Commit 75efdee1 authored by Alex Deucher's avatar Alex Deucher
Browse files

drm/radeon: implement simple doorbell page allocator 



The doorbell aperture is a PCI BAR whose pages can be
mapped to compute resources for things like wptrs
for userspace queues.

This patch maps the BAR and sets up a simple allocator
to allocate pages from the BAR.

Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent f93bdefe

drivers/gpu/drm/radeon/cik.c

+38 −0
Original line number Diff line number Diff line
@@ -121,6 +121,44 @@ u32 cik_get_xclk(struct radeon_device *rdev) 
	return reference_clock;

}



/**

 * cik_mm_rdoorbell - read a doorbell dword

 *

 * @rdev: radeon_device pointer

 * @offset: byte offset into the aperture

 *

 * Returns the value in the doorbell aperture at the

 * requested offset (CIK).

 */

u32 cik_mm_rdoorbell(struct radeon_device *rdev, u32 offset)

{

	if (offset < rdev->doorbell.size) {

		return readl(((void __iomem *)rdev->doorbell.ptr) + offset);

	} else {

		DRM_ERROR("reading beyond doorbell aperture: 0x%08x!\n", offset);

		return 0;

	}

}



/**

 * cik_mm_wdoorbell - write a doorbell dword

 *

 * @rdev: radeon_device pointer

 * @offset: byte offset into the aperture

 * @v: value to write

 *

 * Writes @v to the doorbell aperture at the

 * requested offset (CIK).

 */

void cik_mm_wdoorbell(struct radeon_device *rdev, u32 offset, u32 v)

{

	if (offset < rdev->doorbell.size) {

		writel(v, ((void __iomem *)rdev->doorbell.ptr) + offset);

	} else {

		DRM_ERROR("writing beyond doorbell aperture: 0x%08x!\n", offset);

	}

}



#define BONAIRE_IO_MC_REGS_SIZE 36



static const u32 bonaire_io_mc_regs[BONAIRE_IO_MC_REGS_SIZE][2] =

drivers/gpu/drm/radeon/radeon.h

+21 −0
Original line number Diff line number Diff line
@@ -556,6 +556,20 @@ struct radeon_scratch { 
int radeon_scratch_get(struct radeon_device *rdev, uint32_t *reg);

void radeon_scratch_free(struct radeon_device *rdev, uint32_t reg);



/*

 * GPU doorbell structures, functions & helpers

 */

struct radeon_doorbell {

	u32			num_pages;

	bool			free[1024];

	/* doorbell mmio */

	resource_size_t			base;

	resource_size_t			size;

	void __iomem			*ptr;

};



int radeon_doorbell_get(struct radeon_device *rdev, u32 *page);

void radeon_doorbell_free(struct radeon_device *rdev, u32 doorbell);



/*

 * IRQS.
@@ -1710,6 +1724,7 @@ struct radeon_device { 
	struct radeon_gart		gart;

	struct radeon_mode_info		mode_info;

	struct radeon_scratch		scratch;

	struct radeon_doorbell		doorbell;

	struct radeon_mman		mman;

	struct radeon_fence_driver	fence_drv[RADEON_NUM_RINGS];

	wait_queue_head_t		fence_queue;
@@ -1783,6 +1798,9 @@ void r100_mm_wreg(struct radeon_device *rdev, uint32_t reg, uint32_t v, 
u32 r100_io_rreg(struct radeon_device *rdev, u32 reg);

void r100_io_wreg(struct radeon_device *rdev, u32 reg, u32 v);



u32 cik_mm_rdoorbell(struct radeon_device *rdev, u32 offset);

void cik_mm_wdoorbell(struct radeon_device *rdev, u32 offset, u32 v);



/*

 * Cast helper

 */
@@ -1832,6 +1850,9 @@ void r100_io_wreg(struct radeon_device *rdev, u32 reg, u32 v); 
#define RREG32_IO(reg) r100_io_rreg(rdev, (reg))

#define WREG32_IO(reg, v) r100_io_wreg(rdev, (reg), (v))



#define RDOORBELL32(offset) cik_mm_rdoorbell(rdev, (offset))

#define WDOORBELL32(offset, v) cik_mm_wdoorbell(rdev, (offset), (v))



/*

 * Indirect registers accessor

 */

drivers/gpu/drm/radeon/radeon_device.c

+94 −0
Original line number Diff line number Diff line
@@ -231,6 +231,94 @@ void radeon_scratch_free(struct radeon_device *rdev, uint32_t reg) 
	}

}



/*

 * GPU doorbell aperture helpers function.

 */

/**

 * radeon_doorbell_init - Init doorbell driver information.

 *

 * @rdev: radeon_device pointer

 *

 * Init doorbell driver information (CIK)

 * Returns 0 on success, error on failure.

 */

int radeon_doorbell_init(struct radeon_device *rdev)

{

	int i;



	/* doorbell bar mapping */

	rdev->doorbell.base = pci_resource_start(rdev->pdev, 2);

	rdev->doorbell.size = pci_resource_len(rdev->pdev, 2);



	/* limit to 4 MB for now */

	if (rdev->doorbell.size > (4 * 1024 * 1024))

		rdev->doorbell.size = 4 * 1024 * 1024;



	rdev->doorbell.ptr = ioremap(rdev->doorbell.base, rdev->doorbell.size);

	if (rdev->doorbell.ptr == NULL) {

		return -ENOMEM;

	}

	DRM_INFO("doorbell mmio base: 0x%08X\n", (uint32_t)rdev->doorbell.base);

	DRM_INFO("doorbell mmio size: %u\n", (unsigned)rdev->doorbell.size);



	rdev->doorbell.num_pages = rdev->doorbell.size / PAGE_SIZE;



	for (i = 0; i < rdev->doorbell.num_pages; i++) {

		rdev->doorbell.free[i] = true;

	}

	return 0;

}



/**

 * radeon_doorbell_fini - Tear down doorbell driver information.

 *

 * @rdev: radeon_device pointer

 *

 * Tear down doorbell driver information (CIK)

 */

void radeon_doorbell_fini(struct radeon_device *rdev)

{

	iounmap(rdev->doorbell.ptr);

	rdev->doorbell.ptr = NULL;

}



/**

 * radeon_doorbell_get - Allocate a doorbell page

 *

 * @rdev: radeon_device pointer

 * @doorbell: doorbell page number

 *

 * Allocate a doorbell page for use by the driver (all asics).

 * Returns 0 on success or -EINVAL on failure.

 */

int radeon_doorbell_get(struct radeon_device *rdev, u32 *doorbell)

{

	int i;



	for (i = 0; i < rdev->doorbell.num_pages; i++) {

		if (rdev->doorbell.free[i]) {

			rdev->doorbell.free[i] = false;

			*doorbell = i;

			return 0;

		}

	}

	return -EINVAL;

}



/**

 * radeon_doorbell_free - Free a doorbell page

 *

 * @rdev: radeon_device pointer

 * @doorbell: doorbell page number

 *

 * Free a doorbell page allocated for use by the driver (all asics)

 */

void radeon_doorbell_free(struct radeon_device *rdev, u32 doorbell)

{

	if (doorbell < rdev->doorbell.num_pages)

		rdev->doorbell.free[doorbell] = true;

}



/*

 * radeon_wb_*()

 * Writeback is the the method by which the the GPU updates special pages
@@ -1162,6 +1250,10 @@ int radeon_device_init(struct radeon_device *rdev, 
	DRM_INFO("register mmio base: 0x%08X\n", (uint32_t)rdev->rmmio_base);

	DRM_INFO("register mmio size: %u\n", (unsigned)rdev->rmmio_size);



	/* doorbell bar mapping */

	if (rdev->family >= CHIP_BONAIRE)

		radeon_doorbell_init(rdev);



	/* io port mapping */

	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {

		if (pci_resource_flags(rdev->pdev, i) & IORESOURCE_IO) {
@@ -1239,6 +1331,8 @@ void radeon_device_fini(struct radeon_device *rdev) 
	rdev->rio_mem = NULL;

	iounmap(rdev->rmmio);

	rdev->rmmio = NULL;

	if (rdev->family >= CHIP_BONAIRE)

		radeon_doorbell_fini(rdev);

	radeon_debugfs_remove_files(rdev);

}