From 74838b75379a53678ffc5f59de86161d21e2c808 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Fri, 27 Jul 2012 20:55:27 -0400 Subject: [PATCH] swiotlb: add the late swiotlb initialization function with iotlb memory This enables the caller to initialize swiotlb with its own iotlb memory late in the bootup. See git commit eb605a5754d050a25a9f00d718fb173f24c486ef "swiotlb: add swiotlb_tbl_map_single library function" which will explain the full details of what it can be used for. CC: FUJITA Tomonori [v1: Fold in smatch warning] Signed-off-by: Konrad Rzeszutek Wilk --- include/linux/swiotlb.h | 1 + lib/swiotlb.c | 33 ++++++++++++++++++++++++--------- 2 files changed, 25 insertions(+), 9 deletions(-) diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index e872526fdc5f..8d08b3ed406d 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -25,6 +25,7 @@ extern int swiotlb_force; extern void swiotlb_init(int verbose); extern void swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose); extern unsigned long swiotlb_nr_tbl(void); +extern int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs); /* * Enumeration for sync targets diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 45bc1f83a5ad..f114bf6a8e13 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -170,7 +170,7 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) * Statically reserve bounce buffer space and initialize bounce buffer data * structures for the software IO TLB used to implement the DMA API. */ -void __init +static void __init swiotlb_init_with_default_size(size_t default_size, int verbose) { unsigned long bytes; @@ -206,8 +206,9 @@ swiotlb_init(int verbose) int swiotlb_late_init_with_default_size(size_t default_size) { - unsigned long i, bytes, req_nslabs = io_tlb_nslabs; + unsigned long bytes, req_nslabs = io_tlb_nslabs; unsigned int order; + int rc = 0; if (!io_tlb_nslabs) { io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); @@ -229,16 +230,32 @@ swiotlb_late_init_with_default_size(size_t default_size) order--; } - if (!io_tlb_start) - goto cleanup1; - + if (!io_tlb_start) { + io_tlb_nslabs = req_nslabs; + return -ENOMEM; + } if (order != get_order(bytes)) { printk(KERN_WARNING "Warning: only able to allocate %ld MB " "for software IO TLB\n", (PAGE_SIZE << order) >> 20); io_tlb_nslabs = SLABS_PER_PAGE << order; - bytes = io_tlb_nslabs << IO_TLB_SHIFT; } + rc = swiotlb_late_init_with_tbl(io_tlb_start, io_tlb_nslabs); + if (rc) + free_pages((unsigned long)io_tlb_start, order); + return rc; +} + +int +swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) +{ + unsigned long i, bytes; + + bytes = nslabs << IO_TLB_SHIFT; + + io_tlb_nslabs = nslabs; + io_tlb_start = tlb; io_tlb_end = io_tlb_start + bytes; + memset(io_tlb_start, 0, bytes); /* @@ -288,10 +305,8 @@ cleanup3: io_tlb_list = NULL; cleanup2: io_tlb_end = NULL; - free_pages((unsigned long)io_tlb_start, order); io_tlb_start = NULL; -cleanup1: - io_tlb_nslabs = req_nslabs; + io_tlb_nslabs = 0; return -ENOMEM; } -- 2.30.2