[PATCH 7/7] hexagon: use the generic global coherent pool

From: Christoph Hellwig
Date: Mon Jul 12 2021 - 02:33:16 EST


Switch hexagon to use the generic code for dma_alloc_coherent from
a global pre-filled pool.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/hexagon/Kconfig | 1 +
arch/hexagon/kernel/dma.c | 57 ++++++++-------------------------------
2 files changed, 12 insertions(+), 46 deletions(-)

diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index e5a852080730..aab1a40eb653 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -7,6 +7,7 @@ config HEXAGON
select ARCH_32BIT_OFF_T
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select ARCH_NO_PREEMPT
+ select DMA_GLOBAL_POOL
# Other pending projects/to-do items.
# select HAVE_REGS_AND_STACK_ACCESS_API
# select HAVE_HW_BREAKPOINT if PERF_EVENTS
diff --git a/arch/hexagon/kernel/dma.c b/arch/hexagon/kernel/dma.c
index 00b9a81075dd..882680e81a30 100644
--- a/arch/hexagon/kernel/dma.c
+++ b/arch/hexagon/kernel/dma.c
@@ -7,54 +7,8 @@

#include <linux/dma-map-ops.h>
#include <linux/memblock.h>
-#include <linux/genalloc.h>
-#include <linux/module.h>
#include <asm/page.h>

-static struct gen_pool *coherent_pool;
-
-
-/* Allocates from a pool of uncached memory that was reserved at boot time */
-
-void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_addr,
- gfp_t flag, unsigned long attrs)
-{
- void *ret;
-
- /*
- * Our max_low_pfn should have been backed off by 16MB in
- * mm/init.c to create DMA coherent space. Use that as the VA
- * for the pool.
- */
-
- if (coherent_pool == NULL) {
- coherent_pool = gen_pool_create(PAGE_SHIFT, -1);
-
- if (coherent_pool == NULL)
- panic("Can't create %s() memory pool!", __func__);
- else
- gen_pool_add(coherent_pool,
- (unsigned long)pfn_to_virt(max_low_pfn),
- hexagon_coherent_pool_size, -1);
- }
-
- ret = (void *) gen_pool_alloc(coherent_pool, size);
-
- if (ret) {
- memset(ret, 0, size);
- *dma_addr = (dma_addr_t) virt_to_phys(ret);
- } else
- *dma_addr = ~0;
-
- return ret;
-}
-
-void arch_dma_free(struct device *dev, size_t size, void *vaddr,
- dma_addr_t dma_addr, unsigned long attrs)
-{
- gen_pool_free(coherent_pool, (unsigned long) vaddr, size);
-}
-
void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
enum dma_data_direction dir)
{
@@ -77,3 +31,14 @@ void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
BUG();
}
}
+
+/*
+ * Our max_low_pfn should have been backed off by 16MB in mm/init.c to create
+ * DMA coherent space. Use that for the pool.
+ */
+static int __init hexagon_dma_init(void)
+{
+ return dma_init_global_coherent(PFN_PHYS(max_low_pfn),
+ hexagon_coherent_pool_size);
+}
+core_initcall(hexagon_dma_init);
--
2.30.2