From: Hongda Deng <[email protected]> In previous patch, we make arch_get_dma_bitsize return 0 when dma_bitsize and platform->dma_bitsize are not set. But this will affect lowmem_bitsize in allocate_memory_11 for domain0. Because this function depends lowmem_bitsize to allocate memory below 4GB.
In current code, when arch_get_dma_bitsize return 0, lowmem_bitsize will be set to 0. In this case, we will get "No bank has been allocated below 0-bit." message while allocating domain0 memory. And the lowmem will be set to false. This behavior is inconsistent with what allocate_memory_11 done before, and doesn't meet this functions requirements. So we check arch_get_dma_bitsize's return value before set lowmem_bitsize. Avoid setting lowmem_bitsize to 0 by mistake. Signed-off-by: Wei Chen <[email protected]> Signed-off-by: Hongda Deng <[email protected]> --- xen/arch/arm/domain_build.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c index 6c86d52781..cf341f349f 100644 --- a/xen/arch/arm/domain_build.c +++ b/xen/arch/arm/domain_build.c @@ -265,9 +265,18 @@ static void __init allocate_memory_11(struct domain *d, int i; bool lowmem = true; - unsigned int lowmem_bitsize = min(32U, arch_get_dma_bitsize()); + unsigned int lowmem_bitsize = arch_get_dma_bitsize(); unsigned int bits; + /* + When dma_bitsize and platform->dma_bitsize are not set, + arch_get_dma_bitsize will return 0. That means this system + doesn't need to reserve memory for DMA. But in order to + meet above requirements, we still need to try to allocate + memory below 4GB for Dom0. + */ + lowmem_bitsize = lowmem_bitsize ? min(32U, lowmem_bitsize) : 32U; + /* * TODO: Implement memory bank allocation when DOM0 is not direct * mapped -- 2.25.1
