LinuxQuestions.org - dma_map

Hello,

According to DMA-API.txt (4.1.13):

Quote:

With scatterlists, you use the resulting mapping like this:

int i, count = dma_map_sg(dev, sglist, nents, direction);
struct scatterlist *sg;

for_each_sg(sglist, sg, count, i) {
hw_address[i] = sg_dma_address(sg);
hw_len[i] = sg_dma_len(sg);
}

where nents is the number of entries in the sglist.

I have to implement a "write" from application to device driver.

The buffer passed to the driver is constructed from pages.

What is the value of "nents" ? How can I find it ?

Thank you,
Zvika