Re: alloc_bootmem - Kernel panic

[Asgard <dubalom@gmail.com>]

On 2/7/07, Martyn Welch <martyn.welch@radstone.co.uk> wrote:
> Which leads me to the question: what is the best method to reserve a large (~4MB) coherent buffer for DMA transfers?

May be you should to use alloc_pages with __GFP_DMA flag, and then use
page_address to get address of first allocated page.

> Is there any way of using alloc_bootmem from a driver (compiled into the kernel) without delving further into kernel code?

yes, i think:

-> (~/devel/learn/src/kernels/linux-2.6.19)
[asgard@midgard]$ find drivers/ -name "*" | xargs grep alloc_bootmem
drivers/char/vt.c:        vc_cons[currcons].d = vc =
alloc_bootmem(sizeof(struct vc_data));
drivers/char/vt.c:        vc->vc_screenbuf = (unsigned short
*)alloc_bootmem(vc->vc_screenbuf_size);
Binary file drivers/char/vt.o matches
Binary file drivers/char/built-in.o matches
Binary file drivers/firmware/dmi_scan.o matches
Binary file drivers/firmware/built-in.o matches
drivers/macintosh/smu.c:    smu = alloc_bootmem(sizeof(struct smu_device));
drivers/s390/char/con3215.c:        req = (struct raw3215_req *)
alloc_bootmem_low(sizeof(struct raw3215_req));
drivers/s390/char/con3215.c:        alloc_bootmem_low(sizeof(struct
raw3215_info));
drivers/s390/char/con3215.c:    raw->buffer = (char *)
alloc_bootmem_low(RAW3215_BUFFER_SIZE);
drivers/s390/char/con3215.c:    raw->inbuf = (char *)
alloc_bootmem_low(RAW3215_INBUF_SIZE);
drivers/s390/char/con3270.c:    condev = (struct con3270 *)
alloc_bootmem_low(sizeof(struct con3270));
drivers/s390/char/con3270.c:    condev->read = raw3270_request_alloc_bootmem(0);
drivers/s390/char/con3270.c:
raw3270_request_alloc_bootmem(CON3270_OUTPUT_BUFFER_SIZE);
drivers/s390/char/con3270.c:    condev->kreset =
raw3270_request_alloc_bootmem(1);
drivers/s390/char/con3270.c:        cbuf = (void *)
alloc_bootmem_low_pages(PAGE_SIZE);
drivers/s390/char/raw3270.c:raw3270_request_alloc_bootmem(size_t size)
drivers/s390/char/raw3270.c:    rq = alloc_bootmem_low(sizeof(struct raw3270));
drivers/s390/char/raw3270.c:        rq->buffer = alloc_bootmem_low(size);
drivers/s390/char/raw3270.c:    rp = (struct raw3270 *)
alloc_bootmem_low(sizeof(struct raw3270));
drivers/s390/char/raw3270.c:    ascebc = (char *) alloc_bootmem(256);
drivers/s390/char/raw3270.h:struct raw3270_request
*raw3270_request_alloc_bootmem(size_t size);
drivers/s390/char/sclp_con.c:        page = alloc_bootmem_low_pages(PAGE_SIZE);
drivers/s390/char/sclp_vt220.c:            page =
alloc_bootmem_low_pages(PAGE_SIZE);
drivers/serial/cpm_uart/cpm_uart_cpm2.c:        mem_addr = alloc_bootmem(memsz);
drivers/video/console/vgacon.c:    vgacon_scrollback =
alloc_bootmem(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE
Binary file drivers/video/console/vgacon.o matches
Binary file drivers/video/console/built-in.o matches
Binary file drivers/video/built-in.o matches
Binary file drivers/built-in.o matches

> Martyn
>
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