On Thu, 2017-03-16 at 20:33 -0700, Sukadev Bhattiprolu wrote:
> Define some helper functions to access the MMIO regions. We use these
> in a follow-on patches to read/write VAS hardware registers. These
> helpers are also used to later issue 'paste' instructions to submit
> requests to the NX hardware engines.
>
> Signed-off-by: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com>
> ---
> Changelog [v3]:
> - Minor reorg/cleanup of map/unmap functions
>
> Changelog [v2]:
> - Get HVWC, UWC and paste addresses from window->vinst (i.e DT)
> rather than kernel macros.
> ---
> drivers/misc/vas/vas-window.c | 126
> ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 126 insertions(+)
>
> diff --git a/drivers/misc/vas/vas-window.c b/drivers/misc/vas/vas-window.c
> index 468f3bf..32dd1d0 100644
> --- a/drivers/misc/vas/vas-window.c
> +++ b/drivers/misc/vas/vas-window.c
> @@ -9,9 +9,135 @@
>
> #include <linux/types.h>
> #include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/io.h>
> #include <asm/vas.h>
> #include "vas-internal.h"
>
> +/*
> + * Compute the paste address region for the window @window using the
> + * ->win_base_addr and ->win_id_shift we got from device tree.
> + */
> +void compute_paste_address(struct vas_window *window, uint64_t *addr, int
> *len)
> +{
> + uint64_t base, shift;
> + int winid;
> +
> + base = window->vinst->win_base_addr;
> + shift = window->vinst->win_id_shift;
> + winid = window->winid;
> +
> + *addr = base + (winid << shift);
> + *len = PAGE_SIZE;
> +
> + pr_debug("Txwin #%d: Paste addr 0x%llx\n", winid, *addr);
> +}
> +
> +static inline void get_hvwc_mmio_bar(struct vas_window *window,
> + uint64_t *start, int *len)
> +{
> + uint64_t pbaddr;
> +
> + pbaddr = window->vinst->hvwc_bar_start;
> + *start = pbaddr + window->winid * VAS_HVWC_SIZE;
> + *len = VAS_HVWC_SIZE;
> +}
> +
> +static inline void get_uwc_mmio_bar(struct vas_window *window,
> + uint64_t *start, int *len)
> +{
> + uint64_t pbaddr;
> +
> + pbaddr = window->vinst->uwc_bar_start;
> + *start = pbaddr + window->winid * VAS_UWC_SIZE;
> + *len = VAS_UWC_SIZE;
I'm not sure this works for 4K pages since VAS_UWC_SIZE = PAGE_SIZE but in
reality I think it's always 64K. Right?
Seem like we are mixing pages sizes and hardware sizes here.
(I realise 4K isn't supported yet, but....)
> +}
> +
> +static void *map_mmio_region(char *name, uint64_t start, int len)
> +{
> + void *map;
> +
> + if (!request_mem_region(start, len, name)) {
> + pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
> + __func__, start, len);
> + return NULL;
> + }
> +
> + map = __ioremap(start, len, pgprot_val(pgprot_cached(__pgprot(0))));
> + if (!map) {
> + pr_devel("%s(): ioremap(0x%llx, %d) failed\n", __func__,
> start,
> + len);
> + return NULL;
> + }
> +
> + return map;
> +}
> +
> +/*
> + * Unmap the MMIO regions for a window.
> + */
> +static void unmap_wc_paste_kaddr(struct vas_window *window)
> +{
> + int len;
> + uint64_t busaddr_start;
> +
> + if (window->paste_kaddr) {
> + iounmap(window->paste_kaddr);
> + compute_paste_address(window, &busaddr_start, &len);
> + release_mem_region((phys_addr_t)busaddr_start, len);
> + window->paste_kaddr = NULL;
> + }
> +
> +}
> +
> +static void unmap_wc_mmio_bars(struct vas_window *window)
> +{
> + int len;
> + uint64_t busaddr_start;
> +
> + unmap_wc_paste_kaddr(window);
> +
> + if (window->hvwc_map) {
> + iounmap(window->hvwc_map);
> + get_hvwc_mmio_bar(window, &busaddr_start, &len);
> + release_mem_region((phys_addr_t)busaddr_start, len);
> + window->hvwc_map = NULL;
> + }
> +
> + if (window->uwc_map) {
> + iounmap(window->uwc_map);
> + get_uwc_mmio_bar(window, &busaddr_start, &len);
> + release_mem_region((phys_addr_t)busaddr_start, len);
> + window->uwc_map = NULL;
> + }
> +}
> +
> +/*
> + * Find the Hypervisor Window Context (HVWC) MMIO Base Address Region and the
> + * OS/User Window Context (UWC) MMIO Base Address Region for the given
> window.
> + * Map these bus addresses and save the mapped kernel addresses in @window.
> + */
> +int map_wc_mmio_bars(struct vas_window *window)
> +{
> + int len;
> + uint64_t start;
> +
> + window->paste_kaddr = window->hvwc_map = window->uwc_map = NULL;
> +
> + get_hvwc_mmio_bar(window, &start, &len);
> + window->hvwc_map = map_mmio_region("HVWCM_Window", start, len);
> +
> + get_uwc_mmio_bar(window, &start, &len);
> + window->uwc_map = map_mmio_region("UWCM_Window", start, len);
> +
> + if (!window->hvwc_map || !window->uwc_map) {
> + unmap_wc_mmio_bars(window);
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> /* stub for now */
> int vas_window_reset(struct vas_instance *vinst, int winid)
> {
