+++ /dev/null
-From c6175951b8f95d9f2c30d00ec069cafd23c6f376 Mon Sep 17 00:00:00 2001
-From: popcornmix <popcornmix@gmail.com>
-Date: Sat, 5 Nov 2016 14:14:43 +0000
-Subject: [PATCH] bcm2708_fb: Add ioctl for reading gpu memory through dma
-
----
- drivers/video/fbdev/bcm2708_fb.c | 109 +++++++++++++++++++++++++++++++++++++++
- include/uapi/linux/fb.h | 7 +++
- 2 files changed, 116 insertions(+)
-
---- a/drivers/video/fbdev/bcm2708_fb.c
-+++ b/drivers/video/fbdev/bcm2708_fb.c
-@@ -31,8 +31,10 @@
- #include <linux/console.h>
- #include <linux/debugfs.h>
- #include <asm/sizes.h>
-+#include <asm/uaccess.h>
- #include <linux/io.h>
- #include <linux/dma-mapping.h>
-+#include <linux/cred.h>
- #include <soc/bcm2835/raspberrypi-firmware.h>
-
- //#define BCM2708_FB_DEBUG
-@@ -429,6 +431,110 @@ static int bcm2708_fb_pan_display(struct
- return result;
- }
-
-+static void dma_memcpy(struct bcm2708_fb *fb, dma_addr_t dst, dma_addr_t src, int size)
-+{
-+ int burst_size = (fb->dma_chan == 0) ? 8 : 2;
-+ struct bcm2708_dma_cb *cb = fb->cb_base;
-+
-+ cb->info = BCM2708_DMA_BURST(burst_size) | BCM2708_DMA_S_WIDTH |
-+ BCM2708_DMA_S_INC | BCM2708_DMA_D_WIDTH |
-+ BCM2708_DMA_D_INC | BCM2708_DMA_TDMODE;
-+ cb->dst = dst;
-+ cb->src = src;
-+ cb->length = size;
-+ cb->stride = 0;
-+ cb->pad[0] = 0;
-+ cb->pad[1] = 0;
-+ cb->next = 0;
-+
-+ if (size < dma_busy_wait_threshold) {
-+ bcm_dma_start(fb->dma_chan_base, fb->cb_handle);
-+ bcm_dma_wait_idle(fb->dma_chan_base);
-+ } else {
-+ void __iomem *dma_chan = fb->dma_chan_base;
-+ cb->info |= BCM2708_DMA_INT_EN;
-+ bcm_dma_start(fb->dma_chan_base, fb->cb_handle);
-+ while (bcm_dma_is_busy(dma_chan)) {
-+ wait_event_interruptible(
-+ fb->dma_waitq,
-+ !bcm_dma_is_busy(dma_chan));
-+ }
-+ fb->stats.dma_irqs++;
-+ }
-+ fb->stats.dma_copies++;
-+}
-+
-+#define INTALIAS_NORMAL(x) ((x)&~0xc0000000) // address with no aliases
-+#define INTALIAS_L1L2_NONALLOCATING(x) (((x)&~0xc0000000)|0x80000000) // cache coherent but non-allocating in L1 and L2
-+
-+static long vc_mem_copy(struct bcm2708_fb *fb, unsigned long arg)
-+{
-+ struct fb_dmacopy ioparam;
-+ size_t size = PAGE_SIZE;
-+ u32 *buf = NULL;
-+ dma_addr_t bus_addr;
-+ long rc = 0;
-+ size_t offset;
-+ struct { u32 base, length; } gpu = {};
-+
-+ /* restrict this to root user */
-+ if (!uid_eq(current_euid(), GLOBAL_ROOT_UID))
-+ {
-+ rc = -EFAULT;
-+ goto out;
-+ }
-+
-+ /* Get the parameter data.
-+ */
-+ if (copy_from_user
-+ (&ioparam, (void *)arg, sizeof(ioparam)) != 0) {
-+ pr_err("[%s]: failed to copy-from-user\n",
-+ __func__);
-+ rc = -EFAULT;
-+ goto out;
-+ }
-+
-+ rc = rpi_firmware_property(fb->fw,
-+ RPI_FIRMWARE_GET_VC_MEMORY,
-+ &gpu, sizeof(gpu));
-+ if (rc != 0 || gpu.base == 0 || gpu.length == 0) {
-+ pr_err("[%s]: Unable to determine gpu memory %ld,%x,%x)\n", __func__, rc, gpu.base, gpu.length);
-+ return -EFAULT;
-+ }
-+
-+ if (INTALIAS_NORMAL(ioparam.src) < gpu.base || INTALIAS_NORMAL(ioparam.src) >= gpu.base + gpu.length) {
-+ pr_err("[%s]: Invalid memory access %x (%x-%x)", __func__, INTALIAS_NORMAL(ioparam.src), gpu.base, gpu.base + gpu.length);
-+ return -EFAULT;
-+ }
-+
-+ buf = dma_alloc_coherent(NULL, PAGE_ALIGN(size), &bus_addr,
-+ GFP_ATOMIC);
-+ if (!buf) {
-+ pr_err("[%s]: failed to dma_alloc_coherent(%d)\n",
-+ __func__, size);
-+ rc = -ENOMEM;
-+ goto out;
-+ }
-+
-+ for (offset = 0; offset < ioparam.length; offset += size) {
-+ size_t remaining = ioparam.length - offset;
-+ size_t s = min(size, remaining);
-+ unsigned char *p = (unsigned char *)ioparam.src + offset;
-+ unsigned char *q = (unsigned char *)ioparam.dst + offset;
-+ dma_memcpy(fb, (dma_addr_t)buf, INTALIAS_L1L2_NONALLOCATING((dma_addr_t)p), size);
-+ if (copy_to_user(q, buf, s) != 0) {
-+ pr_err("[%s]: failed to copy-to-user\n",
-+ __func__);
-+ rc = -EFAULT;
-+ goto out;
-+ }
-+ }
-+out:
-+ if (buf)
-+ dma_free_coherent(NULL, PAGE_ALIGN(size), buf, bus_addr);
-+ return rc;
-+}
-+
- static int bcm2708_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
- {
- struct bcm2708_fb *fb = to_bcm2708(info);
-@@ -441,6 +547,9 @@ static int bcm2708_ioctl(struct fb_info
- RPI_FIRMWARE_FRAMEBUFFER_SET_VSYNC,
- &dummy, sizeof(dummy));
- break;
-+ case FBIODMACOPY:
-+ ret = vc_mem_copy(fb, arg);
-+ break;
- default:
- dev_dbg(info->device, "Unknown ioctl 0x%x\n", cmd);
- return -ENOTTY;
---- a/include/uapi/linux/fb.h
-+++ b/include/uapi/linux/fb.h
-@@ -39,6 +39,7 @@
- * be concurrently added to the mainline kernel
- */
- #define FBIOCOPYAREA _IOW('z', 0x21, struct fb_copyarea)
-+#define FBIODMACOPY _IOW('z', 0x22, struct fb_dmacopy)
-
- #define FB_TYPE_PACKED_PIXELS 0 /* Packed Pixels */
- #define FB_TYPE_PLANES 1 /* Non interleaved planes */
-@@ -351,6 +352,12 @@ struct fb_copyarea {
- __u32 sy;
- };
-
-+struct fb_dmacopy {
-+ dma_addr_t dst;
-+ dma_addr_t src;
-+ __u32 length;
-+};
-+
- struct fb_fillrect {
- __u32 dx; /* screen-relative */
- __u32 dy;
projects / openwrt / staging / yousong.git / blobdiff