vchiq_init - done (slots %pK, phys %pad)",
+ vchiq_slot_zero, &slot_phys);
+@@ -368,9 +381,14 @@ cleanup_pagelistinfo(struct vchiq_pagelist_info *pagelistinfo)
+ for (i = 0; i < pagelistinfo->num_pages; i++)
+ put_page(pagelistinfo->pages[i]);
+ }
+-
+- dma_free_coherent(g_dev, pagelistinfo->pagelist_buffer_size,
+- pagelistinfo->pagelist, pagelistinfo->dma_addr);
++ if (pagelistinfo->is_from_pool) {
++ dma_pool_free(g_dma_pool, pagelistinfo->pagelist,
++ pagelistinfo->dma_addr);
++ } else {
++ dma_free_coherent(g_dev, pagelistinfo->pagelist_buffer_size,
++ pagelistinfo->pagelist,
++ pagelistinfo->dma_addr);
++ }
+ }
+
+ /* There is a potential problem with partial cache lines (pages?)
+@@ -390,6 +408,7 @@ create_pagelist(char __user *buf, size_t count, unsigned short type)
+ u32 *addrs;
+ unsigned int num_pages, offset, i, k;
+ int actual_pages;
++ bool is_from_pool;
+ size_t pagelist_size;
+ struct scatterlist *scatterlist, *sg;
+ int dma_buffers;
+@@ -407,8 +426,16 @@ create_pagelist(char __user *buf, size_t count, unsigned short type)
+ /* Allocate enough storage to hold the page pointers and the page
+ * list
+ */
+- pagelist = dma_alloc_coherent(g_dev, pagelist_size, &dma_addr,
+- GFP_KERNEL);
++ if (pagelist_size > VCHIQ_DMA_POOL_SIZE) {
++ pagelist = dma_alloc_coherent(g_dev,
++ pagelist_size,
++ &dma_addr,
++ GFP_KERNEL);
++ is_from_pool = false;
++ } else {
++ pagelist = dma_pool_alloc(g_dma_pool, GFP_KERNEL, &dma_addr);
++ is_from_pool = true;
++ }
+
+ vchiq_log_trace(vchiq_arm_log_level, "%s - %pK", __func__, pagelist);
+
+@@ -429,6 +456,7 @@ create_pagelist(char __user *buf, size_t count, unsigned short type)
+ pagelistinfo->pagelist = pagelist;
+ pagelistinfo->pagelist_buffer_size = pagelist_size;
+ pagelistinfo->dma_addr = dma_addr;
++ pagelistinfo->is_from_pool = is_from_pool;
+ pagelistinfo->dma_dir = (type == PAGELIST_WRITE) ?
+ DMA_TO_DEVICE : DMA_FROM_DEVICE;
+ pagelistinfo->num_pages = num_pages;