Commit 6d146aef authored by Jake Oshins's avatar Jake Oshins Committed by Greg Kroah-Hartman
Browse files

drivers:hv: Record MMIO range in use by frame buffer 



Later in the boot sequence, we need to figure out which memory
ranges can be given out to various paravirtual drivers.  The
hyperv_fb driver should, ideally, be placed right on top of
the frame buffer, without some other device getting plopped on
top of this range in the meantime.  Recording this now allows
that to be guaranteed.

Signed-off-by: default avatarJake Oshins <jakeo@microsoft.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent be000f93

drivers/hv/vmbus_drv.c

+36 −1
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ 
#include <linux/ptrace.h>

#include <linux/screen_info.h>

#include <linux/kdebug.h>

#include <linux/efi.h>

#include "hyperv_vmbus.h"



static struct acpi_device  *hv_acpi_dev;
@@ -101,6 +102,8 @@ static struct notifier_block hyperv_panic_block = { 
	.notifier_call = hyperv_panic_event,

};



static const char *fb_mmio_name = "fb_range";

static struct resource *fb_mmio;

struct resource *hyperv_mmio;

DEFINE_SEMAPHORE(hyperv_mmio_lock);
@@ -1091,6 +1094,12 @@ static int vmbus_acpi_remove(struct acpi_device *device) 
	struct resource *next_res;



	if (hyperv_mmio) {

		if (fb_mmio) {

			__release_region(hyperv_mmio, fb_mmio->start,

					 resource_size(fb_mmio));

			fb_mmio = NULL;

		}



		for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {

			next_res = cur_res->sibling;

			kfree(cur_res);
@@ -1100,6 +1109,30 @@ static int vmbus_acpi_remove(struct acpi_device *device) 
	return 0;

}



static void vmbus_reserve_fb(void)

{

	int size;

	/*

	 * Make a claim for the frame buffer in the resource tree under the

	 * first node, which will be the one below 4GB.  The length seems to

	 * be underreported, particularly in a Generation 1 VM.  So start out

	 * reserving a larger area and make it smaller until it succeeds.

	 */



	if (screen_info.lfb_base) {

		if (efi_enabled(EFI_BOOT))

			size = max_t(__u32, screen_info.lfb_size, 0x800000);

		else

			size = max_t(__u32, screen_info.lfb_size, 0x4000000);



		for (; !fb_mmio && (size >= 0x100000); size >>= 1) {

			fb_mmio = __request_region(hyperv_mmio,

						   screen_info.lfb_base, size,

						   fb_mmio_name, 0);

		}

	}

}



/**

 * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.

 * @new:		If successful, supplied a pointer to the
@@ -1261,9 +1294,11 @@ static int vmbus_acpi_add(struct acpi_device *device) 


		if (ACPI_FAILURE(result))

			continue;

		if (hyperv_mmio)

		if (hyperv_mmio) {

			vmbus_reserve_fb();

			break;

		}

	}

	ret_val = 0;



acpi_walk_err:

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