Re: [PATCH v3 04/10] VAS: Define helpers for access MMIO regions
From: Michael Neuling <hidden>
Date: 2017-03-24 04:53:18
On Thu, 2017-03-16 at 20:33 -0700, Sukadev Bhattiprolu wrote:
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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. =20 Signed-off-by: Sukadev Bhattiprolu <redacted> --- Changelog [v3]: - Minor reorg/cleanup of map/unmap functions =20 Changelog [v2]: - Get HVWC, UWC and paste addresses from window->vinst (i.e DT) =C2=A0=C2=A0rather than kernel macros. --- =C2=A0drivers/misc/vas/vas-window.c | 126 ++++++++++++++++++++++++++++++++++++++++++ =C2=A01 file changed, 126 insertions(+) =20diff --git a/drivers/misc/vas/vas-window.c b/drivers/misc/vas/vas-window.=
c
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index 468f3bf..32dd1d0 100644--- a/drivers/misc/vas/vas-window.c +++ b/drivers/misc/vas/vas-window.c@@ -9,9 +9,135 @@=C2=A0 =C2=A0#include <linux/types.h> =C2=A0#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/io.h> =C2=A0#include <asm/vas.h> =C2=A0#include "vas-internal.h" =C2=A0 +/* + * 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, in=
t
*len)
+{
+ uint64_t base, shift;
+ int winid;
+
+ base =3D window->vinst->win_base_addr;
+ shift =3D window->vinst->win_id_shift;
+ winid =3D window->winid;
+
+ *addr=C2=A0=C2=A0=3D base + (winid << shift);
+ *len =3D 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 =3D window->vinst->hvwc_bar_start;
+ *start =3D pbaddr + window->winid * VAS_HVWC_SIZE;
+ *len =3D VAS_HVWC_SIZE;
+}
+
+static inline void get_uwc_mmio_bar(struct vas_window *window,
+ uint64_t *start, int *len)
+{
+ uint64_t pbaddr;
+
+ pbaddr =3D window->vinst->uwc_bar_start;
+ *start =3D pbaddr + window->winid * VAS_UWC_SIZE;
+ *len =3D VAS_UWC_SIZE;I'm not sure this works for 4K pages since VAS_UWC_SIZE =3D PAGE_SIZE but i= n 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 =3D __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 =3D 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 =3D 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 =3D NULL;
+ }
+}
+
+/*
+ * Find the Hypervisor Window Context (HVWC) MMIO Base Address Region an=d 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 @wind=
ow.
+ */
+int map_wc_mmio_bars(struct vas_window *window)
+{
+ int len;
+ uint64_t start;
+
+ window->paste_kaddr =3D window->hvwc_map =3D window->uwc_map =3D NULL;
+
+ get_hvwc_mmio_bar(window, &start, &len);
+ window->hvwc_map =3D map_mmio_region("HVWCM_Window", start, len);
+
+ get_uwc_mmio_bar(window, &start, &len);
+ window->uwc_map =3D map_mmio_region("UWCM_Window", start, len);
+
+ if (!window->hvwc_map || !window->uwc_map) {
+ unmap_wc_mmio_bars(window);
+ return -1;
+ }
+
+ return 0;
+}
+
=C2=A0/* stub for now */
=C2=A0int vas_window_reset(struct vas_instance *vinst, int winid)
=C2=A0{