From a63444375f08a18a6b2286351606f08d6e9fa63d Mon Sep 17 00:00:00 2001 From: Sudeep Dutt Date: Wed, 22 Jul 2015 11:50:10 -0700 Subject: [PATCH] misc: mic: scif bug fix for vmalloc_to_page crash v4.2-rc1 enabled huge page support for ioremap(..). Calling vmalloc_to_page after v4.2-rc1 results in the crash shown below on the host upon booting X100 coprocessors: BUG: unable to handle kernel paging request at ffffc47c00000000 IP: [] vmalloc_to_page+0x6c/0xb0 This patch fixes this crash by obtaining the fake struct page pointer which is required to be passed into dma_map_sg(..) by calling pfn_to_page(..) instead of vmalloc_to_page(..). Link: https://lkml.org/lkml/2015/7/18/110 Reviewed-by: Nikhil Rao Suggested-by: Toshi Kani Signed-off-by: Ashutosh Dixit Signed-off-by: Sudeep Dutt Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mic/scif/scif_nodeqp.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) diff --git a/drivers/misc/mic/scif/scif_nodeqp.c b/drivers/misc/mic/scif/scif_nodeqp.c index 41e3bdb..6dfdae3 100644 --- a/drivers/misc/mic/scif/scif_nodeqp.c +++ b/drivers/misc/mic/scif/scif_nodeqp.c @@ -357,7 +357,7 @@ static void scif_p2p_freesg(struct scatterlist *sg) } static struct scatterlist * -scif_p2p_setsg(void __iomem *va, int page_size, int page_cnt) +scif_p2p_setsg(phys_addr_t pa, int page_size, int page_cnt) { struct scatterlist *sg; struct page *page; @@ -368,16 +368,11 @@ scif_p2p_setsg(void __iomem *va, int page_size, int page_cnt) return NULL; sg_init_table(sg, page_cnt); for (i = 0; i < page_cnt; i++) { - page = vmalloc_to_page((void __force *)va); - if (!page) - goto p2p_sg_err; + page = pfn_to_page(pa >> PAGE_SHIFT); sg_set_page(&sg[i], page, page_size, 0); - va += page_size; + pa += page_size; } return sg; -p2p_sg_err: - kfree(sg); - return NULL; } /* Init p2p mappings required to access peerdev from scifdev */ @@ -395,14 +390,14 @@ scif_init_p2p_info(struct scif_dev *scifdev, struct scif_dev *peerdev) p2p = kzalloc(sizeof(*p2p), GFP_KERNEL); if (!p2p) return NULL; - p2p->ppi_sg[SCIF_PPI_MMIO] = scif_p2p_setsg(psdev->mmio->va, + p2p->ppi_sg[SCIF_PPI_MMIO] = scif_p2p_setsg(psdev->mmio->pa, PAGE_SIZE, num_mmio_pages); if (!p2p->ppi_sg[SCIF_PPI_MMIO]) goto free_p2p; p2p->sg_nentries[SCIF_PPI_MMIO] = num_mmio_pages; sg_page_shift = get_order(min(psdev->aper->len, (u64)(1 << 30))); num_aper_chunks = num_aper_pages >> (sg_page_shift - PAGE_SHIFT); - p2p->ppi_sg[SCIF_PPI_APER] = scif_p2p_setsg(psdev->aper->va, + p2p->ppi_sg[SCIF_PPI_APER] = scif_p2p_setsg(psdev->aper->pa, 1 << sg_page_shift, num_aper_chunks); p2p->sg_nentries[SCIF_PPI_APER] = num_aper_chunks; -- 2.7.4