bcm27xx: add linux 5.4 support

Tested on bcm2710 (Raspberry Pi 3B).

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 124 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.4/950-0121-vchiq_2835_arm-Implement-a-DMA-pool-for-small-bulk-t.patch b/target/linux/bcm27xx/patches-5.4/950-0121-vchiq_2835_arm-Implement-a-DMA-pool-for-small-bulk-t.patch
new file mode 100644
index 0000000000..477b64d12a
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0121-vchiq_2835_arm-Implement-a-DMA-pool-for-small-bulk-t.patch
@@ -0,0 +1,124 @@
+From c2acd59177043f78446357f560e5436b0318ceb6 Mon Sep 17 00:00:00 2001
+From: detule <ogjoneski@gmail.com>
+Date: Tue, 2 Oct 2018 04:10:08 -0400
+Subject: [PATCH] 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(-)
+
+--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
++++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
+@@ -7,6 +7,7 @@
+ #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>
+@@ -28,6 +29,8 @@
+ #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;
+@@ -37,6 +40,7 @@ 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;
+@@ -57,6 +61,7 @@ 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;
+@@ -161,6 +166,14 @@ int vchiq_platform_init(struct platform_
+ 	}
+ 
+ 	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);
+@@ -339,9 +352,14 @@ cleanup_pagelistinfo(struct vchiq_pageli
+ 		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?)
+@@ -361,6 +379,7 @@ create_pagelist(char __user *buf, size_t
+ 	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;
+@@ -387,8 +406,16 @@ create_pagelist(char __user *buf, size_t
+ 	/* 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);
+ 
+@@ -409,6 +436,7 @@ create_pagelist(char __user *buf, size_t
+ 	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;